unwanted timing changes
07-09-2002, 12:37 AM
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unwanted timing changes
i have a prestolite distributor on a carb'ed 454. (the electronic from points kit with external coil.) last week the ignition module gave out. it's the horseshoe looking kind under the cap. 98$ for the module, ouch. today, i was setting the timing. brought #1 cylinder to tdc on compresssion stroke, heard the poof, saw the mark on balancer reding 0*. made #1 where the rotor was pointing, nothing special. but when i went to tighten the distibutor down after setting initial at 10* after warm up the motor bogged down. timing changed at least by 10* from where i had it set. engine started running bad, missing etc. the timing light was still hooked up to #1 wire and it started firing intermittently or not at all until i revved the motor way up. the distributor wasnt loose, it was snug, just not tight. i think i may try a different distributor. i couldn't get it right with the one in there. at least not after i tightened the hold down clamp. any other ideas?
07-11-2002, 07:19 PM
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Really stupid question for ya excal... did you happen to have a timing light with the advance knob? Did you happen to bump it to off the 0 mark?
That would be way too easy I know.... but I have done it and nearly **** myself before coming around.
BT
That would be way too easy I know.... but I have done it and nearly **** myself before coming around.
BT
07-11-2002, 07:42 PM
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no bt, my light isn't that fancy
. set it at 10* and tightened the hold down clamp and the motor bogged like the cam was walking. the timing went from ten to around twenty and started running like crap and wouldn't act right no matter where i put the timing. very erratic. 
. set it at 10* and tightened the hold down clamp and the motor bogged like the cam was walking. the timing went from ten to around twenty and started running like crap and wouldn't act right no matter where i put the timing. very erratic.
07-11-2002, 08:53 PM
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yes. it would go back to 10*. but the weird part is, the heads and intake have never been milled. and thats the same distributor that i used last year. the only thing that is different in the motor is cam and lifters and valvesprings this year.
07-11-2002, 09:00 PM
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Assuming the bushing in the distributor are tight... why not try shimming the dist. base up incrementally until the shift in timing stops. Then add another .010-.020 for gear backlash. Not pretty... but may get you rollin again.
BT
BT
07-11-2002, 09:49 PM
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i was thinking along the same lines BT. first i was thinking of using marking compound on the dist. teeth to see how deep it is in the cam gear. and if it is deep, shim it up. where do i get shims to fit? i may have to make some i guess.
07-12-2002, 12:17 PM
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Excal.. I would check mcmaster carr for bronze thrust washers. They should have them in various IDs and thicknesses. Nother thought would be multiple gaskets under the housing.
Good luck bro,
BT
Good luck bro,
BT
