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NPR pistons


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..and while this thread is active... Has anyone actually built an LZ23? the only posts i can find on them say there is a problem with the pistons- dunno if its pin height, or...

 

More than a couple of people on this forum have built the LZ23.... I also searched this site, and a few of them were using the NPR brand.

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You could just get someone's used stock KA pistons for cheap. I wouldn't hesitate to get the NPRs. Japanese made stuff is where it's at.

 

 

KA...?????

If there were any of those around......might not of started this thread. :D

And dropped that in instead :P

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..and while this thread is active... Has anyone actually built an LZ23? the only posts i can find on them say there is a problem with the pistons- dunno if its pin height, or...

 

Merlin: The piston stops about 1.5mm before the top of the block when using KA or Z24 pistons and Z22 or L20B rods in combination. This 1.2mm equals 9.3ccs of extra space which helps to lower the compression to a reasonable amount.

 

 

Doug why not run Z24 pistons in it? The finished 2.3 will have a compression of 8.4. With the KA pistons it's 9.829 and likely to detonate with an open chamber U-67. (also you likely have a set laying around)

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Merlin: The piston stops about 1.5mm before the top of the block when using KA or Z24 pistons and Z22 or L20B rods in combination. This 1.2mm equals 9.3ccs of extra space which helps to lower the compression to a reasonable amount.

 

 

Doug why not run Z24 pistons in it? The finished 2.3 will have a compression of 8.4. With the KA pistons it's 9.829 and likely to detonate with an open chamber U-67. (also you likely have a set laying around)

 

 

Yes I do. I think 1 of the blocks outside has new pistons in it....but it might be over bored, larger than a stock Z24.

Hmmmmmm..

 

This is interesting.

 

http://www.bgsoflex.com/crchange.html

 

Not much difference in HP, but I would assume the engine with 9.8 revs quicker, is more efficient and responsive?

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datzenmike said:

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The KA-E pistons in the D21 are like the Z series. The pin is pressed into the rod and is solid, but, is loose enough to turn in the piston. The 240sx KA-E has a pin that is fully floating and turns in the piston and the rod is fitted with a bronze insert to allow it to turn also. Race engines use this to free up a few more hp. lost to friction. The pin is prevented from sliding sideways into the cylinder wall by having cir-clips in each end of the piston pin hole.

 

KA24E rod from a 240sx fully floating with insert....

 

http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/720stuffKA24Epistonrod003Large.jpg

 

The top of the rod has an oil hole to lube the pin.

 

http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/720stuffKA24Epistonrod007Large.jpg

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Yes I do. I think 1 of the blocks outside has new pistons in it....but it might be over bored, larger than a stock Z24.

Hmmmmmm..

 

Doesn't matter the size, you are boring the Z22 anyway. Instead of 89mm bore it to 89.5mmm or w/e.

 

BTW here are my 240sx pistons I 'collected'

 

89mmKA24Efloatingpinpiston004Large.jpg

 

 

.

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Doesn't matter the size, you are boring the Z22 anyway. Instead of 89mm bore it to 89.5mmm or w/e.

 

BTW here are my 240sx pistons I 'collected'

 

89mmKA24Efloatingpinpiston004Large.jpg

 

 

.

 

 

 

Mmmmmmm.....must hoard. :)

 

Gonna go grab a piston and see what condition it's in. Head and pan are already removed.

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Popped the head off....the +.5mm pistons are seized in the cylinders.

Poop....should of had a better tarp on it :lol:

 

Must of had new head bolts installed????

All the other Z22 and Z24 head bolts I have are stamped....13

These are stamped 12.5

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