I have rebuilt the engine on my V12 and I have got to the stage where I can spin it over with no plugs etc just to see if there are any odd noises etc.
No adverse noises but there is no oil pressure at all.
Does the oil pump have to be primed in any way, if so how is it done?
Bob
V12 Oil pump
#2 Re: V12 Oil pump
Dear Bob,
The oil pump picks up from two places:- the main pickup in the centre of the sump and and also from the oil cooler. The main pickup can only get oil if there is sufficient oil in the sump but the oil cooler picks up oil via the excess pressure bypass.
Assuming you have put oil into the sump, at very first startup, this second pickup will be sucking air as the bypass only opens when the big spring on the front is pushed open. This happens at about 60+psi.
To prime at first startup, I'd put oil into an insecticide sprayer and pump it into the port for the oil pressure sender. This will fill all of the oil galleries and cams with oil, aswell as the oil filter assembly. You ought to be able to see the oil pressure light go out and hear the oil sqeezing out as it drips down at the ends of the cams. When you first startup, this oil will be pushed around the engine and it'll build up pressure almost instantly. The excess oil will thus be diverted into the oil cooler which will remain full thereafter.
Without priming, it'll simply take longer to fill up the oil filter cannister and the galleries with oil and thus take more time to build pressure.
kind regards
Marek
The oil pump picks up from two places:- the main pickup in the centre of the sump and and also from the oil cooler. The main pickup can only get oil if there is sufficient oil in the sump but the oil cooler picks up oil via the excess pressure bypass.
Assuming you have put oil into the sump, at very first startup, this second pickup will be sucking air as the bypass only opens when the big spring on the front is pushed open. This happens at about 60+psi.
To prime at first startup, I'd put oil into an insecticide sprayer and pump it into the port for the oil pressure sender. This will fill all of the oil galleries and cams with oil, aswell as the oil filter assembly. You ought to be able to see the oil pressure light go out and hear the oil sqeezing out as it drips down at the ends of the cams. When you first startup, this oil will be pushed around the engine and it'll build up pressure almost instantly. The excess oil will thus be diverted into the oil cooler which will remain full thereafter.
Without priming, it'll simply take longer to fill up the oil filter cannister and the galleries with oil and thus take more time to build pressure.
kind regards
Marek
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#3 Re: V12 Oil pump
Thanks Marek,
I'll try that a little later on. I have already taken off the oil pressure sending casing so it may be easier to inject the oil via this opening.
I'll let you know if I have any success.
Bob
I'll try that a little later on. I have already taken off the oil pressure sending casing so it may be easier to inject the oil via this opening.
I'll let you know if I have any success.
Bob
Bob.
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#4 Re: V12 Oil pump
Hi
You will be surprised how long it takes to prime up the oil pressure spinning the engine over with the starter motor.
I have just rebuilt mine, and it took a couple of 15sec bursts with the starter motor to get oil pressure showing. No pre priming was done.
My mechanic didn't see any problem with this, as we had put plenty of engine assembly lube on all the moving parts. We also packed the oil pump with Vaseline before assembly.
Its running nicely now with around 60PSI when hot, at 100KPH, and 20 at idle.
cheers
Mark
You will be surprised how long it takes to prime up the oil pressure spinning the engine over with the starter motor.
I have just rebuilt mine, and it took a couple of 15sec bursts with the starter motor to get oil pressure showing. No pre priming was done.
My mechanic didn't see any problem with this, as we had put plenty of engine assembly lube on all the moving parts. We also packed the oil pump with Vaseline before assembly.
Its running nicely now with around 60PSI when hot, at 100KPH, and 20 at idle.
cheers
Mark
Mark Brown
1971 S3 Etype, now sold, sadly.
1971 S3 Etype, now sold, sadly.
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