distributor rebuild problems
Thread Starter
Racer
Joined: Nov 2006
Posts: 495
Likes: 1
From: Lubbock TX
distributor rebuild problems
i bought a distributor rebuild kit for HEI. heres the question that i have.
the weights that it came with the kit are shaped differently than the stock ones. there is a smooth rounded side to each of them and a flatter side with rough edges. is this how they should be place. the middle one is flat side down and the other two are flat side up.
and what is the small allen wrench for that it came with?
the weights that it came with the kit are shaped differently than the stock ones. there is a smooth rounded side to each of them and a flatter side with rough edges. is this how they should be place. the middle one is flat side down and the other two are flat side up.
and what is the small allen wrench for that it came with?
Last edited by smon; Jul 4, 2007 at 05:56 PM.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Yep. Aftermarket weights are crap. Use the original weights with new bushings, use gold springs. Toss the vacuum advance and use a fixed AR-12, unless you have low idle vacuum.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Sean -
The "AR-12" vacuum can is a general high performance unit that works very well for most applications where you are pulling at least 14 inches of vacuum at idle (and in "drive," if auto). The actual part number for the unit (NAPA) is VC1838. This unit will give you 14 degrees of vacuum advance, which is a good compliment to an aggressive 36-degree total timing curve (36 total mechanical plus 14 vacuum = 50 degrees maximum possible combined timing; perfect). If you're pulling less than 14" of vacuum in "drive," use part number VC1862. This is the AR31 unit, and it's compatible with engines only pulling 10 inches of vacuum at idle. The advantage of a "fixed" unit is that you know exactly what you're getting and where your timing curve will end up. With the adjustable units, you usually end up screwing around and never really knowing what curve you end up with. Every adjustable unit I have ever seen and worked on has been screwed up beyond imagination, and has been pretty useless.
Use your original weights. The aftermarket weights are not hardened like the originals, and they will wear out in the pivot holes, causing you long-term problems. The aftermarket weights are also not the correct shape to give you a good timing curve - they will really screw up your curve. Use the stock weights with the 2 gold springs as a starting point. This will usually get you full total timing in the 2500-3000 rpm range, which is good. Set the total to 36, and the stock weights will typically give you initial timing in the mid-teen range. But each distributor is a little different, so you have to check your timing curve with an adjustable timing light to make sure it's right. If you need info on setting total timing, drop me an e-mail request for my "How to Set Timing" Tech Paper:
V8FastCars@msn.com
As always, feel free to contact me if you need tuning assistance. Good luck with the setup!
Lars
The "AR-12" vacuum can is a general high performance unit that works very well for most applications where you are pulling at least 14 inches of vacuum at idle (and in "drive," if auto). The actual part number for the unit (NAPA) is VC1838. This unit will give you 14 degrees of vacuum advance, which is a good compliment to an aggressive 36-degree total timing curve (36 total mechanical plus 14 vacuum = 50 degrees maximum possible combined timing; perfect). If you're pulling less than 14" of vacuum in "drive," use part number VC1862. This is the AR31 unit, and it's compatible with engines only pulling 10 inches of vacuum at idle. The advantage of a "fixed" unit is that you know exactly what you're getting and where your timing curve will end up. With the adjustable units, you usually end up screwing around and never really knowing what curve you end up with. Every adjustable unit I have ever seen and worked on has been screwed up beyond imagination, and has been pretty useless.
Use your original weights. The aftermarket weights are not hardened like the originals, and they will wear out in the pivot holes, causing you long-term problems. The aftermarket weights are also not the correct shape to give you a good timing curve - they will really screw up your curve. Use the stock weights with the 2 gold springs as a starting point. This will usually get you full total timing in the 2500-3000 rpm range, which is good. Set the total to 36, and the stock weights will typically give you initial timing in the mid-teen range. But each distributor is a little different, so you have to check your timing curve with an adjustable timing light to make sure it's right. If you need info on setting total timing, drop me an e-mail request for my "How to Set Timing" Tech Paper:
V8FastCars@msn.com
As always, feel free to contact me if you need tuning assistance. Good luck with the setup!
Lars
