First, you are correct that the roller design can always provide more area under the curve than the flat tappet, and thus more torque. The people who say the flat tappet has an advantage are looking at the first few thousandths off the base circle where the point of contact between the lobe and the face of the tappet is at the edge of the tappet. You can see the higher acceleration in the smaller lobe comparison, but it lasts less than 10° and has no impact after that. The roller tappet very quickly takes over in acceleration, and thus velocity, and the pressure angle allows much greater acceleration and velocity. The dyno results prove the point, again as you stated. Very informative discussion, thanks Daniel!
even if flat tappets could make more power. id still stay with roller if for no other reason than the worries of wiping out a flat tappet cam. my light research told me the roller lifters free up about 30-40 horsepower. i didnt study that much because i know the roller is worth the expense. thank you for the free knowledge and taking the time to make these videos!!
I use to run flat tappet cams till I wiped out three in a row pre-maturely (Phosporous-less oil maybe) and then I went to hydraulic rollers till I had lifters collapse on me on me a couple of times. Now I've run a Howards 110183-10 solid-roller with bushing rollers and a rev-kit since Aug of 2018 and I'm not ever going back. I use composite distributor drive gears now too.
I think Powell explained in a previous video, it’s a lack of a crown on the lifters. and taper on the cam lobe that is eating modern hydraulic cams. Manufacture’s cutting corners.
As always, great information. As I am one of those that was schooled, and taught that a flat tappet of either hyd or solid will make better power "all around" than either variation of of roller, of equal specs. Its good to know that the difference is opposite of what I was taught so many years ago. And that's really a good thing, because my conscience has really been beating me up telling me what you just did. LOL Thanks, again for all of your hard work and dedication....
In the beginning you mentioned the cost difference between solid and roller cam and lifter sets. In a future video could you elaborate a little more on this. I’m not up to date on current costs. I knew these cost differences in the 90’s and 2000’s but now things are so much more expensive. Thanks for the information in this video. I really like the content.
Brother man I don't know how you and others keep your sanity answering basic,repetitive, common, and EASILY accessible knowledge from the guys back in the day that you and I have looked up to and listened to in our own personal journey of living and learning.... yall are saints the way yall explain "whatever the subject may be" to the masses... I'd lose the last Lil bit of marbles I have!!!
@powellmachineinc I'm in the process of going through old build sheets from combos I put together for ppl local to me... "it's a side hustle that funds my own bad financial decisions"...... I like grinding heads and not 2 finger pecking on this damn keyboard
Thanks for sharing Daniel, I'll call to let you know what I've got for a build and let you know what I'm looking for in regards to HP, Torque and RPM and the rest and let you decide what cam grind I need. Safer than assuming.
I heard the same rumors that a small flat tappet would beat small roller. I happened to run across hyd roller 880 block and built it with a 210*x215* with a 110* lobe separation cam. i expected it to be a high torque engine but i was quite surprised how much power it had from 2300 to 4800 rpm. i never had it on a dyno but I'm quite happy with it for an old multi purpose truck
Good video ... when talking about full rpm spread hp it's really about the overlap triangle vs your total lift and closing point because at low rpm that overlap doesn't help you ... the difficult part is you still need good lift and flow at 75 degrees after TDC to meet the cfm demand at that rpm ... a proper roller cam will always win on all points except maybe cost in a older engine designed for flat tappet
Low speed power it's critical to have the proper Ivc and Evo, cylinder pressure is every thing, some overlap is your friend everywhere, but how much is dependent on several variables.
@powellmachineinc even in your example the extra duration and so overlap it what cost the power at those rpm ... it takes intake airspeed and exhaust flow to induce a pull .... I have pulled the exhaust closing point back closer to TDC to help those rpm with good results .... it also takes a proper exhaust header that's tuned to produce a pull to really matter ...
My Crane hydr roller for my 440 where sticking bad ie rattling when it was new but leveled out after, was wondering what I could have done different? Keep the vids rolling much appreciated!!!
About the time we built the Daytona 500 , 1975 pole engine at Jenkins Competition , we looked at mushroom ( large diameter down ) tappets . I cant remember if we ever dynoed them . Probably because NASCAR outlawed them . They definitely had quicker rates than standard tappet cams . There was a cutter to cut room for them at the bottom of the tappet bores .
@@powellmachineinc ,,, at that time , and for decades later , NASCAR big boys , was all flat tappet . So as I said we were just comparing the mushroom tappets , to standard size tappets . Till NASCAR mandated the tappet diameter . Ironically the Busch and later Infinity series ( or whatever ) and truck ran rollers .
