The Money Pit

Started playing with timing and got the tape on the balancer before the big snow,and it seems a few degrees up or down from the initial timing setting makes a notable difference.Different searches on the web have lead me to believe the stock weights and top plate would yield a 20 degree curve for the mechanical advance.(Plus the initial 10 would be 30 degree total mechanical).
Has anyone tried just replacing the springs with any luck,or do you need different weights too?Who's advance kit did you use?

john's '81 mouse

Forum member "lars" is one of the resident experts, and there are others, on this topic. He did research and claims that no current after market advance kit works right on a basically stock s/b chevy with an HEI type distributor which is on your '80. Lars has experimented and developed a weight and spring kit which really does the trick, which I and many other forum members purchased from him. Generally speaking, you want about 36 degrees of combined Static and MECHANICAL timing advance to come in completely by 2,600 to 2,800 rpm, with TOTAL advance (static, mechanical, and vacuum) of about 52 degrees. Suggest you email lars, and look in tech section on timing C3.

Larry B.

The stock weights are the best according to lars. Just use various springs and limiter bushings to get the correct curve and limit. I got three different kits,(crane, MSD and Mr. Gasket) each gives you a little chart to go by. I ended up with 6 deg. initial and 26 total at 3000 rpm. No vacuum advance... but that's for my 427. Small blocks react considerably different.

AlwaysWave

Lars is the resident expert, and yes, the stock weights are best. However, I've had very nice success getting the curve right using aftermarket spring kits. My sb is at 10 initial, and 36 at 2800.

Ganey

I have always just replaced the springs as the wts. in the kits never looked better than stock. Works fine.

:cool:

pws69

"...and look in tech section on timing C3"

Where is this "Tech Section" that I keep seeing referred to where "Lars" puts this information?
Thanks,
Paul

Fevre

Look to the top tool bar under 'Tools' then 'Tech Tips' then 'C3'. :cheers:

pws69

Thanks very much. Happy New Year!

vettfixr

I just went through this a month ago on my 74 and it's worth the effort. I kept the stock weights and changes the springs with those that I had from an Accel kit. My biggest problem was the vacuum advance. The stock unit and the adjustable unit from Accell both caused suring at low speed unless I made the advance curve lazy. I ended up getting one of the vacuum advance cans that Lars recommended (B1 unit for points distributor) and it did the trick. I now have 36 degrees static and mechanical advance all in by about 2800 rpm and 52 degree with the vacuum canister activated. No surging at low speeds and the bottom end is really stoudt now. Look at Lar's tech paper and just do what he tells you. One other thing. I played around with timing tapes for years and they were always a PITA and somewhat suspect in their accuracy. When I changed the balancer on my engine I installed a Proform balancer cover that fits over the balancer and is secured by the bolts going into the balancer from the pulleys. It's marked to 60 degrees and you never have to worry about the marks walking. I think I paid about $39 for it and it made life with ignition curves a lot easier. It's also a lot cheaper than the high ticket balancers that have marks engraved all the way up to 60 degrees. If you look at my sig picture you can see what it looks like. I also have a Tavia adjustable timing pointer that makes it easier to pinpoint the timing mark.

The Money Pit

Santa forgot the balancer cover.Can you believe that after how good I was this year?I have my eye on the black Proform cover,and thanks for the info! :seeya