Removal of 1 inch steel pipe from an aluminum head

[dana a]

I have a 1973 Craftsman Surburban with a Tecumseh OH160 engine. The seat for the exhaust valve dropped out of the head. I have another good head. I need to exchange the steel exhaust pipe from the bad head to the good head. Do any of you have any ideas on how to get these pipes out of the aluminum heads? Thanks for any help.
dana a

 

[Rivets]

I would soak with PB Blaster for 24 hours and then slowly heat the head with a propane torch. Using a pipe wrench keep constant pressure on the pipe and it should come free.

 

[sgkent]

as said, PB Blaster for 24 hours on the threads or Liquid Wrench. Iron/Steel rusts, and when it does it expands as it absorbs O2 molecules. A true penetrating oil will have chemicals in it that cause the red rust to change to black rust, which has a smaller molecule size. As the rust shrinks it will help pull the penetrating oil in. Heating the head will cause it to expand and make the removal easier. If that fails get it hotter.

 

[bertsmobile1]

Red Rust = Fe2O3(4 to 6 H20)
Black rust ( actually called mill scale because it forms at higher temperatures ) FeO
FeO is much much stronger than Fe2O3 and a lot more chemically stable.
This is why black iron does not rust very quickly
Black oxide ( technically it is not rust ) is also very porous which is why it takes up an oil film so well to resist rusting.
Basic rules of entropy
That which is formed and stable at high temperatures is very stable at room temperature
Heating the head drives off the water ( which is what makes red rust flakey ) and provides entry cavities for the penetrant / solvent
And because Al & Fe expand at different rates mechanically fractures the bond between the Al2O3 ( aluminium oxide ) & and the Fe2O3 (rust )
In both the cases they jointly hold onto the H20 and some times can even share them
And FWIW the white fluffly oxide on aluminium in damp environments is Al2O3(6H2O)

penetrants / rust release agents that leave a black finish are Phosphates not oxides
And this includes all of the solutions like Rust Buster / Ferro Pro etc

 

[Hammermechanicman]

I have a 1973 Craftsman Surburban with a Tecumseh OH160 engine. The seat for the exhaust valve dropped out of the head. I have another good head. I need to exchange the steel exhaust pipe from the bad head to the good head. Do any of you have any ideas on how to get these pipes out of the aluminum heads? Thanks for any help.
dana a

I have a STRUCK tractor on the shop right now with a OH140 on it and i have a 70's Sears suburban in the barn with a OH160 i want to restore. I have a HH120 on a Sears ST12 i blow snow with and a VH100 on an old Bunton walk behind. I really like the old cast iron tecumseh stuff.

 

[dana a]

I have a STRUCK tractor on the shop right now with a OH140 on it and i have a 70's Sears suburban in the barn with a OH160 i want to restore. I have a HH120 on a Sears ST12 i blow snow with and a VH100 on an old Bunton walk behind. I really like the old cast iron tecumseh stuff.

I've taken a lot of small engines apart. I was really impressed with this OH160. It ran for 49 years till it dropped the exhaust valve seat. I think it's really built strong and I've never seen a small engine with tapered roller bearings on the crank shaft. My OH160 has 2 counter weight gears in the bottom of it. I also have a parts engine and it doesn't have the counter weights. I was told I could just leave the weights out. I figured with the piston at top dead center that should keep the engine balanced if slid back together standing upright. What do you all think?

 

[Hammermechanicman]

It will run without the weights.
Yeah, the things were built like tanks. As long as you don't over rev them they last forever.

 

[dana a]

It will run without the weights.
Yeah, the things were built like tanks. As long as you don't over rev them they last forever.

Will it run just as well without the weights as with? Did you ever put one back together with the weights?

 

[Hammermechanicman]

The engine will vibrate more without the weights i assume. I did a Frankenmotor to save a blown HH120. Used crank rod and piston from an engine that was supposed to be a Dyna-Static balanced engine and used them in one without. None of my engines have those weights. What is the complete engine code off the engine with the weights? Like OH160-1700xxx

 

[dana a]

THE ONLY NUMBERS on the engine are the Sears numbers. There are no Tecumseh numbers. I started the first sentence a few days ago and never posted it and was surprised to see it still there. I was able to get the pipe out of the damaged head and it brought the aluminum threads with it. The good head has a street elbow and I'm going to leave it. I have the engine put back together and on the tractor and started it today. It runs pretty good but the carb needs some adjusting. Then I noticed the vent in the top of the valve cover was puking oil out and the needle jet thing on the bottom of the carb bowl was leaking gas. I took the needle thing out and saw there was no packing to prevent leaking. I assume there is supposed to be something to prevent gas from leaking so I found a small "O" ring and put it on the needle. Next I took that vent thing off the top of the valve cover and cleaned it in gasoline and blew it dry. I thought maybe that valve in the vent may have had something keeping it open. I sucked on the hose and there was no resistance but when I blew into the hose there was resistance but air did pass thru it. I didn't think any air should go thru it. Is that valve supposed to keep the airway completely closed on the up stroke of the piston or just partially closed? I took it outside and started it and the gas leak was fixed and there wasn't any oil coming out of the vent, but I didn't run it as long as I did the first time. I'll try it again tomorrow.
I think I read that the carb screws are both supposed to be set at 1 1/2 turns out from closed to get it started. I'm not very good at tuning a carb. Can anyone give me some pointers on how to do it?