Matching Casings - Advice Please

[paulnobodyimportant]

Late last year I slipped on a Rapido classic 200 barrel, whilst the engine was still in the frame of my Jet200. Time permitting, and I don’t have much, I am currently, renovating this Jet, including replacing the oil seals and checking rest of the motor. However, with the engine out, I have now matched the bottom gasket with the Rapido barrel and found that the casing transfers need to be enlarged, see photo. But can anyone help with the following:
• The transfer at the top of the picture (mag side). If I cut this back to the red line, there is only around 2mm to the stud. Clearly I can’t go that far without someone putting extra weld on, so what is a safe thickness to leave between the stud/casing.
• Looking through some of the threads, it looks like a dremel is out of the question. But could anyone give me a link to buy the right size and type of cutting tools for my drill or dremel.
• Will matching the transfers make a great difference? I know the answer is yes, but would like a bit of education/knowledge about the difference.
Many Thanks

Paul

[DaveTomo]

I've got a classic rapido 200,when I asked them at AF if it was worth having the casing matched,they said no as it was pretty well much designed to bolt straight on with no modifications and for the cost/hassle it would make very little difference.And that was asking them to do the matching of the casing,so fair play to them because I was willing to pay the money.Hope this helps.

[lifes a drag]

as long as the barrel transfers are wider than the casing it wont make mutch difference if any , if the barrel transfers are narrower then the fuel/air mix will hit it like a wall and it wont flow correctly,
most people think there race tuning there engines when there matching the casing to the barrel but in fact there not gaining mutch if anything in the way of perfomance,
you would get more power by inlet and out outlet tuning to be honest,
although most tuners match the casing just in case it makes a difference ,,, and it looks more profesional dunt it

have a go its not that difficult and you will get the satisfaction of doing something yourself ,, and thats worth more than 1 BHP int it ,,
theres lots of pictures and explanations of how to do it if you scroll around these pages,
some of the work done looks top drawer and for lots its the first time doing it ,,

[byron]

...have a go its not that difficult and you will get the satisfaction of doing something yourself...

good words.
I'd probably not go right to the red line on the top transfer; just make sure everything is smooth and flowing, no corners to cause any turbulance.
I've only ever used a dremel to do that