Technical SBC heads non harden seat's will they work or not

Propane in trucks were in farm country many farm tractors used propane and because farmers were already there set up for it trucks were changed over

 

I was not talking about implements, since we are talking street vehicles here for the most part. I am aware that farmers have been using propane for a long time.

 

I use a fuel additive in my pre 72 engines. How much does it help, dont know, so far have not sunk any ex valves. I do not drive thar many miles which is another factor.

 

Whenever I spec an engine to be built for myself, I consider that I might not be the final owner of that engine.

When I spec one for a customer, I consider the same for that customer.

While you all might not drive much, will the next owner? You might drive 250-miles-a-year, will the next owner hit 36 car shows, across the nation, per year?

Big deal! Who cares? That's their problem, you might say.

One problem there, the reputation of the engine builder is on-the-line here too.

If an engine sucks in a few valves in 40k miles, because you saved $150 at the machine shop, not only will the current owner be pissed off, it will make the engine builder look really bad.

It is extra bad if the builder was you.

One more thing: gasoline from when most of the engines that we are using is not the gasoline that we are using today, and what we are using today will not be what we are using tomorrow. Fuel will continue to be revised, as will the modern US fleet. Our cars are an anecdotal footnote, that don't even qualify as a rounding-error.

It is up to us to make them work with what is on offer, or give up.

If you don't plan for the future, you may not have one.

As for all of the schemes involving actual Lead, you are not gambling with getting a "fix-it-ticket" for not having fenders, or loud exhaust. You are gambling with Federal law, and the penalties associated with doing that.

Getting caught pulling that sort of stunt makes the whole hobby look bad, and cold lead to unwanted legislative attention.

 

In referencing the initial question. At our machine shop, it is our practice to install hardened seats whenever possible on vintage engines. Engines such as the sbc as well as other engines with siamese exhaust port/valves are very vulnerable to sinking the valves on those ports in particular, due to the heat in that area. It is also the reason you often see head gasket issues on those type of layouts. OEM iron heads use induction hardening on the exhaust seats in most cases, but even Chevrolet installed exhaust seat inserts in many of the throttle body type heads from the factory in the 1990's. Back in the leaded fuel days, the lead in the fuel primarily caused a chemical reaction with the iron and actually self-hardened the seat. That is why it seems that many engines that were running during the changeover years saw no problems until they had their next valve job, and the seats were ground past the layer of hardening. For that reason, I think the guys running some leaded race fuel in their engines are spot on. Installing seats in old heads can also pose another problem, though, cracking under the seat. On many vintage castings there is much less material in the seat area to be cut out for a seat, and I have seen many that have cracked through behind the seat, after they were installed (most were double hump castings). In closing I think it's best to install seats whenever possible, and Mix in some race fuel when you can't. - Seth