I used your guidance on porting a factory GM Quadrajet intake for my old second gen Camaro with a 400 SBC. It ended up making noticeably more low end torque than the ZZ4 intake I was currently using, and to top it all off it knocked 2 tenths off of my quarter mile E.T.!!
A q jet is the worst carb as it dumps raw fuel into the 2ndarys. It will not make good power as the fuel isn't atomized. It does not go through a venturi. Bloodviking
Dear Mr Vizard, I am a fan of your work and have been since I started to read you articles in motoring magazines from the 70s when I was a spotty faced kid. I bought a mini in the 70s and a book came with it, written by you, all about improving the gas flow on the BMC A series engine, it had a red cover if I remember correctly. I loved that book and would sit up in bed reading it for hours. I was determined that when I was older and had a bit of money that I would use that book to pep up my own cars. Well 5 houses later the book has gone and I`m still left dreaming about cylinder head and valve work. I`m so glad that you are still using your knowledge and skill on engines and I`m glad that in came across your vid by pure chance. Keep on trucking Mr Vizard, a link to my misspent youth. Kindest regards, Paul Blackmore from Liverpool.
There is another way to check those valves and seats. Blue the valve like in the video, using a wooden hammer handle on the head of the valve to hit it down into the valve seat. Do not twist the valve at all. Remove the valve, check the seat on valve and head. Wipe the valve clean or Brakleen it clean, then repeat the exercise to bring the blue on the valve seat back onto the clean valve. Will show instantly if the seat is out of round or has any low spots. Was taught to do it this way 45plus years ago and it has never failed me ever.
I’m kind of surprised that the rockers studs didn’t get pinned or modified. I’ve seen those things pull out on old Ford and Chevy heads with low spring pressure. As always a very informative video. Thanks for sharing.
Its funny ive pulled apart alot of small blocks and a few were race motors too and i have never seen a pulled stud, i have pulled studs with a 5 lb slide hammer and it was a lot of work , factory studs are not pressed in they are cast in , ive never thought screw in studs were necessary when spring pressures are within 50 lbs of stock. I wonder if studs backing out is more a cam side phenomena as opposed to valve spring side ?
@@luckyPiston I’m not sure. I think it’s just a heat cycle thing possibly. The easiest way I’ve seen to pull them is with a little heat and and a tool that utilizes the nut that goes on the stud. You tighten the nut and the stud pulls right out. The last one I saw fail in person was on a freshly rebuilt sbc. Completely stock throttle body engine in a early to mid 90’s pickup. Ran fine on initial startup and developed a miss about the time it got up to operating temp. Pulled the drivers side valve cover and the stud was ready to fall out.
@@JohnThomas-vb9se I will def consider pinning in the future especially if using 1.6 rockers with more spring pressure as the 1.6s increase mechanical load on the stud.
@@luckyPiston ...back in the sixties,,,,,drag cars needed studs to be pinned......Now understand in 1970....chevrolet Z /28 camaro had screw in studs / pushrod guide plates............the earlier race versions of Z/28 [built outside of corporate Chevrolet] were no doubt pinned..............
@@JohnThomas-vb9se I saw an old mechanic fix a "pulled" stud - just removed a valve cover and hammered the stud back down without even removing the rocker !! He claimed it wouldn't pull out for another 100K miles and the car would likely be junked before that.
I built a 186 headed flatop pistoned 350 back in the mid eighties. My stepdad was a pretty good engine builder and showed me how to do some porting and did a 3 angle grind on the them. He also picked out a camshaft with a tight lobe center which was unique for the time. If I remember correctly it was 230/236 @ .050 .480 lift with 108 lc. I think the valve springs were TRW LT1 replacement and I bought a set of PAW long slot rockers. I used a 305 crankshaft and lightened the factory forged 350 pistons to match the weight of 305 pistons. TRW rod bolts handled 7,500 pulls with no problem. I ran a great set of Hooker Super Comp headers 1 3/4 with 3" collectors. It ran really well and surprised a lot of people. I ran ot in a 1967 Camaro on a diet that weighed 2950 with me in it.
Thanks D.V. I have put together countless #s of cylinder heads! I always used a good grease, basically the same way as you did on everything, valves & guides, retainers, shims springs ect! I probably read it in one of your books when I was a teenager! When other engine builders around our area were having problems with guides sticking & or galling issues, we were not! We even had a super stock racer come in to watch how I put heads together! [believe that?] Because he always had his guides fairly loose, because of the crazy high RPM he ran! [he normally used a light motor oil on the valve] But he even stuck them a time or two! All the things you listed, are commonsense engine building practices! Except, not too many have that anymore! You don't need to be told, but the cams with the L/C, [higher numerically number] beause people always seem to get this wrong! Have very rarely ever been faster on the track! We went through all that B.S. with nitrous engines back in the 90s, originally! They were always the quickest down the track, with the lower # L/CA! We tried 4 different cams, in the same engine, & with all different adjustments, to the camshaft & valve adjustment, that they said would be defiantly faster! But they were not! Same engine, same driver, same N2O kits, same track at the best weather time of year! Normally making 3 or 4 passes, for a average, on the different cams & the different cam timing adjustments! The one thing we found out for sure, was the camshaft companies, knew how to sell you camshafts! After all that testing, fuel, time, wear & tear, ect! We only made camshaft changes, after doing lash loops & cam timing adjustments, on the dyno, where the engine was asking for something different! Not the camshaft companies telling us what our engine needed! Thank you again D.V.
So which lobe separation angle did the motor end up liking the best ? Where you always running the cams strait up or were you playing with advance and retard a bit too ? tks
Great to see another video from you. Hope you had a good vacation. I asked Andy if you were ok and he said yes, you were just taking a brake. Thank you for sharing you vast knowledge with us.
Hello and good day David. Welcome back and mighty glad to see you. Love the videos. Good basic tech and insider tips that the new guys should know. Thanks a lot of doing these videos.
Do the 107 and 108 lobe center angles mention work on a 2wd street driven pickup.... Say 4400 to 4800 lbs. Not a tow rig, just a driver. Great information and so well explained.
When I got your book many years ago now, I was operating a SERDI 60 for a living, I noticed that the angles of the seats you recommended correspond with certain SERDI cutters, I put a five angle seat on a set of Chevy 229 V6 heads that I cut out for 1.94's, they went on a 4.3 V6 to bump up the compression ratio, it was installed in a CJ5, it was a great combination! Really enjoy the knowledge your passing on!
Last engine I built I used them. That was back in mid-80's. When unleaded gas came on the scene I quit messing with mods. Started driving 4 cylinders that got 32 MPG running them hard as i could. Slow but cheap to drive!
Well done vid! The name for the paint used inside the head iis "Glyptol" Pat. 3M . liquid insulation for motor windings, transformers etc.. The other reason to use it, it sheets oil so more gets back to the pan quicker. RHS who now is part of comp cams built me a mild 468 BBC for my jet boat. They used Glyptol in the head and in the valley. That was in the 80's. I had no idea till they told me!
