The Stovebolt Site Forums The Shop Area Engine Shop lead additive???????? help please

hey gents. wondering if I should use a lead additive, or marvel mystery oil in my gas to lubricate the valve guides and the top end. I have a 1958 235 c.i. inline six engine.

Hello, Wendell,

No & No (No)
No need for lead additive in your gas.
No need for Marvel Magic Mystery Oil in your gas.
No need for any Snake Oil in any 235 that is in good condition, and is well-maintained, and is well-tuned.

What is your "top end"?

If you take your valve cover off and run the engine, does oil drip/leak out from the rocker arms?

Use an oil filter.
Use detergent oil (you might want to drop/clean your oil pan).
Use a gas filter.
Change the oil and oil filter every 3000 miles (or, earlier).
Keep you engine tuned (valve lash, carburetor, ignition system, timing).
Make sure your road draft tube is clean/clear.

If you want to lubricate the valve guides (and raise the octane rating slightly) add a gallon of Diesel fuel to 19 gallons of gasoline. It's just as effective as lead additives and/or "octane boosters" It slightly increases the specific gravity of the gasoline, and slows down the burn rate, both of which have the effect of a slightly higher octane fuel. A gallon of Diesel costs less than a pint of "additive" also.
Jerry

well thanks guys. oh boy.., I see replies with differing opinions.. It makes sense that the engine oil would most likely be dripping on the rockers, and that would seem like it would lubricate the valve guides ... May I ask you "hot rod Lincoln" your reasoning?
What grade of gasoline would you fellas use ? I used the "middle " grade ..87 . was there lead in the fuel back in 1952 ? I was not around until 1972.. lol. please understand I am not trying to pick a fight or cause argument. I am only trying to learn .. I do not want to upset any one . I am asking for opinions and the facts/ reasoning behind ones opinion.

There are no arguments above that I see, just additional info. Tim is telling you that no additional hoops need to be jumped through if your engine is in driveable condition. Jerry is advising that IF you decide you want additional lube to the guides anyway there's a more effective and cheaper way to do it than buying a can of additive. I don't use any additives in my '38 and have had no issues. Plain base octane regular will be fine for a stock engine in good condition.

Wendell,

Yes, there was lead in gasoline, "back in the day". It was a cheap way to cheaply raise the octane. It was also an effective way to raise lead levels in living organisms (in plants & animals, and in water).

Use regular gasoline in our low-compression Stovebolt engines - Chevrolet 6-cylinder 216, 235, 261 (and, earlier 6 cylinder).

Do not worry (much) about ethanol (10% does not seem to cause much harm). The only additive you might want to use is something like Sta-Bil in a full tank of gas, if you are not going to drive your truck for a month or three (winter hibernation, for example).

If you want to see some question-posting-fire, ask about ZDDP being necessary for Stovebolt engines.

87 is fine. Thats what I run, its low grade in my area. 89 is midgrade

Only concern you should have about gas is using it up, as tclederman pointed out.

Every old car and motorcycle forum has discussions on the topic of valve wear.

Controversial to say least especially as far a valve wear. Suspect the OP is concerned with area that this article addresses........Valve seat recession.

What valve reccession looks like:

http://holdenpaedia.oldholden.com/Valve_Seat_Recession
This engine was running on LPG.

http://automotivemachine.blogspot.com/2011/06/valve-failure-concerns.html


More info on the controversial topic:

http://chicagolandmgclub.com/techtips/general/540.html

https://oldschool.co.nz/index.php?/topic/20751-valve-seat-recession-explained/

https://www.jalopyjournal.com/forum/threads/unleaded-gas-vs-non-hardened-valve-seats.827920/

http://www.hotrod.com/articles/will-unleaded-gas-burn-exhaust-valves-in-muscle-car-engine/

While not being an additive fan.
Hardened valve seats during a valve job is one answer. Many believe it’s not needed ......that’s what makes it controversial. Under light duty use of a collector car plays a huge part in valve wear or lack of wear. Especially if your doing a complete valve job hardened seats install and never look back makes some sense.

I've run my '49 216 as a daily driver for ten years with no additives and I always use the cheapest gas. I've found that my truck doesn't run as good on mid and high grade fuel. If you want to use additives go ahead. The only thing it can hurt is your wallet. I have to admit though, Hotrod Lincoln has me considering the occasional use of diesel fuel. Safe for the engine and the wallet.

A little Diesel is good- - - -5% or less by volume. A lot isn't necessarily better. Putting a TINY amount of gasoline in a Diesel fuel tank supposedly helps keep the injectors clean, but don't overdo it. I'm headed to Washington state next week to inspect a brand new 2018 Freightliner that hand-grenaded the engine when somebody topped off the fuel tank with unleaded gas!
Jerry

Jerry,

Should we change any engine settings (timing & carburetor mixture) if you add a little diesel?

By the way, Jerry, it was nice seeing you calling (in an earlier post) the low-pressure 216/235 engines as "spray oilers" - that designation is much better than the fuzzy/incorrect designation of "splash oiler". I'll be using your "spray oilers" designation in the future.

Thanks,

I don't consider the "improvement" in burn rate or apparent octane rating worthy of tinkering with timing or mixture- - - -it's just a little fudge factor that might prevent detonation on a hard uphill pull, and keep the valve guides a bit slippery from the oily consistency of the Diesel. Back during the Korean war, most of the good-quality gasoline got shipped across the pond, and civilian supplies of gas were notorious for causing carbon buildup in engines. Aftermarket "top engine oilers" got pretty popular that dribbled a tiny bit of "tune-up oil" into the intake manifold through a TINY piece of copper tubing, about 1/8" OD. The oil supposedly lubricated valve guides and minimized carbon buildup on valve stems. Most of those systems used a 1/2 gallon glass jar under the hood with a needle valve adjustment that needed to be refilled every couple of months. That's where Marvel Mystery Oil got its start, I believe.
Jerry

thank you everyone!