Hypothetically if a lobe existed with very near flat flanks for a specific measurement then a flat tappet could have more low lift velocity and acceleration which a roller would need concaved flanks to do the same thing. This might cause a ton of side loading and fatigue on the roller pins. It's a purely hypothetical analysis. But I do think a solid flat is sometimes better because a solid duration at the valve can be shorter than a roller and idle better if you can tolerate some lifter noise. It all goes out the window when you need enough lift to need high valve speeds. Like it might be a money saving strategy around .550" 500hp but I probably wouldn't want a flat tappet at .700" lift. The higher engine speeds will need lobes with better valve control. You're gonna be chasing your tail and breaking parts. If you have a roller block it's probably worth it to stay roller. But if you need a retrofit set of parts you might want to weigh costs.
I think its likely that the flat tappet cam information has come from David Vizard, David has published in his books and said on his TH-cam channel the following . Quote: "The initial acceleration of a flat tappet cam can be significantly higher than a roller cam. In fact, a roller cams strength is its ability to run higher velocities than a flat tappet. What this means is that although the roller cam is slower initially from the seat , it usually allows more lift than a flat tappet cam. For a typical hydraulic valvetrain pushrod V-8 , a roller versus a flat tappet shows that ,for cams bellow about 275 degrees, a flat tappet delivers as much or more area under the lift curve than a roller. For hot street cams, the breakeven point is usually about 278 degree, end quote. For us lay persons . we cant verify this statement one way or the other.
Agree, this is where it came from. I have a hard time watching his videos (DV that is Nov 2022) but he seems to be making a point about some hypothetical cam whose initial ramp is so fast it would push the roller sideways and break it off. Who outside of a very narrow requirement would grind such a cam is beyond me. (Maybe some "stock class" or something. )
You go to a 1.5” diameter flat tappet you can get a lobe that beats a roller pretty handy. Now in an rpm limited deal like a diesel tractor it certainly likely Is worth more power. That being said as rpm goes up holding control on that aggressive profile can throw all those gains out the window.
@ 20 years ago I was doing the cams for one of the big Cummins engine truck pull builders doing 3” turbo motors. Some engines were converted to roller and some ran the 1.5” flat tappets. The .050 duration was within 2 deg with the roller being slightly bigger but the flat tappets were usually up about 50hp at peak but could be as much as 200ft lbs more down around 2500rpm. They peaked hp about 4000rpm but often would hit close to 5000 going down the track.
Real question, I've been interested in an Atkinson cycle engine like Toyota uses in the the Prius. The intake cam seems like a really fascinating round profile. Would you be interested in doing an episode on something like that if I sourced the parts for you?
I was taught that flat tappet lifters will have more acceleration and lift up until you pass 220 at 50 duration for the ft, based on a standard sbc lifter bore. This is due to the way the lobe interacts with the lifter. it's only a small advantage at near stock power levels. Say on a 350sbc 350hp-400hp after that I would imagine the roller is the better option. I could be wrong, I typed this before the video to see if I'm correct or if I was misunderstanding things.
Hmmm, interesting stuff. Y’all ever dealt with the mushroom lifters from back in the day? Personally think it would be interesting to look at the Rhodes lifters and similar, if they actually do vary lift and duration, for the leak down / bleed rate, as advertised. Suspect it’d require a Spintron though.
I experimented with the Rhodes/fast bleed stuff some 45 years ago or so. My experience raised more questions than it did provide answers. Some of my questions remain (IMO) relevant to running hydraulic rollers in some more "aggressive" builds in modern times. In general, I did feel there were perhaps subtle gains to be had in idle, low rpm driveability and vacuum levels in a build that may be a bit "overcammed" for an application. Well, sometimes more than a bit... 😂 While still having some of the benefits of the "big" cam at high RPM. The big question for me was in the variables. Especially spring pressure, oil pressure and even viscosity., and the effect on bleed rate. But in the end, for me- it was the valve closing event off of the designed ramp area that concerned me. They were certainly not "gently" setting down. It worked, a little. But just didn't seem like a good solution in the long run. Back in those times, hammering valves into the seats was a thing to avoid. Well, still is.
Does the same go for a solid flat tappet versus hydraulic roller? I assume the lifter would still be the limiting factor on a cams ramp velocity. I would probably still run a solid flat tappet over a hydraulic roller if the lifters wasn't just junk now, but more than likely the hydraulic roller would make more power, until the lifters start pumping up or collapsing, where the solid ft would just keep pulling with the valve trim under control.
