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spinning oil pump
Posted: Sun Sep 30, 2018 6:16 am
by Jonty
Last week I tried to start my grey motor after sitting for 20 years. I followed the guidance on this site and put some fresh oil in, plugs out, oil on the pistons etc, then took the distributor out so i could spin the oil pump with a drill and a bit of steel rod. I couldn't get any oil to come up on the valve gear at all. I'm not confident to start the motor without seeing oil up top.
So why would this be the case? I'm spinning the pump clockwise - is that right? That could be embarassing...
Or is it more likely to be blocked oil system or pick up? There is a good layer of goop on the inside of the valve cover, but the old oil flowed freely from the sump drain plug. Do I have to drop the sump to check the oil pump gears? If that's the case I might abandon trying to start it in the car, and pull the motor out and give it a good clean up on an engine stand.
Appreciate any advice.
Cheers
Re: spinning oil pump
Posted: Sun Sep 30, 2018 6:22 am
by EK283
Jonty,
After 20 years there could be all sorts of issues with blockages, I seriously would pull it out and go through it that way at least you don't damage anything else whilst trying to start it.
Regards Greg
Re: spinning oil pump
Posted: Sun Sep 30, 2018 6:38 am
by Jonty
EK283 wrote: Sun Sep 30, 2018 6:22 am
Jonty,
After 20 years there could be all sorts of issues with blockages, I seriously would pull it out and go through it that way at least you don't damage anything else whilst trying to start it.
Regards Greg
Thanks Greg - I guess youre right, but I had hoped to see a bit of life before I tore it to bits. It turns over easily and was driven into the shed when it was parked, so I guess it would run. Out it comes then...
Cheers
Re: spinning oil pump
Posted: Sat Oct 06, 2018 7:41 pm
by Craig Allardyce
The oil feed to the rockers is a groove machined into one half of the camshaft bearing journal. You may have to rotate the crank a few turns while you're priming it. I would just chuck a gauge in and check the pressure while your priming it and if all good go for a start. It does take a while for oil to reach the rockers even with the engine running.
Re: spinning oil pump
Posted: Mon Nov 05, 2018 6:43 am
by Jonty
I've done a bit more investigating into the oil pump issues. Pulled it out and cleaned out what I can. The screen was pretty caked in gunk.I tried to measure the back lash in the gears - there appears to be about .023" between the engaged teeth - is this the correct way to measure it?
- oil pump back lash.jpg (583.05 KiB) Viewed 3307 times
From what I've read this is way beyond spec - could this mean the pump wont pump?
Theres a fair bit of texture on the face of the gears too - not sure if that's normal or a sign of wear?
- oil pump gear 1.jpg (438.93 KiB) Viewed 3307 times
- oil pump gear 2.jpg (615.49 KiB) Viewed 3307 times
Re: spinning oil pump
Posted: Mon Nov 05, 2018 7:07 am
by Jonty
SunnyTim wrote: Mon Nov 05, 2018 6:49 am
I think you can buy kits for the pumps these days. Check the pressure relief valve too sometimes you can pack them up with a washer. How was the bottom of the sump was there much sludge? You have saved the motor a bullet by cleaning all the crap out of the bottom end. I think the pump will work but better to give it a birthday while it's out. Where abouts are you?
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Thanks Sunnytim - I'm in Adelaide. There was a thick layer of sludge in the sump which I scraped out with a wooden spoon. Clean now. MIght fill it with clean oil and spin the pump again before finding replacement gears.
Cheers
Re: spinning oil pump
Posted: Mon Nov 05, 2018 10:32 am
by ardiesse
If you position the engine with number 1 cylinder at firing instant and spin the oil pump, you'll get oil up to the rockers. (There's a groove in one of the camshaft journals to direct oil up to the fitting, but it's not machined all the way around.)
Worn oil pump gears are not a great problem, believe it or not. The oil pump will still operate, but the oil pressure at idle will be a little low. But lots of other things make the oil pressure at idle low, like worn main bearings.
It's a good thing that you've cleaned all the sludge and gunk out of the sump.
As you've suggested, clean the pickup screen, reassemble and re-install the oil pump as-is, temporarily replace the sump (don't waste a gasket kit), add oil, set the motor to fire on number 1 cylinder, engage the drill and spin. If you can hear the drill "load up" after a couple of seconds, that's the sure sign that you have good oil pressure.
Rob
Re: spinning oil pump
Posted: Mon Nov 05, 2018 9:20 pm
by Jonty
ardiesse wrote: Mon Nov 05, 2018 10:32 am
If you position the engine with number 1 cylinder at firing instant and spin the oil pump, you'll get oil up to the rockers. (There's a groove in one of the camshaft journals to direct oil up to the fitting, but it's not machined all the way around.)
Worn oil pump gears are not a great problem, believe it or not. The oil pump will still operate, but the oil pressure at idle will be a little low. But lots of other things make the oil pressure at idle low, like worn main bearings.
It's a good thing that you've cleaned all the sludge and gunk out of the sump.
As you've suggested, clean the pickup screen, reassemble and re-install the oil pump as-is, temporarily replace the sump (don't waste a gasket kit), add oil, set the motor to fire on number 1 cylinder, engage the drill and spin. If you can hear the drill "load up" after a couple of seconds, that's the sure sign that you have good oil pressure.
Rob
Thanks Rob - that's really helpful. I'll give it a go.
Re: spinning oil pump
Posted: Sat Nov 10, 2018 9:27 pm
by Jonty
Success! I’ve got oil pumping out everywhere! No need to replace the oil pump gears then. Only a small victory, but satisfying nonetheless. Thanks for the advice.
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Re: spinning oil pump
Posted: Sat Nov 10, 2018 9:41 pm
by ardiesse
Oil coming out of all twelve rocker arms? Number 1 cylinder exhaust rocker (the very front one) tends to be starved of oil if the rocker arm bushes are worn. The classic "bush mechanics' cure" in this case is to put a self-tapping screw in the oil fitting's relief hole.
Rob
Re: spinning oil pump
Posted: Sun Nov 11, 2018 11:02 am
by Jonty
ardiesse wrote:Oil coming out of all twelve rocker arms? Number 1 cylinder exhaust rocker (the very front one) tends to be starved of oil if the rocker arm bushes are worn. The classic "bush mechanics' cure" in this case is to put a self-tapping screw in the oil fitting's relief hole.
Rob
Hi Rob - yep all 12. I took the rocker rail off and cleaned out all the gunk with a rifle rod. Seems to be working fine.
Cheers Nathan
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Re: spinning oil pump
Posted: Mon Nov 12, 2018 7:14 pm
by EK DAZ
Hi All, I once had a tooth break off an oil pump gear which also screwed the tang off the bottom of the dizzy. The gears looked like the picture of your one.( ie , the teeth looked pitted). Perhaps compare with some new gears. - just to be on the safe side. Regards Daz.
Re: spinning oil pump
Posted: Sat Mar 26, 2022 9:19 pm
by FbSTDwagon
Great post this one, very good advice on getting oil pressure on start up of a new engine.
I will follow this advice on my start up.
Cheers Rob, much appreciated
Re: spinning oil pump
Posted: Sat Mar 26, 2022 9:57 pm
by ardiesse
Drew,
Set the engine so that no. 5 is at the firing instant, though.
Rob
Re: spinning oil pump
Posted: Sun Mar 27, 2022 4:18 pm
by FbSTDwagon
No 5 at firing ok I think I understand what you mean