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Discussion Starter · #1 ·
I had to have my cylinder head fixed along with a new piston and cam and valves after the timing belt came loose and caused damage. So i went for a stage I local non-CNC port along with Stealth II cam and 2.02 valves with comp 918 springs. My previous mods which worked very well before the damage included flywheel, haltech trap and a crank pulley.
So after the head, cam and valves upgrade the power seems better at 1/4 throttle upto only 5000 rpm, but when i go full throttle above 3ooo rpm it feels like theres a hole in the engine letting all the pressure out. I mean it revs o.k but it had more power before the H/C and its obvious somethings wrong......Instincts tell me with my limited vette knowledge that theres not enough fuel for the new setup, or air. Can anyone say if the heads were done wrong, or maybe a bad H/C combination because ive benn told a tuning program will sort it out on the dynotest.....Anyone with similar problem on stock tune with H/C?
 

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Sharkfaced said:
I had to have my cylinder head fixed along with a new piston and cam and valves after the timing belt came loose and caused damage. So i went for a stage I local non-CNC port along with Stealth II cam and 2.02 valves with comp 918 springs. My previous mods which worked very well before the damage included flywheel, haltech trap and a crank pulley.
So after the head, cam and valves upgrade the power seems better at 1/4 throttle upto only 5000 rpm, but when i go full throttle above 3ooo rpm it feels like theres a hole in the engine letting all the pressure out. I mean it revs o.k but it had more power before the H/C and its obvious somethings wrong......Instincts tell me with my limited vette knowledge that theres not enough fuel for the new setup, or air. Can anyone say if the heads were done wrong, or maybe a bad H/C combination because ive benn told a tuning program will sort it out on the dynotest.....Anyone with similar problem on stock tune with H/C?
Looks like it needs a tune. That should solve your problem. What cam did they install in your car.

You have a chain not a belt. Did the chain break and cause the damage? A stage one non-CNC must be just larger valve install and valve job. Is that correct? Really need more details.

D.J.
 

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Did a reputable engine builder/tuner do the work or was it a back yard mechanic? Sounds to me like cam timing might be off. A new cam should be degreed in for optimim results with a variable timing set.

Need more info.
 

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Discussion Starter · #4 ·
The guys who did the porting here in Kuwait do the majority of porting for most ls1 engines and they generally seem o.k if not 100% of what they could be with better tools techniques. In my case i can notice a definite problem in the power delivery as you apply more throttle, and the power is a bit lower than when before H/C.
As far as cam installation.....They do alot of cams and seem o.k
Id love to belive its tuning only, as i dont want to change my heads after paying around 2K$ for the fixing and upgrade so far.
 

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I don't know if I would blame it on tuning. My car had a H/C job and I re-installed the stock tune to see what if any difference it made and the car still ran like a scalded dog. You have another issue I believe but I can't tell you what it is. Tests need to be run. It's like a doctor trying to diagnose and illness over the phone, it can't be done accurately. Take the car back to whoever did the work or find another tuner to check it out.
 

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I will send you some AFR heads and a nice cam if you send me a tanker of gasoline. hehehe. Probably about the same cost
 

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Discussion Starter · #10 ·
Yes the valves got bigger to 202's but the in's and out's were ported to stage I

So i added the performance tune(predator) and went to the max of 5 with the fuel and also 5 out of 10 with the timing, and it seems better, but i get codes about lean fuel in bank 1 and 2, any advice on whats happening in my engine cuz i dont understand all this 2 much?
 
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