The V8 Owners Forum -

stevieturbo wrote: ↑Mon Jul 12, 2021 1:33 pm Also

https://www.gomog.com/allmorgan/plus8oil.htm

And a simple cheap priming tool to spin the pump, basically same as I did 25 years ago. Bit of threaded rod and a M10 extension nut with a slot cut out to drive the pump in lieu of the dizzy.
Or you can buy tools cheaply if needed.
Just means you can run up the oil system without having to turn the engine over so you know you can be safe prior to starting.

Must admit I’d not be too keen to use that tool, the slot is not very deep and nothing but skill to keep it central, would hate for that to slip off and damage either the pump shaft or the bore. My tool, although cost a couple of quid engages fully on the pump shaft and has a bush around the outside to keep it central.
You pays your money, you takes your choice.

GDCobra wrote: ↑Mon Jul 12, 2021 5:00 pm

DaveEFI wrote: ↑Mon Jul 12, 2021 12:55 pm I've done quite a few packed with Vaseline, and not had a problem. Never tried priming a dry one with a drill, though. I can't see that working, as it needs a reasonable seal to start sucking.

I’ve tried priming with a drill and never had any joy, that’s with a proper tool which engages fully on the oil pump shaft, ran for ages with drill on fast speed. Nothing!
Packed with Vaseline up to pressure in seconds. If you already have the pump apart packing with Vaseline is a no brainier (unless you’re a bi5 embarrassed about purchasing).

Thing is, if it is bone dry, it has to pump air to lift the oil - which needs a seal of sorts between the gears. If it primes with a drill, it would by starting the engine too - but not recommended if you're not sure. Of course nothing lost in trying a drill - except perhaps the ignition timing. But packing it with petroleum jelly the guaranteed way.

Been looking again at the oil pump relief valve.

Looking at it in close up, there is scoring and pitting in the bore.

The piston doesn't want to drop back in there either.
If I set my bore gauge at the bottom of the bore, it goes tight where the pressure relief port is, right where the scoring and pitting is.

I think I am going to clean the bore up so the piston slides in there nice and then put it back on and see if I get any pressure with a drill down the dizzy hole.

Then I'll try turning over the motor with the plugs out on the starter and see if there's any pressure.

DaveEFI wrote: ↑Mon Jul 12, 2021 5:33 pm

GDCobra wrote: ↑Mon Jul 12, 2021 5:00 pm

DaveEFI wrote: ↑Mon Jul 12, 2021 12:55 pm I've done quite a few packed with Vaseline, and not had a problem. Never tried priming a dry one with a drill, though. I can't see that working, as it needs a reasonable seal to start sucking.

I’ve tried priming with a drill and never had any joy, that’s with a proper tool which engages fully on the oil pump shaft, ran for ages with drill on fast speed. Nothing!
Packed with Vaseline up to pressure in seconds. If you already have the pump apart packing with Vaseline is a no brainier (unless you’re a bi5 embarrassed about purchasing).

Thing is, if it is bone dry, it has to pump air to lift the oil - which needs a seal of sorts between the gears. If it primes with a drill, it would by starting the engine too - but not recommended if you're not sure. Of course nothing lost in trying a drill - except perhaps the ignition timing. But packing it with petroleum jelly the guaranteed way.

Nobody in their right mind would try and prime a bone dry pump. That's why you put vaseline in it.

stevieturbo wrote: ↑Mon Jul 12, 2021 8:54 pm

DaveEFI wrote: ↑Mon Jul 12, 2021 5:33 pm

GDCobra wrote: ↑Mon Jul 12, 2021 5:00 pm

I’ve tried priming with a drill and never had any joy, that’s with a proper tool which engages fully on the oil pump shaft, ran for ages with drill on fast speed. Nothing!
Packed with Vaseline up to pressure in seconds. If you already have the pump apart packing with Vaseline is a no brainier (unless you’re a bi5 embarrassed about purchasing).

Thing is, if it is bone dry, it has to pump air to lift the oil - which needs a seal of sorts between the gears. If it primes with a drill, it would by starting the engine too - but not recommended if you're not sure. Of course nothing lost in trying a drill - except perhaps the ignition timing. But packing it with petroleum jelly the guaranteed way.

Nobody in their right mind would try and prime a bone dry pump. That's why you put vaseline in it.

And if you put vaseline in it, no need to use a drill.