Thank you for listing and giving recommendations on the parts you are using, particularly the brands. This video has been a better step by step than some of the previous. Really good job. It is also very helpful when you mention what products (lubes/pastes/brands etc) you use as this helps me get a better idea of what to bother with, instead of getting perplexed with decisions. I would like to express that I really appreciate that you are teaching me what you have already done the hard yards with David. Thank you so much
The best engine for all around use I've built was almost exactly the same as recommended here. Not my highest horsepower/torque engine, but best all around.
The 400 dampener is for external balance so the 350 8" truck dampener is probably what David meant to recommend that should be used on an internal balanced 350.
@@hotrodray6802 Not many people have a lathe to machine the outer ring totally round. Besides, by the time you do that it will now be a light weight dampener. The reason he said to use that one is because it was a larger diameter and it is heavier. Also the newest factory sbc 400 dampener is from 1976 that more than likely the rubber ring would be dry rotted. A late 1986 to 1995 sbc 350 truck dampener is the larger heavier design and it is already internal balanced and will more than likely have a few more years of service left in it being over 20 years younger.(a Vortec dampener is the larger size but the bottom pulley would need to be spaced out the thickness of the reluctor wheel I think it might be called that is on the crank behind the timing chain cover or source that wheel and install that under the cover so the pulleys line up?) And I did hear what he said but what he said wasn't right for 2022, maybe 20 years ago would be more doable but not now. The sbc 400 dampener would have to be sent out to have machined for $100 an hour plus or minus which would take around an hour and a half and then around another $300 to have it rebuilt! You can still get one of the ones mentioned above for about $20 at a junkyard. I know which one I would choose, what about you?
That mini Cooper trophy reminds me about all the stories ive read on your books as a young boy in the mid 90s, about your mini and you beat way faster cars with a Carbed Mini. I was hooked and i need to learn,. By the time i was 16 i could run cicles around the old timers around me, and could spot manny mistakes in head size, wrong cams,. So Thankful for your willingness to share your knowledge.
It is always a pleasure watching your videos but actually listening Sir I can't get enough love every minute of it thank you for sharing some incredible knowledge
Thank u D.V....this is a video almost anyone can relate to...exclent info for all us poor people...:-D ....! Especily like to see the tecneicks of a master engine builder such as yourself...! Thank u ...sorry for your loss...stay healthy D.V...reguards Brian
Those look like 041 heads. those are great for street builds. I have a set on my old truck. 9.3 static compression, 2.02/1.6 valves and Howards retro roller 485/495 110 lobe separation, Comp full roller rockers 1.52 ratio. intake is an Edelbrock performer with a Holley Sniper EFI. The truck is mean!
@@hotrodray6802 I called and talked to the people at Howards. that was the cam they had in stock. They were having trouble getting cores. They actually recommend a slightly smaller cam for my application with a 108 lobe speration but said this one would work well. It does the job. I don't have the Dyno sheet but if I recall it makes 380 something HP and 400 something torque.
When I went from a performer rpm to a performer rpm air gap on a AMC 360, I had to go to annular booster. I couldn’t get my straight leg 600 to work or my down leg VS 750 to work either. They had big flat spots between the transfer slot and main jets. They had both worked perfectly on the heated performer rpm. The annular 600 summit racing carb fixed my problem. Your buddy Andy from Unity Motorsport pointed this out on one of his videos. I then went and re read your how to tune holleys book and found it all the info in there.
Interesting, Anulars fog a little better so it would be safe to say the air gap intakes are more demanding of a finer mix ? So i have a Vortec 383 with a Edelbrock performer (w/no heat crossover) and when i went from a holley 650 spread bore to the Slayer VS 750 the motor fell flat on its face, it idled just sweet and when you blipped the throttle it was instant revs but as soon as i tried to drive it wouldn't turn past 2k rpm, tried jetting it up but that just wrecked that sweet idle and didn't make it any more driveable , ended up puttin on a Holley 3310 but it didn't run quite as nice as that old spread bore
@@luckyPiston . So the way I understand it is the colder the intake, the smaller the droplet size you will need, to stop it condensing on the intake walls and be a good droplet size by the time it gets from the carb to the combustion chamber.
Very good info David. I use the same Erson PBM springs. They work good and are affordable. The SBI valves, seals are good replacement parts. I liked your tricks on painting the heads with the washers and valve shims. Great idea. Very nice castings you had. That is extremely rare in this day and age. Thanks for sharing. Take care, Ed.
Nice detailed video. We used to pound the valve stems after keeper installation with a dead blow hammer. I don't recall why this was recommended. If a keeper pair was binding a little, it should fully seat itself on the first crank over.
I had really good luck with a rebuilt 406 SBC Shortblock (stock replacement 12.43 cc dish) with #441 (Number inline with runner variation) wiith minor bowl, throat and short turn work, Custom Cam that later became the CC CS 270AH-8 0.313/0.307 (0.501/0.491 w/ 1.6 stamped rockers) 270/280 224/230 108 installed on 105. With a stock '69 QJ Med Rise Intake and 1.625" Headers, it pushed a 4400 lb truck with 3.31, 26" tires and stock converter deep in the 8's / 13's and 7's / 12's on the bottle. The 307 Turbo-Fire Decal on the air cleaner lid was the finishing touch. Getting a heavy street vehicle to run with a stock converter is all about power under the curve not big peak numbers.
In a day and age of computers it is good to see your attention to detail (and not speed). Even though I am a Mopar guy, I will apply your tecniques to the Mope and if nothing else know it is put together right. Love the accent too! Thank you very much.
🔔😎 Many comments/ confusion about LSA / LCA and installed centerline. I'll try. Ford 5.0 HO cam: Intake lobe centerline 118* Exhaust lobe centerline 113* Add together ÷ 2 118+113 = 231 ÷ 2 = 115.5 Lobe separation angle.... Ground into cam Intake lobe centerline 118* is the installed centerline as per the timing gears. 118 - 115.5 = 2.5* advanced Hope this helps. 😎
When I looked at the video title, which promised: "... 60 lbs-ft and 60 hp ..." I said to myself: Well hell, I could make that kind of power, without installing half of the pistons."
Another great video to put to practical use, #DavidVizardPerformance! I can combine this with some earlier porting videos to put some #416 heads on the stock 400sbc in my truck. Bump in compression, and budget as I have the heads already, and it should be a good driver style truck!
David, I have to thank you for your work. It's absolutely incredible knowledge. There's no one I've learned more from. Gale Banks is second behind you. Lots of math on duration, moving torque peak, etc. The one thing I'm going to share with you that blew my mind is on exceeding peak flow lift because it's a factor of time. If you only lift to peak flow, ie 0.600" , then peak flow is achieved for a fraction of a second. If flow goes flat at .600 and you go to 0.700" it creates a square wave flow over time vs a sinusoidal curve with a flow peak. Exceeding peak flow lift leaves a peak flow flat top resulting in greater area under the curve with the same centerline and duration. Square wave lift flow patterns.
Yes...for a point of view of power. But speaking of street engine or "all around" one there is also valve acceleration (cam lobe surface loads), valve side loads and valve spring durability. Power and durability (high mileage) are always in some kind of balance...which you have to decide when building engine.