I know you're busy so if you don't have time to answer this no hard feelings. I have a bone stock 93 Jeep fresh rebuilt 4.0 in a Wrangler and I'm wanting a little more power. I'd like to put a bigger cam in it but that's a bigger job than I can tackle right now. A few companies make 1.7 roller rockers to replace your factory stamped 1.6 but they're around $450 a set. Do you think I'd see enough real world difference to justify the cost in a stock daily driver. Thank you for your time & God bless
I'm really interested in your thoughts on running solid roller lifters on a hyd roller cam. Motor Trend did this in back to back dyno's, the solid was more stable. One of them indicated that it was pretty common with boat racing folks. Been thinking of doing the same in my street car. Thoughts??
I think it was one of the magazines that claimed FT's were faster in the low lift area back in the 90s. Not a big fan of retro fit rollers in short lifter bore FT blocks.
I ask this with all manner of known ignorance, and I'm thankful for the knowledge! I wonder if an engine could be built all things the same aside from valvetrain. Could one built with a flat tappet cam close the gap on the roller if say you compared a HFT and 1.7 ratio rockers vs a roller cam and 1.5 ratio. With the specs being the same at the valve when all combined? Does a higher ratio rocker have the same velocity at the valve as the roller without it.
Thank you I really appreciate your videos getting down in the nitty gritty! Questions from a moron: seems like roller is always better? The real difference is solid vs hydraulic, no? Solid has more aggressive valve events at the expense of maintenance, solid needs to set lash more often? Other than legacy/compatibility when would you pick a flat tappet over a roller?
You can make Very Big power with a Flat Tappet.. You Go Steel Core, DLC coated EDM hole lifter... 200 lbs on the springs... The Cost is up there tho... DANIEL, CAN YOU SHOW US YOUR CAM POLISHING AFTER GRINDING, AND TALK ABOUT CAM LOBE FINISHING...????
One of the points in the previous video was about lifter diameter versus base circle. My understanding that the diameter of the lifter in relation to the base circle can cause scuffing of the low if the velocity is too high. I remember back in the '70s and '80s that Isky came out with a mushroom lifter that was about 1 in OD on the face which helped with the velocity and scuffing off the top of the lobe. Back when I worked at a place called Taylor engine rebuilding and we were running a nitromethane drag boats I was only I was only 18 or 19 years old. I questioned about using hydraulic rollers in street cars and got kind of poo-poohed about that
I can remember people using a 300 inline 6 lifter, have to spot face bottom of lifter bores, it has a bigger diameter base mushroom solid style lifter, yes sbc loves a bigger diameter lifter
A point I think people miss when they debate this topic is, that the roller cam and roller lifters weigh more, especially the retro fit stuff. Which takes more crankshaft power to turn than a flat tappet. And more valvetrain weight is gonna require stiffer springs to keep under control which also takes more power.
Valvetrain weight is a crucial area BUT the frictional losses + the ramp rates and area under the curve alone negates any gain in weight you have running ANY type of roller setup vs flat tappet.... flats are dead technology and have been a LONG time... yes they work, but with the caliber of build todays super "budget" build can be capable of summit & jegs should just pull them from there catalogs and let it die in my opinion
@@ZackeryStang I'm glad they still sell flat tappets for price alone. But don't think rollers have a frictional advantage either. Because you have to take into consideration the sideload into the lifter bore the roller lifter creates, especially at low rpm and right off the base circle. I think flat tappets get a bad name from people still believing you have to run conventional engine oil with them. I personally use full synthetic on flat tappet SBC's without an issue without a zinc additive too.
I realize you are a cam grinder first and a youtuber second, but don't forget the basics. You put up a graph with six traces on it and didn't show us which trace you were talking about, or where at on the trace.
Funny thing ALL true racing engines have direct acting , cam on lifter. When you have an 1 3/8 dia lifter no roller in the world will keep pace with that.
I dont see how anybody with common sense can make that comment just looking at the lobes a roller they're almost square, slamming that valve open fast, holding it open like on a plateau then slamming it shut. I use to tell my buddies if we both have a 5gal bucket under the same size faucet but one faucet takes 5 revolutions to full open and the other is full open at half a turn who gets more water it the bucket in 5 seconds, and the valves have to be closed at the 5 sec mark.
