Subject: Re: MF'r broke down....round two!!! by PeteK on 2011/6/22 22:23:15
Quote:
Matatk wrote: Pete - as always I appreciate your insight.
The cam I am running is the following:
Comp Cams 08-432-8 (xr282HR-10)
When I emailed comp last year about the problem, this was the response I received:
Quote:
If there was any damage to the cam, you would be able to see it while it is still in the engine. That looks like the normal wear with a high volume oil pump and stock gear. The correct material is iron or steel, but it has to be melonized. That is the process that makes the gear compatible with our cams. Now the wear issue will still be there with a high volume oil pump, which is inevitable, but it may not be as bad with the correct gear. I also spoke to one of our engine builders and he said that the original gear was worn with the original cam, and then it was put on a new cam, so that was most of the culprit. As long as the cam gear isn't damaged, I would recommend the GM part # 10456413 distributor gear and some gear marking compound just to make sure the gears mesh correctly.
However, when I check the site, it directs me to the composite drive gear as appropriate for the cam/part #12200:
So that confuses me a bit. As far as I know, it's not billet.
I thought you could get cam walk on a roller block, but apparently that's only on retrofits? Thanks for pointing that out.
The cam gear looks ok while in the block, but I can't be certain. I am going to check the endplay with a screwdriver to see if it moves.
I don't like the low oil pressure, either. I am considering changing the oil pump out. The current pump is a Melling M55HV. I have heard internet stories about high volume/high pressure pumps accelerating wear on drive gears. I can't verify if that's true or not.
My choices for oil pump are pretty much:
M55 - standard volume, standard pressure M55HV - high volume, high pressure M55A - standard volume, high pressure
I am considering just the stock style M55. Thoughts?
I don't like the idea of having to pull the pan but I want to check for damage, at this point.
I will check the distributor for shaft damage/runout. I don't know how to do that, yet, but I will find out. I now have a dial indicator and magnetic base to assist with that.
Any other thoughts/comments?
Matthew
I would recommend not spending money, because you may have a large problem. The metal that was shed from 2 dist gears have been consumed by your engine. The low pressure could be a pump, or bearings. You wont know till you get it running again. My advice now would be to buy the composite gear, and get it running to determine if the oil pressure reflects a hurt engine. In regards to the high volume pump, they do reduce the life of a dist gear, but you should still get 100k out of one, not 1500 miles. To check the dist shaft, remove it from the dist. Set in in a couple of V blocks, and put a dial indicator on it. spin it and record the out of round. I have no idea what acceptable run out is, but I look for .002 or less.
