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If it's within the proper adjustment range, the screw in the can should be changing the amount of vacuum for it to start moving and the amount needed to get it to travel to the stop.
You should have just bought that hook I posted. It would have fixed it and you'd be done by now. This jumping around with all these different parts is just wasting time and energy.
Put it back together with the stock parts. All you needed was something to limit the travel. A piece of hose over the pin in the slot might have done it. A piece of metal mounted to the arm that blocks part of the slot on the can side so the pin can't move as far. Some people weld it. Some people solder on a brass tab to block the pin. Some people use the MSD hook. Some people mount the Accel 99619-1 limiter plate on the can side of the arm by drilling and tapping a hole and then use it to adjust the travel, mounted like in this post.
At any rate, block the pin from travelling as far and you'll lower the amount of vacuum advance which fixes the problem you have. Less than $10 in parts would have fixed it for you, or you can get creative and make something to add to the stock can for free.
Also, as I previously posted. There was someone else making a limited plate that screws on over the advance arm. I've been thinking about it and I believe it is Lars and Henry Olson who came up with it. Send Lars a nice email explaining that you're having trouble and ask for his information on setting up a HEI distributor. He has an amazing amount of knowledge and what makes him stand out is that he will share that knowledge with anyone who asks nicely. He used to even travel around the country and do tuning days called tuning for beer. He's documented the knowledge so he can email it to the people who ask. His email is V8FastCars@msn.com
i like the idea of being able to adjust the can. I just got it within tolerance I believe and need to check. The rest is original again. I get my money back on the rest. I must have missed the limiter or maybe forgot. At any rate I have to plop in the dizzy again and adjust once more. 14-36 out is good for mechanical now just need to check vacuum advance. I asked earlier if my manifold vac jumper around is ok. Not sure still. Also here are pics requested. I need to stop for rain delay and mom’s. Happy moms day. I’ll be back after the fun
also here you go @454green a new keg
Last edited by michael lamoglia; May 9, 2021 at 02:40 PM.
No He means valve guides...
They are the inserts in your heads (usually brass) that are press fit into the heads and the valves get inserted into them... Think of them as sacrificial brass bushings of sorts. The valve seals go onto the top of the valve guides where the end of the valvestem comes up through the valve guide. They both eventually wear but improper valve train geometry makes them wear out even faster. In your case with the stock valvetrain it seems it would just be normal wear and tear. (I second my earlier motion here to reconsider replacing the heads instead of dumping more time and money into the stock heads if in fact your valve guides are worn)
Last edited by augiedoggy; May 10, 2021 at 11:13 AM.
Yep, valve guides in the head. You are describing exactly the same vacuum gauge indication I have with my car. I have isolated it to the #1 cylinder. You likely have blue smoke either on start up or on acceleration off of a light or both. Check your spark plugs and you’ll likely find one or more that are oil fouled. That/those are the cylinders with worn valve guides.
Never smoke. Plugs were pretty gritty that I changed about 10 months ago (just changed them again about 1 month ago). I gappe at .040 out of spec from the sticker on my car which I noticed late. I could have sworn it was .040 but it's .045.
I fear my issue may be related more to two things:
I just changed the head gasket on the passenger side chasing no compression (don't ask) so it may seem I'm a victim of the 'leaky head gaskets' issue on your chart. I also. It may not be dancing all that much but it may be that. I also relashed when I had everything opened (quite a few tries) and it may also be causing an issue?
Once I finish timing hopefully by tonight, I'm going to redo plugs anyway (gap) then I'll revisit this.
Spring are kind of crusty but if they're working you're still OK. Well, the whole top of the shaft is kind of crusty. The parts move freely, right? I see the nylon in there and the weight bushings seem to be in OK shape so mechanically it's not bad, as long as it moves freely.
You can buy cheap spring kits if you want to replace them or tune the advance curve.
If it works, it works. My 79's OEM HEI distributor was in much worse shape. The advance was notchy from corrosion, even with replacement springs, and the curve as RPMs increased was different than as RPMs decreased. I swapped it out for a dist from a ZZ4 crate engine (and still had to shim the endplay out).
You would have noticed all of this when you checked your mechanical advance before. Right now, your problem is that your idle vacuum is less than what the adjustable can needs to be "all-in". If you add a stop to the NAPA can, you might be all set, whichever dist you use.
just got back putting in new ngk plugs don't like the way these feel. When did I start noticing things by 'feel' you ask? When I tore this engine apart the 47th time.
Yep, valve guides in the head. You are describing exactly the same vacuum gauge indication I have with my car. I have isolated it to the #1 cylinder. You likely have blue smoke either on start up or on acceleration off of a light or both. Check your spark plugs and you’ll likely find one or more that are oil fouled. That/those are the cylinders with worn valve guides.
If it works, it works. My 79's OEM HEI distributor was in much worse shape. The advance was notchy from corrosion, even with replacement springs, and the curve as RPMs increased was different than as RPMs decreased. I swapped it out for a dist from a ZZ4 crate engine (and still had to shim the endplay out).
You would have noticed all of this when you checked your mechanical advance before. Right now, your problem is that your idle vacuum is less than what the adjustable can needs to be "all-in". If you add a stop to the NAPA can, you might be all set, whichever dist you use.
ok all put back together new plugs in (much nicer) dropped dizzy at tdc. Here is what I got.No vacuum
Light at zero rpm 685. I rotated counterclockwise to get to 4 degrees btdc so it’s a bit less rough.
Light gun at 23 rpm 3600 still no vac
Back to idle Light gun at 4 to get to tdc. 730 rpm
WITH VAC:
light gun to 15 to get tdc rpms are 845-975 if a/c fan kicks on slows to 845.
Light gun to 35 to get to tdc at 3600rpm. Stops advancing btw starting around 2100ish
We are back where we started I think.
as a test My mighty vac measures 11-14 hg from manifold vac. To get vac can to start advancing I have to pump the mighty vac to 21-24hg
Last edited by michael lamoglia; May 10, 2021 at 08:17 PM.
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
It looks like your vacuum advance maximum is about 11* which it should be for your new vac canister.
Now, with no vacuum connected, advance your initial timing from 4* to 14* at idle. Now check it at 3600 rpm. It should now be about 33* which is very close to where you want it.
Now, with vacuum connected, it should now be about 25* at idle and your manifold vacuum should now have increased and your idle speed. Turn down the idle speed to about 800 rpm. Increase rpm to 3600 and the timing should be about 44*.
Now go for a test drive and listen for any pinging.
Last edited by resdoggie; May 11, 2021 at 10:06 AM.
It looks like your vacuum advance maximum is about 11* which it should be for your new vac canister.
Now, with no vacuum connected, advance your initial timing from 4* to 14* at idle. Now check it at 3600 rpm. It should now be about 33* which is very close to where you want it.
Now, with vacuum connected, it should now be about 25* at idle and your manifold vacuum should now have increased and your idle speed. Turn down the idle speed to about 800 rpm. Increase rpm to 3600 and the timing should be about 44*.
Now go for a test drive and listen for any pinging.
You should just clean up and keep your original distributor flyweights....I noticed in the pics that the bushing in those were done anyhow. Use a combination of springs to get the full mechanical advance (the flyweights) to come in around 2800-3000 RPM. If max advance comes in before that, you may end up with some detonation.
Don't set the timing by the what the factory says, listen to all the posters on here that are saying set it to 36 degrees with the vacuum advance line disconnected from the distributor and the line to the carb plugged.
