tb30570

I'm interested in increasing mid RPM power on my LSJ while keeping a linear torque curve.

Restrictions:
This is for my daily driver so I don't want a high duration cam which will kill fuel economy and decrease idle quality. I'm also not interested in high spring rate valve springs because I don't want to wait around all day during the winter months for the engine to warm up before driving. If there were more E85 stations where I live, I'd probably consider pumping some ethanol, but considering the distance to those stations, it doesn't seem practical.

With those restrictions said, I'm considering increasing displacement, porting the heads, higher flow exhaust, adding -20* F washer fluid injection and improving forced induction.

Displacement:
Many people have used the LE5 crank to increase stroke. Many people have also bored the block out 2mm and used LE5 pistons. How much power can the LE5 crank handle as a daily driver without Cryogenic hardening? How much power can the stock LE5 pistons and rods handle and are there any other options than stock?

Compression Ratio:
With the LE5 rotating assembly, the compression ratio would be higher than with the LSJ rotating assembly. Will the LSJ make more power with less boost and higher compression or more boost and lower compression? If it makes more power with more boost and lower compression, what are the options for lowering the compression ratio? Does anybody make thicker head gaskets? Can you remove material from the compression chamber or pistons?

Forced Induction:
I want a linear torque curve, so a turbo conversion would be a hard sell. A small turbo probably could do it, but I don't think a small turbo would outperform the TVS. A large turbo is not going to have a linear torque curve unless it's spooled up all the time which would lead to premature failure. With lower spring rate valve springs, I don't think high RPM's are really possible. If the redline limit is set at 7k RPM, is there anything to be gained by changing from the M62 to the TVS?

Any other suggestions other than what was previously mentioned?
__________________
LSJ-
RevHard Dynotune, 2.8" pulley, 60# Flowmatched Injectors, NGK 1 Step Colder Plugs, Dual Pass Endplate Op-B, CXRacing Heat Exchanger, Mid Length Header & Downpipe, ZZP CTI 2.5 Over Axel pipe
LS1-
539rwhp

K-Train04RL

iTrader: (1)

just pulley down with bugger injectors a new belt and a tune.

tb30570

I did that about 3 or 4 years ago. I guess I should have filled out my signature.

mrbelvedere

iTrader: (3)

1 you cant bore an ecotec 2 mm 1mm=.039 the sleeves are only .060 thick so who ever told you that is high
2 you dont need to let the car warm up with stiffer valve sprigs before you drive it
3 if you choose a cam wisely it wont hurt fuel economy that much nor will it hurt the idle
4 if you put an le5 crank in you will have to have custom pistons made because the increased stroke will push the piston out of the bore around the top ring or so
5 you cant remove material from the stock piston
6 get a tvs and leave the rest of your engine with a set of 60s and be happy

tb30570

I have 60# injectors. See signature.

I assumed the LE5 and LSJ had the same deck height and the LE5 used shorter connecting rods. If you are saying the LE5 has a higher deck height and the LSJ can’t be bored out 2mm, it probably makes more sense to swap out the short block. Is that what most people do?

What can be done to reduce the compression ratio when using an LE5 short block? Can material be removed from the compression chamber? I’d guess the edges of could be chamfered 1mm to match the bore. Does anybody make thicker head gaskets?

The TVS will support higher volumetric air flow than an overdriven M62. With 60 # injectors and an otherwise stock LSJ, more air will result in extreme boost. From what I’ve heard from other Ecotec guys, a lot of people have blown up their engines with this setup. If the engine is set up with E85 injection, it may be able to support extreme boost. If the engine is set up to rev to 9k RPM, more air can be used without extreme boost. If the engine is set up with more displacement (while keeping the CR low), more air can be used without extreme boost. With just 93 octane and -20* F washer fluid injection with a 7k RPM rev limiter, I’d only be comfortable using an TVS to support higher flow rate requirements of increased displacement (with low CR). The question I have is whether there are significant gains changing from the M62 to the TVS if the boost is around 15psi. Or maybe the question is, can the M62 even achieve 15 psi boost for a 2.4L with a low CR.

Everybody I’ve ever talked to in the LSx world has recommended the valve train be fully warmed up before revving the engine when using higher spring rate valve springs. I’m pretty skeptical this would be different in the Ecotec. It’s possible to drive an LSx under 2k RPM on the highway, but it’s not possible to do this on the Ecotec the way their transmissions are geared.
Broken Comp 921 valve spring - LS1TECH

I agree it’s possible to improve performance with a high lift, low duration, low overlap cam without significantly reducing fuel economy or idle. High lift cams require high spring rate valve springs.

mrbelvedere

iTrader: (3)

the ecotecs are the same deck height and a 2.4 uses a shorter rod but it isent as short as you think its like .006 shorter the main difference is in the comp height and pin location on the piston
the tvs isent that extreme as you have been told the stock pully is 20lbs big deal and as for people popping engines on the tvs its not the blower popping them its the tune
we arent runnign the spring pressures that the ls guys are running and i have never had a problem running a stiffer spring in the winter as for raising the compression it is benificial but if you dont have the octane to support it its not worth it

you sound like your trying to go cheap and make more power if thats the case forget it trying to do a stroker your best bet is still the tvs and a good tuner the tvs can be a 100+hp bolt on with a good tuner

Vander Nars

iTrader: (5)

U should let ur car warm up before u rev it to redline regardless of upgraded vavle springs or not.

383_Stroker

iTrader: (3)

OP, it sounds like you need to stop listening to your sources... If you want easy inexpensive power, slap a tvs on it. you're not going to get out any cheaper or any more reliable trying to build a budget stroker...

tb30570

So if I swap out the m62 for the tvs and get it retuned, it will dyno over 340 hp at the wheels with 93 octane E10? That sounds hard to believe.

If the spring rates for performance LSJ valve springs aren't really that high, I would consider swapping and running a higher lift cam.

I'm not proposing increasing the CR, I'm more interested in lowering it back to stock 9.5:1 after increasing displacement. Is there any proven way to do this on an LSJ?

Vander Nars

iTrader: (5)

300 hp is possible on pump 93, 340+ is a small pulley on e85 range

mrbelvedere

iTrader: (3)

i little over 300 is more then doable on pump