I used to deal some with REED Cams in Atlanta, and Steve Demos worked for them. I think he ended up with some of their masters and maybe equipment. Great guy and a wealh of knowledge. Thanks for the tip!!
Have heard of Reed Cams. I'm wondering what cam characteristics would be optimal for a low compression (8.8, 327) small block.with large 215cc ports that aren't as efficient as newer castings.
Crane used to make some super low rpm torque cams that had stock and even LESS than stock duration with 104 LSA lol. The intake valve closes at like 16° ABDC on the smaller one to build cylinder pressure.
With deep regards to your loss(es) those are a tough, tough, thing. I was able to find a current LS based 108 LSA versus all comers t was from Richard Holdener and yet it showed 108 LSA visibly ahead of everyone else by a significant amount. My hat is off to you.
Yes. Holdener did an lsa test, same cam specs only lsa changes on a 500hp engine. 120, 112 and 108. The 112 lsa made 35 more ft lb to 5500 and matched the 120 after. The 108 made 14 more ftlb to 5500 than the 112 matched the curve until the last 500 rpm where it made 7hp more.
Fantastic learning experience without all the background music when you were sharing your directions/insight. Thank you DV for keeping the music in the transitions only, very much appreciated. I've bought your books from Amazon, how else can we help support your videos/builds/teaching? Thank you.
Can you do this with ls1 style heads? 706,862,243 please. I watch and apply all your gen 1 sbc stuff to the gen 3 heads. Thanks for giving your knowledge away for free. That's some true, blue hot rodding.
That is a 041x cylinder head. It comes from the factory with ports about 10cc larger than other fuelie style heads. I have modded that head to 275cfm with a 2.055" valve but casting thickness must be watched.
Hi Mr. Vizard, you and Cattledog have inspired me to do a 383 build to see if I could do as good of a job. I am using a '79 sbc 350 off my z28. using 13004000 rotating assembly with a SK12-246-3 comp cams. Now I know it is not an 107-108 LSA but it is a 110. I know you poo poo on this but considering cost time and effect I thought it would be the closest match for what I have on hand already without getting special grinds. Hopefully you can watch what I am doing and possibly give me a few pointers oh yes 180 cc flotek heads I am running thus the cam selected.
David, I want to build a copy of this motor, or one like it perhaps. the cam I wish to use is the Howards MC110961-08 with 285 duration, 108 lobe sep. angle and 470/470 lift. It's supposed to be good for 2000-6200 - which is perfect for me. I will use your iron heads or the Jegs copy of the double hump fuelie heads in Aluminum. Best wishes from Down Under Tom!
We've had irrefutably good luck with Isky cams as well. Their 'mega' flat tappets seem to follow your thoughts of a narrower lsa single pattern cam. Specifically the 270, I have experience with in two separate sbc's, and it's a positive one. They seem to run very well in the mid range with the stock cylinder heads.
I have used some of Isky's megadyne cams with grest sucess as their catalog cams are more often usable due to having a tighter LCA than most other companies.
What he is doing here is using dynamic compression to help with overlap and make the engine flow hard early something like this will be done by 5500 if you recut stock cam but would be a monster the whole way
Thank you for such good videos and info. On the topic of Center line, I built a 460 for primarily torque at lower RPMs. The intake center line is 108, but the exhaust is 116. Is this a problem or does the 107 and 108 degrees mostly apply to intakes? When I told the cam company what I was doing, "hulling a large truck camper" this is what they suggested. Lift is 506/519 and Advertised duration is 264/268. Thanks again for your time.
😀this is awesome david and everyone. thank you so much. what if you have dart iron eagle 165cc with 64cc chamber and zero decked block, 7cc relief flat top hypereutectic pistons and 6" rods? Comp XE274H10 cam. i am guess what target cc chambers i am need for pump gas 87 octane ? i am that i am. i am believe the iron eagle 165 has hot exhaust valve and need adjusting because the coolant passage casting has tight area next to valve that does not flow anything, would like to get in there with something to change that , maybe chemically?
I'd probably try thicker gaskets and watch for quench detonation ....before changing piston dish.$$. Pistons can be milled for a dish and retain a quench ring.
The valve and ignition timing are more stable with the larger damper. Timing chains are solid steel under tension and transmit torsional vibrations to the cam, valve train and distributor. The alternative is an expensive belt drive.
Takes a lot of the torsional twist out of the crank, which means more power. Also changes the hormonic rpm range, but that's another story. Years ago HRM did a back to back damper comparison with aftermarket stuff, and the 8" won by a large margin.
My 1970 350 LT-1 had an 8 inch dampner but I don't know if it was stock or not, after watching this I may have made a mistake by using the Scat 6 inch dampner on the Scat 383 assy I installed .
Awesome video David ! Thank you.. here's a question.. what is the criteria on power brake (vacuum) ? how does LSA effect vacuum at idle ? Also, on the use of your COMP height mic, the retainer is down in the step, you have to subtract the measurement of how deep the step is. It's made to measure on the outer diameter of the mic. hope that helps
BTW, for anyone who's interested, I found a way to improve the sound quality. It can be done with a free software program called NCH VideoPad. First you have to download the video as MP4 file. Open it in VideoPad and select the audiochannels in the bottom half of the screen. Then select Audio Effects in the menu and apply Noise Cancellation to both channels. Then remove the right channel by selecting Pan (100% left) and copy the left channel to the right by selecting Surround 5.1. Now you can play the video in VideoPad or save it and use a different videoplayer. You can save the combined effects for future videos.
The presentation on this video was better than some in the past. I would only say you should work on getting the camera closer when you are trying to show something and give it a bit more screen time.
Professor Vizard, Where can these correctly ground camshafts be obtained? When I dealt with Comp Cam I stated I needed a cam for a 390 FE. I calculated the LCA per your How to HP book page 107. I calculated 106LCA. I also asked for 35 degree overlap. I got alot of push back how 106LCA is too narrow rough idle, peaky blah blah blah.. I ended up getting cam on a 110LCA. They said 110LCA is what I needed. I gave in just to stop the guy from dispensing anymore disinformation to me. Where or who can I contact to get what I am asking for? I am sure I am not the only one. Sorry for your loss. Keep up the great content. Thanks.
@@luckyPiston No. I am not confused. I am asking for Lobe Centerline Angle. LCA is not adjustable. LCA is ground into the cam. 110LCA that Comp insisted I needed is too wide for my engine. Per page 107 the 106LCA "in terms of output, delivers the best area under the curve..." for my combo. Lobe Separation Angle LSA is adjustable when timing the cam during install. I have attempted to contact Comp Cams on three separate occasions with no answer back. I have heard of others getting correctly ground cams from them and did not expect to get a salesman looking to push an incorrect catalog grind on me. I have already wasted money getting the incorrect cam. I am trying to fix my mistake and get the correct one.
@@rennypizarro4432 Area under the curve is more a function of lift and duration, the intake lobe centerline angle (LCA) determines where that area is in relation to piston position in the bore at the time of maximum intake valve lift. LCA "is" adjustable. Lobe separation angle (LSA) is ground into the cam, is not adjustable and will determine the overlap of the cam as well as the position of the exhaust lobe LCA in relation to the intake LCA If you spec your cam to be installed at a 106* intake LCA with a LSA of 108* then the cam will have a exhaust LCA of 110* 106 + 110 = 216 ... 216 / 2 = 108 I you grind the exhaust profile in later then you open up the LSA 106 + 112 = 218 ... 218 / 2 = 110 The time when the cylinder is blowin down is changed which effects scavenging which effects torque at lower rpm.
