Sandcast cylinders

[techy5025]

Prior to my obtaining my sandcast, the cylinder head was dinged on the right hand side resulting in rash to three of the fins. The engine runs fine and I have restored the rest of the bike with a few safety concessions such as stainless brake lines.

I am trying to decide whether to tear the engine down an fix/replace the head or just leave it. Which serial/heads could serve as replacements? I know that at some point the heads had an extra bolt. The engine only has 8,500 miles and seems to run great....slight ticking from the valves which I have adjusted twice...only occurs below 1300
rpm or so.

Is it possible to fix fins in place? Engine number is 27xx.

Thanks, Jim

[736cc]

Fins can be fixed in place; I've never seen results. A welder that does such a repair uses popsical splints. I think HONDACHOPPER website is a good active source to post, or maybe try a Google search. Maybe you can try it yourself using JB weld and a couple of Good Humor bars (Toasted Almond?), then painting w/ aluminum paint.

[elisent]

Any good engine welder can fix broken fins although harder in place. I've done it many times on old Indians. Not difficult and totally undetectable. If trying to do in place I would try to find a beat doner cylinder to get a great permanent match. Bead blasting evens out the look when cylinder is off the bike. I rarely disagree with my personal sandcast guru, 736. JB weld with aluminum paint is not the way I'd go unless the fin damage was that slight and out of sight. I also think pep boys "chrome" paint is a better match than aluminum. I do have to give kudos to the popsickle stick idea. I've never heard of that. Maybe that gives better texture to JB WEld than I'm aware of. Once again I learn something new from Andy the master. Eli

[736cc]

The popsicle splints are stacked between the fins as a mold and removed when some type of simple filler has set. Its a quick-fix w/o major surgery. An engine removal and sending out for rebuild usually (like everything else) takes twice as long and costs twice as much, and can open up the proverbial can o' worms of things that make sense, ie: might as well zinc-plate ALL the nuts and bolts, so take the whole bike apart (and zinc the rear brake stay and adjusting rod, seat latch, sprockets, rear pegs, carb parts like choke lever, large idle screws, etc. Hmmm, frame could use re-painting (90% gloss, and believe-it-or-not, gloss black rattle-can KRYLON dries about 90% gloss), spokes can be re-laced, so chrome the rims etc. Sometimes instant gratification (aka hack) makes sense.
Of course, an engine rebuild means you can restore the bike concours correctly and that bike is worth doing as any bike ever made. But don't over-restore it. And thats a trick in itself ; )

[chrisnoel]

.B. works great. Make the bottom of the mold out of cerial box material and the sides out of masking tape. Next day when it's hard form it and sand off the card board with sand paper wrapped around a flat stick. A little finess and you'll never see the damage.

The head I just sold had this type of repair and it was invisible. I had to disclose the locations of the repair's so the new buyer wouldn't be fooled.