Valve seals on my B head

Jeff B. · Apr 3, 2010

I want to start off by thanking all of you whose knowledge of these little tractors makes my path a LOT easier. If I"d have listened to my parents as well as I listen to you guys I"d be a lot better off, lol.
I don"t always follow up on my posts or say so, but everyone that"s here on YT are great folks. Thanks again.
My question for tonight concerns valve seals on my newly machined head. The guy put umbrella seals on it, but the AGCO book doesn"t show any seals at all. Should I take them off before I get done, or what? It will be easy to take them off, but what keeps the oil from running down the valves? It"s got new guides, so it shouldn"t be a problem right away. What was the original thinking on this issue?

Jeff Z. · Apr 3, 2010

You may find using seals on these engines will not let the guides get enough oil.
I would remove them.

DickL · Apr 3, 2010

Your answer is in your post!

Allis Chalmers didn't design the head to need seals and you now have new guides.

They are not needed.

If you remove the seals the valve guides will last longer. If you are not going to use your B as they were bought new to be used to farm 80 acres or mow 5 acres of grass a week, you will most likely not live long enough to have a problem leaving them on.

carbonfibers · Apr 3, 2010

Where did you get your engine head rebuilt? I need to do the same thing on my B. Did you install hardened seal faces to accomodate the unleaded fuel?

Thanks,
Wayne

Anonymous-0 · Apr 3, 2010

If youre guides extend up and are on the same plane as the machined surface for the valve cover gasket then take them off . If the guides have been cut and are below the valve cover gasket machined area leave them on .jmho

Anonymous-0 · Apr 3, 2010

where carbon fibers are you located . We are in Tn and can do what you need from seats to new guides. We strongly believe in bronze guides over the oem cast iron ones those and have vendors for them along with hardened seats.

carbonfibers · Apr 3, 2010

I am in Destrehan, Louisiana about 8 miles west of the New Orleans Airport.

Wayne

DickL · Apr 3, 2010

Bronze guides are fine but run the cost up quite a bit and if you use hardened seats you also do not want to use (oem) valves. I have pictures of standard valves run on hardened seats. They will pound a groove in the valve and remove all chance of grinding them for reuse again.

I have about ten years of mowing at least once a week with unleaded gas. I had a knock last summer and took the engine down. I pulled the valves while I had the head off and sparked the seats and valves. No sign of unleaded fuel causing a problem. They did not need to have anything done.

When I put in new seats I use the new old stock cast seats rather than hardened seats with both oem valves or small block Chevy valves.

Anonymous-0 · Apr 3, 2010

yes dick it does run cost up a tad and for the harden seats . I like them on the exhaust as for the valves I havent ran into to many that arent in need of new exhuast valve its hard to make anything out of the ones that have had years of pitting due to rainning down the exhaust pipe. Customers always have options as long as reasonable such as bushed guides etc.

BushogPapa · Apr 3, 2010

You WILL want to at least leave the Umbrella seals ON the Intake valves...!!!
There is NO reason to remove them..they will only shed the oil that would run down the stem and get sucked down the intake..
As for the Exhausts, what ever you like, but the exhausts will not suck oil down like the intakes will..
Just because there were non used when the tractor was made does not make them a "bad idea"..!!
Do you actually think they had a product that could have been USED in there, way back when..??
probably NOT..!!!

Ron.

Bob Bancroft · Apr 3, 2010

Interesting discussion. Last head I had done they didn't replace the guides. They bored, drilled, or otherwise opened them up and put an insert in there. New seats, valves, and springs, no seals. Works great. I assume the inserts are what you reference.

Anonymous-0 · Apr 3, 2010

Ron actually if you follow allis chalmers build to the tee of making sure the guide is level or slightly above the machined surface for the valve cover gasket. No more oil gets into the cylinder than it would with umbrella guide seals .But if you overlook that little detail in the book you need them . Or you will need them if you run a shorter valve and had to trim the guide down .

DickL · Apr 3, 2010

No more oil will get by the umbrella seals than the lip seal on the crankshaft.

DickL · Apr 3, 2010

What engine? New guides for a B would only cost a portion of the cost of boring and putting in an insert. I can press out the old guides on a little four cylinder and press the new ones in in less than an hour. To bore would involve a set up on each guide before boring it out. I just set the punch guide in the valve guide and press it out. I use the same tool to press the new ones in. Different engines can take different types of guides which uses a different way of replacing them. This conversation was about the B, C, or CA.

Bob Bancroft · Apr 3, 2010

ASEguy · Apr 3, 2010

I would NOT use valve seals if they were not used as OEM equipment. Insufficient valve stem lubrication can not only speed up valve guide wear, but also not allow the valve to properly dissipate heat. Oil clearance is for both concentric valve seating and heat dissipation through the oil clearance specification.

Anonymous-0 · Apr 3, 2010

(quoted from post at 18:01:56 04/03/10) What engine? New guides for a B would only cost a portion of the cost of boring and putting in an insert. I can press out the old guides on a little four cylinder and press the new ones in in less than an hour. To bore would involve a set up on each guide before boring it out. I just set the punch guide in the valve guide and press it out. I use the same tool to press the new ones in. Different engines can take different types of guides which uses a different way of replacing them. This conversation was about the B, C, or CA.

Dick whats the replacement guides from Allis cost the bronze guides are 5.79 a piece my cost.

BushogPapa · Apr 3, 2010

Sorry, Pankey, but I guess you missed the idea of Vacuum being applied to the Intake valve..
Some of your comments border on nit-picking and smart-assisms..
Leave the Umbrella seals ON, at least on the Intakes..

Ron..

DickL · Apr 4, 2010

Just hold on to that thought tight.

I know you will but the evidence is in the pictures.
That is why I take them.

Jeff Z. · Apr 4, 2010

I have two B"s and 2 C"s that work hard all summer. No valve seals. Engines have run fine for 60 years.
The two B"s mow eight acres of grass and the one C was used to cultivate 70 acres of potatoes.

Jeff Z. · Apr 4, 2010

The little bit of vacuum and oil that will get by the guides will not affect the way these engines perform.
We are not building 9000rpm racing engines here.

PS: For people who have no respect for someone's opinion go somewhere else a post your remarks.
They are not welcome here.

Anonymous-0 · Apr 4, 2010

(quoted from post at 21:18:18 04/03/10)
Sorry, Pankey, but I guess you missed the idea of Vacuum being applied to the Intake valve..
Some of your comments border on nit-picking and smart-assisms..
Leave the Umbrella seals ON, at least on the Intakes..

Ron..

I guess ill be nitpicking and smart assism the valve cover is vented to atmosphere for a reason also.

Valve seals on my B head

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