Robby Camero
15+ Year Contributor
- 101
- 0
- Oct 27, 2003
-
Toronto,
ON, Canada
I was about to install my 272's and adjustable cam gears tonight before I noticed something wierd!
I was about to cut the timing belt just to get it off quickly because I plan on using a new one when I decided to line up all the timing marks just for the hell of it. Turns out the cam gears are both out 2 teeth advanced towards the front of the engine. (or is that technically retarded?) WTF???
I have changed a timing belt on my 90 before but havent touched it on my 91. The mark on the crank lines up when the piston is at TDC (checked with dowel and indicator)
The oil sprocket doesnt line up either but it probably wasnt even lined up in the first place due to the non exsistant balencers.
Heres what i know about the motor:
-fully rebuilt about 40,000 KM's ago by a local DSM shop and ran with NO PROBLEMS! I know what a bad timing belt job feels and sounds like cause I did it to my 90 fwd before I finnally got it right. Car pulled hard, never idled funny and seemed like everything was in perfect working order. Although I did have a slightly low vacume but I thought is had something to do with the non existant emissions on the car. It also had a seemingly slow spool but I thought it was due to a small crack in the manifold.
- head work was done, new valves, seating, mild porting
- 95 pistons installed
- crank balenced etc...
- dont know if or how much head and block were decked during rebuild
- I have a multi layer metal head gasket on the engine but I am unsure of its thickness, I "think" its .060" but I will double check.
I didnt own the car when the engine was rebuilt so I dont know exactly what was done to it
I cant get a hold of the shop owner to find out if he remebers what exactly was done to the engine during the rebuild (decking etc...), he is not answeing the phone. (known to do this when he is busy)
My question would be is it possible the cams were put out like this on purpose due to decking of the head and block? Was there a possible mechanical failure?
Two teeth out works out to be like 14 degrees aprox, doesnt it? It doesnt seem right that it would have been done purposly even with heavy decking.
I dont want to put the belt back on by the book and find out that the cams were done like this on purpose, even though I highly doubt it. Thats why I am puzzled at the fact the motor ran great.
Also, can I not just put the belt back on by the book, and carry on with degreeing my cams to the 272 specs? I'm no engine guru but shouldnt I be ok as long as the lift on the intake and exhaust cam is to spec at TDC? But then again, if something is messed, I wont have enough adjustment on the adjustable cam gears to compensate.
Thanx for looking
I was about to cut the timing belt just to get it off quickly because I plan on using a new one when I decided to line up all the timing marks just for the hell of it. Turns out the cam gears are both out 2 teeth advanced towards the front of the engine. (or is that technically retarded?) WTF???
I have changed a timing belt on my 90 before but havent touched it on my 91. The mark on the crank lines up when the piston is at TDC (checked with dowel and indicator)
The oil sprocket doesnt line up either but it probably wasnt even lined up in the first place due to the non exsistant balencers.
Heres what i know about the motor:
-fully rebuilt about 40,000 KM's ago by a local DSM shop and ran with NO PROBLEMS! I know what a bad timing belt job feels and sounds like cause I did it to my 90 fwd before I finnally got it right. Car pulled hard, never idled funny and seemed like everything was in perfect working order. Although I did have a slightly low vacume but I thought is had something to do with the non existant emissions on the car. It also had a seemingly slow spool but I thought it was due to a small crack in the manifold.
- head work was done, new valves, seating, mild porting
- 95 pistons installed
- crank balenced etc...
- dont know if or how much head and block were decked during rebuild
- I have a multi layer metal head gasket on the engine but I am unsure of its thickness, I "think" its .060" but I will double check.
I didnt own the car when the engine was rebuilt so I dont know exactly what was done to it
I cant get a hold of the shop owner to find out if he remebers what exactly was done to the engine during the rebuild (decking etc...), he is not answeing the phone. (known to do this when he is busy)
My question would be is it possible the cams were put out like this on purpose due to decking of the head and block? Was there a possible mechanical failure?
Two teeth out works out to be like 14 degrees aprox, doesnt it? It doesnt seem right that it would have been done purposly even with heavy decking.
I dont want to put the belt back on by the book and find out that the cams were done like this on purpose, even though I highly doubt it. Thats why I am puzzled at the fact the motor ran great.
Also, can I not just put the belt back on by the book, and carry on with degreeing my cams to the 272 specs? I'm no engine guru but shouldnt I be ok as long as the lift on the intake and exhaust cam is to spec at TDC? But then again, if something is messed, I wont have enough adjustment on the adjustable cam gears to compensate.
Thanx for looking
