It looks like I am going to have to tear into the distributor to get rid of my offtheline bog.

I noticed my advance can and rotor have the factory values stamped into them, am I going to be able to find aftermarket parts with the same specs on them, or is it a crapshoot? I remember recurving being discussed extensively for the electronic distributor, but Id rather keep my points style distributor and get that sorted out before I start changing things. Im probably going to throw in an Ignitor kit and leave it at that. but it looks like my vacuum advance is not coming in. It holds a vacuum, but it seems really stiff. Any advice?

I do have a cast iron Prestolite, but I just bought Bluestreak stuff for the other one, and it doesnt seem to work all that much better anyway.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

There aren't any aftermarket mechanical advance parts for any of the slant-6 distributors. Changes to the mechanical advance curve are effected by using a different cam assembly (with a different advance amount) or by grinding or brazing the slots in your existing cam assembly, to increase or decrease the total amount of advance, and by changing the springs and/or bending the spring tabs to change the rate of advance.

There are MANY vacuum advance pods still made for this distributor, but actually buying one is difficult in Canada.

Is your vacuum pod the dajustable type? (hex shaped end)
Try sticking a 3/32 (?) allen wrench up the hose opening to adjust the spring tension.
DD

http://www.dutra.org/doug/draft-webpage ... e-pods.jpg

I thought all vacuum advance cans where adjustable? The stock replacement I got from my local parts store is...even says in the instructions how to do it. You can use different springs from about any mopar distributer.

vac pod regulation= clockwise softens the spring (you need to do that)
CCW hardens the spring. Lighten all the way long the spring and then see if light throttle pinging occurs. If so, stiffen it like 1 or 2 CCW turns each time.

I've recurved many dists and I think I may have found the right curve for my mill. I used lighter springs combined with smaller govnor ratios and smaller vac pods... My preliminar guessin is that stock to mildly worked slants like (or tolerate ) high advance ratios under 2300 rpm but like near 30 at wot or above that range. So I put together my "latest but not last" recurved one using a light spring, a yellow heavy one, a 7.5 approx. govnor and a 8.5 vac pod. Initial timing is 15°. The last 3 or 4° kicks in above 2000 rpm, when vac pod is about shutting down. So I have plenty of advance before 2000 rpm and gradually fades into steady 30° as engine revs up (or wot)
I have solved some temp issues I had with past recurves, and some minor bogs I had around 1800-2000 rpm (I had one or two lil flatty spots)
another one that I liked was a 10 govnor with two light springs (one with a loop end) and 10° BTDC initial, 5 vac pod.
I dunno my compression ratio (altough I know is above 9:1) my cyls are around 170 PSI with a ~7 PSI variation... I have pinging with 97 octane gas @2800 rpm or when wotting, with any curve that goes +30° BTDC.
Mileage not checked... hope is not too bad

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Many of the electronic ('73-up) vacuum advances are adjustable, but most of the points type ('72-down) units aren't. The end of the pull rod is different on the two types of advance, but you can sometimes drill another hole in the breaker plate to allow the use of the later (more adjustable, more available) advance units. Most of the pickup plates in '73-up distributors have two holes, so the later distributors can actually use early or late advance cans.

I haven't been following the all of adventures you have been having with your car, so I'm sure I've missed your earlier posts. My question is: are you sure that the off-the-line bog is caused by the ignition system? Is there any chance that the fuel mixture is leaning-out when you accelerate off-the-line?

Frank

Frank: no, Im not. Ive been messing with my BBS carb quite a lot, with no success. I do have a lean mix, my plugs are sterile. I did notice that my advance seems very stiff, and am weighing several options at once. Im thinking about replacing the advance can, rebushing the carb and going with a richer floor jet or step up rod or both, but have hit dead ends on local solutions for the carb. Until I find a break Ive given up on the carb. Might buy another, not sure yet.

Thanks for the feedback guys.

Dan, I'm probably just lucky, but I haven't encountered a vacuum advance that wasn't adjustable, points or electronic. I know they're out there (unadjustable), but what's the chance of that? Dozens, and most have been points type distributors. I suppose a lot of them could have been replacement pieces.

D/W

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If it ain't broke, fix it!

I haven't run into a nonadjustable vac can in my life neither. Guess we're just lucky. Even the old units that had the connection 90° from tip that I ran into were adjustable ones.

on that carb thing, if you're lean might as well be getting some holley (sorry D/W and DAN) 350 CFM #28 pump shooter. Very nice carb. If your car is pretty much stocker, I'd start at #50~51 jets.

good luck! juan

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Have you checked the basics on the carb? Accelerator pump function, gasket not missing at the bottom of the power enrichment piston cylinder?

There're a few juicy Carter BBS carbs on eBay just at the moment.

well this has been a bad week.

I tried again with the old 1920 I had. I was wary of investing in it since I couldnt find a new metering block for it, but someone led me to J&J Automotive in Stoney Creek. They do a lot of carb stuff apparently. They gave me some jets to try after I showed them my worn throttle shaft holes. A #61 cured almost everything. Just a slight loss of power at tip-in.

So I gave the carb to the guy to re-bush after reluctantly pulling it back off the car, and he destroyed it. He was trying to use bakelite bushings, probably for a larger carb, and drilled it out too much, and the bushings were so heavy going in he split the housing. Can someone tell me why he didn't turn down the OD of the bushings. But there it is, Im stuck with the BBS, which is so lean the car diesels and won't idle in drive.

Dan, I didnt see any gasket at the base of the step-up piston, if that's what you mean. But I also know the KEM kit I threw in it didnt have one, and the Techlit brochure didnt show one on the breakdown. You must mean something else? The pump piston was soaked in oil and flared out nice, I also gave the old ball a rap before throwing the new one in, I even bent the step-up link upward a bit to withdraw the rod as much as I dared.

Im tired of that carb, I already had to epoxy the housing after I straightened the tabs for the through bolts. Someone had muscled them down too much. And Im not about to give my last carb to this turkey to rebush it.

So the problem's solved, for the most part, I just have to pawn my guitar to buy a reman from NAPA and turn down the vac can a touch, if it's adjustable. Thanks to all who participated.

Still looking for a reputable carb shop closeby that can rebush carbs without breaking them.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Yee gods...Bakelite? No, no, no!

The correct way to bush a throttle body is with thinwall brass or bronze bushings of a type similar to those used to bush valve guides.

As long as you need a new carb, do yourself a favor and make it a Carter BBS. The one for the '70-'71 198cid Dart and Valiant is the prime pick.

The gasket at the base of the step up piston only applies to the Carter BBS.

That's what I said. But this was the first guy Ive spoken to that was willing to do it. And I didn't want to blow it. But here we are anyway...
Dan, I'm still torn between the two. Both designs have their respective Achille's heel.

On the one hand, you have the BBS with the floor jet and stepup rod, which are nearly impossible to find if it needs calibrating. Mine's running so lean I doubt simply rebushing it is going to bring it back. And itd be nice to be able to throw a richer jet in temporarily once the new one wears out. Mind you, once its dialed in there's no comparison.

Jets are easy to find for the Holley, but you have that damned metering block that's not rebuildable and is NLA, and once it gets plugged youre finished. Right now Im just trying to get by. The guy says he's got another core coming in tomorrow, and Im just going to limp by and see what this clown does. If he bullocks it up again, Im going to grab my bucket of parts and order a new one. Id order a BBS but Im not sure I can get it dialed in.
yeah, I didnt see one. That might have something to do with it. It wasnt in the kit.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

On the other hand, it doesn't need calibrating.