F250 1985 351W C6
My truck has had all the EGR removed, which as I understand EGR acts as a retardant and spark is advanced to compensate.
After replacing the distributer a few years ago, the only way I could get it to run well was to disconnect the vacuum advance and retard the spark to about 6* btdc.

My question is; is there a distributer that I can use that won't over advance the spark with the vacuum hooked up. Presently the fly weights are advancing as much as it needs to run well, but I'd like it a little better.
thanks

 

Why not recurve the distributor you already have?

 

Bend tabs to increase tension on springs?

 

Can also get an aftermarket dist, I seen a guy on youtube from a budget 302 build he was doing he was using a Mallory dist I think it was with the DSII module. Or maybe it was a Mallory ignition box with the OEM Dist. I cant remember which way it was but it was one way or another.

 

You can get a spring kit cheap.
You can get an adjustable vacuum advance from Crane... again.

Duraspark_distributor_recurve_instructions_index

As for Mallory, I HATE to buy anything from Prestolite.
(ACCEL, Hays, MrGasket, all of it!)
Those bean counters can take all their Chinese $#!* and lose it on the bottom of the Pacific.

 

lol My Mallory dist is from the 70s I refuse to buy a new one though.


I will be saving that link myself though. I might have to recurve mine as I planned on reusing OEM ignition with my roller build just swap the dist gear out for use with a roller cam.


For me I didn't have to change anything when I blocked off my EGR via a aluminum plate between the valve and the EGR spacer under the carb. But I might have to recurve with a roller cam though.

 

Prestolite sold out to a Chinese hedge fund and merged with Zhongshan Broad-Ocean Motor a year ago.

Things have gone downhill since Genstar started consolidation back in the '90's.

 

It's been a couple years since I worked on this, but I believe I did that, to the lowest slot.

Obviously I'm not a top mechanic or I'd not be asking questions. Advancement , as I recall was 36-40* (guess, because damper doesn't have numbers that far) with out vacuum and with vacuum to the point of extreme preignition and faltering, both at about 2100 rpm.

And at the time I could not find a source for springs.

The vacuum advance is O'reilly adjustable and I could not bring it down enough.

I'll go back over the recurve deal again. The 1975 distributer might be the key for me, I have been at the point of buying one of the HIE after markets.

thanks, again

 

Advance is double the number on the slot.
Scott's page shows how to figure advance in thousandths if you want to weld the slot up.

 

Think 18 was the low slot on my dizzy. Which would put it at the 36 that I guessed. I'm not that good of a welder/machinist.

 

18L is a pretty big slot!
All you have to do is put a blob of MIG and file it to the width you need.

I don't know anyone selling just the plates.
The guy whose website I linked does sell whole custom recurved distributors.

We used to sleeve the stop pin with brass tubing from the hobby store.
It's telescoping, so each one fits over the other.
I forget which sizes though...