Pinto engine conversion

[40 Deluxe]

Originally Posted by Lannis

The LP gas thing jumped out at me, because in my experience with Morgan +8 8-cylinder cars with LP fuel What would there be about LP powered engines that would wear out the top ends prematurely?

(I have a 4/4 now ...)

Lannis

LP is a "dry" fuel, that is, it does not do any lubing of the top end. Thus, exhaust valve seat recession is a problem, especially in heavy duty use like big trucks. Hardened valve seat inserts are necessary.

[Lannis]

Originally Posted by 40 Deluxe

LP is a "dry" fuel, that is, it does not do any lubing of the top end. Thus, exhaust valve seat recession is a problem, especially in heavy duty use like big trucks. Hardened valve seat inserts are necessary.

How are top ends in post 1988-cars lubed in this era of unleaded fuel?

Lannis

[40 Deluxe]

Originally Posted by Lannis

How are top ends in post 1988-cars lubed in this era of unleaded fuel?

Lannis

Usually the exhaust seats are induction hardened. There seems to be some kind of difference in the exhaust gas content of LP versus unleaded gasoline. In my career as a mechanic I saw a lot of LP engines with sunken exhaust seats, but very few gasoline engines. The exception being Dodge pickups with the Magnum 360 engine. I worked on a fleet of them at the AZ Hiway Dept. First we had the 1 tons that were used hard. The exhaust seats would recede to the point where the lifters were bottomed out and valves couldn't close. Soon the 3/4 tons started coming in with the same thing. After some more time and miles, the 1/2 tons started failing.

[ModelA29]

Originally Posted by 40 Deluxe

There seems to be some kind of difference in the exhaust gas content of LP versus unleaded gasoline. In my career as a mechanic I saw a lot of LP engines with sunken exhaust seats, but very few gasoline engines.

LP was called a dry fuel and it had no lubrication properties. The harder valves would wear the cast iron heads (or block). It also did not contaminate the oil. Early cars didn't really need lead since the valve spring tension was so low they didn't eat the seats. Ethyl was used mainly to increase octane in aircraft engines to begin with. After WWII compression ratios were going up so they started adding it to all gas. Dow had built a couple big plants to produce it. 2,000 gallons of seawater made 1 pound of bromine and they were producing 15,000 pounds a day.
https://www.dncr.nc.gov/blog/2016/01...ion-kure-beach
They sent my grandfather to the Ethyl plant as head of maint. He lived on site and they got shelled by a Uboat in WWII (it missed entirely). Later he oversaw the building of the Texas plant. Pretty good for a kid that started out at the Dow family chauffeur - his sister got him the job. She was Mrs Dows seamstress.


Tetraethyl lead (TEL) in gasoline was initially used to increase octane and also acted as a lubricant for valve seats, preventing valve seat recession.