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81 NA Dizzy 180 degrees off


zercs280zx

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On mine I just pulled out the little clip what allows the dizzy CAP to only go in one way and moved it to the other side.

This way the little Cyl1 mark is still in the right place.

Edited by duragg
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Thank you....  My friend runs a service station and knows chevys and fords, but he needs to be 1000% sure that when I turn that oil pump 180 degrees in theory the rotor should line up with cylinder 1 on the compression stroke.... I'm sorry to ask what seems like such a simple question I am trying to compensate for not only an engine builder.... but one that specialized in datsuns back in the day... I'm sure he made a very simple mistake for such an experienced machinst.... I need to solidify that the ignition rotor will line up with the location of the number one cylinder according to what the factory manual states in it's picture.... because this idiot installed the oil pump backwards... please... I'm sorry to ask again but is what you are saying is pull the four bolts off, pull out the oil pump, clock it 180 degrees and push it back in... and then my ignition rotor should line up with the number one slot on my dizzy cap per the factory manual... and please excuse me for asking what seems to be such a basic/retarded question but are you saying you can put a screwdriver down the dizzy hole and phsically turn the oil pump gear or do you have to physically remove the 4 oil pump pump bolts, pull it from the block, and rotate it 180 degrees.  Either answeer is fine but I just need to know.

 

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Your not turning the oil pump- you are turning the SHAFT that connects the pump to the dizzy. You have to pull the oil pump and drop the shaft away from GEAR it is engaged to on the crank. You CAN NOT turn the shaft while in the timing cover .

In your FSM shows there's marks to line the shaft up in the pump BEFORE you shove it up in the timing cover that should get you close. Of course this is all done with 1 cylinder TDC. VERIFY position on shaft for the dizzy by looking at the FSM picture of the tang line-up in the timing cover- 11.25 o clock.

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"You CAN NOT turn the shaft while in the timing cover ."

 

I got at least four other people than myself that watched that EXACT thing happen...then retired the engine and made another run to confirm, indeed, the engine CAN skip time that way!

 

Normal procedure is to drop the pump.

 

Unless you pinned the gear, they CAN spin under the right circumstances!

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Pulled the cap on the dyno and the owner said "Well, it didn't drive down here like that!"

Dyno operator took a look... Me, the owner of the car, and the fixit guy around the shop came to see it as well.

Jumped 180 out...

Retimed it, and on the next run, it jumped out 18 degrees...

 

"Whelp, that's it for today..."

 

Tweaked the dizzy to drive it the 120 miles back home....

 

In a way, it was the beginning of the age of innocence for the owner.

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Take the shaft out, drill the hub of the gear and the shaft for a pin, ream for desired pin type, insert pin.

 

Done.

 

I'd use a rolled spring pin, commonly called a roll pin. They are cheap, easy to get, and easy to use, and it's not like you need a huge amount of shear force there. If you're worried about it, double-pin it.

 

It's not the dizzy that really puts the force on the shaft, I think...I think it's the oil pump that really puts the load on it. The distributor doesn't have a lot of inertial load, and not much mechanical load either...but the oil pump certainly has enough to do the job.

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Force Reversals overload the light friction fit and allow the gear to spin.

 

Drilling and reaming for a 3mm hardened dowel, which was chilled via CO2 & Alcohol and press fit into a 240F heated Distributor Shaft and Drive Gear Assembly left us not worrying about a hollow hole in a shaft...

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