Rollers are just better, a flat tappet can only handle so much ramp before the edge of the lifter starts digging into the lobe. The roller wheel has no edge so it can open the valve fast, hold it open longer at max lift then close it fast. Flat tappets cant do that hence the pointy lobes. Rollers are just flat out better, less friction and all. I guess the only downside is spring pressure.
whould see results of assemlying 2 engines one with flat tappet, one wuth roller . Both with same spec. both with same springs and rocker ratios. pull over with torque wrench and see what the difference. I know that is not the way they norally run but what the heck. I am sure it has been done.
If catalysts didn't exist, and oil still contained zinc (etc) you might still have OE flat tappet if only for the inexpensive parts aspects. But thats a simply theoretical "if."
But you don’t build flat tappets anymore. Your business is only doing rollers. I feel this info will be biased (haven’t watched it yet). David Vizard will be my first source on this subject
First, you are correct that the roller design can always provide more area under the curve than the flat tappet, and thus more torque. The people who say the flat tappet has an advantage are looking at the first few thousandths off the base circle where the point of contact between the lobe and the face of the tappet is at the edge of the tappet. You can see the higher acceleration in the smaller lobe comparison, but it lasts less than 10° and has no impact after that. The roller tappet very quickly takes over in acceleration, and thus velocity, and the pressure angle allows much greater acceleration and velocity. The dyno results prove the point, again as you stated. Very informative discussion, thanks Daniel!
@@bdugle1 your welcome
Everyday is a school day. Thank you for your time.
Yeah, we all are still learning!
I second this motion! Thanks for saying this as I feel the same way!
Thanks kindly.
even if flat tappets could make more power. id still stay with roller if for no other reason than the worries of wiping out a flat tappet cam. my light research told me the roller lifters free up about 30-40 horsepower. i didnt study that much because i know the roller is worth the expense. thank you for the free knowledge and taking the time to make these videos!!
@@MrChevelle83 absolutely 💯
I use to run flat tappet cams till I wiped out three in a row pre-maturely (Phosporous-less oil maybe) and then I went to hydraulic rollers till I had lifters collapse on me on me a couple of times. Now I've run a Howards 110183-10 solid-roller with bushing rollers and a rev-kit since Aug of 2018 and I'm not ever going back. I use composite distributor drive gears now too.
Great clarification, and explanation, thanks for sharing, all the best to you and your loved ones
I think Powell explained in a previous video, it’s a lack of a crown on the lifters. and taper on the cam lobe that is eating modern hydraulic cams. Manufacture’s cutting corners.
As always, great information. As I am one of those that was schooled, and taught that a flat tappet of either hyd or solid will make better power "all around" than either variation of of roller, of equal specs. Its good to know that the difference is opposite of what I was taught so many years ago. And that's really a good thing, because my conscience has really been beating me up telling me what you just did. LOL
Thanks, again for all of your hard work and dedication....
@@dougroope8040 💯
In the beginning you mentioned the cost difference between solid and roller cam and lifter sets. In a future video could you elaborate a little more on this. I’m not up to date on current costs. I knew these cost differences in the 90’s and 2000’s but now things are so much more expensive. Thanks for the information in this video. I really like the content.
Will do
Brother man I don't know how you and others keep your sanity answering basic,repetitive, common, and EASILY accessible knowledge from the guys back in the day that you and I have looked up to and listened to in our own personal journey of living and learning.... yall are saints the way yall explain "whatever the subject may be" to the masses... I'd lose the last Lil bit of marbles I have!!!
@ZackeryStang just trying to build a data base for the future!!
@powellmachineinc I'm in the process of going through old build sheets from combos I put together for ppl local to me... "it's a side hustle that funds my own bad financial decisions"...... I like grinding heads and not 2 finger pecking on this damn keyboard
Thanks for sharing Daniel, I'll call to let you know what I've got for a build and let you know what I'm looking for in regards to HP, Torque and RPM and the rest and let you decide what cam grind I need. Safer than assuming.
@@Anthony-nw5zv we have a cam recommendation form on our website
Another great video with a lot of good information!
I heard the same rumors that a small flat tappet would beat small roller. I happened to run across hyd roller 880 block and built it with a 210*x215* with a 110* lobe separation cam. i expected it to be a high torque engine but i was quite surprised how much power it had from 2300 to 4800 rpm. i never had it on a dyno but I'm quite happy with it for an old multi purpose truck
@@tracycurtright2671 definitely
Thanks for the info and keep up the good work!