DaveEFI wrote: ↑Tue Jul 13, 2021 8:35 am

stevieturbo wrote: ↑Mon Jul 12, 2021 8:54 pm

DaveEFI wrote: ↑Mon Jul 12, 2021 5:33 pm

Thing is, if it is bone dry, it has to pump air to lift the oil - which needs a seal of sorts between the gears. If it primes with a drill, it would by starting the engine too - but not recommended if you're not sure. Of course nothing lost in trying a drill - except perhaps the ignition timing. But packing it with petroleum jelly the guaranteed way.

Nobody in their right mind would try and prime a bone dry pump. That's why you put vaseline in it.

And if you put vaseline in it, no need to use a drill.

Drill is cheap and easy insurance. Silly not to. RV8's have always been troublesome for priming, that's why such tools have existed for decades.

rich112 wrote: ↑Mon Jul 12, 2021 7:25 pm Been looking again at the oil pump relief valve.

Looking at it in close up, there is scoring and pitting in the bore.

The piston doesn't want to drop back in there either.

WIN_20210712_19_14_46_Pro.jpgWIN_20210712_19_14_23_Pro.jpg

If I set my bore gauge at the bottom of the bore, it goes tight where the pressure relief port is, right where the scoring and pitting is.

I think I am going to clean the bore up so the piston slides in there nice and then put it back on and see if I get any pressure with a drill down the dizzy hole.

Then I'll try turning over the motor with the plugs out on the starter and see if there's any pressure.

What about the surface of the inside of the pump? -
The pump will need a nice surface finish with minimal clearance from case to tip in order to pump effectively.
It may result in low oil pressure? These pumps where never 'high' pressure even when working well. Might be able to band aid it with some thick oil?
Also as you have the sump of I think I would have a look at some of the main bearing shells to see what they look like?

stevieturbo wrote: ↑Tue Jul 13, 2021 9:13 am

DaveEFI wrote: ↑Tue Jul 13, 2021 8:35 am

stevieturbo wrote: ↑Mon Jul 12, 2021 8:54 pm


Nobody in their right mind would try and prime a bone dry pump. That's why you put vaseline in it.

And if you put vaseline in it, no need to use a drill.

Drill is cheap and easy insurance. Silly not to. RV8's have always been troublesome for priming, that's why such tools have existed for decades.

Got to agree with that. Although I've never had a problem getting pressure with a Vaseline filled pump it makes sense to run the pump with a drill first as you can bet that the first time this doesn't work is when you decide to run the engine first!
Bearing in mind I already have the tool and it's only a case of popping the distributor off for a few minutes it would be silly not to. Mind you it's even easier now the distributor isn't used for the ignition as I don't even have to worry about timing.

SuperV8 wrote: ↑Tue Jul 13, 2021 9:56 am

rich112 wrote: ↑Mon Jul 12, 2021 7:25 pm Been looking again at the oil pump relief valve.

Looking at it in close up, there is scoring and pitting in the bore.

The piston doesn't want to drop back in there either.

WIN_20210712_19_14_46_Pro.jpgWIN_20210712_19_14_23_Pro.jpg

If I set my bore gauge at the bottom of the bore, it goes tight where the pressure relief port is, right where the scoring and pitting is.

I think I am going to clean the bore up so the piston slides in there nice and then put it back on and see if I get any pressure with a drill down the dizzy hole.

Then I'll try turning over the motor with the plugs out on the starter and see if there's any pressure.

What about the surface of the inside of the pump? -
The pump will need a nice surface finish with minimal clearance from case to tip in order to pump effectively.
It may result in low oil pressure? These pumps where never 'high' pressure even when working well. Might be able to band aid it with some thick oil?
Also as you have the sump of I think I would have a look at some of the main bearing shells to see what they look like?

Yes the inside of the pump surface is rough as fruck...

I can tidy it up a little but if the clearance is over 6 thou (0.15mm) then the timing cover is toast I guess.

I might check the big ends and caps. I really want to free up the relief valve and see if I get any pressure with a drill on the pump though... TBH getting the sump off is easy on this car. There's loads of room and clearance.


I am wondering what's first to suffer with low oil pressure though? Camshaft and followers, rockers, conrod bearings or mains?

Whats the best way to take, say one main cap off and more importantly put it back on? This engine has cross bolted mains.

Undo the caps and cross bolts all together, bit at a time?

After inspecting, do the opposite, wind all the bolts back in to the full torqure, bit at a time?

SuperV8 wrote: ↑Tue Jul 13, 2021 9:56 am

rich112 wrote: ↑Mon Jul 12, 2021 7:25 pm Been looking again at the oil pump relief valve.

Looking at it in close up, there is scoring and pitting in the bore.

The piston doesn't want to drop back in there either.

WIN_20210712_19_14_46_Pro.jpgWIN_20210712_19_14_23_Pro.jpg

If I set my bore gauge at the bottom of the bore, it goes tight where the pressure relief port is, right where the scoring and pitting is.

