Darkrider02

iTrader: (4)

bought a 2004 lq4 rebuilt by thompson motorsports. put a vindicator cam, 317 heads, ls6 intake, full bolt ons. m6. only made 320!!!!? tuner said it might be the crank bearings dragging the crank. i already put 500 plus miles on it and everything seems to be fine. oil pressure good, oil looks ok, its not silver. changed to oil twice. car also has the recommended 4.10s.... i dont know what else to do...... any input is greatly appreciated

BadAndy

WTF Dragging the crank?

bww3588

iTrader: (49)

Unless your oil pressure is thru the roof, I wouldn't think clearances are too tight. Did you degree the cam?

redtan

iTrader: (5)

Find a new tuner. Basically, this guy did a shitty job tuning your car, didn't want to take responsibility for it and blamed the engine itself with just about the stupidest reason possible. Seriously...bearings dragging the crank? I don't think I've even heard of that before so he just pulled some fancy engine terms and said that to you.

First and foremost, take it to a real tuner and then see what's wrong with your car.

wildcamaro

iTrader: (15)

Yea if bearings are robbing 100+ hp the motor would of already been mangled...get a new tuner before doing anything drastic

mark21742

What the hell is the deal with these socalled shops lately? Just the other day a guy was told his car wasn't running because his cam might have been in 180 degrees off??? Anyone that knows ANYTHING about an ls motor knows that is impossible!!!!

thunderstruck507

iTrader: (18)

Is it not firing on a cylinder?

Easy way to check is put a timing light on each cylinder to make sure they're firing.

I would also do a compression test.

BAMALS1

iTrader: (16)

I'm going through the samething right now, mine are low also. I'm gonna be taking mine to somebody soon.

Darkrider02

iTrader: (4)

well everything seems to be fine. i know the compression is a lil low but still... the only thing i can think of is maybe the cam wasnt degreed right? but would that really rob 100rwhp?

Blk98Vert

iTrader: (2)

Your compression isnt low, its still at 10.4:1. Sounds like you got a really bad tune.

PREDATOR-Z

10.4 on a LQ4??? Try again

Blk98Vert

iTrader: (2)

My apologies, IIRC on a LQ4 its 9.4

bww3588

iTrader: (49)

If the cam is degreed properly, I would say the low static compression ratio, combined with the low dynamic compression ratio due to overlap could be part of the problem. Maybe advance the cam a few degrees to bring dynamic up some and mill the heads.

1nasty86

iTrader: (63)

Thats a big cam to have with 9.4 compression.... but it should still make more than 320 imo..

Darkrider02

iTrader: (4)

so do you guys think the cam wasnt installed wrong?

TurboBuick6

iTrader: (2)

Did thompson build the engine complete? They know what they are doing there, so if you bough complete I would highly doubt there is any mechanical issue at all.

Darkrider02

iTrader: (4)

just bought the shortblock from them

PREDATOR-Z

With a cam that size, install mistakes would definitely appear in other ways than poor output.
What kind of dyno was used?

KCS

iTrader: (20)

I'd look at the cam. I know of a 408 that lost almost 200whp with a cam 2 teeth off...

Darkrider02

iTrader: (4)

im hoping its the cam a tooth off!!!!