@@JamesBower-l9d glad to do it
Good video ... when talking about full rpm spread hp it's really about the overlap triangle vs your total lift and closing point because at low rpm that overlap doesn't help you ... the difficult part is you still need good lift and flow at 75 degrees after TDC to meet the cfm demand at that rpm ... a proper roller cam will always win on all points except maybe cost in a older engine designed for flat tappet
Low speed power it's critical to have the proper Ivc and Evo, cylinder pressure is every thing, some overlap is your friend everywhere, but how much is dependent on several variables.
@powellmachineinc even in your example the extra duration and so overlap it what cost the power at those rpm ... it takes intake airspeed and exhaust flow to induce a pull .... I have pulled the exhaust closing point back closer to TDC to help those rpm with good results .... it also takes a proper exhaust header that's tuned to produce a pull to really matter ...
what do you think.does a solid lifter cam make more hp then a hydraulic cam and am talking about 600 to 700 lift cam ??
@roadrunner1391 sure, a solid profile is more advantages to making power
So switching to Flat tappet in my BAE Hemi is not a good idea ? LOL , Thanks for the Video, and sharing your knowledge.
I mean.... it's worth a shot....lol
Thanks for the video.
@@paulshurmon138 glad to do it
Great explanation! Have you already covered rocker arm ratios and cam choice? What are the positives and negatives of rocker ratio?
Yes I have
My Crane hydr roller for my 440 where sticking bad ie rattling when it was new but leveled out after, was wondering what I could have done different? Keep the vids rolling much appreciated!!!
just lifer issues most likely, piston clearance, trash ect.
Thanks
HeyHey maybe disassemble clean before insulation
About the time we built the Daytona 500 , 1975 pole engine at Jenkins Competition , we looked at mushroom ( large diameter down ) tappets . I cant remember if we ever dynoed them . Probably because NASCAR outlawed them . They definitely had quicker rates than standard tappet cams . There was a cutter to cut room for them at the bottom of the tappet bores .
@rolandtamaccio3285 the lobe design has the ability for more velocity with a larger diameter lifter, but it's still not close to a roller
@@powellmachineinc ,,, at that time , and for decades later , NASCAR big boys , was all flat tappet . So as I said we were just comparing the mushroom tappets , to standard size tappets . Till NASCAR mandated the tappet diameter . Ironically the Busch and later Infinity series ( or whatever ) and truck ran rollers .
I think David Vizard has a video about this. Seems like he showed the flat tappet can have advantages, in a very specific set of circumstances.
@AtomicFacePunch yeah, I have not seen a advantage
Hypothetically if a lobe existed with very near flat flanks for a specific measurement then a flat tappet could have more low lift velocity and acceleration which a roller would need concaved flanks to do the same thing. This might cause a ton of side loading and fatigue on the roller pins. It's a purely hypothetical analysis. But I do think a solid flat is sometimes better because a solid duration at the valve can be shorter than a roller and idle better if you can tolerate some lifter noise. It all goes out the window when you need enough lift to need high valve speeds. Like it might be a money saving strategy around .550" 500hp but I probably wouldn't want a flat tappet at .700" lift. The higher engine speeds will need lobes with better valve control. You're gonna be chasing your tail and breaking parts. If you have a roller block it's probably worth it to stay roller. But if you need a retrofit set of parts you might want to weigh costs.
I think its likely that the flat tappet cam information has come from David Vizard, David has published in his books and said on his TH-cam channel the following . Quote: "The initial acceleration of a flat tappet cam can be significantly higher than a roller cam. In fact, a roller cams strength is its ability to run higher velocities than a flat tappet. What this means is that although the roller cam is slower initially from the seat , it usually allows more lift than a flat tappet cam. For a typical hydraulic valvetrain pushrod V-8 , a roller versus a flat tappet shows that ,for cams bellow about 275 degrees, a flat tappet delivers as much or more area under the lift curve than a roller. For hot street cams, the breakeven point is usually about 278 degree, end quote. For us lay persons . we cant verify this statement one way or the other.
@@craigritchie1933 I think I just did
Agree, this is where it came from. I have a hard time watching his videos (DV that is Nov 2022) but he seems to be making a point about some hypothetical cam whose initial ramp is so fast it would push the roller sideways and break it off. Who outside of a very narrow requirement would grind such a cam is beyond me. (Maybe some "stock class" or something. )
You go to a 1.5” diameter flat tappet you can get a lobe that beats a roller pretty handy. Now in an rpm limited deal like a diesel tractor it certainly likely Is worth more power. That being said as rpm goes up holding control on that aggressive profile can throw all those gains out the window.
