Wtf?
Thread Starter
11 Second Club
Joined: Sep 2003
Posts: 818
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From: Battle Mountain, NV
Wtf? I have the mods in my sig. Went to teh track yesterday and spun off and amazing......
13.1@104.
Now here is the problems I have had
When tuning the car, at the correct tune for the cam, it pinged. So we took some timing out of it. Still pinged. So we took some more timing out of it. Ping is gone. Now it feels like it has no top end power.
Another thing. With the heads/cam package their was no piston-valve clearence. We notched pistons and it fixed the problem.
Any ideas?
13.1@104.
Now here is the problems I have had
When tuning the car, at the correct tune for the cam, it pinged. So we took some timing out of it. Still pinged. So we took some more timing out of it. Ping is gone. Now it feels like it has no top end power.
Another thing. With the heads/cam package their was no piston-valve clearence. We notched pistons and it fixed the problem.
Any ideas?
Originally Posted by strobelite
I have the mods in my sig. Went to teh track yesterday and spun off and amazing......
13.1@104.
Now here is the problems I have had
When tuning the car, at the correct tune for the cam, it pinged. So we took some timing out of it. Still pinged. So we took some more timing out of it. Ping is gone. Now it feels like it has no top end power.
Another thing. With the heads/cam package their was no piston-valve clearence. We notched pistons and it fixed the problem.
Any ideas?
13.1@104.
Now here is the problems I have had
When tuning the car, at the correct tune for the cam, it pinged. So we took some timing out of it. Still pinged. So we took some more timing out of it. Ping is gone. Now it feels like it has no top end power.
Another thing. With the heads/cam package their was no piston-valve clearence. We notched pistons and it fixed the problem.
Any ideas?
What kind of lift does that cam have to require notching the pistons? I've heard of guys running in excess of .620 lift on the stock pistons without having to notch them....???
Where did you get the tune from and was it done on a dyno, or mail order?
Mike
Confused about the post.
Typically when you pull timing out you will lose power. How much timing did you pull out?
What pistons were in there that you had to notch them? How was the PVC measured?
It's hard to believe that you had PVC problems with the cam that you have. You have to run in the .61X lift land and the block zero deck to come close to the pistons.
Just trying to get a better understanding.
Typically when you pull timing out you will lose power. How much timing did you pull out?
What pistons were in there that you had to notch them? How was the PVC measured?
It's hard to believe that you had PVC problems with the cam that you have. You have to run in the .61X lift land and the block zero deck to come close to the pistons.
Just trying to get a better understanding.
Thread Starter
11 Second Club
Joined: Sep 2003
Posts: 818
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From: Battle Mountain, NV
First off:
I didn't do the work myself.
To answer mikey Yes we actually heard the pinging around 2500 rpm's.
Now to answer both of your question. When the shop took my motor apart my valve seats were demolished and the pistons had scars on them from hitting the valves. Now first We had beehive springs on the heads Which would have caused this. So we switched out the springs and put in titanium retainers. They put the cam back into the motor and still had no PVC. We got a smaller cam, a comp 227/232 STILL no PVC. So the shop came to teh conclusion that they needed to notch the pistons to get the setup to work.
Only thing we have came up with is that the valves in the heads are maybe too big thus leading to the PVC problems.
We had to pull a **** load of timing out. It wasnt a mail order tune, I have a really good friend who helped me out with the tuning part of it.
I didn't do the work myself.
To answer mikey Yes we actually heard the pinging around 2500 rpm's.
Now to answer both of your question. When the shop took my motor apart my valve seats were demolished and the pistons had scars on them from hitting the valves. Now first We had beehive springs on the heads Which would have caused this. So we switched out the springs and put in titanium retainers. They put the cam back into the motor and still had no PVC. We got a smaller cam, a comp 227/232 STILL no PVC. So the shop came to teh conclusion that they needed to notch the pistons to get the setup to work.
Only thing we have came up with is that the valves in the heads are maybe too big thus leading to the PVC problems.
We had to pull a **** load of timing out. It wasnt a mail order tune, I have a really good friend who helped me out with the tuning part of it.
Are you running an aftermarket timing chain and a electric water pump? If so, I'm wondering if the shop installed the cam advanced/retarded instead of straight up. That would explain the piston/valve contact and the destruction therein. It would also explain the pinging and lack of power up top.....
What is the total lift at the valve with the 1.6 rockers you have?
What shop did the work?
Mike
What is the total lift at the valve with the 1.6 rockers you have?
What shop did the work?
Mike
Thread Starter
11 Second Club
Joined: Sep 2003
Posts: 818
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From: Battle Mountain, NV
Got the LT4 timing chain, stock water pump. Had piston to valve clearence pre-taking it to shop. I did head/cam swap in the first place.
Blood Enterprises did the work post-blow-up
Blood Enterprises did the work post-blow-up
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Originally Posted by Mikey 97Z M6
What is the total lift at the valve with the 1.6 rockers you have?
Mike
Mike
I'll assume it's a standard XE grind cam from CC with 1.5 lift numbers of .520/int and .540/exh. Now with 1.6's those numbers turn into .555/int and .576/exh.You really should not have had any problems with PTV clearance at those lifts unless something is severely wrong, like timing events, mis-ground cam etc.. Even if the heads had been shaved .040 (which is a sh!tload btw) it would still leave enough clearance to be safe with a stock block that has not been decked. I've had my heads decked twice now, (one was .010, the other was .015) and they are nearing the valve seats.
Sounds to me like maybe a couple of the valveseats came out a bit causing the valve to not close all the way. Then the piston came up and pounded it a couple times. ? I really doubt you had PTV contact because of the lift of the cam etc just doesn't add up to that being a problem unless the cam is bigger than you realize.
At any rate, there is def. a problem somewhere. Did you happen to buy the cam new or used? I'd probably start by degreeing that cam to make sure it is what you think it is. Mis-ground cams are fairly rare, but it does happen.
I'm assuming you've already looked over the obvious stuff like fuel pressure, thrown codes, etc..?
Mike
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11 Second Club
Joined: Sep 2003
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From: Battle Mountain, NV
Yeah looked over everything like that.
The cam is an Erson cam specifically picked by the guy who did my heads (Lloyd elliot) to be the right combo heads/cam wise. WHen the shop tested the PTV it wasnt even the minimum was like .010 clearence i think or something like that dont exactly remember. But they had to notch the pistons to make it the appropriate amount of clearence.
I guess its going to just take time and ripping it apart again.
The cam is an Erson cam specifically picked by the guy who did my heads (Lloyd elliot) to be the right combo heads/cam wise. WHen the shop tested the PTV it wasnt even the minimum was like .010 clearence i think or something like that dont exactly remember. But they had to notch the pistons to make it the appropriate amount of clearence.
I guess its going to just take time and ripping it apart again.
Aaah didn't realize it was an LE grind. I was just going from the specs in your sig and thought it was a XE grind. That is obviously a high lift grind then. 
Hope ya get it sorted out soon man...
Mike
Hope ya get it sorted out soon man...
Mike
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Joined: Nov 2001
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From: Monroe, SD
sure it is ping and not noisy valvetrain? if it is noisy valvetrain then get a LT4 knock modual and it should take care of the computer. then set the timming back up.
another dumb question are you running atleast 91 octane?
another dumb question are you running atleast 91 octane?
