Any 88 Or 89 Mm Piston Alternatives For Stock L28 Crank And L28 Rod Combo?

[240260280z]

Who can argue with TonyD? The guy is an encyclopaedia and genius!

VW pistons: http://www.aapistons.com/products/vw-88mm-type-1-piston-kit

88mm bore (so standard HG will work)

Looks like 22mm wrist pins too.

39.5mm Compression height/Pin height (Stock 280z is 38.1 so 1.4mm above deck to deal with).

felpro 88.9dia headgasket with 1.1mm compression will reduce the piston height to 0.3mm above head gasket

A 0.9mm shave will give ~ 0.6mm quench as per the recommended 0.56mm to 0.64mm clearance

Compression will be ~ 9.4

Edited March 9, 2015 by Blue

[siteunseen]

So now Canadians DO get it?

Who in their right mind would argue with him?

Edited March 8, 2015 by siteunseen

[madkaw]

Who can argue with TonyD? The guy is an encyclopaedia and genius!VW pistons: http://www.aapistons.com/products/vw-88mm-type-1-piston-kit88mm bore (so standard HG will work)Looks like 22mm wrist pins too.39.5mm Compression height/Pin height (Stock 280z is 38.1 so 1.4mm above deck to deal with).felpro 88.9dia headgasket with 1.1mm compression will reduce the piston height to 0.3mm above head gasketA 0.9mm shave will give ~ 0.6mm quench as per the recommended 0.56mm to 0.64mm clearanceCompression will be ~ 9.4

Nice find. Tony is always pushing the VW parts.

I think the forged stuff is reasonable too

[gnosez]

Blue - I have some 40 over pistons sitting on a shelf and can take a picture and measure them for you tomorrow.

Edited March 9, 2015 by gnosez

[madkaw]

Did you see the 88mm pistons with the 38mm deck height. They call them low CR pistons. Wonder if they are flat tops

[240260280z]

Thanks John,

Maybe I'll go for your set and be done with it if they are flat tops and for sale?

Thanks!

[240260280z]

88mm pistons are now in the country. I should have them in a week.

 

In the mean time I have been refining the design concept.

 

I just rang the shop and they can offset grind the crank by 1mm to 80mm and do the machining for the rod ends.  I'm looking at 2.92 litre with 9.4 compression ratio and optimal squish with a standard 88.9mm Felpro gasket.

 

It will be basically a mini stroker  of 88mm X 80mm that works with existing rods, crank and block as well as a standard felpro head gasket.  It will have optimized squish. The longer stroke and larger bore will increase torque but not require the expensive HG, LD crank, and longer 240z rods of a typical 89mm X 83mm stroker.  It will have ~ 6% less displacement than a 3.1 litre stroker.

Edited May 1, 2015 by Blue

[Patcon]

That's interesting. I have thought about doing an offset grind with a V07 crank but would have to work out the deck height piston issues. I have never calculated what the displacement would be though

[240260280z]

AA Pistons finally arrived.

Compared to an 86mm Nissan flat top piston:

The top ring is 0.7mm lower so shaving the top will not place it too high.

It is interesting that the arrows on a type 1 VW piston point to the fly wheel but the engine turns CW relative to the front of the crank... so the arrows will have to also point to the FW on the Z to get the thrust offset correct.

The pistons do not have oil holes in the pin boss so that will have to be added.

The Nissan pistons have a centre hole drilled in the oil ring gap but these do not.

The Nissan pistons have a steel insert.

Both have slots in the oil ring gap.

7.9mm crown thickness on Nissan and 8.0mm on AA

Edited May 8, 2015 by Blue