@@luckyPiston I think I used LSA when I meant intake centerline. ICL. I am using and defining LCA as defined in Prof Vizard's book How to Build Horsepower. LCA is defined as I described. See pages 103-108. I used the overlap chart provided. I chose 40degrees. I calculated the LCA using my intake valve size (2.09). Calculated the displacement of 1 cylinder (390cuin÷8 = 48.75) next I calculate cuin/intake valve diameter (48.75÷2.09=23.32) I consult the lobe center angle determination chart and find 106LCA. LCA+(overlap/2) = duration. In this case was 252. Comp recommended a cam 255 but was ground on a 110LCA. I think we are saying the same things (other than my LSA for ICL flub) as I recognize you are using Comp Cam definitions. But that said the point of this video is to show how not choosing the correct LCA could be sacrificing torque and hp. In my case I do not wish to give up torque since I plan to tote a camper.
The small block 400 is externally balanced, how are you using that crank dampener on a 355? You do mention the internal balance in the video, I’m confused
My question is about what you just said about damper selection I'm in the middle of rebuilding a factory roller cam 5.7L which as you all know is externally balanced as is the sbc 400 ci engine I have not had it internally balanced. My question is do I use my original 8 inch factory damper or do I use an externally balanced aftermarket 8 inch 400 sbc damper. I'm thinking they are probably about the same as far as controlling vibrations at the crankshaft as long as your flex plate is designed for externally balanced engines or did I miss something. I have played this video 3 times now thinking I'm not getting the point or not understanding the message from the video. I do plan on reusing my original damper and flexplate on this rebuild and using your source to have my roller cam reground to your 107 lsa Please enlighten me if I am wrong about what I'm hearing or misunderstanding
Great Video David … Can I make a request ….. Would you kindly make a similar spec/build video for the Mopar/Chrysler 440 RB. Chevy and Ford get so much attention … a street build would be great. Thanks in advance.
Viscosity ≠ weight. Any SBC with reasonable clearances can use SAE 30. 5W or 10W-30 has better cold viscosity in that it doesn't become as excessively viscous when cold as a mono-grade SAE 30. 0W-30 is even better in this regard if you choose to go synthetic. A good bargain choice is Shell Rotella T5 10W-30.
Why a 107°/108° LSA? If we were doing this to an L31 350 Vortec motor and used a 107° LSA, would that still have enough vacuum to run Power Brakes and accessories in a suburban with fuel injection?
Kevin, you are behind on tech know-how on cams. THE LCA IS NOT, FOR ANY GIVEN ENGINE SPEC, AN AJUSTABLE FEATURE! NOTE:- IF YOU WANT TO GET IDLE QUALITY THEN BE AWARE THIS IS CONTROLLED BY THE OVERLAP USED.
@@marvingvx1 I don't know that I would say "behind"... I'm kinda a newbie and trying to learn. Love your channel! Just trying to absorb it all! Do you have a good video that explains the valve overlap/LSA?
@@kevinflynn1774 Buying his book How to Port Cyliner Heads has this cam information. I won't divulge DVs knowledge here, except this "Running a wider center line angle means your attempting to run more duration than the application needs". This is what costs idle quality, vacuum, and ultimately engine output. For more accurate numbers, and how to get a greater understanding of when and why cam timing needs to change, and what to change it to, then buy the book. If your able to, this applies to any cam operated internal combustion engine, including mulivalve ones. In fact, any book where David Vizard is an author, get it. There is always useful information in everything he publishes.
I used your guidance on porting a factory GM Quadrajet intake for my old second gen Camaro with a 400 SBC. It ended up making noticeably more low end torque than the ZZ4 intake I was currently using, and to top it all off it knocked 2 tenths off of my quarter mile E.T.!!
A q jet is the worst carb as it dumps raw fuel into the 2ndarys. It will not make good power as the fuel isn't atomized. It does not go through a venturi. Bloodviking
Dear Mr Vizard, I am a fan of your work and have been since I started to read you articles in motoring magazines from the 70s when I was a spotty faced kid. I bought a mini in the 70s and a book came with it, written by you, all about improving the gas flow on the BMC A series engine, it had a red cover if I remember correctly. I loved that book and would sit up in bed reading it for hours. I was determined that when I was older and had a bit of money that I would use that book to pep up my own cars. Well 5 houses later the book has gone and I`m still left dreaming about cylinder head and valve work. I`m so glad that you are still using your knowledge and skill on engines and I`m glad that in came across your vid by pure chance. Keep on trucking Mr Vizard, a link to my misspent youth. Kindest regards, Paul Blackmore from Liverpool.
Paul, glad you enjoyed the book.
Mr. Vizard, you Sir, are a legend. Thank you for the wealth of knowledge you've shared over the years.
Thank you for pushing on and spreading your knowledge through hand times. Much love and appreciation for you, your family, and your work. Carry on Sr
David your a legend! We built our first sbc with guidance from one of your books back in 2004. Ty
There is another way to check those valves and seats. Blue the valve like in the video, using a wooden hammer handle on the head of the valve to hit it down into the valve seat. Do not twist the valve at all. Remove the valve, check the seat on valve and head. Wipe the valve clean or Brakleen it clean, then repeat the exercise to bring the blue on the valve seat back onto the clean valve. Will show instantly if the seat is out of round or has any low spots. Was taught to do it this way 45plus years ago and it has never failed me ever.
Hey Boss -i just have got to try this one!!!! Thanks for the tip.
DV
I’m kind of surprised that the rockers studs didn’t get pinned or modified. I’ve seen those things pull out on old Ford and Chevy heads with low spring pressure. As always a very informative video. Thanks for sharing.
Its funny ive pulled apart alot of small blocks and a few were race motors too and i have never seen a pulled stud, i have pulled studs with a 5 lb slide hammer and it was a lot of work , factory studs are not pressed in they are cast in , ive never thought screw in studs were necessary when spring pressures are within 50 lbs of stock.
I wonder if studs backing out is more a cam side phenomena as opposed to valve spring side ?
@@luckyPiston I’m not sure. I think it’s just a heat cycle thing possibly. The easiest way I’ve seen to pull them is with a little heat and and a tool that utilizes the nut that goes on the stud. You tighten the nut and the stud pulls right out. The last one I saw fail in person was on a freshly rebuilt sbc. Completely stock throttle body engine in a early to mid 90’s pickup. Ran fine on initial startup and developed a miss about the time it got up to operating temp. Pulled the drivers side valve cover and the stud was ready to fall out.
@@JohnThomas-vb9se I will def consider pinning in the future especially if using 1.6 rockers with more spring pressure as the 1.6s increase mechanical load on the stud.
@@luckyPiston ...back in the sixties,,,,,drag cars needed studs to be pinned......Now understand in 1970....chevrolet Z /28 camaro had screw in studs / pushrod guide plates............the earlier race versions of Z/28 [built outside of corporate Chevrolet] were no doubt pinned..............
