morini 250

[Cheerful]

Could anyone tell me if a 500 engine would fit into a late 70's 250.

[72degrees]

At a guess, you could get the bottom end in but the cylinders and heads might be a problem. A 350 in a 2C frame is pretty tight squeeze.

[harrymuffin]

If you cut the return loop tubes where they but up to the top rail remove about 2" file half rounds then bend them to the rear, re weld you should just get the whole engine in, but you will not be able to get the heads off. The 350 if you do the same thing will let you take the heads and barrels off which is what I did with my hybrid rather than have to take the engine out. But then what would be the advantage of this with the availability of 350 frames and much easier installation, unless just to see if it would work?