@@bcbloc02 💯 agree
@ 20 years ago I was doing the cams for one of the big Cummins engine truck pull builders doing 3” turbo motors. Some engines were converted to roller and some ran the 1.5” flat tappets. The .050 duration was within 2 deg with the roller being slightly bigger but the flat tappets were usually up about 50hp at peak but could be as much as 200ft lbs more down around 2500rpm. They peaked hp about 4000rpm but often would hit close to 5000 going down the track.
Oh I probably should have said these were 1100-1200hp motors.
Should only run a roller lifter in almost all applications out side of motorsports with that are limited to flat tappet
Real question, I've been interested in an Atkinson cycle engine like Toyota uses in the the Prius. The intake cam seems like a really fascinating round profile. Would you be interested in doing an episode on something like that if I sourced the parts for you?
@@gedavids84 don't know if I'm qualified, I've never seen one
I was taught that flat tappet lifters will have more acceleration and lift up until you pass 220 at 50 duration for the ft, based on a standard sbc lifter bore. This is due to the way the lobe interacts with the lifter. it's only a small advantage at near stock power levels. Say on a 350sbc 350hp-400hp after that I would imagine the roller is the better option.
I could be wrong, I typed this before the video to see if I'm correct or if I was misunderstanding things.
@shanerorko8076 after watching u will have the answer
Interesting discussion, explanation. I'm curious how the mushroom lifter nascar teams used in the SBC compares to a roller or solid lifter?
Ther did it with rocker ratio mostly
Hmmm, interesting stuff.
Y’all ever dealt with the mushroom lifters from back in the day?
Personally think it would be interesting to look at the Rhodes lifters and similar, if they actually do vary lift and duration, for the leak down / bleed rate, as advertised. Suspect it’d require a Spintron though.
300 online six lifter and spot face bottom of lifter bores, this was common all thru 80s, now sum run ceramic lifters
no mushroom stuff, i dont buy into the "variable duration" stuff
@@powellmachineinc We used to sell Rhodes to the unwashed who insisted on buying a bottom of the page cam for a middle of the page build
I experimented with the Rhodes/fast bleed stuff some 45 years ago or so. My experience raised more questions than it did provide answers. Some of my questions remain (IMO) relevant to running hydraulic rollers in some more "aggressive" builds in modern times.
In general, I did feel there were perhaps subtle gains to be had in idle, low rpm driveability and vacuum levels in a build that may be a bit "overcammed" for an application. Well, sometimes more than a bit... 😂 While still having some of the benefits of the "big" cam at high RPM.
The big question for me was in the variables. Especially spring pressure, oil pressure and even viscosity., and the effect on bleed rate.
But in the end, for me- it was the valve closing event off of the designed ramp area that concerned me. They were certainly not "gently" setting down.
It worked, a little. But just didn't seem like a good solution in the long run. Back in those times, hammering valves into the seats was a thing to avoid. Well, still is.
I been building Pontiac engines for 40 year's, we use 90 percent of the time flat tappet cams, not many cam profiles in roller for my customers
You just ain't looking hard
Does the same go for a solid flat tappet versus hydraulic roller? I assume the lifter would still be the limiting factor on a cams ramp velocity. I would probably still run a solid flat tappet over a hydraulic roller if the lifters wasn't just junk now, but more than likely the hydraulic roller would make more power, until the lifters start pumping up or collapsing, where the solid ft would just keep pulling with the valve trim under control.
@@inscoredbz the lifter diameter is still the limiting factor
I know you're busy so if you don't have time to answer this no hard feelings.
I have a bone stock 93 Jeep fresh rebuilt 4.0 in a Wrangler and I'm wanting a little more power. I'd like to put a bigger cam in it but that's a bigger job than I can tackle right now. A few companies make 1.7 roller rockers to replace your factory stamped 1.6 but they're around $450 a set. Do you think I'd see enough real world difference to justify the cost in a stock daily driver. Thank you for your time & God bless
@Yelladog78 it will add about 10 degrees of duration, you probably will barely notice
@powellmachineinc Thank you, glad I asked before dropping the $. Appreciate it sir
I'm really interested in your thoughts on running solid roller lifters on a hyd roller cam. Motor Trend did this in back to back dyno's, the solid was more stable. One of them indicated that it was pretty common with boat racing folks. Been thinking of doing the same in my street car. Thoughts??
@@retorq here ya go
th-cam.com/video/jBDSu3QZRWg/w-d-xo.htmlsi=Yizbkg0Tbv0NiPvt
I think it was one of the magazines that claimed FT's were faster in the low lift area back in the 90s.