@@JohnThomas-vb9se I saw an old mechanic fix a "pulled" stud - just removed a valve cover and hammered the stud back down without even removing the rocker !!
He claimed it wouldn't pull out for another 100K miles and the car would likely be junked before that.
I built a 186 headed flatop pistoned 350 back in the mid eighties. My stepdad was a pretty good engine builder and showed me how to do some porting and did a 3 angle grind on the them. He also picked out a camshaft with a tight lobe center which was unique for the time. If I remember correctly it was 230/236 @ .050 .480 lift with 108 lc. I think the valve springs were TRW LT1 replacement and I bought a set of PAW long slot rockers. I used a 305 crankshaft and lightened the factory forged 350 pistons to match the weight of 305 pistons. TRW rod bolts handled 7,500 pulls with no problem. I ran a great set of Hooker Super Comp headers 1 3/4 with 3" collectors. It ran really well and surprised a lot of people. I ran ot in a 1967 Camaro on a diet that weighed 2950 with me in it.
Thanks D.V. I have put together countless #s of cylinder heads! I always used a good grease, basically the same way as you did on everything, valves & guides, retainers, shims springs ect! I probably read it in one of your books when I was a teenager! When other engine builders around our area were having problems with guides sticking & or galling issues, we were not! We even had a super stock racer come in to watch how I put heads together! [believe that?] Because he always had his guides fairly loose, because of the crazy high RPM he ran! [he normally used a light motor oil on the valve] But he even stuck them a time or two! All the things you listed, are commonsense engine building practices! Except, not too many have that anymore! You don't need to be told, but the cams with the L/C, [higher numerically number] beause people always seem to get this wrong! Have very rarely ever been faster on the track! We went through all that B.S. with nitrous engines back in the 90s, originally! They were always the quickest down the track, with the lower # L/CA! We tried 4 different cams, in the same engine, & with all different adjustments, to the camshaft & valve adjustment, that they said would be defiantly faster! But they were not! Same engine, same driver, same N2O kits, same track at the best weather time of year! Normally making 3 or 4 passes, for a average, on the different cams & the different cam timing adjustments! The one thing we found out for sure, was the camshaft companies, knew how to sell you camshafts! After all that testing, fuel, time, wear & tear, ect! We only made camshaft changes, after doing lash loops & cam timing adjustments, on the dyno, where the engine was asking for something different! Not the camshaft companies telling us what our engine needed! Thank you again D.V.
So which lobe separation angle did the motor end up liking the best ?
Where you always running the cams strait up or were you playing with advance and retard a bit too ? tks
Great to see another video from you. Hope you had a good vacation. I asked Andy if you were ok and he said yes, you were just taking a brake. Thank you for sharing you vast knowledge with us.
As always, thank you for sharing your knowledge with the world!
Hello and good day David. Welcome back and mighty glad to see you. Love the videos. Good basic tech and insider tips that the new guys should know. Thanks a lot of doing these videos.
Do the 107 and 108 lobe center angles mention work on a 2wd street driven pickup.... Say 4400 to 4800 lbs.
Not a tow rig, just a driver.
Great information and so well explained.
When I got your book many years ago now, I was operating a SERDI 60 for a living, I noticed that the angles of the seats you recommended correspond with certain SERDI cutters, I put a five angle seat on a set of Chevy 229 V6 heads that I cut out for 1.94's, they went on a 4.3 V6 to bump up the compression ratio, it was installed in a CJ5, it was a great combination!
Really enjoy the knowledge your passing on!
I always thought the 229 and the 4.3 were completely different motors ?
@@luckyPiston the 200, 229 and 4.3 (262) are Chevy engines, 3/4 of the small block V8, the 225, 252 are Buick engines.
@@stevegarboden2437 I'll be darned, i never considered that that 90* V6 could also be a variant of the 267 and the 305 learn sumpem new everyday LOL !
Didn’t realize those were 041 heads until I caught the casting numbers. Absolutely enjoy the videos. Thank you sir
Last engine I built I used them. That was back in mid-80's. When unleaded gas came on the scene I quit messing with mods. Started driving 4 cylinders that got 32 MPG running them hard as i could. Slow but cheap to drive!
I have used my 1T arbor press as a spring checker and spring compressor using an O2 sensor socket.
Your attention to detail and exact specs is amazing! I will be using your procedures and instructions when I rebuild my Jeep 4.0L, Thanks
Well done vid! The name for the paint used inside the head iis "Glyptol" Pat. 3M . liquid insulation for motor windings, transformers etc.. The other reason to use it, it sheets oil so more gets back to the pan quicker. RHS who now is part of comp cams built me a mild 468 BBC for my jet boat. They used Glyptol in the head and in the valley. That was in the 80's. I had no idea till they told me!
Thank you for listing and giving recommendations on the parts you are using, particularly the brands. This video has been a better step by step than some of the previous. Really good job. It is also very helpful when you mention what products (lubes/pastes/brands etc) you use as this helps me get a better idea of what to bother with, instead of getting perplexed with decisions.
I would like to express that I really appreciate that you are teaching me what you have already done the hard yards with David. Thank you so much
Spray your glyptal outside - its potent stuff.
@@flinch622 what's that supposed to mean?
@@shanedavid814 It means... absent a professional vent hood system, the business of applying insulating varnish will hurt you.
@@flinch622 may I ask what this has to do with my comment to David? Not sure where it fits in?
@@flinch622 but I have my suspicions
Vale`Marvin Burke. Good to see you back David. Hoping to see more of your excellent videos in the future. Regards Greg
So sorry to hear of Marvin’s passing. May the good Lord, bless his soul.
HI DAVID GLAD YOUR BACK HOPE ALL IS WELL
The best engine for all around use I've built was almost exactly the same as recommended here. Not my highest horsepower/torque engine, but best all around.
As always, excellent information.
The 400 dampener is for external balance so the 350 8" truck dampener is probably what David meant to recommend that should be used on an internal balanced 350.
Yeah i think a few of us were thinking that too, it doesn't hurt to clarify as that's what DV is all about anyway. cheers.
Listen again.
DV said use the 400 damper and machine out the weight for internal balance cranks.
@@hotrodray6802
Not many people have a lathe to machine the outer ring totally round. Besides, by the time you do that it will now be a light weight dampener. The reason he said to use that one is because it was a larger diameter and it is heavier. Also the newest factory sbc 400 dampener is from 1976 that more than likely the rubber ring would be dry rotted.
A late 1986 to 1995 sbc 350 truck dampener is the larger heavier design and it is already internal balanced and will more than likely have a few more years of service left in it being over 20 years younger.(a Vortec dampener is the larger size but the bottom pulley would need to be spaced out the thickness of the reluctor wheel I think it might be called that is on the crank behind the timing chain cover or source that wheel and install that under the cover so the pulleys line up?)
And I did hear what he said but what he said wasn't right for 2022, maybe 20 years ago would be more doable but not now. The sbc 400 dampener would have to be sent out to have machined for $100 an hour plus or minus which would take around an hour and a half and then around another $300 to have it rebuilt! You can still get one of the ones mentioned above for about $20 at a junkyard. I know which one I would choose, what about you?
