Since I have the engine out, I decided to upgrade my timing chain and gears to a Cloyes Hex-Adjust. They include a fuel pump eccentric and washer that when installed moves the cam bolt forward. With the chain installed properly and with the cam button installed I can't put the timing cover on as the button sticks out too far. If I remove the cam button, I have .035 clearance between the cam bolt and timing cover (can't really see it in the picture). Is this too much gap and do I need to use the cam button? Pictures attached.

Thanks

 

How thick is the washer?
It'd be good to get around .010-.015 clearance.

 

Are you using roller lifters or flat lifters?

The cam has to be limited in its forward movement with roller lifters, but with normal lifters, the front clearance isn't important, as the cam is pulled backward by the oil pump gear, and does not bear on any surfaces in the forward direction.

- Eric

 

Also when you measure, put the gasket in place, as it will add to the distance. I know some vendors, sell a thicker gasket for the cover to help with this problem.

 

It is a flat tappet cam, so then I should be okay with the .035 clearance. is the cam button really necessary? If so I can grind down the end of the cam bolt and put the button on, or I can add an additional washer to the cam bolt to close up the gap to more like .015.

 

The cam button is not necessary - it's just an added complexity that some people like to put on their engines so they can think they've "improved" them.

Stock Olds engines never had problems with their camshafts walking or with them running against the timing cover.

Of course, it's another story for those running roller lifters.

- Eric

 

Make sure you compensate for your gasket thickness.

 

Hey rkk, How did you make out with this? I'm kinda in the same situation but I'm using a roller cam and lifters.

Thanks..

 

I got some varied thickness shim washers from a starter rebuilder to dial in clearance. When trying to gain clearance you could try a double thin paper gasket or a thick one, or, remove a washer & dial in w/ a thinner one. I used a Mondello style bumper once & ended up turning one surface on a lathe to dial in clearance

Best way to dial in is to bolt timing cover (w/ eccentric, timing chain, dist, et al) on w/ selected gasket & measure end play like you do a crank. Dial indicator on rear end of cam prior to cam plug being installed. I did this on the last 2 engines I built w/ OPP bumper & it worked nicely.