Not a big fan of retro fit rollers in short lifter bore FT blocks.
there's no issue
I ask this with all manner of known ignorance, and I'm thankful for the knowledge! I wonder if an engine could be built all things the same aside from valvetrain. Could one built with a flat tappet cam close the gap on the roller if say you compared a HFT and 1.7 ratio rockers vs a roller cam and 1.5 ratio. With the specs being the same at the valve when all combined? Does a higher ratio rocker have the same velocity at the valve as the roller without it.
@@wtdonovan correct
@@powellmachineinc 😲
@@powellmachineinc many thanks!
Hair cut looks good.
Put some lotion on your hands at night when you rub them together sounds like 400 grit sandpaper
Haha, you got me there on the hands, I've been working too much!
Thank you I really appreciate your videos getting down in the nitty gritty! Questions from a moron: seems like roller is always better? The real difference is solid vs hydraulic, no? Solid has more aggressive valve events at the expense of maintenance, solid needs to set lash more often? Other than legacy/compatibility when would you pick a flat tappet over a roller?
the engine will not always respond to faster valve motion, its not that cut and dry
@@powellmachineinc asking from ignorance: when would you choose a flat tappet over a roller? Both are solid or both hydraulic take that out.
$25 for your time I appreciate it, hope it doesnt just go to coffee
@avp5964 we really appreciate that! So far, any money's go to camera/audio equipment, we really appreciate it!!
@@powellmachineinc Thank you! Appreciate your knowledge and look forward to your videos. Don't forget to relax too, happy Sunday.
You can make Very Big power with a Flat Tappet.. You Go Steel Core, DLC coated EDM hole lifter... 200 lbs on the springs... The Cost is up there tho...
DANIEL, CAN YOU SHOW US YOUR CAM POLISHING AFTER GRINDING, AND TALK ABOUT CAM LOBE FINISHING...????
YA BUT FLAT TAPPIT CAMS SOUND SOOOO GOOD . LOL
So you are adding lift by adding a roller lifter and if so how much?
You're "able " to add lift because a roller isn't velocity limited in the same way as a Ft
I guess that statement that the person made about flat tappets, he was not paying attention on his geometry class.
@@CJ5EVOLUTION definitely
that person was DV
@@V8Lennythe devil is in the details, I'm sure in his videos he said "if" "or" "possibly" "depending" and with that his argument is covered.
One of the points in the previous video was about lifter diameter versus base circle. My understanding that the diameter of the lifter in relation to the base circle can cause scuffing of the low if the velocity is too high. I remember back in the '70s and '80s that Isky came out with a mushroom lifter that was about 1 in OD on the face which helped with the velocity and scuffing off the top of the lobe. Back when I worked at a place called Taylor engine rebuilding and we were running a nitromethane drag boats I was only I was only 18 or 19 years old. I questioned about using hydraulic rollers in street cars and got kind of poo-poohed about that
I can remember people using a 300 inline 6 lifter, have to spot face bottom of lifter bores, it has a bigger diameter base mushroom solid style lifter, yes sbc loves a bigger diameter lifter
base circle and rollers matter , ft not really
Taylor still around I ran Ohley;s shop several summers so he could take a vacation, RIP also Speed o motive small world
I watched this earlier? Was this taken down and uploaded again?
I clarified a few points and reupped
A point I think people miss when they debate this topic is, that the roller cam and roller lifters weigh more, especially the retro fit stuff. Which takes more crankshaft power to turn than a flat tappet. And more valvetrain weight is gonna require stiffer springs to keep under control which also takes more power.
Valvetrain weight is a crucial area BUT the frictional losses + the ramp rates and area under the curve alone negates any gain in weight you have running ANY type of roller setup vs flat tappet.... flats are dead technology and have been a LONG time... yes they work, but with the caliber of build todays super "budget" build can be capable of summit & jegs should just pull them from there catalogs and let it die in my opinion
@@ZackeryStang I'm glad they still sell flat tappets for price alone. But don't think rollers have a frictional advantage either. Because you have to take into consideration the sideload into the lifter bore the roller lifter creates, especially at low rpm and right off the base circle. I think flat tappets get a bad name from people still believing you have to run conventional engine oil with them. I personally use full synthetic on flat tappet SBC's without an issue without a zinc additive too.
@@The0utmode the dyno disagrees with u on all points.
@@The0utmodethe reduction of friction at the roller is also going to reduce how hard the cam pushes the lifter against the bore wall. Don’t you think?
@ Roller lifters don't spin in the bore. The pressure angle created from the roller trying to roll is driving the lifter into the bore.
Did you repost this video?
