Biggest displacement
 

Just a random question about SBCs. How big can you make em displacement wise before you run out of room external dimension wise?

This is going down the road of a custom block being made.

I think i've seen some 500+ ci aftermarket blocks...

434 on a stock block...

Hmm...

I have seen people take stock 400 blocks to 440+ with a lot of machine work. It is very very limited use and costs a ton.

Well thats the question, if Dart were to make a 454+ LT1 block.... ;)

Is the straight up 454 cheaper than making a stock block a 402. Biggest I think you can go stock and thats with sleeving.

I would think the machine work to properly prep a stock block wouldn't be much different than the cost of buying and prepping another block. Most of the cost would be in the bottom end. Only real difference I can see is that the Dart casting would be better than the stocker.

No I mean like Dart casting a 454 LT1 block. So all you do is slap in a rotating assembly.

454 ci LT1... seems like an epic fail coming on.

don't you have a stock rear still?

LOL, yea and no where near the amount of money that block may be IF it ever comes out...


But its is a much better, and safer way of getting to say a 396 or 402 on a GenII block than machining it. And yea, 454, or higher will require some high dollar heads to actually make decent power. Just curious really.

Aftermarket blocks still need prep at a machine shop before assembly begins, just not as much as a used stock block. So make sure you think about those costs as well.

- Justin

LOL you guys are neglecting the fact that I am a poor college kid, I was just thinking hypothetically.

And the work required to prep a 454 LT1 compared to making a 396/402 from a stocker would be minimal.

There used to be another member on here who used to think like this... he didn't last very long.

Alex....at least SNM is smart enough to realize he's a broke college kid and he's not saying that this build is gonna start next month.

- Justin

careful man! dont set your car on fire!

they make a 454 pre-lt1 block, but its more of a show car engine. u cant bore it, cant boost it and nos is a no no. it makes 600hp, but doesnt last long. if u want a really big cube small block u need to go with a block such as a rocket block, which is a tall deck with a raised cam tunnel. these blocks can go to around 468 cu. in. not cheap at all

Rick WI over at NastyZ has been running a Gen I 454 SBC for a while now. I think it's 700-800hp.

in crate engine form they make 600hp, with a cam and some mods u can make more power but good luck with the re-build, there is no way to bore it and the amount of honing u can do is minimal. not a good block for someone who is going to put any type of millage or abuse on it.

Yea and I don't want a BBC in my car. I like my somewhat decent mileage.

I had just heard that Dart had been thinking of casting a large +454 block for the LT1. Now whether its worth the money, I doubt it, its cheaper/easier to go big cubed LSX, but gotta keep the faith. ;)

Seriously? You are using big displacement anything and mileage in the same sentence? Really? A 454 SB and a 454 BB are going to be generally equally thirsty, give or take the 100+ pound weight difference.

Yea but "if" Dart decided to market this idea and "if" I came up with the money, I would get a smaller block, prob a 409 just to say its a 409. And I thought BBC were lower CR than similar SBC, idk.

With a BBC you get better flowing heads. You can build either to whatever compression ratio you need.

Yup, which is why Dart may have a hard time marketing it, LT1 heads just don't enough without a very expensive port job and even then most people convert to SBC heads. But, the idea of a pre cast 396 would be really nice I think.

Owned :popcorn:

Apparently Dart has accepted a few stock blocks for dimensions and what not, so it may actually happen. Would be cool.

And um what? ^

There are no aftermarket LT1 blocks. We tried a few years ago about getting a company to build them, but we couldn't get enough commitment to make it worth doing at a reasonable cost. Unless something has changed that they will build the blocks cheap?

A stock block you can push a LT1 to just over 400 CI but I think it needs to be resleeved. most common is to go 396CI and often people hit the water jackets. Also at this point you better have a good block to start with, you taking allot of material out so you run the chance of starting to twist the block. The few guys running in the 8's with LT1 blocks are pulling the bolttom ends apart often as the twisting is causing the caps to walk. You're looking big money to build one right. A certain "unstable" person has a custom girdle for his 396 LT1.

There is said to be a few "special" LT1 blocks out there floating around that GM had custom cast for some project that was dropped and the blocks made it into the public. They were cast with ( I think ) high carbon, thicker webbing, and with 4.25 bores for 454CI LT1s. They only show up rarely and the bare blocks go for very large dollars. The last one I saw went in the $6,000 range.

as already said, LT1 heads also fall a bit short on their flow numbers. if you know of N2ODave, he runs a set of Rich Petty's heads on his 396 LT1, and the cost to convert then to the LT1 block has no cheap process. But he does have a high winding LT!

If you're thinking 900+ HP, there are cheaper and better ways to go that messing wioth an LT1.

I love my little LT1, but if I ever decide to go for the 4 digit HP numbers that first think I'll do is pull the LT1!