Question about recurving Distributor
Thread Starter
Burning Brakes
Joined: Mar 2016
Posts: 1,008
Likes: 163
Question about recurving Distributor
Hello,
I just bought my first corvette, a 1979 4-speed. I hear alot of people talking about recurving the distributor (which I understand means changing the springs and weights to advance ignition timing at lower RPM).
However my distributor looks like this:
Correct me if I"m wrong, but I don't think this is the stock distributor. Do I still need to recurve the distributor?
I just bought my first corvette, a 1979 4-speed. I hear alot of people talking about recurving the distributor (which I understand means changing the springs and weights to advance ignition timing at lower RPM).
However my distributor looks like this:
Correct me if I"m wrong, but I don't think this is the stock distributor. Do I still need to recurve the distributor?
Melting Slicks
Joined: Feb 2006
Posts: 3,105
Likes: 96
From: Sunrise FL
Its a stock dizzy with an aftermarket coil. You need the curve kit for a normal 1979 Chevy HEI dizzy. While in there you should clean and lube things up.
Also check the vacuum advance and read up (search) on how to set everything.
Also check the vacuum advance and read up (search) on how to set everything.
Drifting
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
Buy a Curve Kit and a Timing light.. first, disconnect vac adv hose ..then see how much initial adv and mechanical advance you are getting and what RPM it maxs out.. Ideal is total advance [ Initial of 10-12* or more on high output motors, plus mech adv ] to get 34-36* all in by 2500-3000 rpm.. start with stiffest springs and work to lightest ..
Last edited by fishslayer143; Apr 9, 2016 at 08:27 AM.
Thread Starter
Burning Brakes
Joined: Mar 2016
Posts: 1,008
Likes: 163
Thanks guys. Will a local auto parts store (autozone, oreilly's, etc...) carry the recurve kit? OR do I need to order it online?
I just bought a dial back timing light, still learning how to use it haha.
I just bought a dial back timing light, still learning how to use it haha.
Burning Brakes
Joined: May 2009
Posts: 850
Likes: 36
From: Providence RI
I like the Crane adjustable vacuum-advance/distributor recurve kits, which have the springs and vacuum-advance limiter plate, along with the adjustable vacuum-advance, and a good set of directions for optimizing your advance curve. The HEI kit is #99600-1, I believe, and that should be available through most online parts-stores, or even perhaps in-store at some places.
Racer
Joined: Feb 2002
Posts: 378
Likes: 19
I sent my distributor to a guy in Memphis TN, he makes sure the bushings are okay, shims the shaft to the right amount of clearance, and sets the curve based on the mtr, what heads are used, type of trans, rear end gear, application. When it returns, he tells you what to set the total timing is suppose to come in at w/o vacuum advance and with the the vacuum hooked up. There's no guess work, he has an old distributor machines. PM me if you want the guy's phone #.
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Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
Is there an drivability issue that needs to be fixed? Research the topic before you start changing springs. Get a timing light and determine what your present curve actually is and then determine if you need to change anything. You can get some springs and then make changes and see what the results are. If you have a Performance Distributors HEI they can be of a lot of assistance. You may just have their coil but likely you have their distributor too. They generally give you a nice performance curve on their distributors so you may have a pretty good setup now.
Last edited by flyeri; Apr 9, 2016 at 08:59 PM.
Melting Slicks
Joined: Sep 2010
Posts: 2,413
Likes: 59
From: Emerald Isle NC
You should check to see if that distributor is a Davis D.U.I. or just the cap from one.
If it is, it should have one of their modules in it. This could have been replaced, however.
It should have an aluminum base. may be tach drive or not.
On the outside of the base, near the cap flange area, it should have a number etched in it.
If you call Performance distributors with that number, they can tell you all about that distributor.
Yes, I have a Performance Distributor in my 71. It's a very fine piece. The tach drives are $$ but worth it.
Carter
If it is, it should have one of their modules in it. This could have been replaced, however.
It should have an aluminum base. may be tach drive or not.
On the outside of the base, near the cap flange area, it should have a number etched in it.
If you call Performance distributors with that number, they can tell you all about that distributor.
Yes, I have a Performance Distributor in my 71. It's a very fine piece. The tach drives are $$ but worth it.
Carter