Clearance issue between cam bolt and timing cover
 

I bought a cam bolt and washer from Precision Automotive a few months ago. Last month I installed it, confirmed that I had 0.006" of end play on the cam (it's a torrington bearing setup from BOP Engineering), and then shortly after that I installed the timing cover using a paper gasket and ultra blue RTV (because that's all I had on hand). Today I decided to re-seal it because the blue RTV bugged me and I finally had some black on hand. When I removed the timing cover, I noticed some aluminum shavings on the cam timing gear. So I checked the inside of the timing cover and found this:

https://i.ibb.co/tqy1rzT/20221121-132527.jpg

I'm not sure what the issue is. It could be the cam bolt head being too tall, or the washer being too thick, or the timing cover being too shallow (I really doubt this last one). This is what the bolt and washer look like, fully torqued with the eccentric sitting flush on the timing gear and the tang engaged in its slot:

https://i.ibb.co/7RZwq6K/20221121-132615-HDR.jpg

https://i.ibb.co/Fw2QrGL/20221121-132621-HDR.jpg

Anybody know what might be wrong here? I'm really glad I found this before trying to run the engine. There was no indication of any issue when I tried turning the engine over by hand.

The stock cam bolt and washer sit below the fuel pump eccentric, so it looks like the bolt/washer combo you are using is too tall and rubbing against the timing cover.

I have a Simms torrington setup on my engine too, but it didn't come with that bolt/washer setup.

My timing set didn't come with a cam bolt or washer at all, those were purchased from a different source. I just checked the bolt/washer that I got from Butler, and the head of the bolt is MUCH shorter. Doesn't stick out past the eccentric at all. However the bolt is overall much shorter as well with maybe half as many threads going into the cam. The washer for both is the same thickness.

I'm thinking the head of the bolt provided by Precision Auto is just way too tall. I'll use the Butler bolt instead and hope there's enough threads. Luckily that bolt only gets tightened to 45 ft-lb anyways

The stock washer is flat if using the fuel pump eccentric. There is an aftermarket washer that has a recess for the cam nose when you do not use the fuel pump eccentric. To me it looks like bolt head goes in a recess?

Yes, but taking into account the recess, the washer I got from Precision Auto has the same stacking height as the flat washer from Butler. The head of either bolt fits inside the recess. The washer definitely doesn't contribute to the extra height. It's all in the bolt head

Good catch - it looks like that washer setup is for when the eccentric isn't used.

https://butlerperformance.com/i-3164...fuel-pump.html

If bolt is longer might check depth of cam hole and make sure bolt isn't bottoming?

Otherwise try grinding the bolt head down and see if you can still get a socket on it?

:confused:

You're right, the bolt is in fact intended for applications where the eccentric is eliminated. That's why the washer is so wide and has a recess. The washer itself isn't causing any issues though, and I definitely like it better than the standard one. It all seems to be working fine with the standard grade 8 bolt that I got from Butler, so all is well now.

https://i.ibb.co/sWHfFSL/20221121-152821-HDR.jpg

If you use it without the eccentric you flip it over. I have 2 motors with those because I am using an electric feul pump on them.

Oh I see, so it goes over the cam snout much like the eccentric currently does. Live and learn! :D

I am glad you had to take it apart, because there does not look to be drop 1 of oil, on the timing chain, nor in the rollers which is even worse!

Am I correct in the way I am seeing that?

If so that chain needs to be removed and soaked in oil.

It soaked in automatic transmission fluid overnight after I cleaned it in an ultrasonic parts washer, then it was coated in motor oil. It's as fully impregnated as it could possibly be. Just doesn't show up in pictures, I guess

Maybe a dumb question, but why would you *not* install the eccentric. I would think if you someday decide to go back to a mechanical pump that would make the changeover a lot easier.

That's a really good point. I doubt the eccentric causes any kind of significant imbalance, especially since the cam turns at half speed. I have no idea why anyone would eliminate the eccentric, even if they don't plan to use it, unless they just didn't have one on hand

Incidentally, it's worth mentioning that Precision Automotive never replied to my email about this. Even if the issue was caused by my own misunderstanding, a reply would've been appropriate. I was willing to understand a late reply due to my email being sent shortly before Thanksgiving, but it's been over 3 weeks now. I'm not impressed.

Some people like the "solid" attachment of the "Butler washer/cup" vs the factory set-up if they are not going to run a mechanical pump. The factory set-up can cause a light rattle noise without the fuel pump arm preload riding on the outer cup. Generally, not a deal breaker either way.

This is why I support, and purchase, buy from those who take the time to support the end user. You can always find it quicker or cheaper but there is a reason they maybe. I too would have expected at least an explanation or a you screwed up email.

Jim

This!. I have one on my latest 455 in case I run a mechanical. 400 in the 81 is stockish so a mechanical but all my others use an electric pump.