Project 74

1974 XLH Engine in 1985 XL Frame

Pictured in IronWorks magazine, April 2005 Readers Rides.

The goal was to put a stroked Ironhead engine into the more modern Evo-styled frame, thus taking advantage of that raw Ironhead stroker power by combining it with a modern, stiffer chassis and better suspension.

The main problem was that iron XLs are right side shift/left side brake and Evo XLs are the opposite, right side brake/left side shift. Since moving the right side gear shift over to the left side of an iron XL would be extremely difficult. I decided to leave the gear shift alone and relocate the brake. Since the 85 frame lacked the fitting where the rear brake crosses over from the left side to the right side, I decided to loose the mechanical drum and go with a disc. I ended up lacing a 1980 hub (dual flange to bolt the disk on) to the 1974 alloy wheel with stainless steel spokes. The rear brake is a four piston Grimeca from the Storz catalog, the left side master cylinder/pedal assembly was fabricated. Both footpeg mounts were extensively modified and bolted to an adapter shaft that was made and bolted to the frame.

The 85 frame had to be cut, sectioned and welded in four places to get the engine to fit. Of course the front and top motor mounts had to be made. The Pingel heavy duty mount was used in the rear. The 85 frame is taller than the 74 frame, allowing the rear rocker box to be removed from the head while the head is still bolted to the jug. So now both heads can be bolted on and torqued up using a torque wrench and then the rocker boxes can be installed and bolted down. No more screwing around with weird adapters when trying to torque the rear head. Threaded bosses were also welded into the frame so that a rubber-mount tank could be used. No more through bolts, the rubber-mount tank is held on with stainless steel socket cap button head bolts. All the extra tabs and dodads were cut off the 85 frame. The ugly fork lock was also cut off the frame and a new fork stop was welded to the neck. A couple of fittings had to be made and welded so that the round oil tank could be installed.

The round aluminum oil tank is from J&P Cycles, it had to have a clearance cutout for the center down tube welded in. A battery box was also welded in. I had to use the smallest battery I could find because there really isn't any extra room for a battery. I can get away with a tiny battery because the electric start has been removed. Kicker Only.

The engine is a 1974 XLH with the S&S 4 5/8" stroker kit, that makes it a 74" 74. The engine had been installed in the original 74 frame for a couple of years. I've ridden it pretty hard and have had no major problems. It easily does 120 mph with the gearing I have. I did take the opportunity of this swap to pull the top end and check things out, it all looked good so it went back together. Cams are HD "P" grind. Pistons; forged S&S. Ignition is by a Dyna 2000i single-fire setup. I use a CV carb that is attached to a home made manifold. (I'll be glad to take them old CV carbs off your hands when ya'll buy them high dollar S&S and Mikunis, them old CVs seem to work just fine on this old Ironhead.) There is also an oil filter that lives where the starter used to, it is bolted to a homemade adapter.

I think the front fork is off a 1993 hugger, the 1974 wheel fit right on to a 93 axle, one spacer had to be made. The 1993 brake lined right up with the 1974 disc, no mods required.

I did all the welding on the frame and oil tank, I powder coated all the small parts (I'd have done the frame but it wouldn't fit in my oven), I do all my own engine and transmission building. I grind my own valves and seats and true my own flywheels. I did all the polishing and wheel lacing/truing. I made all the home made parts except for a couple that were farmed out to a local machine shop working off of my drawings. The whole project took about a year of actual building. I've been saving up parts and planning this for about three years total. I also am a hack web designer. I keep telling my wife how great I am, but she won't fuck'in listen.


Fear No Evo