Engine and Transmission Tech

tips, technology, tools and techniques related to vehicle driveline components

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BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5354 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Still fighting the oil pressure demon.
Posted by: BlownMGB-V8
Date: November 20, 2017 09:33AM

if it works with the drill but not with the distributor, then logic dictates that the oil pump isn't being driven properly. Since the distributor is turning and the engine runs, the only thing left is the drive tang. Perhaps the distributor is not seating fully?


ex-tyke
Graham Creswick
Chatham, Ontario, Canada
(974 posts)

Registered:
10/25/2007 11:17AM

Main British Car:
1976 MGB Ford 302

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Re: Still fighting the oil pressure demon.
Posted by: ex-tyke
Date: November 20, 2017 09:41AM

I had a similar oil pressure incident years ago when I had an Olds engine rebuilt.
There is an oil gallery plug (similar to a frost plug) behind the front cover which wasn't staked into the block at the machine shop and it had subsequently popped out on engine start up and all oil pressure was lost.
.....just another possible check for no oil pressure.


88v8
Ivor Duarte
Gloucestershire UK
(521 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Still fighting the oil pressure demon.
Posted by: 88v8
Date: November 20, 2017 01:43PM

OK so the distributor is turning the pump but perhaps not very much.
Check the roll pin.

I had problems with a 3.5 a while back, wouldn't prime. Turned out the oil pump cover gasket was too thick. Got one from V8 Dev and it was fine.
But that wouldn't prime with the drill and yours will,. So it has to be the dizzie.

Ivor


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5354 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Still fighting the oil pressure demon.
Posted by: BlownMGB-V8
Date: November 20, 2017 02:26PM

It is also possible for the drive tang to be twisted off up in the distributor gear.


jaygerding
john gerding

(18 posts)

Registered:
06/14/2017 09:33PM

Main British Car:


Re: Still fighting the oil pressure demon.
Posted by: jaygerding
Date: November 20, 2017 05:20PM

I have just talked to Tim at T&A Performance. They will sell me a new front cover modified to accept the Rover mounting studs. They will also sell me an upgraded oil pump, but the drive flange is GM rather than Rover ("U" shaped rather than a flat tab.) Is there someplace I can source the proper end for the Mallory Distributor to drive this, or is it something that I have to have machined for me?

It has become quite obvious to me that I have some problem with the front cover. I am willing to drop the $200 required for a new one, as I have talked to several known experts today and no one has a clue.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5354 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Still fighting the oil pressure demon.
Posted by: BlownMGB-V8
Date: November 20, 2017 10:23PM

So a possible mismatch between the oil pump drive and the distributor then is it?


jaygerding
john gerding

(18 posts)

Registered:
06/14/2017 09:33PM

Main British Car:


Re: Still fighting the oil pressure demon.
Posted by: jaygerding
Date: November 21, 2017 03:04PM

Just had a long conversation with Mike at T & A Performance about this problem. He is intrigued enough about it to request videos and pictures of what is happening. Unfortunately, that means tearing the front cover off and opening up the galley under the intake manifold.

So, this weekend that is what I will be doing.

Thanks for all of the input. I will keep you all informed as this moves on.



88v8
Ivor Duarte
Gloucestershire UK
(521 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Still fighting the oil pressure demon.
Posted by: 88v8
Date: November 21, 2017 05:26PM

Before you tear it out, do you have a Lucas dizzie to try? Even if it lacks its electrical innards you could see if it will prime.

Ivor


minorv8
Jukka Harkola

(121 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Still fighting the oil pressure demon.
Posted by: minorv8
Date: November 22, 2017 05:15AM

I had similar problem years ago when I bought an used Mallory Unilite dizzy. The oil pump gears were pre SD1. Mallory Dizzy was also supposed to be for pre SD1 pumps but someone had hacked the very end of the dizzy shaft away. So, Lucas Dizzy out and Mallory in. Started right up but did not have oil pressure. I knew immediately that there is an issue with the dizzy and was not too happy about the shaft mod.

So, I would double check the drive between the oil pump and distributor as already suggested.


jaygerding
john gerding

(18 posts)

Registered:
06/14/2017 09:33PM

Main British Car:


Re: Still fighting the oil pressure demon.
Posted by: jaygerding
Date: November 23, 2017 12:06AM

As previously stated, this distributor and front cover worked just fine on the original 3.5 engine. Also, the mechanism at the bottom of the dist. is fully intact.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5354 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Still fighting the oil pressure demon.
Posted by: BlownMGB-V8
Date: November 23, 2017 11:02AM

What speed does your drill run at? The distributor and oil pump runs at half of crank speed. This could explain the difference. At 1000rpm the oil pump is only turning 500rpm. Many drills turn 2000rpm. Look for a leak on the suction side. It may be pulling air.

Jim


jaygerding
john gerding

(18 posts)

Registered:
06/14/2017 09:33PM

Main British Car:


Re: Still fighting the oil pressure demon.
Posted by: jaygerding
Date: November 28, 2017 05:29PM

I talked at length with Woody from The Wedge Shop today. They have done dozens of these conversions. He made the point that it seems to be sucking air from somewhere in the block. He points out that if the oil pump, etc., were working fine on the 3.5, it is logical to assume this.

Today I opened the top galley under the intake manifold and observed what was happening as I ran the drill. Oil was getting to wherever it needed to be, just not enough. I will be dropping the oil pan this week (again) and try to take a closer look at what is happening under there.

I have started to buy my gaskets in quantity, just in case.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5354 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Still fighting the oil pressure demon.
Posted by: BlownMGB-V8
Date: November 28, 2017 05:44PM

Who woulda thunk it?
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