1968 Mopar Engine - Do I need Lead substitute?

[SuperEd73]

Once gain, I appreciate all the input!!

G-Man, yes I do suspect that I may have to deal with possible ping when I install the new vacuum advance on the carb. I'll deal with that when it finally arrives and I can put it on the car. Good tip for the initial adjustment as well. It doesn't hurt to have a baseline!

Fitz/Big_Jim, I think I'll invest in some Lead Substitute going forward just to be on the safe side. I don't push on the gas often but I do take it out on the highway on the weekends and I do give it a shot of gas at a traffic light once in a whiile just to surprise whatever pulled up next to me.

I also appreciate the explanation as to what actually happens to the heads when the seats are too soft. Wasn't really sure.

Off to the auto store I go...

Ed B.

 

[Bamaro]

You probably don't "need" it unless you drive it a lot and run it hard but even though I don't run my 70 Camaro like that, I always use a substitute in mine. I have used Bardahl Instead O Lead and also one from CD2. I get the containers that treat 240 gallons so it lasts me for awhile.

 

[ted s]

I Use Redlines lead substitute in my 300 and newport.

 

[BUBBA0420]

If you don't run the engine hard I wouldn't worry about it.
You could throw some MMO in the gas for an upper cylinder
lube. That wouldn't hurt a thing. If you want to run LEAD
in the gas you can still buy it.
www.batterystuff.com And look under fuel additives.

 

[SuperEd73]

Hi there, just wanted to revive an old thread. I still have the old Dodge. Just wanted to see if over the past 3 years opinions have changed on this one? Right now I've just been running premium fuel and usually put in the recommended mix of MMO listed on the bottle. I do occasionaly put some lead-sub instead of the MMO. Should I put anything else in the tank? Carb cleaner? Regane? Techron?

Thanks!

Ed B.

 

[ted s]

so what about 72-74 bb heads?

 

[andyd]

set the idle mixture a bit rich. I burnt 2 exhaust valves on a 66 Valiant slant 6 by leaning out the mixture too much when running lead free gas

 

[demarpaint]

Originally Posted By: andyd
set the idle mixture a bit rich. I burnt 2 exhaust valves on a 66 Valiant slant 6 by leaning out the mixture too much when running lead free gas


+1

As far as the lead substitute goes, Lucas UCL, TCW3, or MMO will help.

 

[Torino]

Put a gallon or so of blue avgas in it every once in a while. John--Las Vegas.

 

[Steve S]

I had a 70 Challenger with the hypo 4 bbl motor and aluminum manifold and headers, 4 speed . It wouldn't even compare to a big block.

 

[ted s]

huh? no idea what motor you had?

 

[TheTanSedan]

1971 Chrysler 383

One of my last posts on that car.

So long as I avoided long 75 mph runs with A/C at full and four other people in car, I didn't strain the engine. (I also wasn't doing burnouts). On occasion I would run some "jet fuel" (VP Racing Fuel) but that stuff was expensive AND I was told that it and 93-octane didn't blend well. But just a few gallons into that 23-gallon tank and top with pump gas seemed to help.

The main thing is to tune it for todays gasoline. You may need an entirely different set of ignition advance curves, and may need to re-jet carb as well.

When I pulled the heads on mine at 100k there was no apparent valve recession ('346's with non-hardened seats).

I ran plenty of FUEL POWER FP-60 and the idle was more stable on a hot soak getting off the highway and then being stuck at a light; plus was able to dial back idle speed a hair. Vacuum readings were good. This car responded REALLY well to FP-60. (Lucas was similar, but cost a lot more per gallon additional cost).

I also ran LUBE CONTROL LC-20 in synthetic oil. Recommend the MolaSoak to you next time you change sparkplugs. Fog the neighborhood after taking it for a run, and do the water-dribble-down-the-carb from an ancient Coke bottle like we did in the 60's and 70's then some fresh spark plugs.

BALDWIN B2-HPG is your oil filter friend.

You might do some more reading on the lack of zinc in todays oil to see if one of those additives is a good idea.

MMO, SeaFoam . . don't waste your money.

.

 

[morris]

any 1966 chrysler will NOT have a lean idle jets from the factory.
1968 was the first year for factory lean idle, they will have a slight flat on mid exhilaration. get the small drills out drill the idle drill it to .032 -.035

 

[dnastrau]

Originally Posted By: demarpaint
Originally Posted By: andyd
set the idle mixture a bit rich. I burnt 2 exhaust valves on a 66 Valiant slant 6 by leaning out the mixture too much when running lead free gas


+1

As far as the lead substitute goes, Lucas UCL, TCW3, or MMO will help.


A lean idle mixture should not burn valves as the idle circuit has a negligeble affect on the air/fuel ratio at higher speeds. This is where main jets, power valves, metering rods take over. The idle mixture screws basically affect idle mixture - not high speed mixture.

IMHO just adjust the idle mixture screws equally to get the best idle with the highest vacuum. All an over-rich idle mixture will do is waste gas and potentially give you a rougher idle quality.

 

[morris]

the idle jet and the idle mixture screws are two different things. when they put the lean idle jet in you cant compensate with the idle mixture screws. you have to take the top off the carb, then drill the idle jet. all chrysler cars from 1968 on have lean idle jets. i must have drilled at least 50-75 carbs. allso at some point they sealed the idle mixture screws. but theres a way around that to. i have a story about a 1969 dodge van with a slant 6, of my freinds that wouldnt idle. drilled the idle jet. we got it to idle at 300 rpm, no joke