Bad LS SHP block machining from Dart - Always check any aftermarket parts!
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- เผยแพร่เมื่อ 16 พ.ย. 2022
- I know I have shown block being out before, but this is an aftermarket block from dart that didn't get machined so well. I'm not sure if this is how every block leaves their factory, but this one must have been put out on a Friday! Always a good idea to check aftermarket parts!
I worked in a local machine shop for 3-4 years, and i dont care what brand, or how expensive it was, we would check every piece, cranks, rods, pistons, blocks, heads, does not matter if they say theyre polished, or at a finished size. The percentage of stuff thats off is staggering. Check everything always.
Preach! Always important to check!
I even check the factory parts weights I also balanced piston, rods, and wrist pins to within 0.1gram I do the same to cir clips ect being precise is key
Back in the day they called it “ balanced and blue printed “
@@rickjohnson1632 and thats why it always costed so much more to do than an average rebuild. And people would always wonder what kind of work they were getting done with that phrase.
@@dondagy9109 my reply to them would be “ you get what you pay for”
Always figured a good machine shop was a best friend!
You got that right!
Something about a freshly machined surface that is so satisfying.
it is very pleasing to the eye.
Oh hell yes. I learned to check every single part that hit the shop - new or used.
The NEW parts that came in were incredible.
I remember resizing brand new connecting rods, surface ginding oil pump housings to get the clearances in tolerance etc...
When your name is on the invoice!
Today it’s imperative to check everything. The discipline and value of quality control has for the most part been abandoned.
Yep! All parts are subject to inspection! The one you don't check is going to be the one that fails! And we want ZERO failures!
Every block manufacturer states that it still needs finish machine work to get to your spec. Not surprised with your find.
Yes, most do need to be checked! But even if there was a couple extra thou left on top, you would think with their equipment it would at least be straight!
Pffft . I had to dust off the box the deck height gauge was in when I started my endeavor back in the early 90’s . I could not believe even back then how F’d up even factory stuff was . We (collectively, changed when I got into the shop and profiled and engine properly) were building 355ci roundy round engines and some offshore power boat engines . Even medium, life propane generator 502 blocks were .004-.013 off . Worst I had seen was a Motown block that we eventually scrapped the thoughts on the block and sent it away . Perfect example of supply and demand rush jobs .
Very true! Tolerances are everywhere these days. And it is really bad considering how accurate the equipment is!
Sounds like dart needs to step there game up !
Just a little better checking before it goes out the door!
I dont even want to know what that machine costs!! Makes you wonder how "off" the old 60's muscle car blocks are ... great work
They aren't great, worse than this one, that's for sure!
Believe it or not, you can buy those machines used with low hours on them pretty reasonably priced.
@@Motor-City-Mike that's how we got our Bridgeport and south bend lathe.
One came from a shop that was going to CNC and all the old stuff was pushed in the corner, you can basically get things like that for scrap value sometimes.
Beautiful work and machine 👏
Thank you very much!
Great work! Nice setup, can you show more of the fixturing and how you are setting up your blocks in the machine?
Sure! I can put a video together for that in the future!
@@paragonengines1924 I am wondering how repeatable the angular movement is where the block is fixtured? Is it hydraulic?
It is within .0002" usually. The arc angle repeatability at the block radius is about .003". But I have written the program to rotate the block in a way that takes the play out of the gears, so when it locks in, it repeats under .0005". It is gear driven with an air brake.
I've gotten many Dart heads that the valves don't seal. A must to check everything.
I agree, always double check!
The Dart block looks fantastic after being decked!
Didn't turn out too bad, did it!
The Machine shop in Portland Oregon I use sees many Dart new blocks for corrections missed at Dart .
I am not surprised!
Dart states in the literature for sbc shp that deck height is nominal +/- and usually left tall for the builder to dial in. The fact that it's not perfect is no surprise
Yes, they do state that. But you would think with their equipment, it would at least be straight!
@@paragonengines1924 ever check a new OEM block, check 10, especially older stuff, the tolerance was pretty wide.
@@b.c4066 Doesn't matter. We are talking small production after market premium cost, not OEM.
Great video
Thank you!
