Scooterotica

Anyone re profiled a standard 200 head to fit a re bored 70mm barrel themselves? Anyone done this at home using a profiling tool such as a Dremel. I bought 225 head from one of the Indian Ebay sellers and its not up to scratch, but I've had Indian std 200 heads before and they were no problem. The diameter increase is easy to match with the bore. It's just the profiling and blending. I've never attempted it, but I have a spare head and it could save me a lot of $$ if the squish and main chamber remain the same. Any tips? Cheers

I’ve often wondered how it’s done and thought of using one of those profile combs you sometimes see to get the profile from the piston then transfer that to the head.

cylinder head reprofile best cut on a lathe combustion chamber shape and volume use a dremel or better a die grinder wirh large tungsten finish with flap wheel

It doesn't look like much of challenge at first glance a couple of mm bigger and then just blend to the original profile extended out a bit. But it wouldn't be a precision job. I have in the past used a standard 200 head on a 70mm barrel but with a thicker head gasket (two actually) cut to the cylinder size, just to get an engine running. This worked but performance was affected. Not massively but not where it should be. Compression was down a bit but no damage to piston or head even at the outer edge. Might just give it a go with the head I've got. I'll wait and see if there are any more replies. Done a search on the web and cant find any pics or guides which is unusual.

I've found a local machine shop that does rebores and he can work the head too. He can open up the mating face to the new diameter. He can also blend and profile the outer edges of the head to the same contour as the original. So at least I now have a fallback option. But still interested to see if it could be a DIY job though. Was hoping someone had done one or attempted one?

Seems unlikely to be a good job.to me.
I try to get my squish to 0.9 to 1.1mm.

I think it would be nigh on impossible to stay within 0.2mm with a dremmel.

Might be wrong though.

Hmmm. When you put it like that Hendy it does sound a bit of a tall order.