valve seats

H

Hank Z

New member
I have recently been told that if I don't install valve seats in my model A block I will have major problems down the road because of the lack of lead in the gas. also that adding a lead additive makes the fuel too heavy for the updraft carb to run right. any thoughts?
 
The Model A was designed and built before the widespread introduction of lead into gasoline. Don't see why using "unleaded" gasoline in it would hurt one bit.

As to the leaded fuel being too heavy -- They seemed to run OK for years with leaded gasoline.
 
Leaded gas was not widely used in 1930. Modern gas does have lubricating additives I believe. One of my engines has hard seats on the exhaust, the other does not, a nd no trouble with either. If you are having the engine rebuilt, hard seats do not add a lot to the bill, and it will renew the height of the seat, as your block has perhaps had the seats ground a few times, and may sit low. If you do not plan to rebuild the engine right now, I would not worry about it.
 
I do not think that hard seats are needed for Model A engines. If one insists on hard (stellite) seats then they should be installed on the exhaust valves only. The cost is moderate. Think about if they loosen up and cause trouble down the road. It has happened to others, not me. If they are not there, they cannot cause problems.

Vic
 
Hank Z said:
I have recently been told that if I don't install valve seats in my model A block I will have major problems down the road because of the lack of lead in the gas. also that adding a lead additive makes the fuel too heavy for the updraft carb to run right. any thoughts?
Click to expand...

I haven't heard the RUMOR for a few years now. I thought it finally died, but I guess not. I would not install valve seats unless they were needed to repair a crack or the original seats are recessed.
 
You need to find another source to listen to.
Maybe try your plumber, the advice will be just as useful.
Valve seats are not needed.
Lead additive too heavy? That is REALLY funny.
 
Lead was for high compression engines.
As the Ford was to be sold on the world market I doubt it was designed for lead.

ethyl-gaslarge.jpg
 
Tom Wesenberg said:
I haven't heard the RUMOR for a few years now. I thought it finally died, but I guess not. I would not install valve seats unless they were needed to repair a crack or the original seats are recessed.
Click to expand...

Again, I agree with Tom.
This topic came up a while ago and I'll repeat here, the comment I made then.
I see no point in removing good solid cast iron from the area of the valve ports to replace it with a hardened seat which may come loose. These blocks are prone to cracking at the valve seats (especially if they get hot) so why would you make the area weaker?
 
Hank Z said:
I have recently been told that if I don't install valve seats in my model A block I will have major problems down the road because of the lack of lead in the gas. also that adding a lead additive makes the fuel too heavy for the updraft carb to run right. any thoughts?
Click to expand...

Wow, I was so caught up in the first part that I totally missed the second part that someone told you.:o

That's a new one I'd never heard before. I don't know how to even respond to it, except to say "it's a gas".:D
 
Hank Z Wecome to the barn! Someone is not just pulling your leg, but both legs!
But just but, when we stop our motors and gas drips out the carburetor, just could the drips be extra lead falling out of suspension and not a bad float/seat :-). And any oil you like
is far better than oils back 80+ years ago. There are no Dumb questions, some jog our minds, some piss us off, some just make us laugh. Again Wecome have some fun,learn and get expert help at the barn!!!
 
well folks, I sure do appreciate the speedy feed back. It appears I can delete that worry and source. next question i have is what caused a piston to crack? I was cleaning the carbon off the top of them and noticed it. the intake valve was not seating properly on that cylinder causing the backfiring.? sorry forever4 about my lack of decorum. I will try to do better next time.
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Gathering information by reading and hearing from others is one way to learn.

Gathering information by experience is another.

Agreeing with that stated above, I drove my Model A for over 25 years with Amoco lead free gas with absolutely no adverse effects on valve seats or valves.

Experienced that plugs stayed much cleaner as well as the combustion chamber.

For those later "searching" for this valve seat subject, there are at the least two (2) statements still heard often today that we can rightfully dismiss in 2016 as 100% B.S.:

1. You need hardened valve seats in your Model A to burn unleaded gas.

2. I have no "Classified Information" on my server.

No doubt there will be more ..... we just have to wait.
 
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