With flathead engines having the valve seats in the engine block, how do the old flatheads hold up with undeaded fuel? Can machine shops fit new hard steel valve seats into the flatheads? What is the view of using lead substitutes in the fuel of engines never overhauled and fitted with harder valves and valve seats to withstand the higher temperatures of 'dri' unleaded fuel? (I am thinking about this issue in anticipation of picking up my recently purchased '51 F1.) I have been using CD2 lead substitute in my 70 MGB, but the engine is being overhauled this winter with hard valves and valve seats being fitted. On tear down, the valve seats were badly erroded.

 

The '51 and older flatties had hardened exhaust seats, but they were dropped for '52 and '53. Even though your truck is a '51, I wouldn't count on it having hardened seats, though. It would be fairly rare for a 50-year-old truck to never have had a rebuild or an engine replacement. You wouldn't know for sure unless you opened it up.

But with that being said, yes, it is possible for a machine shop to install hardened seats. They do it all the time. Some machinists and machine shops might balk at doing that kind of work to a flattie, but any machinist worth his salt can do it. If you ever get to that point and have trouble finding someone, I can put you with my guy in Lafayette. He loves these old Ford motors.

As for whether or not the lead substitute is necessary, I personally wouldn't worry about it. You can use it if it makes you feel better, but the only engine I've ever found with serious seat recession problems was a '60's small block and it had been ran HARD. Besides, the valve spring tension in these things is pretty low and they don't turn that fast.

Ya know, we're only about 40 miles apart. We ought to get together this spring and talk trucks!

 

I'll be coming right by Otterbein (231 & 52) when I head to North Salem to collect the pickup I have purchased. I often prefer that route rather than I65, even though I live 1 mile west of I65 on SR 114. (the 215 exit between Morocco and Rensselaer) Maybe we could meet for a brew at the 100 Mile Steak & Chops place in Fowler. My wife and I enjoy a meal there occasionally. Thanks for the info!

 

I wouldn't waste the time or money putting hardened seats in a flattie, and I sure wouldn't want to thin the deck or valve pockets down any more to install them. Contrary to what is frequently posted, lead was bad for valve seats, but good for octane. It didn't "protect" seats, it caused deposits that could lead to burned seats.

"Lead substitutes" are just Marvel Mystery oil or similar, no benefit proven in any tests.

 

Hmmm...... North Salem...... Would that happen to be a red truck that you found on an eBay classified? If so, I tried a couple times to talk myself into calling him, but the last thing I need right now is a third Bonus Built. It sounded like a pretty good deal. If you ever need help, parts, etc., don't hesitate to give me a shout. And yeah, I'd love to get together for a beer. Let me know when and I'll see what I can do. I work and sleep odd hours. I live in Otterbein, but my trucks are actually in storage in Templeton. You'll pass within 200 feet of them as you head east. Small world!