I recently did a stock rebuild on my 95 Z with the exception of a mild comp cam. after about a week of running well, the oil pressure fell to nothing. After towing home, i pulled the intake manifold off and found this...

http://img.photobucket.com/albums/v3...776/cam004.jpg

i guess some people are saying that comp cams have a tendency to do this especially when you use the old oil pump gear. i ordered a new oil pump gear but im scared im about to chew up another $70 part. anyone heard or had this same problem with aftermarket cams?

also, i haven't been able to check the teeth of the cam yet but people are saying the cam is usually a harder metal so that it breaks the distributor or in the LT1 case the oil gear first. this true?

thanks

 

Happened on my camaro (not in sig, 94). I took the engine out 2 months ago or so and seen the same thing. I sold the cam to one of my friends so I hope the same thing does not happen to him. It was a hotcam.

 

You have found the problem with using incompatible gears.

See this and call Comp cams for your solution.
http://compcams.com/technical/Catalogs/106-07/235.pdf

 

so what material is our stock oil pump gear? Comp cams seems to think its mild steel but other people who have had the similar problem are saying its already iron but the cam is hardened.

 

I thought they were cast. But to be sure, ask rskrause.

 

took the gear to PAW they seemed to think that the gear was mild steel, so now i have an iron one in there and everything is working for the time being. thanks

 

i have heard that the gears can be eatin by the meiling HV oil pumps.......that has happened to a friend of mine about 3 or 4 times

 

The cams ending with a part number of -8 are cast cores and should not eat the gear if everything in the motor is ok. (Oil pump, alignment of cam vs. distributor hole)

So for example a 07-503-8 is a shelf "CC503" cam.

A billet core is a -9 and you either need the cam gear changed on the core or run a compatible dist/oil pump drive gear.

Bret

 

What would be a compatible oil pump drive gear? What would you recommend, Bret? What do you have to check for as far as the metal shavings in the oil?

 

Bret, the cam being run that chewed up the oil pump drive gear is a -8 cam so it should be cast and therefore totally compatable, correct?

Could a missing cam retaining plate be the issue here? I know Crayz28 personally and I he didnt intstall the cam or the timing cover.. Would this be indicative of that or would more catastrophic issues have occured?

Thanks!

 

I would think that a missing retainer plate could certainly cause this.
How many miles did you have on the rebuild before you had this happened?

 

about 300 miles.

pulled the timing cover today. guess what... no plate behind the timing gear. somebody has some explaining to do

http://img.photobucket.com/albums/v3...amplate005.jpg
so screws probly mean no plate im guessing

 

Hopefully someone who has built more motors then I have comes in and give you some info but if that cam was able to move back and forth I would think it could easily cause enough of a miss alignment to chew the teeth off of the oil pump gear.

 

Well that's why it's fubared. The retaining plate keeps the cam from moving in the block. Without it added thrust will be applied to the cam and oil drive and eat the gear like crazy.

Bret

 

my buddies car did this he used the polymer oil gear drive and it has held in strong for several years of street use I think he had to use a bushing for the diff between the drive and gear