Yes i edited it and clarified a few point
@@powellmachineinc Thanks you are quality
What about a solid flat lifter?
we cover that in the vid
@powellmachineinc Cool I'd like to see that comparison. Very few hydraulic cams in what I'm into.
I wonder why the mechanical flat flat tappet made a little more power above 5400?
it was hyd
Because of the extra duration
It was a bigger cam, +10°@050
I’m of the mindset that the reduction in friction alone would increase available power output.
Yes it does
@@powellmachineinc I can’t believe this debate is still ongoing really. I thought it was settled fact already. I guess not. lol.
🔔😎🇺🇸
Thank you Master Daniel.
YeeeeeHaaaaw!!!
lol, welcome
Just pull the valve cover off and watch the valves😂
Its true that flat tappets have faster ramp rates for a given cam profile but that does not mean they will make more power
we demonstrated that isnt true
So what you're telling me is that the best way to get you to make an interesting video is to say something wrong in the comments. 😝
@@gedavids84 lol, well....
were leaded brass/ bronze flat lifters ever tried out? should stop them wiping out the cam lobes, since it's not iron on iron.
Iron is to abrasive for that
@@powellmachineinc or the brass is too soft to handle the spring pressure, but ok.
I realize you are a cam grinder first and a youtuber second, but don't forget the basics. You put up a graph with six traces on it and didn't show us which trace you were talking about, or where at on the trace.
Funny thing ALL true racing engines have direct acting , cam on lifter. When you have an 1 3/8 dia lifter no roller in the world will keep pace with that.
ohc i do agree
true race engines have cam acting on finger follower.
Eff hydraulic rollers.....solid rollers ftw
@@HioSSilver1999 lol
This is a myth from David vizard’s books. The caveat was at “low lift”, the context indicated low total lift, not at less than 0.050”. 🙄
@@shane-222 I think we put it to bed.
I dont see how anybody with common sense can make that comment just looking at the lobes a roller they're almost square, slamming that valve open fast, holding it open like on a plateau then slamming it shut. I use to tell my buddies if we both have a 5gal bucket under the same size faucet but one faucet takes 5 revolutions to full open and the other is full open at half a turn who gets more water it the bucket in 5 seconds, and the valves have to be closed at the 5 sec mark.
Because the roller curve takes up the rest, vs a flat angle of a flat tappet. All being said modern profiles on both, rollers are better.
Rollers are just better, a flat tappet can only handle so much ramp before the edge of the lifter starts digging into the lobe. The roller wheel has no edge so it can open the valve fast, hold it open longer at max lift then close it fast. Flat tappets cant do that hence the pointy lobes. Rollers are just flat out better, less friction and all. I guess the only downside is spring pressure.
It's the valve motion that the piston sees- hence the mechanics can favor the F/T lobe.
@arthurking6549 obviously you didn't watch the video, that is addressed.
@@powellmachineinc You are good- just not Mike Jones good.
@@arthurking6549 lol
Eh? What happened here? Re-upload of shorter video?
Ok, found reply below.
Fixed a few points
so much more to the race mochine than the cam.
I think maybe a dude running a roller will be more
picky the way build the engine and whole car.
whould see results of assemlying 2 engines one with flat tappet,
one wuth roller . Both with same spec. both with same springs and rocker ratios.
pull over with torque wrench and see what the difference.
I know that is not the way they norally run but what the heck.
I am sure it has been done.
Two virtually identical builds will not necessarily make the same power curves. There are many minute variables.
Simple answer: if flats had any advantage oems and aftermarket would still be using them 40 years later...
@@joeinmi8671 yup
If catalysts didn't exist, and oil still contained zinc (etc) you might still have OE flat tappet if only for the inexpensive parts aspects.
But thats a simply theoretical "if."
@@mbliss01 I see your point but they still wouldn't exist imho. Even the tried and true b series Cummins went roller.
But you don’t build flat tappets anymore. Your business is only doing rollers. I feel this info will be biased (haven’t watched it yet). David Vizard will be my first source on this subject
Yooooo
@
can't get a cam and lifters from Chevy for hundred dollars anymore.
Can't buy a brand new Impala SS for $3500 either and gas ain't 30 cents.
You can't buy a good new car either they are all junk. I'd rather pay more for SBC parts than buy a new car that costs more anyway.
For LS stuff, you dont usually need to buy lifters. You use the factory lifters and trays with an aftermarket cam.
I'm not going to watch, the answer is no, rollers make more power, reply if incorrect.
If ft made more power you'd still be grinding ft cams.
Yup