GM Forum - Buick, Cadillac, Olds, GMC & Pontiac chat

GM Forum - Buick, Cadillac, Olds, GMC & Pontiac chat (https://www.gmforum.com/)
-   General GM Chat (https://www.gmforum.com/general-gm-chat-88/)
-   -   Zilla's initial autopsy: (https://www.gmforum.com/general-gm-chat-88/zillas-initial-autopsy-263718/)

willwren 09-03-2007 03:45 PM

That's the price we all risk paying when we mod.

There may be more truth to the gas station putting 87 octane in there than I thought. I'll have to play it careful when I start it up again. I may increase pulley diameter for safety in the meantime.

Good thing I had that rather monstrous 2.3" on there when it happened. It could've been much worse.

I've done some local searching (NW area) and have found a couple good candidates for replacement. It may be in the budget within a couple weeks.

This engine will be kept for rebuild for a rainy day.

13secGTP 09-03-2007 09:17 PM


thats strange that it bent the ground electrode like that, and didn't even break the ceramic.
Its actually very common the bend the electrode like that when you chip a piston. I chipped 4 at IDD in 06 and still ran a 13.0-change the plugs-tune and go-lol.

However from the pics it doesn't look like a chipped piston, it looks more like it was tapped by the piston. I agree with the compression results showing a chipped piston.

Hans 09-04-2007 05:31 AM

I'm also curious as to what happened. I dont see how the 2.3 and low octane would kill it. I'm still trying to picture in my head how the piston would do that to the plug.

BillBoost37 09-04-2007 07:16 AM

It's not actually the piston Hans..is a chip from the piston. Small enough piece to impact without destruction.

Chipping pistons is actually pretty common in our motors once you step things up to certain levels.

willwren 09-04-2007 08:10 AM

Hans, I'm running a 2.3" pulley on a GEN3 setup. Think about it. And if 87 octane actually did go in the car that night like I suspect, a chipped piston is definitely on the menu.

93-SSE 09-04-2007 08:33 AM


Originally Posted by willwren
Hans, I'm running a 2.3" pulley on a GEN3 setup. Think about it. And if 87 octane actually did go in the car that night like I suspect, a chipped piston is definitely on the menu.

Anyway you can check the fuel thats in the car now?

Well like i said before, i believe it was the 'night from hell thread', that sucks but its fun going through it. Have fun with the repairs, hopefully it may not be quite as bad as you think. And have fun with your upcoming mod...whatever the heck it is :lol:

willwren 09-04-2007 12:34 PM

4 Attachment(s)
Found a good replacement candidate with better compression than my GOOD cylinders, which are well above minimum spec (even the 'bad' cylinder is still good, but not good for making power).

Also just checked out a little toy from the tool shack here at HP. Fiberoptic borescope with a built-in light and articulating end. It also comes with a 90° little mirror for looking straight up or down. With this, I'll be able to fully inspect the entire cylinder bore, piston, head, and valves from the inside.

Here's a vid of the gizmo in action:
https://i21.photobucket.com/albums/b...h_MOV04796.jpg

And some images from it. Focus is an effort when holding the borescope AND camera, but clarity is amazing using my eyes.

Precision ruler graduated in 10th's and 100th's of an inch:
Attachment 43103

Attachment 43104

Attachment 43105

Attachment 43106

lash 09-04-2007 12:55 PM

Certainly not something you normally want to see happen. But like you said, these things can happen when you start pushing things beyond a certain point.

I must say that you seem to be takinng it remarkably well. ;)

harofreak00 09-04-2007 01:06 PM

Fiberoptic borescope = Cooler than Zilla 8)

BillBoost37 09-04-2007 01:08 PM

Nice boroscope. It's awesome the way you can check tools out to have the ability to know what is going on inside the cylinder.

It is sad to see the motor go at such a low mileage. Like you said though..the new compression on the motor you are looking at should be great for making power.


All times are GMT -4. The time now is 06:57 PM.


© 2024 MH Sub I, LLC dba Internet Brands