I am going to use an ls7 derived engine for my vehicle and would appreciate your thoughts on the specification.
From reading this forum, it seems that the ls7 crate engine is not the ideal platform to modify if you want over 600rwhp due to initial cost & strength of the block.
The Vehicle is not a corvette, its a 4x4 and this forum seems to be the best source for information on the ls7.
My requirements for the engine is to have the best combination/ compromise of the following :-

No less than 600rwhp, low down torque, reliable under sustained heavy loads, good fuel consumption to be kept in mind ( ive read the standard engine gets 28mpg in the corvette ) the engine will get submerged in water completely time to time ( this could crack a turbo ? ) run on pump gas & be hospitable enough to drive over the continent of europe.

The specification I have come up that is not standard ls7 is :-

Alloy block - Dart billet or ls7x,
Darton liners
Procharger running at 5-7 psi with intercooler ( not as hot as turbo and may take to being covered in submerged in water better ? )
standard ls7 heads, all pro or ls7x ? titanium valves
Forged rotating assembly- lunati internals crank, rods, JE coated pistons with 9:1 CR ?
Modified cams of some type
Standard dry sump system ?
Water/ meth injection.
1 7/8 jba headers, kooks ? straight for max torque ?
intake manifold- some kind of cast aluminium plenum for FI
bank?
Ron Davis Aluminium Radiator
Other parts I would leave to the engine builders preference.

Any advice very much welcome.
TIA

 

What kind of 4x4 is this? How much will it weigh? What is the purpose - a race, pleasure diving...

A truck, want low end torque, mileage, going to be submerged in water... I'd be thinking diesel. A slighty modified Duramax.

With all the electronics/ignition on a gas engine, they don't do well under water.

 

You would be better off using an LS1 based block to do the Darton sleeve setup. Unless of course you have the block. The LS1 blocks are far cheaper and you end up with the same result.

I don't know if I would bother with the whole dry sump system either as it was designed to keep oil in the motor under hard G's. For a 4x4 how many G's can you expect.

If you are building this thing from scratch I would stick with the GEN3 parts in the lower end and use the LS7 stuff up top. If you use LS7 heads you will either have to use a stock LS7 intake or spend $3800 for a custom one from someone like Wilson.

What PCM is going to drive it? If it's an E38 you will need a crankshaft with a 58x reluctor wheel. If not its a 24x.

You may also want to consider a iron block if you are going to pound the hell out of it!

Howard

 

The vehicle weighs about 4200lbs fully laden, it is for what we call in the UK call challenge events like the one in russia, ladoga. It has swamp land, forrests, lots of mud, rock crawling and fast racing along shorelines.
A diesel was my first choice, but they were too heavy and large in size.
lightness is the main factor here, hence the high power low weigt ls engine. I will place the electronics as much in the roof as possible.
I thought the dry sump would be good as the vehicle can be several minutes at severe angles, so not for the g force rather just getting a steady supply of oil.
Dont know about the PCM, havnt got into much detail yet.
thanks

 

World Products makes an after market LS7 block which is a fair amount stronger then the GM LS7. Among other things it has extra bolt holes for the heads, better main caps and studs etc.