3B Coupe conversion update...

[archiboy24]

The most frustrating part about this oil problem is, I can't seem to find a single person who's experienced this! I've even talked to a few mechanics and they're stumped. I'm having to dismantle the engine piece by piece (Doug, I know what you're going through!) again to try to find the needle in the haystack!

[Greg_S]

The things that seem obvious to me to check, that you have probably tried are.

That you have fitted the shield in the sump to stop the crank frothing all the oil and that the oil pump is working correctly, inc the pressure relief in it.

Greg

[archiboy24]

Yes, I have checked all of those items. Although, I'm beginning to suspect that the pump may be the culpret. I can't see why though; it was working properly before. The only thing I can think of was that the oil pump was media-blasted to clean it up. Perhaps some particles got inside. But one would think that this wouldn't cause immediate symptoms, but rather it would gradually wear.

[Stick Insect]

Hi Archiboy,

oil pumps work on very close tolerances, I would not think that media blasting it would help.

What media was used and pressure?
Glass beads,?
silicone oxide?
walnut shells?

If the pump is worn this can lead to poor pick up irregular pressur and not least cavitation. Think about a ships propeller when it starts off, there is a lot of churning and the prop develops 'air' bubbles which are really vaccum bubbles, a worn pump will not help.

David

[archiboy24]

The key to what you are saying is "worn". As I said previously, the engine has not been run long enough since the rebuild (about 5 minutes in total) for that kind of wear to happen so quickly, in my opinion. One would think that if indeed foreign matter got into the gears of the pump (and I'm talking residue from glass beads, not nuts and bolts), symptoms would not be evident for at least some time, after significant wear occured. Having said that, I agree that anything that gets into the pump is not good. But the more I think about it, the more I'm sure my problem lies elsewhere...

[Stick Insect]

Originally posted by archiboy24
Yes, The only thing I can think of was that the oil pump was media-blasted to clean it up.

This quote made me think the pump was used and then blasted, I must have misunderstood.

I flow oil pumps when I build an engine (always a new pump). to increase flow.

David