Lower oil pressure after cam change

[bhardy]

We changed the cam and all is very fine!! It's like a rocket above 3500 rpm!

The only thing is the oil pressure, before the change it was about 20 at idle and up to 40 with higher revs. Now it stays at 25ish at higher revs and drops to almost nothing when at idle..... Anyone got an idea why it changed??

[chassis 33]

Did you replace the cam bearings while you were at it? It could be that the bearing diameters are smaller on the new cam and you're looking oil pressure from there.

Regards
Iain

[andymadmak]

bhardy said:

We changed the cam and all is very fine!! It's like a rocket above 3500 rpm!

The only thing is the oil pressure, before the change it was about 20 at idle and up to 40 with higher revs. Now it stays at 25ish at higher revs and drops to almost nothing when at idle..... Anyone got an idea why it changed??

I had exactly the same thing, although mine will still go to 40 at high revs (4 - 5k ) when hot. I asked Mike (BoostedLS1) about it and he said it was fine. The RV8 needs flow, more than pressure apparently. Richard Thorpe agreed, so I've left mine. It all still works 7k miles later!

Andy

Edited by andymadmak on Friday 7th July 17:04

[adam quantrill]

As long as the oil pressure light doesn't come on hard on idle I wouldn't worry. I have put over 40k on an RV8 with thse pressures. It's all about flow.

You might want to check the oil sender connection in case it's dirty, and the water level if you had to undo any hoses, if it's running a little hotter the pressure will be lower.

- Adam

[GreenV8S]

The front cover would have been taken off of course, is there any chance the oil pressure relief spring has broken or the plunger has stuck?

[350zwelgje]

As long as the oilpump drive is ok (only achilles heel of rover V8 engine). If not it could kill the engine....
And if you want/need just a bit more oil pressure:
- Use a bit thicker oil (like move from 20W40 to 20W50), 60 is also available but not recommend as it is too thick.
- Replace oil pressure relieve valve spring with new, or even a bit uprated (normally not required, and could cause more wear on the oilpump drive...)

Myself have installed a new oil pressure relief valve (std) and using 15W50 oil as before. No other changes and oilpressure is up with like 10-15% (cold/hot and idle/reving).

Rob

[bhardy]

The oil pressure relief spring could very well be the problem. I'll take it out after BBWF and replace it with a new one, just in case.

Thanks for the advice, guys!