manifold questions

Rossputin · Aug 23, 2009

Hello again, all,

My intake/exhaust manifold and the exhaust pipe, (which does a u-turn and sends the hot air downward, leaving the pipe around the level of the back axle, are completely rusted.

Do you think it's possible to use a knotted wire wheel or something like it on an angle grinder to get the rust off and continue to use the part, or do you think I need to buy new parts?

Also, what's the best way to clean the holes in the engine block which match up to the holes in the manifold? They seem to have a lot of black build-up.

Thanks again!

RGK

Janicholson · Aug 23, 2009

Rust is to be found on all cast iron exhaust manifolds. If you clean it to metal, and have it ceramic coated (never done to tractors, but found on some Jaguars and other high end cars) it would not rust. If it is so rusty that big flakes are chipping off, a minor wire brush is OK, but I would not get carried away. The tubing and muffler are just steel. They also rust soon after ownership begins. If rusted out, replacing with stainless steel is expensive, but last a lifetime. A small diameter rotar7y wire brush will work, but do not get material flakes or wire pieces down it holes, They can cause instant knocks and ring land collapse when the piston tries to compress a solid. Blowing a heavy blast of air through the spark plug hole through the open exhaust valve and out the open port. (requires doing each several times and getting the valves open fully when doing it because particles go everywhere). JimN

ScottyHOMeY · Aug 23, 2009

Careful on that manifold if it's really scaled up and don't get too aggressive in cleaning it up. You've been around here long enough to see posts about the running problems cause by vacuum leaks (at the gaskets or from holes in the manifold). If it semms llike it's at all fagile and you want to save it, I'd suggest a very light cleaning with a stiff but soft brush, then treat it with a phosphoric acid solution like Ospho or Jasco. That will convert the iron oxide to iron phosphate and will stave off further rust (same concept as the bluing on a gun barrel). It won't have a like-new finish, but it will be black when you're done and might add some life before it ultimately has to be replaced.

Best thing to clean up the inside is to have it tuned right. Soot in the intake ports of the manifold is a whole other thing, but you should expect some on the exhaust side. Carb adjustments will cut down on the extra fuel making soot, but a good hot run, properly tuned, will keep the soot down in that area.

Rossputin · Aug 23, 2009

Scotty,

That sounds like a good plan. Do you know if the phosphoric acid solution is available at Home Depot or any other place I'm likely to have around?

RGK

ScottyHOMeY · Aug 23, 2009

Not sure about the Ospho, but I've found the Jasco product at Lowe's and at HD. In the paint department. It's lime green in color (I think Ospho is more blue), in a round quart bottle. My brother couldn't find it and whether online or on the phone got in touch with Ospho and located someone in his neighborhood who carried it.

manifold questions

Rossputin

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Janicholson

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ScottyHOMeY

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Rossputin

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ScottyHOMeY

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