Only from what I've seen 14/18 hp verticals (singles) seem to be most common kohler ohv engines used by a few compared to most with briggs. As far as rods I would upgrade the twins to billit but personaly have no need for a 1cyl one. Ours regularly hit the mid 8k's and an occasional high 9k when breaking loose on straits with a slightly loose stock bottom end. The stock rods seem to be fne on these as I've seen several turning them higher at other s.east outlaw tracks. Of the few broken rods I've seen it appeared the piston or rings were not fitted correctly and siezed in the cyl. with dark blueing effect in mid stroke area of wall from heat or to thick of oil. There are many areas of these engines that I feel could use some upgraded parts. Billit cam blanks for singles with adjustable steel gears, a dogbone for roller rockers that doesn't require as much block clearancing. A kit or assembly to tap horizontal oil pickup in vertical oilpans, spacers to give more rocker clearance to valve cover or taller a taller cover all together. Light tension gap-less rings, lighter pistons, pins and lightened billit cranks(balanced to assembly) / custom aluminum flywheel-greatly improve acceleration. As far as singles all these areas have no off the shelfs available to my knowledge. I think many that run kohler would highly consider buying some of these parts if they are resonably priced and of good quality. Most would not attempt to interbreed or try to make their own parts in these areas. Any of these parts would have saved us and several others considerable time when building, but we only run what we fab ourselves. There may be a market for rods of this engine, but personally speaking I see a larger potential for most of the others listed, to help those not willing to make their own parts build stronger and more reliable motors. I see it as a good thing to have people with your abilities trying to help other racers, don't let others discourage you, no mater who you are or what company it is, there was a starting point somewhere.
Twin parts might do as good, but with more competition.
Gotta run and lighten the tension on some sb ford 4.6L(281HO) rings (hint,hint).
Butcher.
JD, heard you on answering machine,I didn't get to phone in time. Turn off id block and call back.
(sorry, off-topic)
Butcher.
