shovel bottom EVO top

All
Has anyone had any experience with this conversion? It has ran OK for a few years but got tired quick. I would like to go back to a shovel top.
Are the cylinder studs in the same pattern on the shovel as the EVO or were the original holes welded up and redrilled for the EVO cylinders?
F

I have only seen two different forms of this modification. One is to weld the cases and re-drill the stud holes and drains in the appropriate locations. I have seen this mod butchered pretty badly; holes for studs not perpendicular to deck causing studs to be crooked as well as studs pulling out the threads during first torque sequence. The second method is to use an Axtell cylinder which was specifically built for the conversion. It is cast iron with the Shovel bolt pattern on the base and the Evo on the top. I know of one motor with this mod that has a ton of miles with a turbo and good results.

Sounds like you might have the first type of this modification (hopefully without the poor workmanship). If it was me, I would rebuild the Evo top to avoid welding the cases a second time.

I have been running one since 1987.

I just built an engine like this, against my better judgement, for a friend. When it was all said and done it ended up being a good engine. His goal was to put it into a Shovel frame with no mods. First, yes, I had to re-locate the cyl studs. The combination was: Evo Sportster rods, pistons(highly modified) cylinders, heads, and Special Flywheels by T&O with a short stroke. I think it ended up at 67" or so. I have seen and heard it run and it seems fine, but it WAS a pain to build. EVERYTHING down to the pushrods and tubes had to be modified.

this sounds like one of those things that are all very well as far as they go, but don't provide anything you can't achieve more easily by another combination of parts.

I see this with my JAP and Jawa engines, both were in production in various forms over long periods of time with various formats. There are a small number of variations which are worth doing for very specific reasons, several which are possible ways of using parts to hand to no real benefit but nothing lost either, and quite a few which are a lot of work for no useful reason

would it not be simpler to mount an Evo engine in a Shovel frame? Just asking, I've never seen one which makes me think that perhaps it isn't worthwhile

My engine is using S&S wheels and is 88" Stock EVO rods. Simply relocate the holes for the studs, weld up old holes, face the gasket surface and bolt it together.