You are right - was not thinking clearly there.
That mini Cooper trophy reminds me about all the stories ive read on your books as a young boy in the mid 90s, about your mini and you beat way faster cars with a Carbed Mini. I was hooked and i need to learn,. By the time i was 16 i could run cicles around the old timers around me, and could spot manny mistakes in head size, wrong cams,. So Thankful for your willingness to share your knowledge.
Welcome back David , and thank you again for your excellent insight into powerful engines for the home builder. Cheers
It is always a pleasure watching your videos but actually listening Sir I can't get enough love every minute of it thank you for sharing some incredible knowledge
Thank u D.V....this is a video almost anyone can relate to...exclent info for all us poor people...:-D ....! Especily like to see the tecneicks of a master engine builder such as yourself...! Thank u ...sorry for your loss...stay healthy D.V...reguards Brian
I am glad to see you again. Good show! This is something I been hoping for. Thank you.
Those look like 041 heads. those are great for street builds. I have a set on my old truck. 9.3 static compression, 2.02/1.6 valves and Howards retro roller 485/495 110 lobe separation, Comp full roller rockers 1.52 ratio. intake is an Edelbrock performer with a Holley Sniper EFI. The truck is mean!
DV's calculation program probably recommends a tighter LSA.
@@hotrodray6802 I called and talked to the people at Howards. that was the cam they had in stock. They were having trouble getting cores. They actually recommend a slightly smaller cam for my application with a 108 lobe speration but said this one would work well. It does the job. I don't have the Dyno sheet but if I recall it makes 380 something HP and 400 something torque.
My grampa said that the most important specs of any build was a four on the floor and a fifth under the seat.
Always appreciate your time and videos
When I went from a performer rpm to a performer rpm air gap on a AMC 360, I had to go to annular booster. I couldn’t get my straight leg 600 to work or my down leg VS 750 to work either. They had big flat spots between the transfer slot and main jets. They had both worked perfectly on the heated performer rpm.
The annular 600 summit racing carb fixed my problem. Your buddy Andy from Unity Motorsport pointed this out on one of his videos. I then went and re read your how to tune holleys book and found it all the info in there.
Interesting, Anulars fog a little better so it would be safe to say the air gap intakes are more demanding of a finer mix ?
So i have a Vortec 383 with a Edelbrock performer (w/no heat crossover) and when i went from a holley 650 spread bore to the Slayer VS 750 the motor fell flat on its face, it idled just sweet and when you blipped the throttle it was instant revs but as soon as i tried to drive it wouldn't turn past 2k rpm, tried jetting it up but that just wrecked that sweet idle and didn't make it any more driveable , ended up puttin on a Holley 3310 but it didn't run quite as nice as that old spread bore
@@luckyPiston . So the way I understand it is the colder the intake, the smaller the droplet size you will need, to stop it condensing on the intake walls and be a good droplet size by the time it gets from the carb to the combustion chamber.
Downleg annular always win.
Thanks, David. I am glad to see you are back at it.
David this was a phenomenal video! Thank you for all these tips!
Thank you DV . RIP MB
Glad to see you back. You have been greatly missed ! 👍
I went to one of your classes at your home. Met Marvin ,was one of the most down to earth people. David could you do a carb. tutorial
Sure - will try for next spring.
Always very interesting. Great dedication to your dear friend Marvin. All the best to you. Looking forward to part 2. 👍😎👍
I like this a lot. Very clearly explained with excellent well illumined video. All of the old school tricks, but brought up to date.
Very good info David.
I use the same Erson PBM springs.
They work good and are affordable.
The SBI valves, seals are good replacement parts.
I liked your tricks on painting the heads with the washers and valve shims.
Great idea.
Very nice castings you had.
That is extremely rare in this day and age.
Thanks for sharing.
Take care, Ed.
Nice detailed video. We used to pound the valve stems after keeper installation with a dead blow hammer. I don't recall why this was recommended. If a keeper pair was binding a little, it should fully seat itself on the first crank over.
I was taught to bump them to insure they're seated.
Great to see you back sir
I had really good luck with a rebuilt 406 SBC Shortblock (stock replacement 12.43 cc dish) with #441 (Number inline with runner variation) wiith minor bowl, throat and short turn work, Custom Cam that later became the CC CS 270AH-8 0.313/0.307 (0.501/0.491 w/ 1.6 stamped rockers) 270/280 224/230 108 installed on 105. With a stock '69 QJ Med Rise Intake and 1.625" Headers, it pushed a 4400 lb truck with 3.31, 26" tires and stock converter deep in the 8's / 13's and 7's / 12's on the bottle. The 307 Turbo-Fire Decal on the air cleaner lid was the finishing touch. Getting a heavy street vehicle to run with a stock converter is all about power under the curve not big peak numbers.
👍 More produced torque makes a converter stall higher.
In a day and age of computers it is good to see your attention to detail (and not speed). Even though I am a Mopar guy, I will apply your tecniques to the Mope and if nothing else know it is put together right. Love the accent too! Thank you very much.
Thanks Rupert
Good information David. From one David to another keep the good stuff coming.
So sorry for your loss Mr. Vizard. My condolences to you and yours.
really like your detail and experience. great work
Thanks!
Thanks for the video David I know it's not easy for you to do you but keep I'm sure Marvin would like you to do that
🔔😎
Many comments/ confusion about LSA / LCA and installed centerline.
I'll try. Ford 5.0 HO cam:
Intake lobe centerline 118*
Exhaust lobe centerline 113*
Add together ÷ 2
118+113 = 231 ÷ 2 = 115.5 Lobe separation angle.... Ground into cam
Intake lobe centerline 118* is the installed centerline as per the timing gears.
118 - 115.5 = 2.5* advanced
Hope this helps. 😎
When I looked at the video title, which promised:
"... 60 lbs-ft and 60 hp ..."
I said to myself:
Well hell, I could make that kind of power, without installing half of the pistons."
LOL 👍👍😎
Thank you for another great lesson
Another great video thanks again always like to see your videos I learn something new every time
THANK YOU DAVID, YOU ARE APPRECIATED.
Thank you David.
Another great video to put to practical use, #DavidVizardPerformance! I can combine this with some earlier porting videos to put some #416 heads on the stock 400sbc in my truck. Bump in compression, and budget as I have the heads already, and it should be a good driver style truck!
FREE is a good price 👍👍😎
The trick with the milling machine is pretty ingenious. I'll have to try that with my drill press.
David, I have to thank you for your work. It's absolutely incredible knowledge. There's no one I've learned more from. Gale Banks is second behind you. Lots of math on duration, moving torque peak, etc. The one thing I'm going to share with you that blew my mind is on exceeding peak flow lift because it's a factor of time. If you only lift to peak flow, ie 0.600" , then peak flow is achieved for a fraction of a second. If flow goes flat at .600 and you go to 0.700" it creates a square wave flow over time vs a sinusoidal curve with a flow peak. Exceeding peak flow lift leaves a peak flow flat top resulting in greater area under the curve with the same centerline and duration. Square wave lift flow patterns.
