1934 Scout (58" Stroker Motor) Info
Here is a special little Stroker motor with some character. It uses an original low milage set of 1934 Scout cylinders with fresh high quality Nickle plating. It uses a one year only set of 1939 Scout "Bonneville" heads that I custom "fly-cut" for the pop-up pistons. The cylinders were at standard bore, with nearly perfect seats. It is now at .020" over-bore. It uses Ross forged pistons with a .150" pop-up. It has a set of late Scout heavy-duty rods. The flywheels are from T&O, and perfectly balanced with a 60% ratio. The flywheel assembly was trued to near perfection. It uses a very good set of "741" cases, and cam cover. I prefer the "741" cases, because they are identical to Sport Scout cases, except that they have a "Timing Hole" like a late Chief at the 12 O'Clock position. I use them on my Twin-Scout LSR bike!
Becuase this motor has about 2/3 of the finning of a late Sport Scout, I wanted to build it with a lesser powerful state of tune. So, I used an NOS set of standard cams, and a good late set of standard lifters, that I repaired with "Stellite" at the lifter's arched pads, which lift the push rods, and I added a set of my "Needle Bearings Rollers" that I make for my Scout Racing Lifters. It is a new package with standard cam specs. Since this is a 58" Stroker motor, the motor size is increased by about 30%, while the compression also goes up by nearly 30%. This motor should make at least double the power of a stock 45" motor (with using a Mikuni VM36 carb), and it will have a lot of low end torque. You will be able to gear this motor way up for freeway speeds!
The cylinders got a racing 5-angle valve job, with Teflon seals for the intake valves for better top end performance. It uses "Manley" stainless steel "extreme duty" intake valves that I have made. The exhausts are from "Kibble-White" that are "Black Diamond" black-nitride coated. The valve guides are from Starklite, and honed to the perfect fit. I also use .050" copper head gaskets from "Cometic Gaskets", that I have made. I gave up on factory head bolts, and switched to stainless-steel studs, and special nuts, and washers. The original setup with head bolts usually stripped out the threads in the cylinders, and I have repaired a lot of them. Instead, my studs are beveled at the bottom, so they can pick up every thread available. Then I use the early beveled edge washers, and ARP brand grade-10, 12-point flange nuts. Now, I get a consistant amount of torque, and NO stripped threads!
It has a good 1939-46 original Iron Oil Pump, that I rebuilt with new gears. I used an original distributor with new shaft, bushings, and an electronic "Pointless" ignition. I modified the cases to accept a 1947 Chief Oil Sump Scraper. This is a very good mod! It uses a Mikuni VM36 carb, on a late stock intake manifold with an adapter plate that I make, which is very efficient, and powerful.
The primary is from a "741", which is the same as a Sport Scout, but without the window for a Magneto drive above the clutch (a cleaner look!). The clutch has new factory style discs, and a new throw-out bearing. The tranny case is good, and uses above average used original "741" gears and main shaft. It has a new cluster gear shaft, and new sealed bearings for the case. I did the mod with thrust washers on both sides of the cluster gear (good mod!). It uses the late style "Chief" seal on the shaft output. It is also modified with a tranny oil level plug, and a new oil fill location, because I have done the "3-way" oiling job like the 1952-52 Chiefs, where they seal off the tranny from the primary, so now the motor can use 50Wt for the motor, 30Wt for the primary, and 90/140Wt gear oil for the tranny. A much longer life setup!
Motor Spec Sheets
Parts List, Prices, and Total Costs
Picture Gallery below, during the Build
So, what do you think?
James R. Mosher