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Discussion Starter · #1 ·
Greetings! Two questions.
Building a 2l from a short block out of an '84, an era I am unfamiliar with. Does anyone know why the crank pulley has 4 threaded holes on the perimeter of the side facing the radiator?
I have nothing on hand that looks like it should go there, but am worried I am missing something.
Also, if I am pretty sure the crank pulley is original to the engine, any problem with going ahead and indexing the pulley (scribing degree marks) based on the location of the TDC mark ("P"), or should I wait and index only after initial mock-up with a dial gauge confirms the mark is dead-on TDC?
TIA!
rsj
 

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it's almost a alfa romeo spider
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it's for an added a/c pulley that bolts onto the main pulley, don't worry about it, if you have no a/c in the car. 'p' is top dead centre... 'm' is for maximum advance... but aging don't worry , the pick ups on the flywheel and the ecu do all the timimg.
 

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Discussion Starter · #3 ·
Thanks for clearing the first query up Bianchi - as to the second one, I have only the bare short block and will be putting it in to an earlier 105 chassis, so no flywheel pickup or ecu help - can I count on "P" being perfect TDC, or should I wait for dial gauge confirmation (with attendant possible delays)?
Thanks!
 

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it's almost a alfa romeo spider
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as longs as you don't move the poimter,,, you can.. it's bolted to the pointer holder.. but just to make shue..re-time it..only take a few extra mins.
 

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Discussion Starter · #5 ·
Thanks - I had totally forgotten about the adjustable pointer!
 

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FWIW, since you have the engine torn down, I would use the 'positive stop' method to find true TDC - it's more accurate than a DTI IMO. Only special equipment required is a protractor of some kind you can attach to the crank pulley (print a paper one is fine) plus some kind of plate to bolt across the top of #1 piston.

Fit plate, wind crank forward until piston hits plate and stops, note reading. Wind crank backwards until piston has gone back down and returned the 'other way' and hit the stop again, note reading. Work out the exact centre of the two figures you got....that's true TDC.

Using a DTI on a piston at TDC is always going to be slightly inaccurate due to the geometry and any play in the system. It's fine as a method in general of course, and in some situations is the only sensilbe option...but if you don't have a DTI, why buy one to make a job less accurate than it could be.

HTH
 
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