Chainlube
Well-Known Member
Or just a plain old drill press.
Brand new GRUBEE SkyHawk GT5B 69cc compared to GRUBEE SkyHawk GT5A 66
- Thread starter digital_life
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Cisco
Well-Known Member
It's too bad they didn't have the transfer port blades in opposite directions, could have configured a swirl.
Cisco
Well-Known Member
What's your solution?
Chainlube
Well-Known Member
Cut the back of the transfer to angle to the intake. It's still good even if it's rounded at the back.
Chainlube
Well-Known Member
Here's a little picture with the cuts marked out on this old jug. If you look closely, you can see that the exhaust side of the transfers aren't cut evenly.
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Street Ryderz
Well-Known Member
The new cylinders are much easier to correct than the old ones with open access and the over all volume and quality of the castings in the tracks are WAY better!
Also the porting on the new ones is MUCH better right out of the box.
Street Ryderz
Well-Known Member
I just got some goodies ordered to play with, LOL.
Hi Thomas, I'd like to get 1 x SKU B-54TZ , 1 x SKU GT5B-R , 2 x SKU B18,B19,B26,30c-69, 1 x SKU BOFENG-CARB, 1 x SKU HP-HEAD
product.variants.choose_variant 47x38mm (GT5A, GT5) - $34.99 47x40mm (GT5B) - $34.99
Thank you!
Hi Thomas, I'd like to get 1 x SKU B-54TZ , 1 x SKU GT5B-R , 2 x SKU B18,B19,B26,30c-69, 1 x SKU BOFENG-CARB, 1 x SKU HP-HEAD
product.variants.choose_variant 47x38mm (GT5A, GT5) - $34.99 47x40mm (GT5B) - $34.99
Thank you!
Chainlube
Well-Known Member
You know, when you look up into the transfers on that cylinder the top portion where the air flow enters the cylinder is correct, it's turned back toward the intake.
That was the last one of ten I bought off aliexpress, all those ran really well without a bunch of fuss and file.
Chainlube
Well-Known Member
Street Ryderz
Well-Known Member
Transfers are scary to many because you can really kill the power if they are not right so many don't touch them, the shape, size and angles all have to work with the rest of the engine for best results.
The first and foremost important thing is the size or volume of both combined, they should be the same size as the carb used since they can't flow more than the carb let trough it makes no sense to be larger, this also effects velocity.
To find the true area of the transfers you need to measure the open height and width of each then use online calculator to get the equivalent dia this figure gets cut in half because it's doubled when considering the cross section of each, just as an example lets say we have a width of 22mm with a height of 10mm that's an equivalent dia of 15.9mm so best suited to a 16mm carb, this would be typical of a stock transfer port but will not support the use of a larger carb and so you have to increase the area for best results.
There is a whole lot more to trying to explain the shape, angles and correcting these but it has been covered here before and this reply is long all ready LOL so more to ponder.
The first and foremost important thing is the size or volume of both combined, they should be the same size as the carb used since they can't flow more than the carb let trough it makes no sense to be larger, this also effects velocity.
To find the true area of the transfers you need to measure the open height and width of each then use online calculator to get the equivalent dia this figure gets cut in half because it's doubled when considering the cross section of each, just as an example lets say we have a width of 22mm with a height of 10mm that's an equivalent dia of 15.9mm so best suited to a 16mm carb, this would be typical of a stock transfer port but will not support the use of a larger carb and so you have to increase the area for best results.
There is a whole lot more to trying to explain the shape, angles and correcting these but it has been covered here before and this reply is long all ready LOL so more to ponder.
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