Consequences of adjusting oil pressure??

[Defender Mike]

HI all,

Here's a question for the experienced series 1 owner. I just adjusted my oil pressure via the adjustment bolt left side of engine just above the sump. My pressure was sitting on 38/40 lbs at cruise when at operating temp and dropping to around 15/20 lbs at idle . Now after about 3/4 turn inwards I am getting 48/50 lbs at cruise and 25 lbs at idle. There is plenty of adjustment left and I could increase it further the book says 55 to 65 lbs. Before I go any further are there any consequences of increasing the pressure by the adjuster? will it wear my pump out quicker ?, will my engine fume etc .:)

Mike

[klonk]

Hi Mike ,
Increasing your oil pleasure back to the original specs shouldn't cause you any problems. Low oil pressure is caused by either worn oil pump, worn relief valve or worn crank bearings. In this case I would guess the relief valve spring might have lost its tension. It wouldn't cause anymore blowby as that is caused by leaking compression past the rings. The oil pump pumps the oil around the engine and to get back to the sump it has to go through the relief valve or out the crankshaft bearings. Either way it gets thrown around in the crankcase. By adjusting the relief valve you are diverting a bit more to the crank bearings instead of out the relief valve outlet. Oil pump will be fine wear wise as long as its in manufactures specs.
Remember it can be easily reversed if need be.

Steve

[mfc]

Mine went up to mid to high 50's at 3o mph in 4th after I replaced the big ends , timing chain and touched up the valves.. Drops to bout 35/40 at idle when Warm ... Backing of or tightening the relief valve made little difference . Replacing the missing metering valve in the oil line banjo bolt on the back of the head stopped excess oil flooding into the head .

[mfc]

Ps the 60 psi is for later 2l engines ( cartridge oil filter on drivers side) canister types are a fair bit lower fwiw...

[chazza]

Might be a good idea to pull the relief valve oot and clean it and the plunger housing before adjusting anymore.

Wrinklearthur posted an interesting point about oil pumps he has known on tractors, which broke when the pressure got too high!

Cheers Charlie

[mfc]

Yea Charlie , one reason I put a gauge in mine... Keep an eye on it , there is a change in psi with the change in oil filter setup from 35 psi in the 1953/4? To the paper canister ones from 55 onwards 60 psi . Setting it is the same though. I cleaned mine up when I had the pump out to check ...
Cheers mark

[Defender Mike]

After the initial rise to 50 psi at cruise its now settled back to 45 psi. However at idle its staying above 35 where before it was down to 20 or lower.
Mike

[mfc]

Sounds more like my figures ( 30 mph in 4th on a flat road.... As per book ) around 57 psi at 30 mph And 28 34 psi at idle at operating temp. ( from memory book says up to 65 at 30 mph and over 25 at idle) that's as close to 65 psi as I wanna go in an unrun in engine.
Cheers mark
Ps I'd take the pump out and have a peek next time you have the sump off.. It's fairly easy to do...peace of mind:)

[Defender Mike]

Sounds more like my figures ( 30 mph in 4th on a flat road.... As per book ) around 57 psi at 30 mph And 28 34 psi at idle at operating temp. ( from memory book says up to 65 at 30 mph and over 25 at idle) that's as close to 65 psi as I wanna go in an unrun in engine.
Cheers mark
Ps I'd take the pump out and have a peek next time you have the sump off.. It's fairly easy to do...peace of mind:)

I'm replacing the sump gasket soon so will do it then

[mfc]

You can get a replacement ball from a bearing joint btw...