944S2 engine recommission after rebuild

[AndyKRD]

Hi all, new to the site and require help.
Bought a 944S2 to do up a year or so back, ended up taking full engine & transmission out to replace seals & replace 2 broken valve spring. Anyway after getting engine back in and restarting it, the top end isn’t getting any oil to it, sounds like a clanky old diesel. Taken cam cover off and disconnected oil pipe to the cam chain tensioner, turned engine over without spark plugs on starter but no oil coming out. BUT I do have 4 bar oil pressure on the gauge?!
I have seen that some say you need to run the engine for up to 15 mins to get oil back into the hydraulic tappets etc, just concerned that it will wreck the valve gear by the time this has happened. I don’t know, do you require higher revs to get the oil into the head? I’m using 10W40 oil but sure if this would cause oil starvation to the head.
Any help or advice appreciated, thanks.

[tr7v8]

They can take ages to get oil to the top end. Once they warm up & the oil gets a bit thinner they tend to quieten down.
One trick is to drain all the oil & refill it as that will "wet" the top end. Otherwise its persevere, maybe some earplugs!

[AndyKRD]

Cheers, I’ll do some serious priming with the cam cover off, refit and go for it again. Just paranoid that I’ve done something wrong with the oil pressure valve but hopefully not!

[scam75]

+1 for what Jim says. My top end was noisy for a few mins on first start after my rebuild. Been perfect since.

[sgl1966]

Make sure cylinder head OPRV isn’t stuck .

[sgl1966]

Actually its called pressure reducing valve by the factory . Can cause problems if stuck shut .

[pauly]

Glad to see you're still around Simon, I thought you may have left the fold after selling up.