Lead Substitute

[John Parmelee]

I have a 63 250hp and in the past used a lead substitute along with premium gas. Is that still reccomended for are old high compression engines? Ifso, where can I get some?

Thanks

[Wayne W.]

Re: Lead Substitute

You dont need it.

[Ed Jennings]

Ditto *NM*

[Dave Suesz]

Yeah, you don't need it...

The lead was supposed the preserve the iron valve seats, that's why unleaded engines have hardened inserts. If you're driving your car 10-15k a year you might have to have inserts installed in your heads- in 10 years. This turned out not to be the bogeyman it was predicted to be when leaded gas was going away.

[Eugene B.]

Re: R U guys saving me $'s

Gentlemen,
I would be interested in more information regarding this subject.

I will soon be having my '65 250HP motor refurbished. I was planning to spend the additional money to have it converted to a "no lead" motor. It will be driven 5K-7K miles per year.

From the information above, I can save the cylinder head modification costs and never ruin the exhaust valves.

Right?

Thanks,
Gene

[John H.]

Re: R U guys saving me $'s

Gene -

At 5K-7K miles per year, you have many years of trouble-free miles ahead of you without any modifications (unless you plan on towing a loaded trailer at 100 mph)

[Dave Suesz]

IF...

your valve seats are worn down, the normal practice is to add a hardened seat. Ta-da! This is also the "unleaded" conversion. I had a '66 engine with well over 200k redone a while back, already had a couple of valve jobs. Needed 6 seats. I opted for 16, figured since the engine was already apart, I'd end the issue. Notice the mileage, at least 150k+ was on unleaded gas, engine has 10.5:1 compression. I gotta think unleaded is not a problem.

[Dennis C.]

Re: IF...

I lower the compression to about 9.5 - 1, put hard seats where the exhaust valves reside and drive the car. So far, seems to work well. Dennis

[Wayne W.]

Re: IF...

The Govt. did extensive test in `74 in conjunction with major university research labs. They tested under grueling conditions. The conlusions were that 1) unless the engine was used to pull continuous heavy loads at high engine limits, valve recession was negligible. 2) Additives were useless. If you added enough to reduce recession, you would gum up everything.

[Eugene B.]

Re: Thanks gentlemen *NM*

[Art B.]

Re: IF...

I used to put lead substitute additive in both of my C-1's. After less than a year, the spark plugs would foul. I quit using it and have not replaced spark plugs for several years.