Priming twincam????

[nomad]

Any tricks?
Can't get oil pressure even after priming the pump. Is this normal or am I looking at an engine tear down?

Kurt

[h20hamelan]

Your sure there is the correct amount of oil in the sump
Did you pack the pump with Vaseline
Sometimes it can be more than 30 seconds of cranking, 1min?

After all this, I would pull the pump and have a lookie loo
You pulled the cap off the oil filter, and the last filter square O ring didn’t stay behind on the pump housing?

[512BB]

What have you done to the engine? Has it just been rebuilt, just had an oil change? You do not say. Not enough info given.

Leslie

[jono]

I've had this every time with a newly built TC.

A very experienced engineer friend told me to 'just start it' and the pressure will come up. I did and he was right, a few seconds after firing up came the pressure.

It's counter instinctive but it's always worked for me.

[mark030358]

ditto the above comment

[cabc26b]

I’ve only had this problem with one of the new uprated pumps - packing with grease or vasoline is what fixed it .

[elans3]

Happened the first time I ever fitted a pump to an Elan, or Escort, or Cortina, Since, I have always used the vaseline trick, plugs out, spin it over, and within 5 secs, up comes the pressure. Priming doesn't have much effect, as most of it runs out when you bolt the pump up.

[nomad]

Nice to know I'm not the only one......
Fresh rebuild with new pump and spin on filter. Spinning it over with plugs out using the starter like I've done many times before. I'll try the Vaseline trick.

Kurt

[h20hamelan]

You filled the oil filter with oil prior, filled?

[512BB]

' Priming doesn't have much effect, as most of it runs out when you bolt the pump up'

I am not sure what type of priming you write about, but this is the type of priming I carry out after an engine build, see picture. Obviously everything is buttoned up on the engine and the only place oil runs out of is the bearings. I can even hear oil being exuded from the cam bearings, so quite reasuring. That tells me that ALL the oilways are full of oil, and therefore if pressure does not come up straight away when the engine starts, I do not fret.

'Fresh rebuild with new pump and spin on filter. Spinning it over with plugs out using the starter like I've done many times before. I'll try the Vaseline trick'

Ahh, so now we know. New no name pumps are notorious for having problems. If I rebuild an engine that previously had a quality named oil pump fitted, I refit that pump with a new O ring after cleaning it out and examining the rotor. Old quality pumps by AE or Holbourn Eaton are miles better than ones available today, even after 100k miles. And lets face it, how many engines have done that sort of mileage before they are pulled apart, not many.

I fitted a new pump to an engine I built, bought from Paul Matty about 8 years ago. It massively under performed, in that the maximum psi on the gauge was 30 when hot. Thought it could not possibly be the engine Fitted up a different gauge, same result. It could only be the pump, which it was. Fitted a new old stock pump, normal pressure was resumed. 45 psi hot at 3000 rpm, 20 psi on tickover. Perfect.

So to conclude, you need to be very careful with just packing an oil pump with grease and starting the motor. There could be other things like the relief valve that could be faulty, and pressure may never come up.

Leslie

[2cams70]

Lots of old wives tales existing about this particular topic. Don't waste your time priming oilways, packing pumps with grease or vaseline, cranking the engine with plugs removed to try and get oil pressure. It's all bull****. Ford who designed and built the engine in the first place never deemed all this fanfare necessary upon first startup of their newly built engines and you won't find it mentioned in any OEM factory workshop manual.

The pump was not designed to supply oil pressure at cranking speeds. It was designed to supply oil pressure at normal engine operating speeds.

Just start the thing. If you don't get oil pressure within a couple of seconds of engine start shut it down immediately and do not start it again until you identify the cause of low oil pressure

[512BB]

'Lots of old wives tales existing about this particular topic'

Yeh, mainly put about by you. I could go on, but I wont. Haven't got the time or inclination. Do what you want to do good people. Its your engines funeral.

