The Stovebolt Site Forums The Shop Area Engine Shop Lead Additive 235 anyone????

I filled up my fuel tank for the first time the other day. Since all you can get these days is unleaded gas and it was designed for leaded fuel, should I be using a Lead Additive in my 1954 235-6?

Well I decided what could it hurt and dumped in a bottle of it. I also filled with the highest octane that I could get. First time I figure, let's splurge a little.

There is no sense in taking the cylinder head off and install new valve seats, just to be able to burn leaded gas, for no more than a bottle of lead substitute cost.

On my Model A **** , I machined the block for harden Stainless Steel valve seats inserts, but I was already in the block for an overhaul and that was the time to do it.

With the 235, I don't know if they have valve seat inserts or not and if they do, are they heat treated?

What do all you other Chevy owners do, with an older engine, that you are running on today's fuel?

John Niekamp

I've run old engines hard on unleaded for years with out a problem. If you plan on hauling heavy loads and really working the engine, go for the harden seats. Even a daily drive can live a long life with out them. Its made it this long hasn,t it? Joe

The compression ratio of the motor is so low, that hi-test is an absolute waste of money and you may cause damage. Good quality 87 is way more than what these trucks were meant for. Fire up your owners manual, and you'll see what I mean.

Lead provided lubrication for the old unhardened valve guides. If your motor was rebuilt after 1982, it is most likely ok with hardened guides.

I'm not sure that I share K10's views, but then again, I run 93 in almost every vintage engine and especially in the bikes. It makes a huge difference in some engines, and not so much in others. Like in life, timing is key.
[img]http://www.oldgmctrucks.com/smilies/gmcsmilie.gif[/img]
[img]http://www.bmwmoa.org/forum/images/smilies/1drink.gif[/img]

Kook
I always thought it was the valve SEATS that were replaced with hardened ones. Do the valve guides also get replaced with hardened ones?

Kook, I believe tetraethyl lead was originaly used for octance boost, but as a side benefit it helped transfer heat from the valve head to the seat.Normal cast iron guides have no problem with modern fuel.Without lead, the exhaust seats and valves run hotter causing errosion of the seats, thus the need for seat metal resistant to the errosion.
Usually the seats aren't a problem if the engine is not used too hard. But old valve seats get pounded from years of use, recessing the seat and even peening it over.The recessed valve hurts breathing and decreases spring pressure and changes valve train geometry because the valve stem sticks up higher.When replacing the seats, the valve is restored to original specs.By the way, stainless exhaust valves were used as far back as the 30's ,but it makes sense to replace the valves when doing the head, 235's can use Chevy small block exhaust valves.If you'r doing the head, the 70-100 bucks for new seats is money well spent.

Tony/Brian - Brain fart - SEATS is correct.

It doesn't hurt to run your valve lash a bit on the loose side, especially in the summer. That keeps them on the seat a bit longer and transfers the heat better. Running your exhaust valves at 0.018 instead of 0.012 does absolutely no harm and doesn't affect the performance much. It may run a bit noisy but its good for the valves.

I use the lead substitute all the time in all my old vehicles. Saving $1 per fillup so I can spend $600 to rebuild the head sounds like bad math to me.

My opinion of the un-leaded gas, causing valve burning and seat problems, is about the same as the R-12 versus R-134a Freon systems, won't interchange hype, when 134 first came on the market. I have been running a '40 216 engine, '59 283 engine,'69 396 engine, '69 383 Mopar and '66 421 Pontiac on unleaded gas, ever since hi-test leaded gas was taken off the market. Not saying I might never have a problem, but so far no valve or head problems. Is the lead additive needed? It won't hurt, but nothing bad happens if you don't use it. This is from my personal experience, over the years, someone else may have a different opinion.

I like to spice up my old ORIGINAL Stovebolt trucks with some 140 octane aviation fuel & a fuel preservative along with "Turner Laboraties" Lead Substitute.
Look for the one that says "Real Tetraethyl Lead ".

Kook ? .. you are a chemist ?? Whats your take ?

In one rebuild book I've read (can't remember which one, might even be for the Sprite) it mentioned the hardened seat issue. What the book said was, if the head has any decent amount of miles on it from the time before no-lead, there is probably enough lead embedded in the seats to protect them for quite some time. No need to rush a valve job until actually necessary, and use additive only if it makes you feel better. I have no idea how accurate that info is, but it was in the book. Any metalurgists out there to debunk this theory?

Metal gets work hardend from repeated hammering. I suspect that if the seats don't get hot enough to anneal then they are hard enough to be safe, if they had enough miles with lead on them. The seats on my engines are fine and I never run them with lead. I figure the rings are going bad before the valves anyway, the way I drive. I watch for seat recession by checking the valve clearance. If they get tighter over time the seats are burning but if they get looser the valve train is wearing.

The valve seat recession is caused by micro welding of the valve head to the seat by high combustion temperatures in modern engines.

In my fuel tank I use an octane booster and a lead substitute.
In my oil I use an oil additive.
In the cab I use an air freshener.
In the tires I change the air with fresh on a monthly basis and add tire conditioner.
Rain X on the glass.
Wax on the paint and brightwork.
Don't forget the anti static powder for the radio.
Armor All on the seat.
Graphite in the locks.
Silicon brake fluid.
And I wear a condom when I drive.
Nothing can happen but it costs me about $200 per fill up.

What additive do you put in your red taillight fluid? And what kind of lubricant do you put on the muffler bearing?

This thread is a perfect example why I love this site... Good info that cracks me up at the same time. Although some of it aint exactly useful info... I run hi octane in anything that sits, cause I cant drive em all, and a carb cleaning or fuel additive to keep the varnish away just aint my style. I think for all the years my toys get stored with hi octane, they have cleaner fuels resulting in less junk in the system to cause problems. I do use the lead additive in the ol 6 tho, just cause it does make me feel better about that heat transfer theory. By the way, where DO ya get that good taillight fluid...

Don't forget the Tornado to make the intake air swirl.

And magnets for the fuel line and oil filter!

I'm waiting for an amber fluid additive so I can update to more modern looking turn lights.

Jim

There is a point at which I must make protest.
I must vehemently disagree with Tony!
Armor All is junk! Never, ever put it on a condom
OR a car seat! Use Maguires!

Where do you get a condom big enough to put on your truck?

As for the lead issue, when I bought my 52 I went to WallyWorld and got a quart bottle of lead substitute and put it to use. No valve problems. When I bought a used 235 from a friend, it had two burnt exhaust valves, he did not run a lead substitute. I had the shop install hardened seats and moved on.

Armor Al should be banned, use KY Jelly.