EXACTLY.👍
That's a point grossly misunderstood by most all.
Run all the lift possible for your duration.
Yes...for a point of view of power. But speaking of street engine or "all around" one there is also valve acceleration (cam lobe surface loads), valve side loads and valve spring durability. Power and durability (high mileage) are always in some kind of balance...which you have to decide when building engine.
You are a very good man, a professor of the craft, I would love to have you work on my engine🇺🇸👍
I used to deal some with REED Cams in Atlanta, and Steve Demos worked for them. I think he ended up with some of their masters and maybe equipment. Great guy and a wealh of knowledge. Thanks for the tip!!
Have heard of Reed Cams. I'm wondering what cam characteristics would be optimal for a low compression (8.8, 327) small block.with large 215cc ports that aren't as efficient as newer castings.
DV's cam calculator will tell you
Rodney, yes I know Steve and plan on doing business with him!
@@DavidVizard Fantastic! I have admired your work since I was 10yrs old in fact, and I just turned 55! Cheers!
Crane used to make some super low rpm torque cams that had stock and even LESS than stock duration with 104 LSA lol. The intake valve closes at like 16° ABDC on the smaller one to build cylinder pressure.
With deep regards to your loss(es) those are a tough, tough, thing. I was able to find a current LS based 108 LSA versus all comers t was from Richard Holdener and yet it showed 108 LSA visibly ahead of everyone else by a significant amount. My hat is off to you.
Yes. Holdener did an lsa test, same cam specs only lsa changes on a 500hp engine. 120, 112 and 108. The 112 lsa made 35 more ft lb to 5500 and matched the 120 after. The 108 made 14 more ftlb to 5500 than the 112 matched the curve until the last 500 rpm where it made 7hp more.
Fantastic learning experience without all the background music when you were sharing your directions/insight. Thank you DV for keeping the music in the transitions only, very much appreciated. I've bought your books from Amazon, how else can we help support your videos/builds/teaching? Thank you.
Spread the word Dudebro.
Condolences for your loss David
Can you do this with ls1 style heads? 706,862,243 please. I watch and apply all your gen 1 sbc stuff to the gen 3 heads. Thanks for giving your knowledge away for free. That's some true, blue hot rodding.
If u follow his advice you should have a nice street engine thank u David for the best advice possible
That is a 041x cylinder head. It comes from the factory with ports about 10cc larger than other fuelie style heads. I have modded that head to 275cfm with a 2.055" valve but casting thickness must be watched.
Charlie - with your excellent porting skills this is nothing les than I would expect!! Take care my friend.
DV
@@marvingvx1 Thanks, David. Cheers!
Hi Mr. Vizard, you and Cattledog have inspired me to do a 383 build to see if I could do as good of a job. I am using a '79 sbc 350 off my z28. using 13004000 rotating assembly with a SK12-246-3 comp cams. Now I know it is not an 107-108 LSA but it is a 110. I know you poo poo on this but considering cost time and effect I thought it would be the closest match for what I have on hand already without getting special grinds. Hopefully you can watch what I am doing and possibly give me a few pointers oh yes 180 cc flotek heads I am running thus the cam selected.
Great video sir
10:59 ... 400 SBC stock dampers are for the external balanced 400's, Yes? This is an internal Bal. 350???
I have been missing Andy too
Interesting that you went with the hi-temp lithium grease instead of assembly lube for the valves and springs.
That probably saved a few dollars too.
David, I want to build a copy of this motor, or one like it perhaps. the cam I wish to use is the Howards MC110961-08 with 285 duration, 108 lobe sep. angle and 470/470 lift. It's supposed to be good for 2000-6200 - which is perfect for me. I will use your iron heads or the Jegs copy of the double hump fuelie heads in Aluminum. Best wishes from Down Under Tom!
We've had irrefutably good luck with Isky cams as well.
Their 'mega' flat tappets seem to follow your thoughts of a narrower lsa single pattern cam. Specifically the 270, I have experience with in two separate sbc's, and it's a positive one. They seem to run very well in the mid range with the stock cylinder heads.
I have used some of Isky's megadyne cams with grest sucess as their catalog cams are more often usable due to having a tighter LCA than most other companies.
Still building horsepower!
What he is doing here is using dynamic compression to help with overlap and make the engine flow hard early something like this will be done by 5500 if you recut stock cam but would be a monster the whole way
Great video! Subscribed!
Now do not install the small o-ring seals that go on the valve stem? Just under the keeper’s
David do you still have plans to release a SBF book like your building max performance SBC engines? Love your information thank you so very much!!
I hope so!
I feel like I should be sipping wine while I'm watching this.
Thank you for such good videos and info. On the topic of Center line, I built a 460 for primarily torque at lower RPMs. The intake center line is 108, but the exhaust is 116. Is this a problem or does the 107 and 108 degrees mostly apply to intakes? When I told the cam company what I was doing, "hulling a large truck camper" this is what they suggested. Lift is 506/519 and Advertised duration is 264/268. Thanks again for your time.
when he says 107-108 center line, he means Lobe Separation Angle or LCA, intake Center line is the Intake lobe Center line when installed
😀this is awesome david and everyone. thank you so much. what if you have dart iron eagle 165cc with 64cc chamber and zero decked block, 7cc relief flat top hypereutectic pistons and 6" rods? Comp XE274H10 cam. i am guess what target cc chambers i am need for pump gas 87 octane ? i am that i am. i am believe the iron eagle 165 has hot exhaust valve and need adjusting because the coolant passage casting has tight area next to valve that does not flow anything, would like to get in there with something to change that , maybe chemically?
I'd probably try thicker gaskets and watch for quench detonation ....before changing piston dish.$$. Pistons can be milled for a dish and retain a quench ring.
can you make a video on why the big damper is better? it sorta goes agaisnt the less rotating mass is better idea.
The valve and ignition timing are more stable with the larger damper. Timing chains are solid steel under tension and transmit torsional vibrations to the cam, valve train and distributor. The alternative is an expensive belt drive.
Takes a lot of the torsional twist out of the crank, which means more power. Also changes the hormonic rpm range, but that's another story.
Years ago HRM did a back to back damper comparison with aftermarket stuff, and the 8" won by a large margin.
My 1970 350 LT-1 had an 8 inch dampner but I don't know if it was stock or not, after watching this I may have made a mistake by using the Scat 6 inch dampner on the Scat 383 assy I installed .
Lobe center line angle. Can you talk more about that some time please? Thanks
There are heads that give more power in part from a smaller combination chamber. Not all from flow
Awesome video David ! Thank you.. here's a question.. what is the criteria on power brake (vacuum) ? how does LSA effect vacuum at idle ?
Also, on the use of your COMP height mic, the retainer is down in the step, you have to subtract the measurement of how deep the step is. It's made to measure on the outer diameter of the mic. hope that helps
LCA does NOT affect idle vacuum - overflap does.
What do you think about the 291 castings?
And the #3892690 crank??😉
Hello does anybody know how to filter out the white noise from these videos? I have much difficulty hearing what David says :(
No white noise on mine.
@@hotrodray6802 Hello, on what device are you watching these videos?
