sfab
X
- Location
- Canada, QC
i realise that its going to be a hell of a job to match all the oversized ports on the sleeves. lot of meat to remove...
Damn dude you’re workin' fast! :bigeyes:
It looks like you're building a Frankenstein motor with those 61x cases, did you ever think about running some 62T cases?
Great work BTW. :fing02:
These sleeves are 40mm from the top exhaust port to the cylinder surface which is the same for the 61x. The transfer ports are 58mm from the top and 74mm at the bottom so they can be used with flat top pistons. The stock 61x sleeves have transfer ports that are 54mm from the top and 68mm from the bottom. If these cylinders are to be used in an OEM dome style piston engine, the deck surface will only require light machining to match the sleeve tops to the deck surface. All transfers will need to be raised approx. 2.5mm (varies due to your desired port timing) and a 1mm base gasket spacer plate needs to be installed.is the port timing on these sleeves the same as a standard 61x or are they raised
good stuff keep those pics coming
These sleeves are 40mm from the top exhaust port to the cylinder surface which is the same for the 61x. The transfer ports are 58mm from the top and 74mm at the bottom so they can be used with flat top pistons. The stock 61x sleeves have transfer ports that are 54mm from the top and 68mm from the bottom. If these cylinders are to be used in an OEM dome style piston engine, the deck surface will only require light machining to match the sleeve tops to the deck surface. All transfers will need to be raised approx. 2.5mm (varies due to your desired port timing) and a 1mm base gasket spacer plate needs to be installed.
Also they can be finished for use as a set of "flat top" cylinders because a flat top wiseco pistons are shorter than OEM pistons preparation for each will be as follows: for use in a flat top piston engine this cylinder will require machining approx. 2.5mm off the top cylinder deck and minor top edge port work to get the port timing where you want.
Oh, And how do you like those NW sleeves im thinking about getting the same ones. Are you happy with how they look for porting? I know they come preported.
Be sure to widen the transfers in the casting to match the sleeve, but do not raise them. Also, keep the roof angle in the casting intact, while keeping the sideways angle in the casting and sleeve matched up (should all be pointing toward the boost port)
What sleeves are those, where'd you get them, and how much were they?
Those look like different sleeves then the ones I've seen with the same part number from Northwest. Can you tell me what the exhaust port height and transfer port height is, measured from the top of the cylinders edge?
The stock Yamaha 61x cylinder has a below-deck exhaust port height of 39.6mm and all the transfers are the same height - 55.4mm.