Newbie needs help

topcatcustom · Post by **topcatcustom** » Tue Jun 02, 2009 8:08 pm

But Mr. Des says you only need a vent to atmosphere from each rocker cover! But I suppose std covers only have 1, I was just thinking it would tell you if there was excess CC pressure or not...

kjon · Post by **kjon** » Tue Jun 02, 2009 8:29 pm

The dipstick idea is an interesting one... As far as I know its is the original, but tomorrow ill measure the stick & tube & maybe you guys can let me know if the combination sounds ok..
As to the the breather system, I've got the early P6 covers, the nearside has a filter while the drivers side is connected via a Y piece to the two carbs.. i did wonder if i should have a PCV valve in there, but don't quite understand what difference it would make?.. As to how much oil its using, thats hard to say.. Its probably about pint every hundred miles or so..

Thanks again all

Jon

RoverP6B · Post by **RoverP6B** » Tue Jun 02, 2009 10:01 pm

Hello Jon,

The breather arrangement that you have,...this could be the problem.

On an engine fitted with SU carburettors, there should be a breather located on the off side rear of the engine which will vent the lifter gallery.

Air is drawn down into the engine at this point, venting the crankase, fumes then return and exit through each rocker cover and into the carburettors via flame traps.

Another question,....which rocker covers are you using? Are they the early rounded P6 type with ROVER engraved into them, or the latter square type?

If you are using the early ones,...did you also fit the splash panels onto the rocker shafts?

Ron.

RoverP6B · Post by **RoverP6B** » Tue Jun 02, 2009 11:30 pm

oh just on your oil pressure figures. I had a look in one of my P6B (Rover 3500/3500S 1968 till 1976) workshop manuals, and the quoted oil pressures are,...30 to 40 lb/sq in @ 2400 rev/min and 55lb/sq in @ 4000 rev/min.

Ron.

jefferybond · Post by **jefferybond** » Wed Jun 03, 2009 9:20 am

CastleMGBV8 wrote:Jon,

Sounds like you have at least a couple of problems.

Firstly as others have stated, white smoke (steam) = water ingress into a cylinder or cylinders, are all the plugs the same colour or do some look as if theyv'e been steam cleaned?

Yes indeed. A simple and guaranteed way of finding out if it's water or oil is to simply check the oil and water levels to see if they are dropping.

CastleMGBV8 wrote: Secondly the excess oil in the valve chest areas, I would suggest that for a pre 1994 engine that 60 PSI at 5000 RPM is more than a little high which suggest that your prssure relief valve may be stuck closed.

It does sound strange that the oil pressure keeps on rising. The oil pressure relieve valve acts a bit like a regulator, in that it limits the maximum oil pressure. The RPM that this limit is reached by is dependent on temperature.

For example, my oil pressure relief valve limits at about 3 bar (45psi). When cold, it will hit 3 bar at idle, but not go any higher no matter what the revs. When hot, it will be about 1.5 bar at idle, and hit 3 bar at 3000rpm, but still go no higher over 3000rpm.

If the pressure keeps on rising, it suggests that the valve is never opening. Either it's stuck or someone has put in a silly strong spring.

On the subject of valve stem seals - I originally had the old 'tap washer' type seals, and they were useless - I had blue smoke when hot at idle. I changed my guides and seals to the new type, and the smoke disappeared. It is possible to change the guides yourself by heating the heads in a domestic oven (when the wife is OUT!), and using a threaded bar/socket to pull them in/out. Even so, I still found that the new type seals did not locate very well on the tops of the guides, and some kept popping off. Needed some mods to the seals and some loctite to keep them on, which was a pain in the ar$e and not expected at all! Did the trick in the end though.

Jeff

kjon · Post by **kjon** » Wed Jun 03, 2009 9:51 am

Hi Ron, thanks for the oil pressure info, sounds like mine's perfect according to those figures, I looked at the ones given in Des Hammill's book which are alot lower..
As to your question re the rocker covers yes they are the early round type & yes I did fit the splash panels, however I don't have the vent on the back of the lifter gallery.. Is that necessary? I assumed that the one in/one out arrangement of the later engines would be ok..
I'm becoming more & more convinced that its the rockers that are the problem, I saw a short piece of film on here the other day showing a motor running with the covers removed (cant find it again now though..) but that looked completely different to mine, there was very little oil visible, mine however is swamped, you can see it pumping out the side of the rockers..
I was also told by a local engineer the the V8 is not known for over oiling the top-end, can anyone confirm this?..

Thanks again

Jon

kjon · Post by **kjon** » Wed Jun 03, 2009 10:08 am

Hi Jeff, I agree it doesn't seem right that the pressure should continue to climb, guess I'd better remove the valve to check its not suck, do you know if the pump will still self prime if I remove it?
As to the valve guide oil seals, I wish now I'd used the later heads but don't want to tear it all to pieces again if I can avoid it..
Ironically I can remember being told by a guy at RPi not to bother fitting the tap washer type seals as they were useless & that oil going down the guides was not a problem on these engines.......

Thanks

Jon