Maybe the camshaft you used. Like others have mentioned, you just went the wrong way with a lot of things.

Carcraft, on the other hand, paints a different picture about heads, injectors, and changing out the camshaft:

http://www.carcraft.com/techarticles...ifference.html

http://www.carcraft.com/techarticles...t_results.html

 

2 things. Show me one person who has positive dyno results from a cam on OUR ls4 engine. Not the gm 5.3 truck engines. That article is not about our engine. better injectors will not give you more power unless you are making enough power to overload your current ones.

I am going with a larger cam now and i am going to be posting the results. So we will see in about 2 weeks.

As far as different size pistons go, ours have a smaller diameter.

 

I'm hoping nmp0089 comes out with some impressive numbers since he has the LS6 intake.

We'll see I guess.

 

I really hope this new set up works out for you. And I can't wait to hear about the resaults.

 

you should know that strokers are not about the horsepower. as the longer stroke will net you huge gains in the torque profile in low and mid range. that is where the gain is at with strokers. 8-10k is also very high for a stroker. 4k for the crank or not.

the ls4 just like all lsx based alumium platforms can accept a bore of .015 , this would allow ls4s to reach 3.9 , the same as the ls1, and ls6s. This also will mean you can run the very popular piston sizes. so cost would not be all that bad.

on the cam issue..i highly doubt the ls4 is less acceptable to gains from cam swap than any other lsx engine.

more people need to think outside the box within the ls4 community, they need to take those risks and stroke their engine and or bore it and show the aftermarket that good power can be had from N/A ls4 and not fall back on the FI because it is easier.

 

im sure he will since the ls4's biggest restriction on the top end is easily the intake manifold

 

3.78 + 0.015 = 3.795

 

i dont think he knew the initial bore of the LS4 (3.78)

 

I know.

One more time, our motors are going to respond much differently to cam swaps. What works in a 346 cu in motor isn't going to work the same in ours. Not only do we have a smaller displacement overall but the tiny bore shrouds the valves to a much greater extent. That's the limiting factor with our motors once the intake and exhaust are openned up.

 

this shady milkman must be an idiot.

 

He's got the basic principles right.

 

yeah he knows his LSx engines very well EXCEPT the LS4, hes one of my good freinds, lives 4 miles from me, hes the one with the black T/A i posted a video of me and him racing.

 

wow that is quite embarrassing. on my calcs i was thinking .15 forgot a 0

i am thoroughly impressed with the ls4 for what it is. i think there is some seriously potential there for the ls4s...people are just going to have to spend the cash and be outside the box for a little bit.

my very rough calculations ..if someone runs a 4" crank you will be at a 359ci and with a 4.1 a 368..this is just with the stroke. no boring ..a good amount of torque is to be had

 

^ this is true. that is why i think any bit of bore, even a .015 will benefit you guys. i am quite confused on the motivation behind GM to not give you guys the 3.9 bore with the 243s and then to neuter the hell out of the set up even more with that thing they call a intake manifold. I know levi talked about using my old ls1 intake and doing some fab work. that should be quite the improvement in itself. Gm had quite the chance to make the ls4 a powerhouse.

 

That bore (.015) is basically a hone, it's like 1 cu. in. right? We could do that and put in some forged pistons/rods and fog the motor to hell and back. GM neutered it because they never expected the aftermarket to pick up for these cars, imo. There was no reason to make it a beast, it's FWD.

 

that is too bad too..because like i said the ls4 is a good powerplant and could have been something special

 

THIS!

and fixored.

 

OK, so I was reading on this Fiero forum and this guy was saying he was taking his ls4 out to a 5.7 said there was enough room in the stock sleeve. So I go to thinking what if gm used ls1 sleeves and didn't bore it out as far if that was the case you would be able to make it a 346.Just a thought!!If I had a block laying around I'd take it to a shop and have it checked out to see if this would work but I. Heres the link http://www.fiero.nl/forum/Forum2/HTML/098254.html The post was made by Isolde

 

That guy also states that the max bore for the ls4 is 3.905 which would be an ls1 bored out .015. He is also an automotive machinist

so we have three opinions here

A. What he says is true

B. He is a machinist and doesn't know WTF he is talking about

C. He's some douche bag on a forum trying to be cool.

 

Ok so I have done some more looking around and found that our main and rod journals and bearings are the same as the Ls1,2,6.In theory you should be able to use a ls2 crank with the right machine work.