Austin! How are ya man? Good to see you on TH-cam. Hope you’re doing well out there in Tennessee
It’s Cody from ace customs
Doing well man, hope you have been too!
Always check your Blocks, Heads..etc..etc! Had a friend who bought some assembled heads for his build. I asked him if he took them to a machine shop and had them decked, flow tested or at least had them checked to make sure they were within spec across the deck on the head. He laughed at me which I tried not to take personal seeing as I've worked for both Chevy and Ford as a Master Tech and for the last 5 years for a Professional IMSA Race Team. (He works in HVAC) I tried explaining to him the reason behind it. But he didn't want to hear it. 4 Blown head gaskets later and a bent rod he still was in denial while I helped him pull the motor and take it down to the machine shop. After a good talk with the Machine Shop owner he apologized to me even though I told him it wasn't needed. Dont get me wrong, I've slapped plenty of out of the box heads on builds. But they usually were budget projects I was just toying around with and having fun. He was putting a lot of money into his build but insisted he do all the work and I was just trying to save him one giant headache.
Very true! There are plenty of companies that put out good work, and this may not be the case for every dart block. But sometimes a double check can save a big headache down the road!
Another thing that's SUPER common is poor valve sealing to the seats -
The next set of new heads you handle, as a quick check pour just a little bit of solvent in the port side and see if they seal, you'll be surprised at how few actually have a good seal at the seat!!
LOLOLOL I have same history and almost the exact same story. Funny how GM techs end up working for Ford (better money) and building Chevrolet engine for their Dumb Roundy driver friends
Nice work. I bought a Dart Little M Pro block a few years back. Nothing was straight requiring lots of work. Still running strong today.
They are a solid piece, for sure. Once the machining is done, they will put in a lot of work!
The instructions from DART specify all surfaces must be checked before machine work. The decks are usually 'roughed out' a few thousands of an inch above the DH specs. The big blocks are .004" to .006" above the 9.800 or 10.200 advertised specs. Just as the cylinders are rough bored, leaving around .007" to .008" for boring and honing. However, sometimes an engine builder will assume everything is square and ready to assemble. The only thing that is ready out of the box is Cracker Jacks. Everything else needs preparation.
Yep! It's always best to double check everything!
@@rollydoucet8909 You are referring to "rough finish" blocks I find the same issue with finished blocks from dart.
@@bad406camaro The block in this video isn't new, see the carbon deposits at the top of the bores. The machine in the video will finish the decks exactly parallel to the crank center. Dart uses the same type of machinery, as does the shop where I work. The blocks are set up on the main bearing bores, which sit on a fixture that is dead-accurate, and the end result is a deck surface that is perfectly in line with the crank centerline. The block in the video was obviously resurfaced differently at one time and not parallel to the crankline.
Was it align bored wrong? Did you measure the Z axis of the bores to the crank centerline or the deck surface? Love that you use a surfometer/perthometer to check surface finish. A lot of small machine shops skip that step.
The line bore was straight and round, but the decks did measure differently to the crank centerline. In this case we measured the deck to the centerline and not the bores. If the bores are straight to the centerline, then everything is square now. I don't use it on every block, but it is important to know you're getting the right finish!
@Paragon Engines I started in a small machine shop where the owner would use his thumbnail to "check" surface finish. Ended that career in a modern facility where we used real instruments to check Ra, Rz and PMR with surfometers and a tallyround on cranks, cams, and output shafts. Keep up the excellent work!
The ol' "calibrated thumb" never lied once lol. Sounds like you ended up at a top-notch facility!
This has been a issue with Dart for as long as i have purchased Dart blocks. I have seen some .007 off square on Dart, Motown, little M and SHP SBC. I think the lower quality blocks come out during Post cup season months. Things seem to be better summer to mid-summer but delivery time is also much better
Interesting correlation, it makes sense. Still always pays to double check!
Motown blocks aren't Dart, but World/PBM.
@@ToddWrightthedrummer Sorry I forgot the comma`s WRU grammar police
Is it me, or were there visible head gasket blowout marks exactly where those low spots were on the first pass?
On the one side of the engine, it blew out the head gasket and put a hole in the head! So, yes, you are seeing the damage from that failure.
