Complete bottom end re build

[Kevin Bacon 5]

Yeah, that's the idea mate. Oil Man is the man for that....

 

I'm wondering if the non-return valve in the block (near cyl 1) is blocked? Apparently VRs don't like going over 4000rpm if this is the case, but unfortunately it's a head off job to check it.....and loud tappets (i.e. CLACK CLACK CLACK, not a constant ticking) would indicate they are not full of oil.....a common sign this valve is knackered if everything else is good.

 

But as Stealth have had it, they would (or should) know to check that when the head is off.

[dr_mat 0]

Surely that would result in excessively HIGH oil pressure?

 

** edit - but I suppose it depends where you measure it!!

[Kevin Bacon 5]

Yes precisely mat, *below* the head level...i.e.. valve blocked, or partially blocked, tappets don't get oiled, tensioner doesn't tension and cams start welding themselves to followers.... but to do that it needs to be totally blocked but it would explain a load of oil been thrown at the bores....the excess pressure has to go somewhere.....out of one of the crank seaks aswell usually....

 

Oil pressure readings are usually taken from the Oil pressure sender with T off.... which is below the head.

 

But I'm not saying that's what it definitely is..... just offering a little more info on the matter.

 

They very rarely ever go like that....but as with everything, it's not unknown!

[dr_mat 0]

See, I had assumed that the non return valve would be on the return-to-sump side of the head, not the supply-from-pump side.

[Kevin Bacon 5]

That is how it's configured, but if the ball bearing in the valve jams.... as I say, it's very rare, but not unheard of. Oil returns back to the sump via oilways in the head & block anyway, so I think the NRV just makes sure there is an uninterupted flow to the head, i.e. inbetween starts....