Front Cam Bearing - is placement critical?

[oz]

I went to start the reassembly of my '69 302 yesterday and found that the new front cam bearing was not installed quite true. The one edge is slightly sub flush to the front of the block while the other edge sticks out slightly. I read in the rebuild manual that the bearing has to be square and .005" to .020" subflush.
My question is, how critical is this dimmension? I realize that the bearing has to be square but what is the effect of this bearing being either too close or to far from the front of the block? Will I have oil pressure issues if it is too far from the edge or timing gear oil starvation if it is too close? I have a hard time immagining that when these engines were new that a .005" to .020" subflush range was held by the factory.

Thanks

 

[SuperDave]

If it we mine, I'd be concerned too. If the bearing were improperly seated (out of square) you can't help but have problems later. The cam running in the out of square bearing would cut it sufficiently to wear the bearing and cam prematurely. If you are going to run the engine hard, this will come sooner rather than later.

 

[mustangracer]

I'd be more concerned about it not being square to the block face. It sounds like it's not, and as SD said, that'll cause early wear issues. I'd also be concerned about the rest of the bearings if the easist one to get right isn't!

As to the factory tolerances, they were actually pretty good at those kinds of things generally. Most of the time they would have a special tool designed to automatically set it at the proper position.

 

[oz]

I took the block back last night and got the front bearing straightened. The rebuild manuals says to install the front bearing from the rear of the block so that the cam bore helps keep the installation tool straight. He obviously didn't do that on the front one. The inner bearings should be no issue but I need to check the back one since he could have done the same thing to it.

When I asked about the spacing of the bearing to the front of the block (.005" - .020") he said that it wasn't critical because the timing chain is lubricated by oil splash instead of having an oil passage to it.... whatever, I am happy with the positioning of the front bearing now.

Thanks.

 

[Mach1steve]

check em all

if one is wrong, other could be.

Rule of thumb..... check twice, rebuild once.