Thursday, January 6, 2011

Another Mystery Vintage Drag Bike

This bike is just extreemely cool. Yeah....that's extreemely with an extra "e." That's just how cool it is.

Ron is one of those guys that I have yet to meet in person, but courtesy of the magic of the Internet, we have corresponded, leading to a phone call or two. It's pretty obvious what the connection is. Ron and I share a passion for vintage drag bikes. In fact, when I first met Ron it was in response to a post I made about some old drag racing parts that I eventually turned into "The Knuckledragger." It seems that Ron had purchased a vintage drag bike of his own, and hoped that he could scare up some information on its history. And that wasn't even this bike!

That's right, it seems that Ron is becoming something of a vintage dragbike hoarder. Seriously Ron, I am starting to wonder why these cool old pieces keep finding their way to you, or is it just because you live right. Anyway, if you are new to this blog, or don't remember Ron's other bike, here is a picture and a link.

But, back to the drag bike at hand; The JAP. At first glance, the uninitiated may find a number of things puzzling. First, what exactly is it? Next, why is it named "THE JAP"? Well, that is fairly easy to clear up. THE JAP is, as with many competition machines, a marriage of many years and makes of parts. The crankcases are 1944 Harley Big Twin Flathead (UL). The top end is where things start getting interesting though.

There was a company building motorcycle engines in Great Britain since the turn of the last century (that would be 1900 to you youngsters) by the name of J. A. Prestwich Industries. Named for its owner/founder, his motorcycle engines soon took on the abbreviation J.A.P. So the simple answer would be that this bike sports a J.A.P. top end, and hence the name. But hold your horses! That is not actually a J.A.P. top end. As can be seen in the pictures, the letters "G.C." on the rocker box don't quite match the normal "J.A.P." lettering on a genuine J.A. Prestwich engine, as seen below.

The G.C. actually stand for Gus Carlheim. It seems that Mr. Carlheim was well known in the world of midget race cars. Working with J.A.P. engines for those racers, he eventually produced his own heads as a performance upgrade for those engines. Kind of like S&S building heads for Twin Cams as a performance upgrade....but now take it one more step and put those S&S heads on a Victory. Yeah, sorta like that.

While Ron doesn't have much info on the history of the bike, he has been inside the motor, and so has some of the details. The 2 inch valves, intake and exhaust. are actuated by UL cams that have been heavily modified for increased lift and duration. Displacement is 86 cubic inches via 3 7/16" bore and 4 5/8" stroke. Ron says the flywheels that were in the motor still showed traces of originally being formed with a cutting torch, though he chose to replace them with a set from Truett and Osborn. Compression ratio is a healthy 12.5:1.

Power is relayed to the M&H slick via a standard Harley Davidson clutch and four speed transmission. Not shown in the pictures is the pair of 42mm Dellorto SS1 carbs which feed the hungry monster. One of the most "endearing" aspects of this hybrid is the "hardware store" elbow which is brazed into the seat post to link the original VL frame to the raised top frame rail. One has to wonder if the builder did some moonlighting as a plumber (or perhaps he was a plumber who did some moonlighting as a drag racer).

Known history of the bike is very skimpy and all hearsay. The riders name may have been Eddie McDonald or Eddie McDowell. The bike may have been purchased from a SoCal shop called Cheetah Engineering (of early chopper seat fame?) possibly in 1969. The story goes that it had been dismantled in 1970, and found a home under a bench until 2009. Shortly thereafter Ron purchased THE JAP and undertook the process of reassembling it.

While I am happy to see another piece of drag racing history in good hands, both Ron and I would love to hear from anyone who might be able to fill us in on some of the history of THE JAP.

A special thanks to Pete at The VonPetrol Pages for sending me these pictures of the JAP and allowing me to post them here.


Dan said...

That is a neat bike Lee.

Webster World said...

It looks really cool. Well done. Though the short rake is, Well too short for me.