Distributor Springs

Geek's 65 · 04-26-05, 02:59 PM

Have read alot of threads about the mechanical advance springs in the distributor and how you can change the advance schedule by changing the springs. Also how at idle, they are supposed to hold off advancing until about 1300 RPM. Mine don't. They advance immediately and my guess is that they are even working at idle. so I need to buy new springs. Now the stupid part. What do I ask for to get "stock" schedule springs? And if those don't seem right, how do I spec getting stonger/weaker springs? Is there some method to this?

Thanks in advance.

JohnZ · 04-26-05, 03:14 PM

The umpteen varieties of GM springs haven't been available for decades; you'll need to "mix-and-match" different combinations of springs from aftermarket advance kits to tailor the curve you want, or most shops that still have a Sun distributor machine usually have lots of old springs in their "stash". If you can find a shop with a Sun machine, they can set up the curve you want in about 20 minutes.

maxphunn · 04-26-05, 07:22 PM

[quote=JohnZ] most shops that still have a Sun distributor machine usually have lots of old springs in their "stash". "

So John, that is where all the springs have gone, you Sun machine boys have them.

Here is a pic of my Allen Syncrograph.

Max

JohnZ · 04-27-05, 07:13 PM

Nice machine! I bought a Sun machine in 1972 for $100 at a Sheriff's tax auction for a bankrupt gas station, and sold it in 1978 when I moved; should have kept it - sure beats setting up curves on a running engine with a dial-back timing light. Hindsight is 20-20

bobherr46 · 05-17-05, 08:24 PM

Check the Summit catalog. They furnish 3 sets with the new HEI distributors that they sell. Maybe they also sell the springs seperately. - Bob Herr

Sky65 · 05-17-05, 09:34 PM

I belive the springs for HEI and standard points distributors are differant. The HEI are larger?
I bought a set of Mr Gasket springs for my 65. I think there were light, medium and heavy two of each. Ran about 10 bucks.
I also had problems with the advance coming in around 750 RPM. I found I had too much advance as well. I think it was around 30 deg if memory serves me. I installed a larger stop bushing. This reduced the amount of total mech advance and put a little more tension on the springs at low speed.

bobherr46 · 05-17-05, 10:27 PM

Got curious and pulled out the Summit catalog. They list a HEI advance curve kit for $4.50 but nothing for a points distributor. If you are not trying to stay "box stock" may want to pop for a new HEI unit. - Bob

jerrybramlett · 05-17-05, 11:11 PM

Maybe I can save you some trouble.

HEI springs are too long and will not return your mechanical advance weights to the idle position reliably.

Mr. Gasket advance kits for points distributors contain three sets of springs with different tension levels: Super Wimpy, Weak Suck, and Almost Okay. These kits also contain weights that are shaped incorrectly to use with stock springs. Don't waste your money. These spring/weight combos all come in before 800 rpm.

GM no longer sells any advance springs for points distributors.

Chevy passenger car distributors with used springs are common at swap meets and on eBay. They're a cheap source of used parts, but they usually contain springs that are too stiff to use in pairs to create a performance advance curve. You can, however, combine one passenger car stiff spring with one aftermarket Almost Okay tension spring to get a pretty good curve.

I can buy a "reproduction" of the '58 - '61 FI distributor advance spring for $3 each from my FI parts wholesaler. But, it doesn't produce the stock advance curve for that FI distributor or even a good performance curve.

I'm about to test a spring design that should have the correct length and tension to substitute for the stock '64-5 FI distributor advance springs. If it tests okay, I should be able to sell them in pairs for $5 including postage within a month or two. We'll see how it goes.

Geek's 65 · 05-18-05, 04:41 PM

Jerry, Any clues on where to find springs for a non-FI distributor? Weak, Sucky, and Almost seem like what I have.

05-18-05, 05:28 PM

Quote:

Originally Posted by jerrybramlett

Maybe I can save you some trouble.

HEI springs are too long and will not return your mechanical advance weights to the idle position reliably.

Mr. Gasket advance kits for points distributors contain three sets of springs with different tension levels: Super Wimpy, Weak Suck, and Almost Okay. These kits also contain weights that are shaped incorrectly to use with stock springs. Don't waste your money. These spring/weight combos all come in before 800 rpm.

GM no longer sells any advance springs for points distributors.

Chevy passenger car distributors with used springs are common at swap meets and on eBay. They're a cheap source of used parts, but they usually contain springs that are too stiff to use in pairs to create a performance advance curve. You can, however, combine one passenger car stiff spring with one aftermarket Almost Okay tension spring to get a pretty good curve.

I can buy a "reproduction" of the '58 - '61 FI distributor advance spring for $3 each from my FI parts wholesaler. But, it doesn't produce the stock advance curve for that FI distributor or even a good performance curve.

I'm about to test a spring design that should have the correct length and tension to substitute for the stock '64-5 FI distributor advance springs. If it tests okay, I should be able to sell them in pairs for $5 including postage within a month or two. We'll see how it goes.

keep us posted, as I am in need of original spec SHP advance springs . . .