Back! (With my OC-46 again.)

[Dianne]

It has been a long time since I have been here - back in about 2005 when I was rebuilding my 1952 OC-46 with the 3 cylinder Hercules engine. I rebuilt it from a pile of scrap, used it for a few years for some major work around the property, and then  it has been parked for quite a few years.

I needed it again this summer so I got some fresh gas, topped up the fluids but, when I did I had coolant coming out of the exhaust manifold  My friend came over with his big Case tractor and helped me get the loader off and this afternoon I pulled the cylinder head. I can't SEE a hole between the coolant passage and the cylinder but the way the coolant came pouring through, there has got to be one there somewhere!

The cylinders look okay but I need to get a valve spring compressor and take the valves out to get a good look in the head. I suspect a cracked head. A good friend is an excellent welder so I have asked him  to have a look at it. I hope to gawd that I can fix this head! There is probably less than 50 hours on it since new valves, guides, seats, and springs! If it can't be fixed, I am going to be on the hunt for another head 

Thankfully it cranked okay once I got the head off (after I gave it a little "encouragement" with two 12 volt batteries in parallel ROFL!)

Anyway, just thought I would drop in and share my misery LOL!

[Dianne]

Found my problem! A piece of  cast is  completely broken out on the #3 exhaust port directly into the coolant passage. Still haven't heard from my welder. I wonder if I could sleeve the exhaust port with some stainless steel and high temperate adhesive? Wonder if anybody makes an adhesive that holds up to exhaust temperatures right next to the valve?

I would hate to have to  change heads. This one has less than  50 hours on it since a complete rebuild!

[Blake Malkamaki]

It's hard to tell from your picture... how far from the seat and how far from the valve stem is the hole? Could it be plugged with a pipe plug and then machined off? They do install hardened valve seats and use some kind of adhesive to hold them in, so there is something that will hold up.

Blake

[Dianne]

... how far from the seat and how far from the valve stem is the hole?

The hole is about half way between the  valve stem and the manifold mounting face but it is 1/4" wide and 1/2" long. It also includes a radius where the more-or-less round passage transitions to rectangular  so a threaded in plug would have to be pretty large.

I was also concerned that if I had one spot that corroded, gawd knows what other flaws there might be!

A replacement head seemed like a good idea under the circumstances.