Any engine builder worth his salt should always measure everything. Every time.
Preach!
Who would have thought. A buddy of mine that does brakes for a living, says you should always cut new rotors. Not always, but, sometimes he finds rotors way out of round and flat. With his name on it, he cuts it, always now. Jack.
Good idea, stopping is VERY important!
Great video
Was the intake deck checked?
You mean where the valley cover sits? No, it doesn't do anything but seal up the valley, so they usually don't need to be checked.
VERY COOL .. VERY KNOWLEDGEABLE .. THANK YOU .. 🇺🇸 USA 🇺🇸 USA 🇺🇸 USA 🇺🇸
Thank you! just trying to spread the knowledge!
With so many moving parts, how do you differentiate between variances in the piece, and variances in the machine?
The bar that the block sits on is precision ground to around .0002" out of round. The level of the bar is within .0001" across the x and y-axis. The Machine has a tolerance of about .0002". So, any variation measured in the block, is in the block. Everything with this set up is based off of the centerline of the crankshaft, so everything gets blueprinted off of that.
@@paragonengines1924 Setup and Maintenace is everything!
Do you think that problems like this may be attributed to some degree to internal stresses in the block working themselves out over time?
Not this much movement!
Is it difficult to bore a v8 with that machine? Looks pretty tight in vertical clearance. Also, I've heard you can order blocks unfinished for a little cheaper and have a local shop finish the machining to proper specs
There is enough clearance by a couple inches. I have another video up showing the boring of an SBC. Yes, if you don't have dart machine the whole block, it will be cheaper.
Would core shift during casting be the cause of decks being that much off? That's a known common problem.
No, because it is a machined surface that should be trued to the centerline after casting. Water jackets could be shifted in reference to the cylinder, Etc. But the machined surfaces should all the true to each other.
Hi, I'm not a machinist. The holed for the head drilled and tapped are they now out of square?
If they used the deck surface at the datum to start from, then yes. Generally, the head bolt holes aren't going to be off far enough for it to cause an issue.
Is that machine how you get that sweet mustache so perfect??? I think I figured it out. Lol
The wind from it makes just the right curl!
If it's so far off compression should been off. then total amount off makes piston hit head. plus brings heads closer too crank makes pulleys off and brackets that if to much was taking off
Oh yes, compression would have been different in every cylinder on that side. There is usually enough wiggle room in the quench to make up for removing some from the block before the pistons get too close to the head. We do check every motor though and can trim the pistons if needed!
I’m pretty sure it says somewhere in the Dart website that final machining will be required for assembly. Specifically deck height…
Bro what? After they charge that much for the dogshit they sell
@@8bbboy636 just went back to make sure… Yup. The dart website has several pages that explain the process for final machining and assembly for their blocks. Next time read the instructions.
@DeltaVTX well I would but I didn't buy it directly on their page so it did not come with those instructions and still mort blocks for the price are already machined
@DeltaVTX and I can still not find where it says it I was reading their page and it says, "All development, machining and assembly are done at Dart’s own facilities in order to maintain the highest standards of quality."
@@8bbboy636 newdart.wpenginepowered.com/wp-content/uploads/LS-Next-Iron-Block-Information-Packet-B06.pdf
Im thinking that surface being off was the cause of the head gasket failing?
No, the whole block being tilted wouldn't be caused by a head gasket.
How's the VF4 treating you for block work? Any reason why you chose Haas over other brands?
It has been working great! Huge time savings and more accurate! One big reason for me was cost. It's about half the price of the Rottler and Centroid machines and I didn't need the 5th axis. I also like the support system from Haas and they have very robust software.
@Paragon Engines I appreciate the response! I run a VF2YT at work but at home I have a similar sizesd mill that I'm doing a Centroid conversion on. I'm always wishing I had the Centroid A560 to do block work and porting... I'm glad the VF4 is treating you well! Have you considered getting a column riser to get some extra Z height or is it unnecessary for the work you do?
That sounds like a fun project!
I don't believe the VF-4 has the option for the column riser. I did get the lower profile table, which gave me 3 more inches. I haven't had a problem with clearance for all the blocks I'm doing, but it was close when I was measuring things out before I got the machine to figure out what was going to fit.
