Remember_54

SORRY for my English..


Ok will start from start:

I have Hummer H2, 2003 (Car VIN # 5GRGN23U53H101047)

Engine: LQ4 Generation III,364 CID (6.0L) 16V V8 4.000" (101.6mm) General Motors Vortec

Magna Supercharger on it which were installed before and worked fine with engine: http://www.magnacharger.com/pdf/manual-HummerH2.pdf

So we decide to rebuild engine:

I spoke with Paul Hennelly from Paschal Performance Engines Inc
so after long desiccation we made part list:

Pistons 14510-030 Probe
Rings CR1009 35 (file fit set)
Rods LG3-6125LSH RPM
Main bearings BC409J 010
Rod bearings BB253J 010
Cam bearings
Coatings: Pistons ceramic top coat, skirt coating & rod bearing coating
Manley stainless steel valve 1.55" LS
Manley stainless steel valve 2.00" LS
Manley timing set LS 3-bolt with captive Torrington thrust bearing and 9 keyway sprocket.
Comp Cams LS valve springs
Comp cams LS camshaft XR265HR 212/218 degree @ 0.050" 0.558"/0.563"lift
Melling high volume oil pump Chevy LS
Head bolt set LS engine (2 req.)
Comp cams performance roller lifters Chevy
Comp cams Chevy LS pushrods
Edelbrock high volume water pump Chevy LS engine
Magnuson 2.8" supercharger pulley

The compression should be at 9:1

So after installing all this we decide to rebuild transmission to so I bought this monster rebuild kit: racetransmissions .com

along with Torque Converter: 1800-2000 stall converter with anti-balloon plating

so we did everything rebuild trans and engine!!

We start enigne, rpms hold fine not going up and down, but engine is vibrates much, we checked mount all fine, also belt idler start making noise and going up and down hard, not as normal, when you shift from P to D or R engine going off, when you push more accelerate it like no enough power to push car, and then stops again, we check ECU, it was shown ignition problems, we erase all mistakes and checked again no any problems in ECU, when my electrical fans start it start vibrates more, I mean when electrical loads apply to engine it also start vibrates more..

The issue is make me worried :

1. Fly wheel is factory (maybe I need to buy new) ?? or that thin peace of metal can really course so much vibration??
2. Harmonic balance also factory one, but it running straight if you look with the belt on it, when engine running
3. Comps camshaft which was changed maybe not matching computer ?? but we call to supercharger guys who was tuning ECU after charger installation, they said that it should be fine, and you do not need any tuning on computer
4. Torque converter which was on car is much bigger that the one I bought, maybe that can make so much vibration?
5. Crankshaft been not change, it is factory one we just grind it one size bigger for new bearings, when shop been grinding it they say it is not curved, but I`m not sure does they did balancing or did they need to do balance?

I really do not now what to do trying to find some help, i`m leaving In Azerbaijan, Baku and here no any professional guys or tech to support me, we do not have even GM dealer here, but I`m trying to do everything by myself with some good guys who rebuild engines before, so any suggestion from what that happened and why engine is vibrate too much PLEASE HELP, we build engine is looking nice but it is not working and we can not understand why

Please HELP guys really need help.. already one month can not sort this issue.. truck just in shop .. and we do not know from where to start....

Remember_54

valve timing ?
a lot of guys saying that this could happen because of your new comp shaft which use new timing chain maybe it is wrong gas distribution?

Remember_54

another idea maybe the weight of rods and pistons can make this imbalance?

Con rod imbalance (not likely as new con rod was matched for weight with other 8 same like a pistons)

Throttle body balance (not yet performed due to unavailability of balancing tool - even not sure how to do it)
Do we need to do throttle body balance? and what is for?

I think maybe to order new fly wheel with crankshaft along with damper ? but I’m not sure if this new crankshaft will much my piston and rods weight?

my email: is gasanovr@gmail.com

checking it every 5 minutes maybe somebody will help me with this issue?

TurboGibbs

iTrader: (6)

My best guess would be you have your camshaft timing a tooth off on your timing chain.
Balancing the engine is good to do, but not a must. The engine not being balanced won't cause the issues you are having. Pull the water pump, harmonic balancer and timing cover back off and check the cam timing. You will need to loosen the oil pan bolts to get the cover back on properly. Good luck!

Remember_54

thanks for reply

So you think, that we need to adjust timing chain? this timing chain has different positions our one for a moment is R2 (Manley timing set LS 3-bolt with captive Torrington thrust bearing and 9 keyway sprocket)
it has A2, A4, A6, A8 , 0 , R2, R4, R6, R8, so what I understand it to change position but to which one?

the guys also trying to help here
https://www.performancetrucks.net/fo...10#post4518210

TurboGibbs

iTrader: (6)

You need it set on the 0 key way but you have to make sure the dots on the upper and lower sprocket line up with crank sprocket dot at the top and camshaft sprocket dot at the bottom. It is a common mistake and easy to do. It will cause issues like you are having it the dots are one chain link off.

TurboGibbs

iTrader: (6)

Before you go into the engine, check and make sure all your ground wires were hooked back up. There are some on the back of the engine and one or two on the lower driver's side front if I remember correctly on most trucks. I've never worked on a Hummer though so they may be a little different.

Remember_54

THANKS for reply ...

I`m sure that dots are right.. i think if they are not right the rpms start playing, or maybe i`m wrong..

So what you saying is to move from R2 to 0 position, i will try it, but the guys from engine performance said that it not making different in vibration, actually i`m new on this timing chain, so will try to put it in 0 position.. but if it possible can you explain what all this position is mean?

Remember_54

we have 3 main ground wires and they all been hooked up.. no any wires left in a engine..

Remember_54

any more ideas guys?

HELP HELP HELP