An inept machine operator, (who shall remain un-named) managed to grind through one of the intake ports on my '56 heads. The hole is at least 1/4 inch in diameter, about 2 inches down the port. Can this be repaired with a welder and re-ground, and if so, what is the procedure?
There's a local shop here that does that type of work almost exclusively, and gets rave reviews. I've had the opportunity to speak with them, hang out a little, and watch 'em work. The key seems to be to heat the casting until the whole thing is completely red-hot...then weld...then cool...then machine. They make an "oven" specifically for each job. It's pretty basic, and simply consists of some sort of "fire-bricks" or blocks of various sizes, stacked into a box in a size that will accomodate the casting being worked on...a bottom, sides and top, with an opening at one end. Once the casting is enclosed in this fire-brick structure, they insert a large torch into the open end, and start heating the part. Takes some time, but after a while, the whole casting is red-hot...then they do their work. From the talk I've heard, there isn't much they can't fix.
You might get yourself a Hemmings and look in the Services section for Cast Iron Repair. Might be somebody near you. If you look online I have seen some people who do large engines. May do small also
If the intake port does not go into water a good epoxy is a very good repair. Should the hole be into water than cast iron welding is the answer either by a marine or machine repair facility or by yourself. Welding cast iron on a non stressed item such as a head can be done can be done by brazing. Preheating the area is important in order to spread the stress over a larger area. The stress is due to the fact that cast iron, unlike cast steel, is extremely inflexible and will easily crack if heated in a local area thus you spread the heat. Whoever may try to weld it has to ensure that the ares is very clean before welding and that the oxy acetylene torch is soot free (slightly more oxygen to be safe). After the weld is complete the area around the weld is kept warm for a minute or two then the torch can be moved into a larger area for a bit then shut the torch off and let the head cool down completely by air.
Many thanks for the info., guys. Because these heads are no longer a dime a dozen, I think the job calls for a Qualified Pro. I'll try a couple of good machine shops in the area....
Hey 36rokit, May be a day late with this tip, but have you checked with Central Cylinder Head, 1041 S.E. Brooklyn St., Portland, OR.? Telephone there is (503) 234-8896. This firm has done lots of rebuilds and repairs on our favorite early engines. If you decide to use their service, let us know if they fixed your problem, and how they did it. Good Luck!! mr50s
While successful weld/braze repairs are done with a TIG welder, the best way to repair iron, heads, blocks, and many other iron parts, is heating to above the critical temp(red/yellow), gas welding with iron rod and flux, then reheating and controlled cooling. One of the down sides to this method is that all critical machined surfaces need to be inspected and remachined as needed. In some cases bolting or clamping the part to a block of stable metal will reduce distortion. The part should be heated in a furnace or kiln. While torch heating maybe better than nothing, compared to a furnace or kiln torch heating is uncontrolled and uneven.
Appreciate the edjication and tips, guys! Thought there might be at least a couple of different ways to go with this to salvage the head. These days, I'm sure they are getting a little difficult to find, especially the '56 models! Think I'll give Central Cyl. Head a try. They usually have some great eye candy to look at, as well.... Robb
Here is the guys you want. http://www.midwestcylinderhead.com/ I have had them fix a 351C closed chamber, heavily ported head that swallowed a valve at 8000+RPM. It put the valve through the top of the combustion chamber and into the water jacket alongside the valve guide. For $250 they fixed it and you honestly couldn't tell which cylinder it was. Ran for 2 more years without problems and we sold them. That guy still runs them. They have also fixed 2 rare blocks for us that others considered junk. Very highly recommended. You won't be sorry with these people, they understand us. Always something unique and non-replacable lying around there. SPark
call larry here in tacoma wa. http://www.localcarsdealers.com/washington/tacoma/290220-all-cast-inc.html he is the man for the job. does all the repair in this area and that includes all of the Lemay vehicles and has for 30+ years. not cheap but done correct.
To the guys above, who responded to my plea earlier in the month, and for anyone who may be curious, I wanted to follow-up with one more "THANKS", and let you know that I was successful in getting the head repaired. I took mr.50's advice and took it to Central Cylinder Head, in Portland, and Allen was able to do a rather simple repair. Thankfully, the damage was located next to a pushrod hole and not a water-jacket. He pressed a valve guide of the proper size into the pushrod hole and reamed the i.d. slightly for clearance. Works great and the cost was very reasonable. Lucked out on this round!!
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