Blkdoutbird

iTrader: (5)

I was wondering which would be a better motor for boost an LS2 402 or an LS3 418.With everything being the same the only difference being the bore size which route would you go and why?I was going to order a 402 but started thinking maybe the bigger bore would be a little more beneficial, however after reading about the core shift issues with the LS3 blocks now Im not so sure.Tell me what you think guys....TIA

MY99TAWS6

iTrader: (3)

Generally the bigger the engine the better in just about every circumstance.Bigger engine give more hp and more torque on and off boost. Bigger the engine the quicker it can spool up the turbo. Downsides are mostly bigger costs more. I was going to go with 427 but difference in price over my 408 was just too much to me. I set my goals and figured out what I would need to meet them.
Course I went iron block not aluminum block as wanted max strength and wasn't too worried about the little bit of extra weight.

Other advantages of bigger engine is you shouldn't need as much boost to reach your power goal as on smaller engine. This can have advantages. Easier on the head gasket,lessened chance of lifting heads..

Also not familiar with the ls3 but maybe going to 418 or beyond thins things out too much and makes it not as good an idea for boost. Another reason why sometimes an engine size that is good for NA build is not so good for a FI build.

Blkdoutbird

iTrader: (5)

Well the motor will have just a hone on the bores so the liners will have a good amount of material left.I have also read on here that with larger bores the piston has a tendency to rock more causing oil consumption issues, I will be buying a motor from HKE so the build quality is not worrying me its if an LS3 stroker has any mechanical shortcomings that would make the 402 a better choice for FI....

rwb

There is no replacement for displacement, especially for a street car. You will have more torque down low as opposed to having to rev up the motor to move (see honda's).

Blkdoutbird

iTrader: (5)

Any other opinions on the issues with the LS3/L92 blocks?

EPP

iTrader: (22)

I feel that the jury is still out on how much stress the LS3 block can handle. Personally, I'd go with the LS2 as it has proven itself. Bob

Gordon0652

iTrader: (4)

Look into the LS2, Bob has a customer with a CTS-V and an LS2 with a F1a pushing 800rwhp! Love that car.
I think a few people have seen 900-1000rwhp on the LS2 block...

Blkdoutbird

iTrader: (5)

Thanks for the input guys....

vase

Hi guys,

I'm new in this forum and I have been searching for information. I found this thread and it's just what I'm looking for. I know it's an old topic but I didn't see any point in setting up a new one since someone has already asked about this matter.

This topic is a year old so is the general opinion still the same? Stick with the LS2 for forced induction over the LS3?

Thanks!

EPP

iTrader: (22)

Welcome aboard! We done some good horsepower builds with the LS3 engines in the past year, and haven't had any problems with them. Bob

vase

Thanks buddy

Do you think an LS3 based build can be pushed close to 900whp with forced induction? I would like to stay with the aluminium blocks because they are light weight but I don't want my engine to explode in the first dyno session either

Thanks for your help.