Camshaft timing findings - ZR-1 Net Registry Forums

09-24-2009

After pulling the LT5 this past weekend I finally got around to checking to see what the issue was before taking off the heads. I wanted to confirm how far off the timing was due to lower compression by 20-25 lbs on the entire bank of left side.

Set the camshaft locator

Right side no problem and pins placed.

Left side confirmed timing is off, did not check approximately how many degrees off but I'm sure the experts can tell by looking at this.

Removed pin to try to show how far off.

09-24-2009

A shot of the other cam alignment for pin.

On a different note, here is the other piece of the key for the crankshaft/torsional damper that was left in. Easily taken out with tap of punch and ready for new key from Jeff. Still can't figure out how and when this happened, but not during my ownership of this Z.

More to follow. I'll start taking off the heads now that I am satisified I at least checked before disassembly. I was very afraid of all of this (right Jeff, Carter, Tom, Brad, Rick and others?) I feel more comfortable the more I read, watch the CPT video and work on this LT5. Thanks to this great Z brotherhood, even I can do this.

flyin ryan · 09-25-2009

Can't say it's surprising...last one I had apart looked about the same, was out to lunch

. Works good now though

.

09-25-2009

Quote:

Originally Posted by flyin ryan

Can't say it's surprising...last one I had apart looked about the same, was out to lunch

. Works good now though

.

flyin ryan,

Do you think being this much off was the root cause of the lower compression across this entire bank and also the smoking issue I was having? I can't imagine I have piston ring issues causing the lower compression and smoking with only 53K miles.

Thanks!

tomtom72 · 09-25-2009

Subscribed!

It's okay if I just sit here in the corner & watch? I promise I won't make any noise... I wanna learn.

carter200 · 09-25-2009

Tom,
Pull up a seat and watch the show. It promises to be a good one

09-26-2009

Quote:

Originally Posted by tomtom72

Subscribed!

It's okay if I just sit here in the corner & watch? I promise I won't make any noise... I wanna learn.

Tom,

I hope there is value to my drama. I just figured I would share what happened to me. You sure have a lot to share too so don't be shy.

flyin ryan · 09-27-2009

Hey Craig, been gone racing my Stingray on a short road trip the past couple days. Pistons & cylinder walls look good from what I can tell/see. At this point not sure what the root of your smoking is coming from? It's something, just need to dig a little deeper. What were your pumping compression numbers?

09-28-2009

Quote:

Originally Posted by flyin ryan

Hey Craig, been gone racing my Stingray on a short road trip the past couple days. Pistons & cylinder walls look good from what I can tell/see. At this point not sure what the root of your smoking is coming from? It's something, just need to dig a little deeper. What were your pumping compression numbers?

Hi Ryan,

Thanks for helping out and I appreciate your input. The smoking was a wide open throttle only and I don't exact color but it appeared to be blue when I could try to look behind. Complaints from people following complained about the smell on the freeway with Corvette Club convoy.

My compression numbers were:

1 = 175
3 = 190
5 = 187
7 = 185

2 = 205
4 = 215
6 = 215
8 = 220

Second time for left bank:

1 = 190
3 = 185
5 = 185
7 = 185

Thanks again, I'll post the pics from the other head removed today.

09-28-2009

So I finally got the right side head off after getting some help from my neighbor that build VWs. I guess the left side yesterday stole all my energy because I could not do this side by myself and the bolt were a bugger.

Cylinders # 2 and #4

#6 and #8

Cylinder #2 and 4. What is up with the different color valves. My spark plugs had this same color and Marc H said someone else using Royal Purple had the same color too. So it this a Royal Purple thing? I will be using AMSOIL from here on out.

#6 and #8. The head gaskets were a surprise and look almost like new.

So the next step is to take off the only pan, girdle and inspect the bearings. First I have to prep the heads to ship off to Greg Van Deventer to let him work his magic. I can really see how the port work in heads and top half makes the LT5 come alive after getting this far into the motor.

09-24-2009	#1
HAWAIIZR-1 Guest Posts: n/a	Camshaft timing findings (updated with heads) After pulling the LT5 this past weekend I finally got around to checking to see what the issue was before taking off the heads. I wanted to confirm how far off the timing was due to lower compression by 20-25 lbs on the entire bank of left side. Set the camshaft locator Right side no problem and pins placed. Left side confirmed timing is off, did not check approximately how many degrees off but I'm sure the experts can tell by looking at this. Removed pin to try to show how far off. Last edited by HAWAIIZR-1; 09-27-2009 at 02:28 AM.

09-25-2009	#3
flyin ryan Join Date: Aug 2006 Location: Edmonton, Alberta or Phoenix, Arizona Posts: 2,741	Re: Camshaft timing findings Can't say it's surprising...last one I had apart looked about the same, was out to lunch . Works good now though . __________________ There are no limit's mans ingenuity, just as mans ingenuity will never conquer the forces & behavior of this planet...Smokey Y.

09-25-2009	#5
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Camshaft timing findings Subscribed! It's okay if I just sit here in the corner & watch? I promise I won't make any noise... I wanna learn. __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

09-28-2009	#10
HAWAIIZR-1 Guest Posts: n/a	Re: Camshaft timing findings So I finally got the right side head off after getting some help from my neighbor that build VWs. I guess the left side yesterday stole all my energy because I could not do this side by myself and the bolt were a bugger. Cylinders # 2 and #4 #6 and #8 Cylinder #2 and 4. What is up with the different color valves. My spark plugs had this same color and Marc H said someone else using Royal Purple had the same color too. So it this a Royal Purple thing? I will be using AMSOIL from here on out. #6 and #8. The head gaskets were a surprise and look almost like new. So the next step is to take off the only pan, girdle and inspect the bearings. First I have to prep the heads to ship off to Greg Van Deventer to let him work his magic. I can really see how the port work in heads and top half makes the LT5 come alive after getting this far into the motor.

09-24-2009	#2
HAWAIIZR-1 Guest Posts: n/a	Re: Camshaft timing findings A shot of the other cam alignment for pin. On a different note, here is the other piece of the key for the crankshaft/torsional damper that was left in. Easily taken out with tap of punch and ready for new key from Jeff. Still can't figure out how and when this happened, but not during my ownership of this Z. More to follow. I'll start taking off the heads now that I am satisified I at least checked before disassembly. I was very afraid of all of this (right Jeff, Carter, Tom, Brad, Rick and others?) I feel more comfortable the more I read, watch the CPT video and work on this LT5. Thanks to this great Z brotherhood, even I can do this. Last edited by HAWAIIZR-1; 09-24-2009 at 02:46 AM.

09-25-2009	#6
carter200 Join Date: Jun 2004 Location: Texas Posts: 2,431	Re: Camshaft timing findings Tom, Pull up a seat and watch the show. It promises to be a good one __________________ 95 ZR-1 BLK/Gry #392 LT5 Reg# 868 RIP ZR1NET Founding Mem #155

09-27-2009	#8
flyin ryan Join Date: Aug 2006 Location: Edmonton, Alberta or Phoenix, Arizona Posts: 2,741	Re: Camshaft timing findings Hey Craig, been gone racing my Stingray on a short road trip the past couple days. Pistons & cylinder walls look good from what I can tell/see. At this point not sure what the root of your smoking is coming from? It's something, just need to dig a little deeper. What were your pumping compression numbers? __________________ There are no limit's mans ingenuity, just as mans ingenuity will never conquer the forces & behavior of this planet...Smokey Y.