I think I am going to clean the bore up so the piston slides in there nice and then put it back on and see if I get any pressure with a drill down the dizzy hole.

Then I'll try turning over the motor with the plugs out on the starter and see if there's any pressure.

What about the surface of the inside of the pump? -
The pump will need a nice surface finish with minimal clearance from case to tip in order to pump effectively.
It may result in low oil pressure? These pumps where never 'high' pressure even when working well. Might be able to band aid it with some thick oil?
Also as you have the sump of I think I would have a look at some of the main bearing shells to see what they look like?

Poor finish on the inside of the pump is less than ideal and may lose some pressure but unlikely to drop pressure completely or suddenly. What would worry me more is that this most likely indicates that the engine has had poor quality and/or contaminated oil in it at least at some point in its life,

I seem to recall fitting a different pressure relief valve to my pump which was spherical in shape (a tadpole rather than a slug) which is less likely to bind up in the hole. Also fitted a higher pressure spring, not really necessary but does give peace of mind.

Personally I think I'd get that valve running properly in the bore put it back together (packed with Vaseline) and spin the pump over with a drill before I'd start tearing the engine apart. This is one of the "usual suspects" which would give exactly the symptoms described, sudden and complete loss or pressure so would make sense to check first.

Fix the relief valve and go from there

I would not be wasting time/effort removing the sump and bearing caps.

And as already said, cut open the oil filter and inspect it. If there is no large signs of trauma, lots of metal etc.....then chances are things are fine.

Work smart, not hard.

Pretty well all the RV8s I've stripped have scoring in the pump housing and end. How much it affects the performance, I've no idea. But doesn't stop them delivering at least some pressure.

As regards the priming thing, I take the plugs out and spin it on the starter till I see oil pressure (after filling with Vaseline, obviously). I reckon that less work that having to set the ignition timing again. And that makes sure oil is on all the bearing surfaces, before starting. I'm not convinced the drill method will do much more than fill the oil passages. Oh - I do have a drill adaptor, so I have the choice.

DaveEFI wrote: ↑Tue Jul 13, 2021 11:59 am Pretty well all the RV8s I've stripped have scoring in the pump housing and end. How much it affects the performance, I've no idea. But doesn't stop them delivering at least some pressure.

As regards the priming thing, I take the plugs out and spin it on the starter till I see oil pressure (after filling with Vaseline, obviously). I reckon that less work that having to set the ignition timing again. And that makes sure oil is on all the bearing surfaces, before starting. I'm not convinced the drill method will do much more than fill the oil passages. Oh - I do have a drill adaptor, so I have the choice.

As I said earlier you pays your money, you makes your chice, main reason I start with the drill method is "just in case" there's always the possibility of a failure to prime, just because it's never happened doesn't mean it never will.
Personally I think it's easier to drop the dizzy out and replace it than taking all the plugs out (particularly on my car) even when I had to do timing, cam isn't going to move so mark up dizzy and put back in same place, close enogh to start.

Running pressure up with the drill wil get the oil up to pressure and circulating, It's got to go somewhere once galleries are filled. OK there's an argument to say its not the same as having the moving parts, er, moving but I think a good starting point. After that I'd rather run the engine under its own power than on the starter, prefer to have the engine running at 8-1200 RPM than around 200 on the starter as that will give better pressure and (probably more importantly) flow.

DaveEFI wrote: ↑Tue Jul 13, 2021 11:59 am Pretty well all the RV8s I've stripped have scoring in the pump housing and end. How much it affects the performance, I've no idea. But doesn't stop them delivering at least some pressure.

As regards the priming thing, I take the plugs out and spin it on the starter till I see oil pressure (after filling with Vaseline, obviously). I reckon that less work that having to set the ignition timing again. And that makes sure oil is on all the bearing surfaces, before starting. I'm not convinced the drill method will do much more than fill the oil passages. Oh - I do have a drill adaptor, so I have the choice.

And clearly you're not understanding that spinning over a dry engine when waiting to prime can potentially cause harm, especially when you've already had pump issues.

Priming with a drill takes barely a few minutes, he's already said dizzy timing is irrelevant even though that only takes a few seconds as it would be going back in the same position it was removed, and priming with the drill adds safety. Win win.

As said...work smart.

Just checked clearance on the oil pump and despite looking rough I couldn't get a 4 thou feeler in there. 3 went in just. So not as bad as I had feared. Its 2 thou new I think.

Going to make a drill drive so I can spin it up, after packing with vaseline of course and see if I get any pressure.