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Discussion Starter #1
Hi
I have fully rebuilt my 1750 engine and set up the oil pump as per the book with the slot at the top of the shaft facing from front to back of engine when at top dead centre. the book shows the distributor rotor should point to the front of the engine. unfortunately the rotor is at 90degrees to the key at the bottom of the shaft so the rotor points down towards the bottom of the engine. I have 2 other distributors lying around and they are the same. is the book wrong or am I missing something. I found another post where a member had the same issue but there was no conclusion. can anybody shed some light?
it would be greatly appreciated

cheers Ian
 

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Some photos show install in the front cover, front cover OFF the block. Others show install with front cover ON the block. the helical crank gear will cause the pump to turn slightly as the front cover is installed. Therefore the pump link will be in different positions.
The correct install has the distributor rotor pointed to #1 ignition wire contact, cover on, engine at TDC with both front cam lobes pointed OUT. One tooth off either way can be easily corrected loosing the distributor in it's mount lock.
If your front cam lobes are pointed IN @ TDC mark, and distributor rotor points to #1 contact, you will have pump (and distributor) mounted 180 degrees out.
It sounds harder than it is. Read this through as you play with the assembly. Check your work before installing sump.
Does this help?
 

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Gordon:

I don't think Ian's problem has to do with the installation of his oil pump; it sounds more like something internal to the distributor. He writes: "the rotor is at 90 degrees to the key at the bottom of the shaft" suggesting that when the slot in the oil pump shaft is horizontal, the rotor is pointed vertical.

I know the drive cog at the bottom of the distributor can be installed 180 degrees off, but didn't think it could go on 90 degrees off. And I don't think the advance mechanism can be assembled 90 degrees off. So if I understand the situation correctly, I'm a bit stumped here.
 

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That's easy Jay IF it's a JF-4 with mechanical advance. It it possible in incorrect assembly to get the longer of the two weight stop pins not in its hole in the plate below. One can with great difficulty force the points plate over the misassembled advance. The whole thing is usually locked up at that point, but as the rotor is bolted to the cam, and the cam part of the advance, it can be beaten together 90 degrees off. I only know this because one core Bosch JF-4 I once bought was assembled like that. The FORCE method of rebuild.
On other distributors, he could have an oil pump main shaft broken at the cross pin hole that has moved the top link 90 degrees off. These can break inside the upper bronze gear collar, so as to be unseen and seemingly a solid, unbroken main shaft.
Yes, your explanation voids my earlier note Jay.
 

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Discussion Starter #5
engine is fully assembled and the cams in the right place oil pump is fine, the key way is aligned front to rear at the top of the shaft, this is as per the book/manual. it then shows that the distributor should have the rotor pointing to the front of the engine, this would mean the rotor and the key would be in the same plane. I have 3 distributors ( all of them are mechanical advance ) and all of them have the rotor at 90 deg to the key on the end of the shaft, ( one distributor has been sitting in an engine for more than 30 years) I can only feel the manual is wrong. I found another post with the identical issue.
I will just set the distributor to align cylinder one and the rotor. Rob at manning said to ignore the book.
 

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Agree. If it's final set-up and dist. position is correct running, you are all set. That was my original thought, and the way I've done it for 50+ years.
 

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Agree. As long as the distributor's advance mechanism works (e.g., all three of your distributors aren't mis-assembled as Gordon describes in post #4), then so what if plug #1 is fired from the bottom of the distributor cap rather than the forward position.

This discussion piqued my curiosity enough to pull out my box labeled "spare distributors" and have a look. I had a Marelli and two Bosch. The Marelli has its drive cog parallel to the rotor, but both Bosch have it at about 80 degrees. So perhaps your manual was written for a Marelli, but you are installing a Bosch.
 

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Gets worse as the assembly books don't differentiate. They just explain that the rotor will move as the front cover is installed on the block with pump installed on the cover. I made a pump index location tool from a spare distributor drive link and rod that fits in the distributor mount bore so I can "adjust" the pump drive position when installed for any distributor and rotor position.
 

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I spoke with Ian about the Problem.
He says he followed the book as per diagram.
Easiest solution is leave it alone and wherever the Rotor points= Number 1.
Ian is a perfectionist,,and I dont blame him for that,,,so he can reposition the oil pump distributor drive to put the rotor button where he wants,,,,,,If he wants to that is.
Knowing Ian,,im sure he will.
Call me if you need any instruction Ian
 

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Kinda fun thread for some of us...
 
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