Bushes for fitting type1 lifters to WBX case- what tolerance

Alexb1969 · Post by **Alexb1969** » Sat Sep 08, 2007 12:02 pm

Building my first Oxyboxer at the moment - just bought some phosphor bronze tube to machine up some conversion bushes on my lathe - I assume that these should be a tight press fit into the wbx case - but how tight ? whats the usual 'fit' that you machine to ? as obviously i dont want these working loose once the engine is together

Any advice appreciated - thanks Alex

eugene · Post by **eugene** » Sun Sep 09, 2007 2:31 pm

I bought tool steel type 1 lifters for my type 4 engine and the for the instal i was told to:
Bushings interference fit: +0,03 to +0,05mm.
The clarence between lifter and bushing are 0,04 to 0,06 in cold condition. The diameter in case must be 19mm +0,00/- 0,01

He is using alu bushings but i will use alu-bronze ones, so i'm aiming for a +0.05mm interference fit.

PS: the case doesn't get so hot as heads so 0.03 of interference will be probably enought also for bronze bushings.

Alexb1969 · Post by **Alexb1969** » Tue Sep 11, 2007 1:12 pm

eugene wrote:I bought tool steel type 1 lifters for my type 4 engine and the for the instal i was told to:
Bushings interference fit: +0,03 to +0,05mm.
The clarence between lifter and bushing are 0,04 to 0,06 in cold condition. The diameter in case must be 19mm +0,00/- 0,01

He is using alu bushings but i will use alu-bronze ones, so i'm aiming for a +0.05mm interference fit.

PS: the case doesn't get so hot as heads so 0.03 of interference will be probably enought also for bronze bushings.

Cheers - thanks for that