What was total height after final haircut ?
Ended up at 9.232 after it was all said and done!
nice video good content
Thank you!
liberal arts grad here, so be kind.... when you fix the deck angle, does this translate into more power, or better longevity, or...? I realize that all machinists want to approach perfection, but where would the customer see the benefits?
It will be more power because each of the cylinders are contributing equally. It also makes sure the measurements we have later on down the line are more consistent so we can achieve the tight tolerances we need to make the most power.
.007 out
No big deal.
Well within tolerance!
Maybe a tolerance from 50 years ago!
Perfect example of it can be bad, you better check it.
Yes, always double check!
Wow I thought expensive aftermarket blocks would be better then OE blocks. Wow
Me too! But you should always double check!
Thank you. This is very important.
Ive recently bought a dart block and its machined very poorly it leaks oil and everytime we fix the leak another appears plus the gaskets and seals just dont fit as good as stock on it never would recommend a dart block
I have had good luck out of them once they are machined right.
DART make high quality products. Can you post of video of how you confirm precision alignment of your main bore shaft?
If your main shaft isn't perfectly parallel to your head you will see this type of variation.
I may do that at some point. Basically, I run an indicator in the spindle from one end of the shaft to the other to check both the Z and Y plane. I generally get it under .0005" over 30 inches.
But it would be consistant on both sides
Not sure what you mean by that, could you explain further?
@@paragonengines1924 Just replying to Teds comment about the possible error of your setup. If the fixture was out, we would see similar results on both surfaces when block is rotated. But we don't. As a Journeyman machinist myself and also work with engines, I understand the setup and can see there is no error within said setup. That block is wacked. I would have found that on my Horizontal boring mill that was made in the 40's.
Any time I buy something I take it apart and verify measurements, clean, and remove burrs or other random crap.
It doesn't matter who makes the part, mass production quality control will always be worse than what one person working on one part can do. I pretty much live by the russian saying "Trust but verify"
Yep, that is the truth!
I could see a block coming from the factory, Chevy that is, being off a few thou, there engines are off a couple thou on every surface. Dart should be better than that for what they git for those blocks. That said, Chevys most always run for several hundred thousand miles before the tranny's go out. Good vid thanks
I agree! Even if they are "rough cut" they should at least be straight!
I wonder if these blocks are "aged" long enough between being cast and being machined?
They also need to be aged between initial machining and final machining.
I think everything is done too fast these days. Too much "just in time"
production.
The issue with JIT production (as related to performance parts) is when the season ends the parts MFG are pushed harder to produce. With the increased pressure comes increased errors. Just my experience
Yeah, I believe dart has switched to machining the block to order, which means it could have sat there for a year, or just showed up.
I would agree!
I understand it's not correct but I don't see being 7 thou out changing compression much, also unless you're running a very wild cam PTV clearance won't be an issue, the engine I assume is boosted which leaves a little more room to wiggle with PTV clearance.
If it were me I would just rub the deck with a rag and some brake clean then send it.
You are right, it would still be running if it weren't for the head gasket failure that melted the head. The block had to go up into the machine anyway to fix the damage from the blow out, it just so happened we found the other side of the block way off. Plus, we can make it right and this guy dailys this 1200 HP Camaro, so he doesn't want any issues!
.007 will not effect anything?
It will affect a few things from compression on those cylinders to quench distance being in or out of spec.
Where are you guys located?
We are located near Cookeville, TN
@@paragonengines1924 ill be in the market for a dart block this spring. Could you guys provide an give her the once over in case its like this unit lol
Of course, we can! Just let us know, we can get the block for you too if needed!
@@paragonengines1924 does your phone number start with 661? I think i found your website
this block is alumunium?
It is cast iron.
@@paragonengines1924 oh..why dont you use grinding stone?thx
The CBN cutter we use is faster and cleaner (chip cleanup) than a grinding stone. Plus, we also cut aluminum heads and block in this machine, so we wouldn't be able to use a grinding stone on those.
@@paragonengines1924 sir,how about the RPM?feeding?thanks
1500 RPM at 10 IPM.
For the amount they charge these days I wouldn't be happy....
