Crank case transfer port question

Hello ,

I am hoping I can get some advice from the forum on perhaps what is a straightforward question. I hoping to start building up my engine. I have bought an already ported D3 barrel, which I am putting on (at present) stock D3 cases. I understand it is crucial to match the transfer ports at the bottom of the barrel to those on the crank cases.

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My question is, what shape do the transfers ports need to be, below where the barrel and crank case meet? Do I widen the crankcase ports using the same angle as the origional factory ports, or is a different shape more desirable?

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Thanks for your time!

Andy

Added a picture, in case I wasn't making much sense- quite likley!

Matching the crankcase to the barrel is definitely worth while.

Personally I would go for a large radius rather than following straight down with a small radius at the bottom.

Smoothness is more important than a polished surface.

hope that helps

Mick

Mick,

Yes, that is helpful, Thanks!

Where do Bantams race in Vancouver? -- or even in Canada?

John-Boy -- nul-nul, Seven-&-a-Half -- citizen of Canada, UK & Deutschland Überalles!!!

I am building a Bantam racer to race here in the states. I am planning on racing it in the 200gp class with AHRMA. I currently run a C15 in that class and previously I raced a Triumph Cub. I am building a 125 and a 175 engine.

Andy- not the same one from the original post

john bass wrote:

Where do Bantams race in Vancouver? -- or even in Canada?

John-Boy -- nul-nul, Seven-&-a-Half -- citizen of Canada, UK & Deutschland Überalles!!!

Well really I am just building a Bantam with a race motor in it. I thought it would be an interesting and relatively inexpensive project. I almost have all the parts after a lot of ebay, auto jumble and craigslist purchases. So I am excited to get going with the build!

Thanks young man! I just thought perhaps you would start a Bantam Racing Club in Vancouver. I was ten years in Montreal and it was snowmobile or car racing there with no sign of MC racing.

Cheers!