MM, be careful with welding up the head with any serious amount of weld. There was a time. many years ago when one of the four cylinder Fords had an issue with cracking between the valves. A friend of mine welded up a whole bunch of them after experimenting with the first couple. It required a pretty serious support clamp assembly to keep the head straight enough for remachining and everything needed to be machined. This was a non race application, strictly warrantee.
Pete
Yes, all of the above. And they probably were not concerned about raceworthiness either. The way I see the problem is that the Rover cylinder head material is not the best to begin with. I know from past experience that welding porous alloy heads is no fun. The micro-voids in the castings are always filled with "contaminants", like anti-freeze, lubricating oil and my favorite, corrosion. The process is still a pain, even when the heads are pre-heated in an oven, to "burn off" the contaminants. And if the head is pre-heated long enough & hot enough, bye bye heat-treat for sure.
On welding of alloy cylinder heads which were "good" material to begin with, (LM25 for Cosworths or Lotus TwinCams, 356 for US produced heads),
extensive welding damages any heat treatment that the head may have undergone. Once the head is heat treated again, to improve material strength, it
inevitably needs to be completely re-machined, a giant pain in the keister . . . . . and expensive . . . . . .
Welding the head is my idea of a "cascading nightmare" . . . . . . .
My concern about the Rover is that I do not know anyone who has small enough tooling to re-machine the cam bores. And I do not want the nightmare of oversize tappet bores, etc . . . . . . .
Consider this: The factory Rover engineers solved a "head gasket" problem by going to an MLS gasket AND an additional stainless steel shim, inserted between the head face and the MLS gasket. Their explanation was that the "shim" "prevented the gasket from "digging into" the head under load. Hmmmm, either they had inadequate clamp load, or, soft head material, or, thermal cycling breaking the compression seal. Or maybe a combination of all three. I think that any of those issues need to be minimized, from the outset on this build, if the engine is going to have a chance to produce 125/130 bhp,
reliably. For you cubic inch guys, that's 2.13 bhp/cubic inch, normally aspirated. The best way to accomplish this is to be "smart" rather than "hopeful" or "lucky" . . . . . .
Fordboy
Topic: Milwaukee Midget (Read 3266786 times)