The "What If It Was Yours..." LQ4 engine thread...

[GeoffP]

I've been doing a lot of dreaming lately about my next engine build and thought it's been a while since I posted anything on PT so I thought I'd make a little game out of it:



The starting point is a high mileage LQ4 (304,000 mi) pulled out of a 2003 2500HD and the car it's going in is a 68 Camaro with a stock spec iron block LS1 running an LS2 intake setup and e40 ECM. Primary use for the car is autocross and road course racing but it also gets driven to work regularly (3 mi commute).

So...what would you do? Think big, small, and everything in between and explain your thought process for your choices!
The rules are:
1) You have to use the LQ4 block as the basis for the build.
2) You can reuse anything from the LS1 or LQ4.
2) It has to be unique (no copy cats!).
3) The engine you "build" has to theoretically run.

This thread is meant to stretch your imagination and spark some engine building discussion. It doesn't matter if you don't know how to build an engine! Participation means you might learn something!

[67rally]

4.030" bore, 4.0" stroke to 408 cubes. Port the 317's. Twin Turbo it and add a healthy dose of nitrous.

[FlyDoc]

lets make it 427CI.
Billet crank gun drilled & lightened, billet rods, custom pistons, CNC ported heads, bronze guides, hollow stem titanium valves locks & retainers, billet cam gun drilled, belt drive, Hydraulic roller lifters, rev kit, chrome molly push-rods, steal 1:6.4 roller rockers, rocker stud Girdle, 3.0L positive displacement supercharger (not turbos, or a Paxton type) 85mm throttle body, water and methanol or just methanol injection, oiling- dry sump 7 stage pump scavenging from 3 in the pan, 1 in the cam valley, 1 in back of each head. 12 qt oil tank, external filter and oil cooler, fluid dampener, lightened aluminum flywheel.

I forgot the fuel system.
8 injectors, billet fuel rails, vapor works tank and pumps, and to control the whole thing a Holley donator EFI computer.

I think that covers the basic kick ass engine.

[GeoffP]

Great - let's keep it going!

[GeoffP]

Ok here's my input on the engine:

1) Bore it .030 with flat top pistons and make it an LS2 clone with a TSP 224R and their ported 243 heads.
2) Bore it .060, buy a full LS3 rotating assembly and make it an LS3 clone with a TSP 224r (or bigger) and LS3 heads.
3) Stroker kit
4) quality rebuild and turbo charge it.

None of my ideas are nearly as aggressive as yours - thanks guys! I hope a few more folks will chime in on this.

[srh3trinity]

To be really off the wall you could destroke it and make it to spin high rpm's. From what I have read you start running into valve train problems at higher rpm's. Also, people say you can spin aftermarket rotationg assemblies too and not give up displacement.

[FlyDoc]

it all depends on your use of the engine is going to be. making a destroked engine is good for a short track.
it would make a good SCCA for here on Oahu HI. are courses are short. in my bone stock RX-8 I can doe most in 1st gear, at 9500rpm. it is just in that range to fast for 1st and to slow for 2nd.

[Tom Welch]

Re use the rods and crank, new dished pistons, ls3 heads and intake, custom ground cam from Engine Power Systems, Stainless Works headers, Our Engine Analyser program shows this combo putting out almost 500 hp and over 450 lb ft. Nothing fancy, but a solid combo. We have this exact engine in a 67 Firebird, Smooth idle lots of power off idle.

[GeoffP]

Glad to see a few more comments! I thought this thread had died already.