BTW, for anyone who's interested, I found a way to improve the sound quality. It can be done with a free software program called NCH VideoPad.
First you have to download the video as MP4 file. Open it in VideoPad and select the audiochannels in the bottom half of the screen. Then select Audio Effects in the menu and apply Noise Cancellation to both channels. Then remove the right channel by selecting Pan (100% left) and copy the left channel to the right by selecting Surround 5.1. Now you can play the video in VideoPad or save it and use a different videoplayer.
You can save the combined effects for future videos.
The presentation on this video was better than some in the past. I would only say you should work on getting the camera closer when you are trying to show something and give it a bit more screen time.
Professor Vizard, Where can these correctly ground camshafts be obtained? When I dealt with Comp Cam I stated I needed a cam for a 390 FE. I calculated the LCA per your How to HP book page 107. I calculated 106LCA. I also asked for 35 degree overlap. I got alot of push back how 106LCA is too narrow rough idle, peaky blah blah blah.. I ended up getting cam on a 110LCA. They said 110LCA is what I needed. I gave in just to stop the guy from dispensing anymore disinformation to me. Where or who can I contact to get what I am asking for? I am sure I am not the only one. Sorry for your loss. Keep up the great content. Thanks.
LCA: lobe center angle and LSA: lobe separation angle are not terms that are interchangeable.
Perhaps this is why you had problems with Comp ?
@@luckyPiston No. I am not confused. I am asking for Lobe Centerline Angle. LCA is not adjustable. LCA is ground into the cam. 110LCA that Comp insisted I needed is too wide for my engine. Per page 107 the 106LCA "in terms of output, delivers the best area under the curve..." for my combo. Lobe Separation Angle LSA is adjustable when timing the cam during install. I have attempted to contact Comp Cams on three separate occasions with no answer back. I have heard of others getting correctly ground cams from them and did not expect to get a salesman looking to push an incorrect catalog grind on me. I have already wasted money getting the incorrect cam. I am trying to fix my mistake and get the correct one.
@@rennypizarro4432 Area under the curve is more a function of lift and duration, the intake lobe centerline angle (LCA) determines where that area is in relation to piston position in the bore at the time of maximum intake valve lift. LCA "is" adjustable.
Lobe separation angle (LSA) is ground into the cam, is not adjustable and will determine the overlap of the cam as well as the position of the exhaust lobe LCA in relation to the intake LCA
If you spec your cam to be installed at a 106* intake LCA with a LSA of 108* then the cam will have a exhaust LCA of 110*
106 + 110 = 216 ... 216 / 2 = 108
I you grind the exhaust profile in later then you open up the LSA
106 + 112 = 218 ... 218 / 2 = 110 The time when the cylinder is blowin down is changed which effects scavenging which effects torque at lower rpm.
@@luckyPiston I think I used LSA when I meant intake centerline. ICL. I am using and defining LCA as defined in Prof Vizard's book How to Build Horsepower. LCA is defined as I described. See pages 103-108. I used the overlap chart provided. I chose 40degrees. I calculated the LCA using my intake valve size (2.09). Calculated the displacement of 1 cylinder (390cuin÷8 = 48.75) next I calculate cuin/intake valve diameter (48.75÷2.09=23.32) I consult the lobe center angle determination chart and find 106LCA. LCA+(overlap/2) = duration. In this case was 252. Comp recommended a cam 255 but was ground on a 110LCA. I think we are saying the same things (other than my LSA for ICL flub) as I recognize you are using Comp Cam definitions. But that said the point of this video is to show how not choosing the correct LCA could be sacrificing torque and hp. In my case I do not wish to give up torque since I plan to tote a camper.
Renny, sorry but you're wrong.
LSA and LCA are the same.
You're confusing INSTALLED CENTERLINE ANGLE,
See DV's book for explanation.
The small block 400 is externally balanced, how are you using that crank dampener on a 355? You do mention the internal balance in the video, I’m confused
Watch the video again. He explains it.simply
Didn't DV say mill it to zero ?
Thank you for your knowledge share.
My question is about what you just said about damper selection I'm in the middle of rebuilding a factory roller cam 5.7L which as you all know is externally balanced as is the sbc 400 ci engine I have not had it internally balanced. My question is do I use my original 8 inch factory damper or do I use an externally balanced aftermarket 8 inch 400 sbc damper. I'm thinking they are probably about the same as far as controlling vibrations at the crankshaft as long as your flex plate is designed for externally balanced engines or did I miss something. I have played this video 3 times now thinking I'm not getting the point or not understanding the message from the video. I do plan on reusing my original damper and flexplate on this rebuild and using your source to have my roller cam reground to your 107 lsa
Please enlighten me if I am wrong about what I'm hearing or misunderstanding
Great Video David … Can I make a request ….. Would you kindly make a similar spec/build video for the Mopar/Chrysler 440 RB. Chevy and Ford get so much attention … a street build would be great. Thanks in advance.
It's in the future but yes I will.
@@DavidVizard Great news, Thanks.
What a perfect excuse to acquire a new toy!
Her: You want to buy a _WHAT?_ 🤯
Me: It's just a small milling machine, honey. David told me I need it. 😁
Thanks for the great video.
David thanks again for your informative videos. I'm curious as to what weight engine oil you use in these small block chevys?
Viscosity ≠ weight. Any SBC with reasonable clearances can use SAE 30. 5W or 10W-30 has better cold viscosity in that it doesn't become as excessively viscous when cold as a mono-grade SAE 30. 0W-30 is even better in this regard if you choose to go synthetic. A good bargain choice is Shell Rotella T5 10W-30.
David is that you?
Why a 107°/108° LSA? If we were doing this to an L31 350 Vortec motor and used a 107° LSA, would that still have enough vacuum to run Power Brakes and accessories in a suburban with fuel injection?
Kevin, you are behind on tech know-how on cams. THE LCA IS NOT, FOR ANY GIVEN ENGINE SPEC, AN AJUSTABLE FEATURE! NOTE:- IF YOU WANT TO GET IDLE QUALITY THEN BE AWARE THIS IS CONTROLLED BY THE OVERLAP USED.
@@marvingvx1 I don't know that I would say "behind"... I'm kinda a newbie and trying to learn.
Love your channel! Just trying to absorb it all! Do you have a good video that explains the valve overlap/LSA?
@@kevinflynn1774 what David said was 107 or 108 installed intake centerline angle. That is different front lobe seperation angle.
@@bcbloc02 Thanks! I'll have to rewatch it.
th-cam.com/video/y_ZUdTd2IcY/w-d-xo.html
This video explained a lot.
@@kevinflynn1774 Buying his book How to Port Cyliner Heads has this cam information. I won't divulge DVs knowledge here, except this "Running a wider center line angle means your attempting to run more duration than the application needs". This is what costs idle quality, vacuum, and ultimately engine output.
For more accurate numbers, and how to get a greater understanding of when and why cam timing needs to change, and what to change it to, then buy the book. If your able to, this applies to any cam operated internal combustion engine, including mulivalve ones. In fact, any book where David Vizard is an author, get it. There is always useful information in everything he publishes.
I can read fast but not that fast awesome video thank you for your knowledge Sir
I have a pause button.