distributor recurving ?

-
AdamR

AdamR

Big Member
Joined
Dec 31, 1969
Messages
17,342
Reaction score
562
Location
Bethel, CT
I need to re-curve my distributor so that I can gain more initial advance with out gaining more total. Right now I have 18 initial and 34 total. I think I really need another 4 to 8 degrees to clean up my idle. Is this something I can do or do I need to send it back to FBO for another re-curve ?

Right now I have a idle speed of 1000 to 1200rpms in neutral. To get the idle this high I had to crank the idle screw on the carb all the way in. The carb is a custom built Thermoquad. It will be going back for a bit more work but Im sure my timing isnt helping.

This is an 11:1 340 with a 260/265 @.050 solid cam.
 
I dont think I will get it much lower then 1000. Maybe it will idle lower with more timing and some more carb work but its not going to idle lower than that right now.

For what its worth, The guy that built the motor and dyno'd it had it set for a 1200rpm idle on the dyno with the old Holley carb. I know he likes to keep the idle higher then most people do.
 
I'm also wondering if locking out the timing and adding a start retard would be a better way to go ?
 
Because of the cam I suspected that the idle need to be that high. Back in my Buick days I ran Q-jets for awhile and I had a similar problem of having the idle screw cranked in to get it to idle. The problem was the small primaries can't move enough air closed down to let it idle. My fix was to adjust/bend the secondary closed stop so the secondary butterflies were just cracked open to let more air in the motor. I was then able to close the primaries down some.


Chuck
 
Adam, are you going to drive this thing on the street? If so I would probably stay away from locking the dist. You will more than likely end up with detonation if you do. I would more than likely run 36 to 38 degrees total time and initial of about 16 to 18 with a rapid advance. That way at lower cruising rpm's it will not detonate quite so bad or try to as easily. Is this a stock dizzy?
 
Yes it will be driven on the street. This is distributor that I had Don a FBO recurve a few years ago for the Barracuda. Its set at 18* int, 34* total in at 3000rpms. It was curved for a different motor/converter/rear

I"ll have to throw the timing light back on it and double check but if I give it much more int timing it kicks the starter back.
 
to recurve it shouldn't be too hard... to get the timing in faster ( iall mine is in by 2100 rpm) you just need to play with the different spring combos ( in by 2200 is usually on medium and one light spring) to get more advance at idle and keep your total you just need to shorten the slots in the advance place some... most guys weld them shut some and fine tune it with a file.... unless iofcourse the thing has an adjustable advance plate in it...
 
Might be worth while picking up a MP distributor with the adjustable mechanical advance. Then to dial your motor in it will be as simple as loosening a couple of set screws and using the appropriate spacer from the Mallory kit to set what ever total you want.
 
Talked to Don today. Its on its way to him in the morning. Not worth doing it myself for the price. He's going to set it at 26 intial and 34 total and bring it in fast.
 
No, he has to weld up the slots more. And seeing my carb is back to Demon Sizzler right now I may as well send the distributor out for $50 too.
 
You must log in or register to reply here.
-

Back
Top