Oil pump clearance

[fastharry]

Hi all, im new to the forum, Im building a 1957 A7 . I have a problem with the oil pump casing not clearing the drive gear on the crank, The supplier of the pump seem to think that the crank is to far to the right which would move the gear nearer the pump, In my mind the only way that could happen is if the shoulder/thrust face on the new main bearing bush is to thin. It has been shimmed to .002" for end float, I will enclose some pics, What would help is if anyone has a motor on the bench, could they measure the depth from the gasket face of the oil pump to the end of the crank where the gear pushes up against, It may tell me if the crank is to far over without having to strip the whole engine down, the supplier seemed to think that the drive gear was sticking out to much compared to the middle timing gear. The second pic is withe nut screwed tight.

[Peter in Aus]

Hi & welcome
I had this problem just ground a bit off the pump housing.
If the timing gear is not to hard to get off take it off and make sure it is going right home could be some thing behind it not allowing it to go right home.
Peter

[mugwump]

Check that the woodruff key isn't jumping back out of the slot which could prevent the timing pinion going fully home.

[RichardL]

Hi & welcome
I had this problem just ground a bit off the pump housing.
If the timing gear is not to hard to get off take it off and make sure it is going right home could be some thing behind it not allowing it to go right home.
Peter

Harry,

Welcome to the forum. Mind sharing a bit about how you came to be interested in A7/10s and maybe whereabouts you're located? From what I see, it does seem the two choices are gear not seated or crank too far to the right. I suppose a third option might be an incorrect gear, but I wouldn't know of one that is close but not quite the same thickness.

Peter, looking at Harry's pictures, was your interference as much as Harry's? That seems too much to grind out of the pump.

Richarx L.

[muskrat]

G'day Harry,  .
I'll put money (haven't got much) on the pinion not seated fully on the crank. They are a tight fit.
Cheers

[Peter in Aus]

Peter, looking at Harry's pictures, was your interference as much as Harry's? That seems too much to grind out of the pump.

Richarx L.
[/quote]
Richard, can't just remember how much but it was not much. I had a A10 timing gear instead of one for the A7 long stroke engine that I have, so just put it down to being not the same.
Since then I have seen a few timing gears and they seem all the same except the timing mark is one tooth different. that was no problem to me just moved it one tooth when timing! pity help the next bloke that gets it he is going to hate me
Peter

[muskrat]

G'day Harry, I'm back.
I thought I'd give the old girls pump a service.
With a straight edge across the crankcase face there is 10 thou" clearance to the teeth of the pinion, so with a 10 thou" gasket there should be 20 thou" clearance to the pump. If the pinion sticks out proud it should only foul on the boss for the through pump screw (the top one I think (oldtimers setting in)).
Cheers

[RichardL]

I thought I'd give the old girls pump a service.

I believe that's a different forum, sir. 

[mugwump]

Perhaps an obvious thought, but have you tried tapping the pinion on any further by using a socket or similar and not relying on spannering it into position.

[fastharry]

Thanks guys for the input. This is the gear that came with the engine when stripped, it is a good sliding fit with just a mild tap. The key is a good tight fit and has not moved, the only thing different is the bronze main bearing and the oil pump. I am located in Leicester Uk and have built several A65 and Triumph twin engines,  I am building this engine for a friend but it's my first A7/10 so im asking him to be patient with me, i have had one Alpha bronze bearing with a thrust face a 1/16" to thin in the past so i am thinking in that direction, I have been waiting for this pump for months so the engine is all together apart from the timing side, I was hoping someone might give me a measurement similar to the type in the picture.   I got 0.525"

[muskrat]

G'day Harry.
I'll pull the pinion off  tonight and measure.
On both my A's the crank pinion is very tight on the shaft.
Cheers

[fastharry]

Just had an email from SRM they took a measurement from the face of the drive gear to the crankcase gasket face and got .015" mine is 006" so i don't think 009" is the cause of the problem.

[duTch]

 G'day Harry, I can't give any measurements, but Looking a your first photo, it seems the cutaway is more or less even on both sides, ie; needs more cutaway on engine side (?)
  What is the source of the pump?

   I remembered I replaced my pump a while ago, so dug the old probably '52 vintage pump out for a look. Until I saw it, I'd forgotten
 that I must've had a similar issue to you, as I then remembered carving some material away to make some clearance to the crank pinion(see Pic), on the pump that came with the engine, but replaced the crank and pinion and used that setup to do a couple of thousand miles before stripping it down for a refurb.
     Can't recall any other relevant detail, and even when I replaced the pump, still forgot the 'artwork', but the new cast iron 'high-flow' one hasn't cause me any grief- have done a fewK miles since- maybe I better check
 


 

[fastharry]

Hi duTch, the pump is from Draganfly, It has a new centre body with a used nose that holds the drive gear, I get a bit ***** off when you pay lot of money for something that do's not fit, i guess i should be used to it by now with these classic after market parts,

[duTch]

 Yep, I concur there.... I also meant to ask how it compared with the old pump, hoping it's still around, does it fit ok ?