Hi folks,I'm looking for a bit of advice (re-assurance) about a Villiers(ish) based engine I'm building.
Using a re-lined MDS barrel and head fitted onto a set of Alpha crankcases with a narrow Alpha crank (No flywheel provision......battery,coil ignition.)
My problem is that when assembled the larger Alpha crank flywheels foul the piston skirts. I relieved the piston skirts,rounding off piston skirt corners but removing no overall piston length (really close though).
It gets worse,on assembly I was expecting to jack the cylinder up,however at BDC the piston crown is.100" (2.55mm below exhaust port and .235" (6.0) below liner top.
i'm thinking that the best thing to do is to machine metal off of the top of the crankcases (.100"+) where they connect with the barrel.
I know that whilst doing this the piston skirts will foul again and will need clearance,also base of barrel liner will need reducing the same amount to clear crank flywheels.Doing this will reduce overall piston (Nametab) length by .100"+.
I expect this will account for faster piston/bore wear,but is it completely out of order?
Am I going the right way????,
Advice would be appreciated.
(By the way, the problem is caused by Alpha leaving more metal (thicker) on the top of their C/cases compared to Villiers).
Using a re-lined MDS barrel and head fitted onto a set of Alpha crankcases with a narrow Alpha crank (No flywheel provision......battery,coil ignition.)
My problem is that when assembled the larger Alpha crank flywheels foul the piston skirts. I relieved the piston skirts,rounding off piston skirt corners but removing no overall piston length (really close though).
It gets worse,on assembly I was expecting to jack the cylinder up,however at BDC the piston crown is.100" (2.55mm below exhaust port and .235" (6.0) below liner top.
i'm thinking that the best thing to do is to machine metal off of the top of the crankcases (.100"+) where they connect with the barrel.
I know that whilst doing this the piston skirts will foul again and will need clearance,also base of barrel liner will need reducing the same amount to clear crank flywheels.Doing this will reduce overall piston (Nametab) length by .100"+.
I expect this will account for faster piston/bore wear,but is it completely out of order?
Am I going the right way????,
Advice would be appreciated.
(By the way, the problem is caused by Alpha leaving more metal (thicker) on the top of their C/cases compared to Villiers).
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