My friend Paul came by the shop this week and brought his knucklehead along to do some light maintenance on it and to fix what he thought was a stuck rocker arm. He was riding the bike a few years ago and heard a loud bang and the bike quite running. This bike is very special and was built and tweaked by Harry Mollenaar in the fifties. The bike is 85 inches and has a ton of special parts and hand made features. I have known about this bike for years and seen lots of pictures of it, but this week was the first time that I actually got to touch it and see what it was like.
In this picture you can see the special cast aluminum cylinders that Harry worked with Eddie long on casting. Eddie Long was a genius from ohio that most people recognize from an awesome old photo of a jdh drag bike with a knucklehead top end. These cylinders are an inch taller than stock cylinders and the frame had to be jacked up to shoe horn the engine in the frame.
The gas tanks on Harry's bike are widened mid 36 to 39 tanks and really pretty cool. The bike has a 36 shift arm and a 3 speed and reverse gate. Also note the adjustable rake hydra glide fork.
The left side of the bike is really cool too, the fenders are stock hydra glide trim, and the bike looks like a nice combination of different harley parts from various years.
Check out this cool aluminum pressure plate.
Here is the problem that caused the valves to come out of adjustment. The cylinder had been previously welded back when Harry had it. The cylinders are cast aluminum with a pressed in cast iron sleeve. the cross section of the cylinder is very thin and weak. In some spots there was only .030 of aluminum. Performance "upgrades" didn't have very much longevity in this case.
The rear cylinder was easy to remove, the front one was a bit more effort. The heads had studs sticking out of them so that they could have nuts used to retain them.
ouch.
upon closer inspection the flywheels were made out of billet steel and had a four and a half inch stroke.
The rods are sa rods, which are out of a vl. The cam was stock
and here was the other mystery that unfolded. the belly numbers of the case have an f stamped in them. I have seen plenty of 40e- cases, but never an f. I have heard that Harley had planned on introducing the 74" fl model in 40 but didnt have a chance to iron out the bugs in time. maybe this was a pair of prototype cases, who knows though. Have any of you guys ever seen an f in a belly number on a 40 case?
The heads were in pretty good shape and made out of stuff that Harry had in inventory, they are large port heads, with 38/early 39 rocker shafts, and 37 rocker boxes. we are going to build a 68 inch motor to put back in the bike so that Paul can have trouble free and careless riding for the rest of his life. I respect the amount of work that went into making this motor a possibility, but it didn't work and the formula is not sound.