1925 Rover 16/50 oil pressure woes

[Guest Ken G]

Well, I?m afraid the time is coming to take my oil pressure problems seriously, with professional help. I did my standard outing yesterday (San Francisco down the coast to Half Moon Bay for brunch), and the loss of oil pressure on downslopes and tight left-hand bends is getting worse. Ironically, the engine is actually going better (maintaining speed up hills better) although I haven't done anything. While I was out, I parked on the flat (nothing flat at home), hiked for two hours, and on returning to the car, looked at the oil level before starting and again after idling for a couple of minutes; as I had observed before, the level dropped seriously, from well above the mark to well below it, and was sufficiently low that I am not surprised at the pump starvation when the oil sloshes away from the pump. I dare not put much more oil in there or it will be above the splash plate (the owner's manual warns against over-filling). I have to assume that there is an oil return passage blocked, but I wasn?t able to find it last time I had the oil pan off. Although I didn?t check yesterday, I have in the past used a stethoscope and heard oil trickling back for many minutes after a run, somewhere in the neighborhood of the (wet) clutch.

A different, probably unrelated, problem is that for the first few miles, the pressure is stable at 60 psi, as set by the pressure release valve, but once the oil (10/30 multigrade) is good and hot, the oil pressure even at high speed doesn?t reach 60 psi but sits in the 30-50 range. Having had the pump to pieces, I don?t think the problem lies there, so I guess the bearings need examination (the Babbitt was redone a few thousand miles ago, in England before I received the car).

Can anyone recommend a firm in the San Francisco Bay Area capable of dismantling as necessary the engine/gearbox of a 1920s car, to check and if necessary renew bearings and to find out where the oil is being retained? The car is drivable, so I can probably get it there if it?s within 60 or 70 miles. I know of British Car Specialists in Stockton, California, but that is a bit far.

Ken G, 1925 Rover 16/50 (San Francisco)

[Guest sixpack2639]

Ken, I don't have any idea how to help you with this so I posted a link to this on a UK forum i'm a member on. I hope you don't mind. Carl

http://www.aacint.com/forum/topic.asp?TOPIC_ID=17616

[raycuk]

Hi Ken

I'll try and have a look around to see if there are any UK web sites that may be of use for you.

First thing I would say is it may be your oil. The old engines were designed to run on 20/50 oil as the build tolerances were much lower than they are on modern engines. 10/30 oil seems too thin. I had a Triumph Stag with the original V8 engine which I (mistakingly) put a 10/30 oil into. The car used all of it on a 60 mile run. I then tried a fully synthetic and it did the same. Purchased some Duckhams 20/50 and it never used oil again (Not in any quantity anyway.

I would also check to see if the sump baffle is in place or the oil pick up pipe hasn't moved.

I'm no expert on these cars as the oldest car I ever worked on was a 1937 MG TA.

Like I said. I'll have a scout round here in the UK to see if there's any forums that can help you

Take care

Ray

UK.

[raycuk]

Here's a few.

Have a look and maybe something will be of use for you

www.oldclassiccar.co.uk/forum/

http://www.vintageknowledge.co.uk/

http://www.svvs.org/makes.shtml

http://www.prewarcar.com/links_related.asp?make=Rover

Hope these are of some help for you

[Guest Ken G]

Raycuk (pronounced chook?)

Thanks for your posts, but I don't quite understand why you cite UK sites. I am in San Francisco, and am looking for a recommendable firm within driving distance that can, and is willing to, work on the engine of my Rover. Although I would indeed be interested in being in contact with others who have this model (very rare), I am confident that my problem is not intrinsic. It didn't occur for the first 200 miles or so that I drove the car before I had to replace a cracked exhaust valve.

I don't believe the pump starvation problem has much to do with oil weight, and indeed it exists with straight 30 and both 20/50 and 10/30. Anyway, to the extent that viscosity might affect the issue, one might expect thicker oil to take even longer to trickle back via an obstructed passage, that is, to make the problem worse rather than better.

The lack of suggestions for SF Bay Area companies is disappointing and surprising to me. Has no-one in the area with an antique vehicle had major engine work done?

Ken G, 1925 Rover 16/50 (San Francisco)

[Dave7]

Ken,

You just mentioned something, but this is a long shot. The problem started sfter you replaced an burnt exhaust valve. Could the problem perhaps be related to a cylinder head gasket that was put the wrong way around, or that was missing a drain hole. The oil is thus accumulating in the tappets?

Dave

[raycuk]

Hi Ken

I put the links on there so as to help you to contact some people in the UK with possibly the same vehicles where you could contact them and maybe get an answer that may be simple solution.

Sorry if it wasn't what you wanted.

I appreciate your location but sometimes with the help of the WWW the answer to a problem can be found.

Good luck with it

Rayc UK

[Guest Ken G]

Thanks, Raycuk and Dave7.

In fact, one UK site did turn up something useful because for reasons I didn't dig into, it pointed to a company restoring old British cars (particularly MGs, I think) that happens to be in San Martin, California, which is only 80 or 90 miles from me and therefore a possible drive. The other company that I know of is a similar distance in the opposite direction.

I did indeed install a new head gasket (which was cut to match an old one, and the maker missed a hole, a water passage!), but that cannot account for the problem because there are no oil passages through the head gasket. The oil comes up to the valve gear via a vertical tube enclosing the shaft that drives the overhead camshaft and magneto, and returns under gravity via a vertical tube that encloses the shaft for the steering; neither tube is within the head. (You have to see the drawing; it's really quite straightforward but difficult to describe in words).

Ken G, 1925 Rover 16/50 (San Francisco)