aaddpp

I was talking to the owner of a machine shop that has done some really nice work for me - not the same shop that did those pins. We were discussing the oil check valve in the heads since I asked him to replace them as one had a scratch on the seat where the ball sits. I explained what is recommended to do to secure the seat in place, but he's not a fan of "glue" / staking. After some discussion he suggested machining a small groove just above the top of the check valve to place a retaining clip - this should address any possible movement of the valve seat ever again. Right now it's a thought, and he's not even looked to see what's available in parts.

So, I wanted to toss the idea out to the 928 forum to get your thoughts on whether you think this would work, or even if it's been tried before. Any thoughts or feedback would be great.


Thanks,
Dave

928er

it sounds like a much better solution.... I'm not a fan of glue and stake either....

aaddpp

Yup, I'm in the same boat. It might be overkill, but I like the idea of something that blocks the seat rather than holding it in place with resistance.

Concerns are how the retaining ring will sit when the heads / block reach their running temperature - I'm worried the spring will catch on the retaining ring and either become stuck, damaged, or break. I no longer have the heads at home (they're at the shop), so I can't measure or play around with them to get a sense of how it would operate. Does anyone have a high resolution photo of the oil check valve with the oil channels visible?

Thanks,
Dave

Mrmerlin

it would be possible to cut a groove into the area above the seat then a round body snap ring get fitted then the ball then the spring I dont see how that spring will touch the snap ring as the ball will be between the seat and spring,
The snap ring will sit just above the edge of the seat so its a low profile fitment.
It would still be a good idea to use green locktite when fitting the seat.
The WSM has pictures and describes how to fit the seat

aaddpp

Completely missed your post until now - sorry. So it seems like there is sufficient space between the oil holes and the top of the valve seat to machine a slot for a retaining clip. I'm warming to the idea of the clip since a seat came out more easily than I have expected. As for the clip style, I had a round clip with square edges in mind since I think there is a small gap between the top of the seat and the wall of the "chamber" in which it sits - a square edge clip could pass over the gap. On the other hand, if I use a square edge ring, I'd be worried the ring could hang over the top edge of the seat - seat is probably only a mil or so think. If this happened, I could see a scenario where the spring might catch on the edge of the clip since I think the spring probably does a zig zag when its pushed up by the ball / oil flow (its fairly light weight metal, and not very ridged). A circular retaining ring like you suggest would make this simpler - perhaps it will work. I agree about the green loctite and plan to use it along with the clip if I have the shop install one.