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timing cover wear

Posted: January 30th, 2012, 6:05 pm
by Grego
Instaling my timing cover this afternoon, so I went by the dealer to pick up a new spring and pin for the cam. when I got home I started comparing parts and taking measurements. For 159,000 miles I did not think the wear was too bad. The old pin measured just .001 under new and the spring .003 under new. Got to looking at the cover dimple and could see a slight swirl where the cam bolt has made some slight contact. measured with a straight edge and feeler gauge and had .015 from under bottom of cover. Does that measurement sound right, has anyone else taken that measurement. I don't think I'm being too picky reading some of the story's on here.
Still trying to figure out how to post pictures. :huh:
Thanks, Greg.

Re: timing cover wear

Posted: January 30th, 2012, 9:14 pm
by Grego
Just wondering if it's time for a new cover? Can't seem to find any specs on this one.

Re: timing cover wear

Posted: January 30th, 2012, 9:20 pm
by Retlaw01XJ
Where exactly is the 0.015"? I don't follow you on that.

I put my 2001 with Crower cam together yesterday. Went with a solid pin. It's actually below the surface of the cam bolt head. I have 0.014" clearance between the pin and cover.

Re: timing cover wear

Posted: January 30th, 2012, 9:31 pm
by Grego
I looked at what I had written and it is't clear. That nub is reassessed below the inside cover face. Straight edge held over the inside of the cover, .015 below that is the top of the nub. You went with a solid pin and no spring?
Thanks

Re: timing cover wear

Posted: January 31st, 2012, 10:19 pm
by Retlaw01XJ
Grego wrote:Just wondering if it's time for a new cover? Can't seem to find any specs on this one.
I can't help you there, I bolted mine together the other day. :mrgreen:
But my 2001 cover does have a quarter-sized recess, with the nub in the center. Originally had the cam retention plate, so there was no wear on the cover.
A couple of guys here are using a solid pin instead of the spring loaded original. The thought being it won't allow the cam to move fore and aft in the block. In extreme cases, the cam can cause a 'rod knock' sound as it moves out and slaps back against the block. I had a V6 Buick that did that too. There's also speculation excessive movement may contribute to cam bearing wear or even failure.
I believe Chris set his up with 0.005" end play. I ended up with 0.014" when I cut the pin a little too short.
Now that I think of it, I should have measured the end play with the stock cam and retaining plate setup to find a good target clearance to shoot for.

Re: timing cover wear

Posted: February 1st, 2012, 9:14 am
by Grego
Thanks for the info on that! Tues morning I went ahead and installed the cover with the new spring and pin. The 4.0 that I am currently running in the wrangler now has 275,000 miles on the ticker and I've owned since new, that cover has never been off. This motor still runs nice and smooth with the usual ticks and sounds of this particular engine.
I'm trying to learn everything I can building these motors so I can turn the one I am running into a stroker, and have a good running spare. This motor was going to be the stroker but work got really slow here in the northwest, carpenter by trade. I was also a little concerned about the longevity of the stroker, talking to a few folks that have purchased a few of these motors. Reading the stories on this website I will be able to draw some conclusions on what to do and what not to do. What a great website! :cheers:
Also still running original oil pump running 40-45 psi down the highway.
Original head gasket, I've never overheated this motor.
I thank everyone for there help and input with my questions!
Greg.