Leslie

[2cams70]

When you build an engine:

1) Make sure there are no air leaks between the pickup pipe and the pump. This is critical. Air leaks here reduce the ability of the pump to suck oil from the sump. I've seen a few engines destroyed by this error in assembly.
2) Oil the pump gears with engine oil not vaseline or grease when you assemble it. That's all the gears ever see in normal use and there's no need to use anything different just because it's a new build. That's what it tells you to use in the OEM workshop manual. Whilst Vaseline may be a great lubricant for certain biological parts it was not designed to be a lubricant inside an engine or for oil pump gears. You don't need to dismantle the pump to do this - just dribble some oil into the intake and rotate the pump slowly by hand to ensure the gears are well coated.
3) Fill the oil filter or oil filter canister with oil before you fit it
4) Check the PRV valve in the pump to ensure it is free before you fit it.

[512BB]

'I could go on, but I wont. Haven't got the time or inclination'

Well, I have found some time in my busy schedule and I have the inclination for 5 minutes.

'Don't waste your time priming oilways, packing pumps with grease or vaseline'

Well, I agree with the don't use vaseline bit. Why would you use vaseline, it won't break down and emusify with the oil, unlike grease. Using oil to lubricate the pump is fine if you are going to start the engine shortly after having done so, but if the engine wont be started for some time, use a bit of grease, as that will stay in place forever. Oil will just drain away in short order.

'If you don't get oil pressure within a couple of seconds of engine start shut it down immediately and do not start it again until you identify the cause of low oil pressure'

You have stated that there is NO oil pressure, not low oil pressure, and who's oil pressure comes up within a couple of seconds? Certainly not any engine I have built, or even just changed the oil and filter on, and that is with priming the oilways on the former. I have had oil pressure take fully 15 seconds to come up when just doing an o & f change. And yes, I always fill the filter. Explain that one.

'Make sure there are no air leaks between the pickup pipe and the pump. This is critical. Air leaks here reduce the ability of the pump to suck oil from the sump. I've seen a few engines destroyed by this error in assembly'

Not sure what you are on about here. The pick up pipe is an interference fit in the block, or should be. How can there be any air leaks there? Anybody not aware of that should not be assembling engines.

Lastly, you state that priming an engines oilways after an engine rebuild is a waste of time. Well let me pose this. What would an owner of a properly rebuilt engine using assembly lube prefer to happen when starting the engine for the first time if two options were available? That the engine is just wered over whilst the fuel bowls fill up and maybe some oil pressure comes up, maybe it does not. Maybe say 15 seconds. Then the plugs are put it and the engine is wered over some more until it hopefully it starts. Maybe another 15 seconds, but sometimes up to a minute, and then possibly another few seconds until oil pressure finally shows on the dial.

OR. Prior to the above, the oil ways are completely filled with oil and then the above procedure is followed, only filling the oilways first, when the engine starts, pressure comes up almost immediately.

I know what I prefer, and will continue to prime the oilways on a fresh engine prior to initial start up. How long does it take? About 15 minutes start to finish. Time well spent I feel.

Leslie

[2cams70]

'Make sure there are no air leaks between the pickup pipe and the pump. This is critical. Air leaks here reduce the ability of the pump to suck oil from the sump. I've seen a few engines destroyed by this error in assembly'

Not sure what you are on about here. The pick up pipe is an interference fit in the block, or should be. How can there be any air leaks there? Anybody not aware of that should not be assembling engines.

Yes this is critical. With the press in type pickups the press interference fit is often lost or significantly reduced over several remove and refit cycles over the life of the engine. Unless the tube is a tight fit in the block over the whole circumference you can get an air leak happening here. The pump will suck in air instead of oil and you can get air bubbles mixed in with the oil. Air being a lot lighter than oil will be sucked by the pump preferentially to the oil. It's like drinking with a straw that has a hole in the side of it at the top. I use some low strength loctite 641 retaining compound on the tube before fitting it to ensure there are no air leaks.

Similarly with the earlier screw in type pickup you need to ensure that it is torqued correctly and that any sealing washers and the sealing surfaces are in good condition