|
|
![]() |
#1 |
Junior Member
Join Date: Jul 2007
Posts: 6
Likes: 0
Liked 0 Times in 0 Posts
|
![]()
I have seen the same thing due to detonation. I would defineately check the rod bearings, as has been said if it was detonation there should be some evidence at the bearings. I thought I heard that there was a problem with some VP fuels not being to spec (dont remember where I heard it). I was wondering if it showed any evidence of being lean that might account for higher engine temps also and could cause some burning of the piston material. Just a thought.
|
![]() |
![]() |
![]() |
#2 |
Senior Member
Join Date: Aug 2004
Location: So. Cal.
Posts: 651
Likes: 4
Liked 54 Times in 33 Posts
|
![]()
If the dist was not moved after the cam slipped the ignition timing retarded right with it. If the ignition timing was reset after the cam slipped he could have been putting too much heat in the combustion chamber due to the advanced ignition timing. Also the late intake opening would not allow a complete burn of the A/F mixture at the rpm's he was trying to spin. Too much of that will make carbon deposits in a hurry. Lots of leftover unburned fuel.
If there was THAT much stuff laying in the cylinders the tops of the pistons would look like the surface of the moon. kinda. Heavy sandblasted look anyway. |
![]() |
![]() |
![]() |
#3 |
Member
Join Date: May 2005
Location: Covington, La
Posts: 311
Likes: 63
Liked 83 Times in 20 Posts
|
![]()
Everytime I had detonation it hammered the rings out causing some 30 to 40 % cyl leakage. This was after 10 to 15 runs and evey run would get a little worst. Additionally, we would take the engine out of the car and remove the oil pan only to find what looked like sludge in the pan. The engine looked like we never changed the oil in 50,000 miles! What a mess and a costly on at that! L little colder spark plug and C-14 racing gas cured the problem.
__________________
John Duzac D/S 4448 STK |
![]() |
![]() |
![]() |
#4 |
Senior Member
Join Date: Dec 2001
Location: Elysburg, Pa
Posts: 733
Likes: 359
Liked 327 Times in 121 Posts
|
![]()
When the cam is retarded beyond normal the exaust valves may hit the pistons. The compression will go down at the same time so your chances of a detonation issue where there was none before are almost not possible. Paul.
|
![]() |
![]() |
![]() |
Thread Tools | |
Display Modes | |
|
|