I am not using the vaccum advance on my stock distributor. I wanted the mechanical advance to come on stronger as there was a big lul in power from idle to 2000 rpm. I stertched out the heavy advance spring a little and put it back in. It comes up much faster on the curve now. No expensive recurve kits. I am going to get the MSD distributor anyway here soon so I thought I would just play with it. I love it. Does anybody know how much advance the 18L slot is supposed to give you? My timing light stops responding past 2,000 rpm for some reason. I now have my initial timing at about 16BTDC and it is very responsive and idles great.

 

I just did some reading.. The 18L slot will give you about 36 degrees of advance. This is a fairly new distributor as the last one quit working. The last one must have been the 13L mechanism as there wasn't near that much advance. Probably gonna figure out how to put a stopper in there to keep it from advancing too much. Can I buy a 13L mechanism from anywhere? Just got to Missouri and there aren't too many scrapyards in the area.

Also, FYI: The engine doesn't ping even with 50 degrees advance. I'm sure it runs better at a much lower setting.

 

You got it right, the number on the slot is the number of degrees advance for the dizzy, multiply by 2 and you get crank degrees.

The dizzy's have two advance slots and only use one of them, I forget what the combinations are but I think they are 3 or 5 degrees (6 or 10 degrees on the crank) difference. You can use either slot depending on how much total mechanical advance you want. To make it advance less you can slip a sleeve on the advance stop and that will reduce it by a couple of degrees.

Barry

Don't know if you saw this but shoe posted some info on the dual-point conversion:

http://www.superford.org/registry/ve...618&original=1

 

I guess the stretched spring doesn't work too well. When the engine revs up it doesn't let it idle back down becasue the dizzy advances too easy. Where can I find a lighter spring? I can't figure out why you would want 36 degrees of advance. Even if you start at 6BTDC then you total out at 42BTDC and then if you run the vacuum advance who knows how much you will get. I am going to find a 10L or 13L cam for it. Thanks for that site Barry.

 

You're welcome!

Some engines do run that much centrifugal advance especially when the initial spec is around 0*. The added advance from the vacuum advance does push it up there but remember it only happens at part throttle. I was surprised when I first saw that but it's normal.

The 13L cam is the hot ticket btw. That gives you 26* centrifugal and add to that 12* initial for a total of 38*.

Barry

 

Nobody sells kits or cams for these distributors. I might go junkyard hunting monday and see if I can score the cam and spring. Nobody sells a recurve kit either. I have 2 more months in Korea. I'm going to switch to MSD then and get all the goods I need to curve it the way I want. I can live with the 12BTDC timing but it has to come up fast. The stock spring is horrible.

 

Just looked at Mr. Gaskets catalog. They sell a kit of performance springs for our distributors. It is about 4 bucks. O'rielly will have it here Tuesday for me. Part number is 925D. It is only a set of the two springs but they have less tension than stock. It advertises full advance between 2,000 and 2,800 rpm.

 

You read my mind, was just doing a search on Mr. Gasket!

Barry

 

They always have that oddball stuff when you need it don't they? I need to get some of their timing tape too. I have a silver marker line for the 40BTDC mark. I have a feeling I'm not the only one.

 

I like Mr. Gasket stuff.

Your engine likes 16BTDC, must have a hell of a cam in there!

In that case I'd run the 10L cam which would give you 20* cent. adv. and 16* on the crank for a total of 36*. That might ping if it comes in too quick, keep a good ear open when you nail it and check for blue smoke too.

Barry

 

I run the 343801 cam from crane. It will run at 12 but is awful doggy coming off idle. It runs even better at 20 but that equals way too much total advance. I was thinking the 10L might be the way to go though. Wonder where to get one? The 13L was as low as they came stock weren't they? I also loose a bunch of vacuum at 12BTDC too. Brakes get a little soft.

 

FYI,

The crane adjustable vac advance includes recurve springs. (3 of them)

I got called out of town before I had much time to play with the timing, but my brakes are alittle soft at 12degrees with the 801 as well. I think I'll try your 16 when I get home.

 

Thanks for the info. Our cam isn't really that big and has 0 degrees overlap@.050. I don't know why it likes so much. I'm afraid to see how much the solid cam I am thinking of putting in there is going to require.

 

Sean,
Did you find the dizzy cam that you wanted? I was able to locate a distributor rebuilder here in Oregon that supplied me with one of each after I told them what I needed. Realize this is a ways from home for you, but in case you get desperate I'd bet they could fix you up too. If my rememberer is right, the 10x15 slots are one cam, and the 13x18 on another. Just couldn't make it too easy for us! Anyway, drop me an e-mail if you want the phone number.
Steve

 

Thanks man! I would take you up on it but I am going to get the whole MSD setup when I get back from Korea. I do appreciate the offer. I am just playing with the stock one before I get rid of it. I am going to try and fill the slot to reduce the amount of advance. MSD just makes it way too easy.