Ls1 speedway engine
 

ok all you ls1 engine gurus,I have a question for you.in New Zealand there's a speedway class called superstocks(YouTube it) that run 4 litre engines.now my question is
what would be the the most cost efficient way to get a ls1 down to 4 litres but still produce good horsepower and torque?
the rules are:
4 litres,10 to 1 compression ratio,valve lift is restricted to 500 tho and a 4 barrel carb.
can it be done and still produce good horsepower.the top cars are banging on 450hp with truckloads of torque.im interested in trying the ls as I believe it will work or am I dreaming.thanx in advance for your feedback

A short stroke crank would be the best way to achieve this. You could get a short stroke crank and some very long rods custom made.

Was hoping to get away with a custom crank.we were thinking of sleeving all 8 cylinders using rb30 pistons.remember we aren't engine builders so just kinda guessing.even if we sleeve down each cylinder do we still have to have a custom crank?

Not engine builders, but are going to sleeve a block?

I think the RB30 has an 86mm bore. Combined with the 92mm stroke of an LS1, you have ~4.2 liters.

Yes we aren't engine builders but we're going to get someone to build it.thats where the problem is.
We live in Australia and just trying to get someone to sit down with us and listen falls on deaf ears,everyone is negative and can't understand why we want to make an 5.7 a 4 litre.we just want to know can it be done without spending mega dollars on a crank,will it rev,and have good hp and torque figures,we just can't get anyone to at least look at what we want to achieve.

Use a 4.8 crank. You'll have less displacement to start with.

there you go,some progress.now to research 4.8 crank.thank you

So JoeNova.so if you were to build our hyperthetical 4 litre ls from top to bottom how would you do it and what figures would you get.to be really competitive we would need to produce anywhere from 420-500hp.cheers

Down this way, wouldn't a 1UZ be a far simpler and more cost effective approach...?

I understand doing things because it's different but just sounds like a whole lot of hassle.

In Australia,where we reside,LS engine are dirt cheap,not so much in NZ.back in the day people said the same the bout drivers using 350 chev engines,sleeve them down,de stroke them blah,blah.so we want to be pioneers with the LS,cause no ones done one,how do we really know how expensive it's going to be.
If we have to go the whole custom crank way so be it,but I'm not going to let a few negative people opinions put me off until someone with cold hard facts tells me so.
So come on peeps help us out alittle.we really want to give this thing a crack

Using an 83mm stroke crank from a 4.8, An 86mm piston would put you around 3.85 liters.

What heads?

That's what I want to know to.we know ls heads are good standard,we are only limited to 10-1 comp ratio but heads are pretty much free

The LS heads won't work very well if you sleeve the bore diameter down. The smallest valve arrangement came in the 706/862 castings with 1.89"/1.55" valves. Anything under 3.63" bore and they physically won't even fit the bore. I think a custom, or heavily worked 4.8L crank would be your best bet.

This really doesn't sound like a very good class for a LS to be competitive.

I get the LS is cheaper in AU (you lucky bastards!) but the UZ is already 4L, this is all I was getting at, that said, it'd also cost a shitload to get up to 400hp+ NA... sounds like a pretty dicky rule book to be honest with modern engine choices at hand.

Sorry if I came across negatively, was not the intention. I'd love to see you do this though. Have you seen the smog legal LS3 thread recently, where a guy is lightening it all to rev it to the moon?
De-stroke an audi 4.2 v8?

S2kiwi,algud bro,just want to be different aye,cause of the initial cost of the LS seemed like a good idea,Audi would blow the whole budget before turning a spanner lol
KCS,old Skool 350 chevs,302 fords are still competitive when bought down to 4 litres,that's why we thought an LS would work,but now am starting to think it's going in the to hard basket,cheers for everyone's input

How are the SBC/SBF engines being brought down to 4 liters?

Some are sleeved some are destroked.the class calls for engines no more than 4 litres.a lot of guys are using the Toyota and Nissan quad cam v8 but there's still a hell of a lot of guys using ford and Chevy v8s

Sleeved 4.8, Solid roller and a lot of RPM. Should be good.

I would think the OHC engines would be doing pretty well. Especially with multiple valves per cylinders.