Removing an early CC exhaust elbow?

[John DeBree]

I have a couple K161's off of Model 70 CC's. The exhaust elbows are in pretty good shape, but seem to be virtually fused to the engine block by 60+ years of rust. Are there any tricks to removing them, or should I just leave it? New ones seem to be made out of unobtainium, so I'm afraid of damaging the elbow, or worse, damaging the engine block. I wire brushed the visible threads, and have been soaking them with penetrating oil, but I'm not optimistic. I don't HAVE to remove them, but I'd like to while I'm cleaning up the block.

 

[PACub100]

Heat. Use a torch and heat up the elbow and surrounding area and apply even pressure to break free. Trust me, don't use jolting or tapping methods like the PO did to the 1650 I'm working on...

 

[mgwin]

You mention you have been using penetrating oil. Have you used any PB blaster? This stuff works better than anything I have used.
Not knocking anything else, but it has worked wonders with me.
Make sure the locking nut is plenty loose.
I used PB on an exhaust elbow on an original. I also had to get my nerve up.
Soaked it good and left it for about two weeks. Soaked it good again and left it for a day or two. (still getting my nerve up)
Finally got up enough nerve, sprayed it once again and tried it. That sucker came right out with a decent amount of even pressure. I would have never believed it!
Here is a pic of it on the left, before loosening the nut and spraying it with PB:

 

[John DeBree]

Yeah, I'm using PB Blaster. I'll keep soaking it a while longer before I have a go at it. The lock nut is loose on mine- stripped, actually. I took a wire brush to the exposed thread to give the PB more of a fighting chance.

 

[glippert]

"New ones seem to be made out of unobtainium"

Cracked me up!

 

[John DeBree]

Somewhere I saw a new Kohler one for $147.

 

[dware]

Somewhere I saw a new Kohler one for $147.

Next time try some Kroil oil , some call it Kano Kroil. First used it in an oil refinery breaking bolts subject to high heat and salt water.
I find it superior to PB Blaster .
Be very careful with heat , the block is cast iron and can crack with heat .

 

[John DeBree]

I have a can of Kroil as well. I'll hit it with some of that, too. I've read that a 50-50 mixture of acetone and automatic transmission fluid will out-perform anything else, but I tried it once and was underwhelmed.

 

[dandre]

I have had good luck heating and melting wax into the joint. I don't know why, but the wax seems to soak into the rust.

 

[lelder]

May laugh me out of here but---- heat up block slowly then squirt amonia inside elbow best ya can and back it out.

 

[danderson]

I have had good luck heating and melting wax into the joint. I don't know why, but the wax seems to soak into the rust.

Capillary attraction.

 

[Dan Page]

My cub has the head stripped. I will attempt to make an adapter, it looks like pipe thread so if it can be tapped out a little larger I will put a sleeve in it and attempt that. I don't know if it would be a good idea but in the collision trade we use what is called shrinking. You heat the part up to red hot and dowse it with water causing it to shrink. Works good with sheet metal etc but I do not know if it would work on a larger part. In addition if it is a cast iron piece do not even try it.