Itinerant Air-Cooled

RSorak 71Westy wrote:The tightest clearances inside your entire engine are in the lifter. A tiny piece of dirt is probably in the old lifter and causing it not to stay pumped up.

This was almost certainly the case. You can see from previous photos how dirty it was in there. From the very little internal work I've done on this engine, I know it's very dirty in there. It will only be a matter of time until another lifter fails and/or the entire engine will need a rebuild. Hopefully it will last through this summer.

RSorak 71Westy wrote:Lifters need to be broken in to get them spinning in their bores, if a lifter doesn't spin it will fail. The higher engine speed during breakin ensures plenty of oil to them and helps them get spinning.

Hopefully I did enough high-speed running to get it spinning good. I suppose I won't know for sure until something fails which, I assume, would take at least a little while to rear it's ugly head. That said, I'm relatively confident I did the lifter break-in correctly. Thanks for the reply.

Congratulations! I knew you would succeed.

The lifter/cam lobe interface is lubed by oil splash. The goal during the break in is to have lots of oil splashing onto these surfaces, which higher engine speeds promote. I'm sure yours will be fine.

I wouldn't worry about the difference in set screw position between different rocker arms. Mine are like this too. You are correct that the key is to establish a baseline for each valve and compare against that baseline in subsequent adjustments.

I'm not sure I agree that a lifter will fail if it does not spin it its bore. Look at this photo of the lifters that came out of my engine after I first bought the Bus. It's clear from the wear pattern that they were not rotating for a good portion of the 20,000+ miles they were in there. Yet they countinued to function perfectly. That rotation is a function of the contour of the lifter face and cam lobe. In my case, the aftermarket cam was apparently not correct because new lifters with this same cam did not rotate either. Replacing the camshaft and the lifters cured it.

vwlover77 wrote:Congratulations! I knew you would succeed. ... I'm sure yours will be fine.

Thanks again Don! I certainly would have had a much more difficult and time consuming experience without your help! Maybe someday I'll get the pleasure of meeting you so I can thank you in person!

Glad to be of help! I would love to meet the whole lot of IAC "westerners" someday! I'm continuing to keep the Maupin dream alive, but it won't happen this year.