Vortec355

Has anyone heard of a 408/410 Lt1 stroker, or running a 4 inch stroke in a LT1 block. Reason is I'm looking for 2816 alloy pistons for a 4inch stroke 4.030 or 4.040 bore with a 6 inch rod. All I can find are 4032 alloy.

Formula350

iTrader: (3)

You could always go back to GEN I and modify the LT1 intake (or get a TPiS Mini-Ram) for a LT1 clone. GM sells new GEN I blocks with more metal that lets you push them into the 450ci range and hold 800hp. World Motors has similar blocks. Like their BBC is punched to 632ci

But I would think you could punch an LT1 to that since it's possible to do .060. Not sure how safe it is though heh People who do that probably just race the motor a few times.

Wonder if you could punch it way out and then sleeve it like the LT5?

Sorry I'm not much help :\

95FbFormula

iTrader: (25)

It is possible to make a 409 LT1 but it wont net anymore gain then a 383-396 LT1 due to the fact that the LT1 intake cannot flow enough to support it so unless you are going with a single plain or sheet metal intake its not worth the risk.

Formula350

iTrader: (3)

That's right, I remember reading that as well. It also costs your first, second, third born as well as your wife. So it just isn't worth it due to the fact it doesn't give anything more.

daniel6718

iTrader: (36)

lt1 problems are the intakes restriction....would be pointless unless you went with sheetmetal or single plain

TwoFast4Lv

iTrader: (8)

HEY Who is telling you about my next engine!

vtec

iTrader: (1)

do it with a sbc instead. get a badass intake/tb for it, standard dizzy, and a megasquirt or f.a.s.t. wont be LT1 anymore, but who cares? its nearly the same motor minus the opti and some other subtle differences. and a 408 would be no problem then.

engineermike

I say do it. The LT1 intake isn't great, but it can be worked. Raising the runner roof's helps alot. If you wanted to get serious, you could cut off the top and radius the port inlets better.

As for the cid, I'm running .060 at 20+ psi boost with no problems. I've heard that the LT1 block is a fairly stout piece and weighs about the same as a bow-tie block. I've heard of folks running up to .100 over if the block is sonic-checked. Even if you stopped at .090, you would only have to run a 3.875" crank to get 407 cid with less clearance issues. Or, if you wanted to run a 4" stroke, that would get you all the way to 420 cid.

By the way, the extra cubes WILL give you more low-end and peak torque whether the heads/intake flow well enough or not.

Mike

Vortec355

I don't have an LT1 sorry, I'm looking for pistons. I have a 2000 truck block that I'm putting a 4 inch stroke into. I have the crank and rods and I'm trying to find pistons. I can't seem to find 2618 alloy forged pistons. I want to spray it with a 250 shot. I thought this would be the spot for this thread since I'm using Bowtie Vortec 215 heads which have LT1 GEN II chambers. I really don't want to spend $800 for a set of pistons to be custom made, if I can find someone who makes them already.

the_merv

iTrader: (88)

Unless I read something wrong..that is a LSX based Engine, which fits a 4.000" Stroke Crank very well with no clearance issues. That's what Crank I have in my 6.0 Block..which came from a 2002 Truck.

AdioSS

iTrader: (2)

the old L31 was still available in some 2000 model trucks. I believe they offered the old GMT800 style as a Classic and the big van didn't move to Gen3 stuff until even later.

To put a 4" stroke in a Gen1/2 SBC with 6.0" rods, you'll need pistons with a 1.025" compression height.

the_merv

iTrader: (88)

That's suprising to hear..
I just bought a 1999 Sierra with the 5.3l in it, a friend of mine has a 1998 that has a 350 Gen I in it..BIG difference between the two..

Vicious95Z28

iTrader: (1)

Ditto!, Good to be cautious tho Merv!

JasonShort

iTrader: (242)

Vortec355, this is the Gen2 SBC (aka:LT1) section. It seems that you have a standard Vortec/GenIII truck platform which is technically considered to be "LSx". Please try reposting your question in the "Gen III Internal Engine" section.

Can you verify forsure that you have a Gen II engine? If not, I'll move this thread to a more useful section for you.

Jason

the_merv

iTrader: (88)

I guess he's got a Gen I..I asked the same thing..

engineermike

Forgive my ignorance, but I've never heard of a Bowtie Vortec 215 head that has LT1 Gen 2 chambers, but bolts to a LSx block. If you're talking about the Vortec large-port, they definitely won't bolt to the LSx block. I also can't see any reason to use Gen 2 chambers over the superior Gen 3 chambers.

Mike

Formula350

iTrader: (3)

Because they sound better?

engineermike

Okay, I just checked and can find no such Gen 3 head. The closest I can find is the Bowtie Vortec 206. It has L31 chambers, not LT1 chambers and most certainly won't bolt to a Gen 3.

Formula350

iTrader: (3)

Just by looking at any head between Gen I/II and III, none will bolt up. And when you make a new engine from the ground up, you don't reuse old tech, since it's from scratch. Some ideas and theories always go along for the ride, but I couldn't see them doing any LT1 tech on an LS1 except maybe way back in the alpha-LSx testing days.

They make a lifter valley and move it into the head deck on the LSx.


Where as the older one is in the intake valley.


Unless I'm misunderstanding >_> Totally possible lol Basically what I got out of it is he was putting LTx heads on an LSx, yes?

the_merv

iTrader: (88)

I think the guy that started this thread needs to post a pic of what he has..

I'm still goin with my Theory that it's a Gen III LSX Engine..