Piston sizes

[haubstr]

My dad bored his L20B out 20 over and now needs new forged pistons to compensate for the turbo he is putting on(got the turbo, exhaust manifold, and down pipe for free). The turbo is off of a Corvair Spyder, so probably not much boost... What would be the size of pistons he needs for this? Is there a stock Turbo Z engine we could get the pistons from?

 

Thanks

[datsunaholic]

20 (0.020") over isn't bored out enough for 280ZX pistons. The L20B was 85mm bore originally, the L28 was 86mm. Boring .020 only results in 85.5mm; so you would have to bore a full 1mm which is approx. a .040 overbore. I seriously doubt you will find off-the-shelf .020 oversize L20B forged racing pistons today, but they probably existed at one time. It actually might cost less to simply have the block bored out to 86mm and use STD 280ZX-Turbo pistons, but I would find the 280ZX forged turbo pistons first.

[haubstr]

Thanks!

[Bugeye]

It actually might cost less to simply have the block bored out to 86mm and use STD 280ZX-Turbo pistons, but I would find the 280ZX forged turbo pistons first.

 

by doing that would he be able to use stock l20 rods and crank?

[ssfwgn]

by doing that would he be able to use stock l20 rods and crank?

 

both pistons have the same pin height, so yes.

[Bugeye]

thats what I thought. I was thinking about boring mine to an 86mm and using them

[hang_510]

i think i have a set of CAST 0.5mm over L20 pistons, new rings/pins-cheap

IIRC they have the small dish(like stock) in them.

[banzai510(hainz)]

isnt the stock 280zx turbo pistons cast anyways

 

at 5 pound boost who cares

 

http://www.kb-silvolite.com/spistons.php?action=Mfg4l&mfg=Nissan&Div=Nissan&l=1952 mine were 76bucks about 2 years ago

find a dealer near you by calling them up and they will tell you where if somebody has a box in inventory ,the bottom set of piston is 9071 is a really deep dish piston. 9048 are stock 11.36cc dish

[Bugeye]

the OP is looking for boost, im looking at options for a rebuild

[Xnke]

There are no factory forged pistons in ANY size in any of the Z or L series engine. If you want forged, You gotta go custom.