I agree!
check every thing , dons engines
You know it!
Great video another demonstration of quality control failing at SHP and elsewhere in the aftermarket industry.
Also people doing the work who don't possess an once of integrity, they don't giving a SH#T. Sad your spending that type of money and getting questionable merchandise.
Very true! the least we can do is our best to make it right!
So an engine that's been run and disassembled that needs machining is the manufacturer ?
Yah sure
More like someone didn't check it when they first put it together, or they machined it and did a terrible job.
Dart heads always need work before install.
Yep! I would say most aftermarket heads need a little work to be right!
Amazing how many companies , manufacturers and garages charge you for shit that's done incorrectly or just not done at all ! And it seams to be industry standard practice !!!
Very true! We are generally the ones fixing all of those problems!
lol, are all those Dart batches bad ? yikes
I don't know if they are, but it always pays to double check!
Dang, someone at Dart must have been sucking a big donkey banana when they were working on this block. That's terrible work coming from a company like Dart, specially for what they charge, just like you said. Great vid!
either a Friday or a Monday I would guess!
@@paragonengines1924 😂
And how much do those blocks cost ? What’s their excuse for that level of shitty prep/attention to detail?🤷🏻♂️🤦♂️
I believe they are well over 2K now, but I haven't checked in a while.
@@paragonengines1924 for that much for a bare block, you’d think it would have better attention to detail…🤦♂️🤷🏻♂️
Ahhhhh..........Are you for real?
OMG.......Close up and go away.
People.......These blocks are rough cut for a reason.....The reason is that you can machine it to YOUR specs.
This was not a rough cut; it was sold to the customer as a finish machined block. But if I close up and go away, who is going to machine the block to your specs?
You are totally wrong. SHP blocks are fully machined OR available with only the bore unfinished. Period.
However, you can purchase an unfinished block that has unfinished bores, decks, main an cam bores, lifter bores,etc. Those may be what you are thinking of.
Yep! dart offers a myriad of way you can purchase the block from unfinished to completely finished. I think they even offer to hone to block to final size and surface finish if you request it!
@@paragonengines1924
They do.
That's NOT Good !!
It's not!
That's all you see is LS - LT videos they're getting boring
We have some coming up with some different engines so stay tuned!
Sadly soon all combustion cars and trucks including classics will be banned from public streets in entire EU and Scandinavia :-(
In Germany the Green Peoples Party gave order to shorten fuel supply from 2025
on by reducing all conventional fuel stations to only one state operated central gas station per city or county. Car washs will be forbidden too because they are climate killers, now they want to slow down all the gas station pumps from 20 litre per minute to 2 litre per minute...From 2027 on in the EU certain car spare parts will be banned too....as exhaust systems, turbo chargers and even some engine and gearbox oils...California and New York will do the same from 2027 on.... So no investments should be done in oil burning cars any longer....They even created a new kind of crime here, called emissions and smoke crime.!!! (BABVVEN & TEBBVEN & BEFVO laws)!!
Yeah, I know that is the way the world is going. I believe there is going to be more pushback from people than they are expecting, at least in the US. Electric is the future, but until then, internal combustion will still be around.
I know as a young kid living in Germany way back in the early 70's my parents had a 69' Dodge Coronet with a 383 V-8 engine and my dad said the cars engine loved the high quality fuel that was coming out of their gas pumps..I remember seeing some Blue and sometimes Red color..maybe that was "regular" gas and not the unleaded or ethanol based stuff we have here now in the USA now ? I enjoyed this video a lot..now I know about these $2500 + dollar Dart blocks that look so great in the catalogs and online companies that sell their products.
Have u checked deck height ?
Yes, I checked it after I was done. I believe it was 9.232".
Are the both same height front crank ?
Yep!
So!
Absolutely nothing!
OK!
Really ya its not perfect. Does it need to be tho 🤔
Well, when you're paying that much, it should at least be a little closer!
And if your going to run power adders hell yes it needs to be flat and straight. lS engines need all the help they can get in head gasket sealing areas.
Sounds like you have tried to make some real power with an LS before...
@@paragonengines1924 No not me. I have watched cleetus and other big youtube racing channels pop head gaskets that`s all.