Bad LS SHP block machining from Dart - Always check any aftermarket parts!

Do you think that problems like this may be attributed to some degree to internal stresses in the block working themselves out over time?

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’m pretty sure it says somewhere in the Dart website that final machining will be required for assembly. Specifically deck height…

Great video

So!
Absolutely nothing!

.007 will not effect anything?

Hi, I'm not a machinist. The holed for the head drilled and tapped are they now out of square?

lol, are all those Dart batches bad ? yikes

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 !!!

Have u checked deck height ?

How's the VF4 treating you for block work? Any reason why you chose Haas over other brands?

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?

this block is alumunium?

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

I've gotten many Dart heads that the valves don't seal. A must to check everything.

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)!!

.007 out
No big deal.
Well within tolerance!

Something about a freshly machined surface that is so satisfying.

That's all you see is LS - LT videos they're getting boring

Always figured a good machine shop was a best friend!

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

Sounds like dart needs to step there game up !

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"

Where are you guys located?

Dart heads always need work before install.

Is it me, or were there visible head gasket blowout marks exactly where those low spots were on the first pass?

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.

And how much do those blocks cost ? What’s their excuse for that level of shitty prep/attention to detail?🤷🏻‍♂️🤦‍♂️

Really ya its not perfect. Does it need to be tho 🤔

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 .

Great video
Was the intake deck checked?

nice video good content

The Machine shop in Portland Oregon I use sees many Dart new blocks for corrections missed at Dart .

Perfect example of it can be bad, you better check it.

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.

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.

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

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!

For the amount they charge these days I wouldn't be happy....

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.

Every block manufacturer states that it still needs finish machine work to get to your spec. Not surprised with your find.

Wow I thought expensive aftermarket blocks would be better then OE blocks. Wow

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

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.

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!

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

With so many moving parts, how do you differentiate between variances in the piece, and variances in the machine?