PV Cars: oil stays in valve cover to long ?

[cuppy65]

I hope someone here can shed some light on this problem before I tear it down .I have a 1965 B 18 motor I'm putting in my pv444. It's a motor I got from a junked 65 pv and it looked so clean under the valve cover and had good compression so I wired it up and rebuilt the carbs and it started right up and sounded great . However the oil pressure went to 60 lbs and never decreased ,although I couldn't let it run long because I didn't have the radiator hooked up. Anyway , I noticed when I changed the oil that the new oil stayed in the valve cover a long time and didn't drain down very fast . I don't think this is right and I'm thinking perhaps the high oil pressure and the slow draining threw the head are related problems. I didn't change the head gasket , could it be the wrong head gasket or the right one on wrong , blocking the oil ports ? Or can the oil gallery or port become blocked some other way ,and if so , can they be cleared with out removing the head?
Thanks all.

[Derek UK]

You're probably being over cautious. New cold oil (20/50?) will take a while to drain down as the only exits are the small holes where the push rods are. 60psi is a very good initial pressure and that will reduce as the engine warms up. If it settles at about 45psi that is good too. To me it sounds as if you have lucked out and got a good replacement engine.

[Othen]

I'd tend to agree with Derek UK: it is a simple OHV engine, by the time the oil gets up to the rocker box it is under almost no pressure and gravity just drains it back down via the pushrod tubes. 60psi sounds very healthy.

:-)

Alan

[142 Guy]

60 psi at idle may or may not be high. Since you were not able to bring the engine up to temperature, that combined with an oil with a high lower number (i.e. 20W50 or straight 30W) could easily generate 60 psi on start up with a cold engine. 60 psi at idle on a hot engine would probably have me wondering.

The issue with oil collecting under the rocker cover may or may not be a problem. How did you determine that oil was collecting? As part of an oil change did you pour fresh heavy weight oil into the rocker cover on a cold day and noted that draining from the rocker area was slow? At around 0C 20W50 oil has a consistency approaching marmite and drain down to the crankcase would be painfully slow.

As noted by Derek UK, the primary oil return path is around the push rods. If you still think you have an oil return problem it takes about 10 minutes to remove the rocker stand and the pushrods and then you will be able to look down the holes to see whether there is anything obstructing the return of oil such as a poorly formed gasket.

As I recall the diameter of the pushrods on the B18 and B20 are 5/16". There are some aftermarket 'performance' pushrods that are 3/8". When installing the 3/8" pushrods you are supposed to relieve the pushrod openings. I don't know whether you can actually fit 3/8" push rods without doing the relieving. Its easy to check the diameter of the pushrods - 60 seconds with a vernier caliper. If they are the oversize ones check for correct relieving in the openings.

[cuppy65]

Thanks for the reply's , It was fairly cold here yesterday , Pennsylvania. I just thought it strange that I poured oil in and for 5 to 10 minutes it sat inside the valve cover . I need to hook it all up and , before the front goes on , hook up the radiator and get it warm. .

[Volvo_133]

As above. With a secondhand engine it will be a good idea to run the engine with the rocker cover removed, prove oil appears from all 8 rocker oilways and check how quickly the small volume of oil returns around the pushrods.

[Bob Meadows]

This may not apply to a Volvo engine as I don't know your model etc:~

A similar problem has been experienced on a post war Riley engine.
These have oil grooves on the underside of the head ie facing the gasket that the push rods pass through, designed to aid the oil draining back into the engine block.

If the head has been heavily skimmed without having the grooves made deeper
then a high build up of oil can occur in the cam covers.
Hope it helps.
Bob.

[142 Guy]

Originally Posted by Volvo_133

As above. With a secondhand engine it will be a good idea to run the engine with the rocker cover removed, prove oil appears from all 8 rocker oilways and check how quickly the small volume of oil returns around the pushrods.

Did that - once. When I was much younger I was advise that the best way to check valve lash was on a running engine. Bad plan. On a B20, with the rocker cover off on a running engine it takes less than 2 minutes for everything in the proximity of the engine to be splattered with oil.

That is a good plan if you restrict 'run' to cranking the engine with the ignition disabled. A short burst of cranking will allow you to confirm that you have oil flow to the rocker stand without creating a huge mess.

[blueosprey90]

I was at the race track last summer where a fellow was running a newly rebuilt 1275 cc MG Midget engine. The gist of the problem was that oil didn't want to return to the sump, but rather seemed to be pressurized within the valve cover, then forced out through the top valve cover hose to the catch can. One lap at speed and the catch can was full and oil sprayed all over, probably out of the vented oil fill cap.

There were a variety of theories:

one that might apply to your issue was excessive crankcase pressure caused by piston rings that are worn, leaking and tired, or have not seated properly. Gasses blow by past the rings into the crankcase. Venting from the rocker cover has these blow by gases going up the push rod holes keeping overhead oil from draining down via gravity.

another was oversize push rod diameter, preventing oil from returning to the sump.

another was obstructed/diverted oil flow caused by improperly installed oil gallery plugs, improperly aligned camshaft bearings, improperly installed gaskets and the like.

Hopefully, your puddling is just an artifact of the cold engine.