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No oil pressure ?? Help
https://www.ausmini.com/forums/viewtopic.php?f=2&t=89204
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Author:  69cooper [ Sun Apr 19, 2015 4:06 pm ]
Post subject:  No oil pressure ?? Help

Hi guys , I am trying to get oil pressure on a motor that has been recently rebuilt by someone else, I have used all the right tricks to prime the pump and have spent several minutes turning the motor over, with the feed pipe union disconnect, still nothing

I have also tried pressurizing with low pressure air , and all I get is air coming out of the oil feed hole.

I have tested same method on a spare motor and it works fine by forcing oil up the suction pipe and through the oil pump.

I am thinking that either the gbox - motor flange o ring is missing or the suction pipe has not connect properly to allow air to flow directly through oil pump ??

The motor is A+ I am not sure of it's background, would it make any difference if it was and auto block ??

Any help would be appreciated,

Mal

Author:  Mick [ Sun Apr 19, 2015 4:37 pm ]
Post subject:  Re: No oil pressure ?? Help

Have you tried feeding oil backwards to prime the oil pump from the outlet to the filter pipe?

Author:  drmini in aust [ Sun Apr 19, 2015 7:03 pm ]
Post subject:  Re: No oil pressure ?? Help

I went through this recently on a rebuilt motor.
Initially I blamed the thin paper pump gasket, but making a thicker one didn't fix it.
Some aftermarket pumps do not have a big enough chamfer on the corner where they sit into the block. They hit the slight radius in the block, this stops the thin paper gasket from sealing, so the pump sucks air.
Solution- pull the pump out and sand, file or grind a bigger 45deg chamfer on it.

Author:  Beanie [ Sun Apr 19, 2015 7:12 pm ]
Post subject:  Re: No oil pressure ?? Help

I had this recently on a motor I put together , was about ready to pull the motor out and inspect the pump when it was suggested by a friend to pull the line off where it comes out of the block , put a hose pipe or something into the block and suck the oil up ... I did this and it worked a treat ... Never been a problem since

Beanie

Author:  69cooper [ Sun Apr 19, 2015 8:58 pm ]
Post subject:  Re: No oil pressure ?? Help

Thanks Doc , I think I may have the same issue.

Beanie I have tried to suck oil through but you can feel suction at the rocker cover port, not good :-(

I will stew on issue for a couple of days , but sounds like engine out fix

M

Author:  drmini in aust [ Sun Apr 19, 2015 10:33 pm ]
Post subject:  Re: No oil pressure ?? Help

Whilst I had the pump off, I fitted an alloy plate to seal the gearbox casing up to the 1st motion shaft. Then I filled it with oil up to the top of the plate, stuck some plastic tube into the oil inlet port, and sucked oil up. NO bubbles. :) This proved there was no air leak at the O-ring on the sump flange. Sanded the pump chamfer, fitted a new gasket, all was good then.

Author:  Irish Yobbo [ Mon Apr 20, 2015 11:12 am ]
Post subject:  Re: No oil pressure ?? Help

Always a good idea to test your oil pressure before putting the engine back in. I tested mine with an electric gauge, a battery and a bolt in the flywheel as a handle to crank the engine. A bit dodgy, but does the trick!

Image

Author:  69cooper [ Mon May 04, 2015 7:17 pm ]
Post subject:  Re: No oil pressure ?? Help

Pulled motor today and found the issue, looks like recess for pump is around 200 thou deeper than standard , pump pulls up against stub on spade drive. Should their be a spacer ??

Image

Author:  Morris 1100 [ Mon May 04, 2015 7:23 pm ]
Post subject:  Re: No oil pressure ?? Help

Let me guess, it is an auto motor that has a manual gearbox bolted to it?

Author:  drmini in aust [ Mon May 04, 2015 7:34 pm ]
Post subject:  Re: No oil pressure ?? Help

Morris 1100 wrote:
Let me guess, it is an auto motor that has a manual gearbox bolted to it?

Looks like it to me. You need an alloy spacer, 6.5-7.0mm thick. With a gasket both sides.

See the info and pics I put up on Todd Miller's website-
http://www.austinamericausa.com/

Scroll down to technical advice >engine >Converting an Automatic Block to Manual Transmission Block:

Author:  Mick [ Mon May 04, 2015 7:36 pm ]
Post subject:  Re: No oil pressure ?? Help

Irish Yobbo wrote:
Always a good idea to test your oil pressure before putting the engine back in. I tested mine with an electric gauge, a battery and a bolt in the flywheel as a handle to crank the engine. A bit dodgy, but does the trick!



You could make that into a garden diorama :)


drmini in aust wrote:
Morris 1100 wrote:
Let me guess, it is an auto motor that has a manual gearbox bolted to it?

Looks like it to me. You need an alloy spacer, 6.5-7.0mm thick. With a gasket both sides.

See the info and pics I put up on Todd Miller's website-
http://www.austinamericausa.com/

Scroll down to technical advice.


If one was to use an auto pump, what would the effect be on a manual engine? Power loss? or more?

Author:  drmini in aust [ Mon May 04, 2015 7:39 pm ]
Post subject:  Re: No oil pressure ?? Help

Auto pump is 2" wide, oil goes out to a pipe behind the torque converter>auto trans>back to engine.
Won't work or fit in a manual.

Author:  69cooper [ Tue May 05, 2015 8:59 am ]
Post subject:  Re: No oil pressure ?? Help

From the pictures on mini spares it looks like a 1275 has been fitted, 998/1100 pump doesn't have stub extension on spade shaft. ?

Author:  drmini in aust [ Tue May 05, 2015 9:56 am ]
Post subject:  Re: No oil pressure ?? Help

69cooper wrote:
From the pictures on mini spares it looks like a 1275 has been fitted, 998/1100 pump doesn't have stub extension on spade shaft. ?

If it does have a 998 one, grind a 45deg x 2mm chamfer on the pump body and refit it. Use some grease on the gasket. Then remove it and inspect the gasket for good marking.
[edit] I have to say, I have never seen a 1275 auto block get converted to manual without a spacer. Because the oil drilling usually comes through the corner, 1/2 in the spacer and 1/2 in the block.
Image

If it is a 1275 manual pump in an auto block, it MUST have a spacer.

Image
If the motor has never been run since assembly, I would pull the relief valve seat out and check the 2 holes have been blocked (see pic above). If these are not blocked, you will NOT have oil flow through the filter. The oil will go directly into the back of the main oil gallery instead. :(

Author:  ba_dm_tsh [ Tue May 05, 2015 11:39 am ]
Post subject:  Re: No oil pressure ?? Help

Would the engine number not reveal whether it was originally an auto block?

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