Aaron Neubauer Posted March 31, 2009 Posted March 31, 2009 I will hopefully be picking my L28 up this weekend after being in a hayshed for 15 odd years. Its a F54/N42 combo out of a patrol. I plan to overbore .040" and use my LD28 crank with L24 rods but hopefully use Z22S pistons to obtain a capacity of 2960cc (I'm trying to stay under 3000cc). These pistons have a pin height of 35.00mm and a 9cc dish (correct me if I'm wrong ). These would need to be flycut by about 1.6mm to obtain zero deck height and hopefully this would be enough remove the dish to give flat tops (rough calcs give CR of 10.45:1 on a standard 88mm HG). I've read on the ozdat forums about some guys flycutting L series pistons by up to 3mm which gave me this idea. I'm ignoring the effect of cam lift and valve recessing for the time being. I am trying to obtain a sample piston to find the thickness of the crown and if the dish can be machined out. Does anyone know if this can or can't be done or is it kinda uncommon? I welcome criticism also Quote
C.A.R. Posted March 31, 2009 Posted March 31, 2009 Yes it can be done - but the crown thickness may be an issue. FWIW, Phil or Bill @ http://bitsofitaly.com/services do this sort of work. I've used them before many times. If you give them a spare piston (like from a wrecker) they'll be able to tell you if it can be done or not. Quote
luvemfast Posted March 31, 2009 Posted March 31, 2009 What do you mean by "flycut"? Is this clearance for the valves? Like a spotface. Or Are you talking about taking material of the end of the piston? Like on a lathe? A "Flycut" is something different to me in my trade, more like what you would do to a head. Quote
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