KA24 bore out?

[95_NISMO_HB]

I was reading in another thread somewhere about a guy who bored his KA .5 over... anyone else heard of this being done and if so... what pistons should I go with?

[SPANK_TANK]

r uu sure u mean .5 as in half an inch

[95_NISMO_HB]

This is a direct cut from his post... not a half inch...sorry for the confusion LOL
"My KA has been bored .5 over the equivelent of 20 thousanths of an inch"

[jdoe44]

that would be .020, and pronounced "twenty over"

maybe .5mm? Is he outside of the US?


Anyway, it's not a huge difference in displacement. It's basically a stock rebuild. You would order pistons "twenty over."

[95_NISMO_HB]

I think he's an Aussie and I was looking more for a brand name on the pistons...
when it come to engine components I really only know parts for my Mini (1970, the real ones)
I really want to pull the full potential out of the KA and stay naturally aspirated... any other ideas beside the rebuild would be welcomed.

[osupride]

bore it 40 over :)

[89miNISSAN808]

.5 meaning 0.5 liters over, thats what he means right?
so OP is looking towards a 2.9? ok, but is it possible to 60 over?

[osupride]

the more you bore, the thinner your walls are so you can only go so far ;) or chance blowing a hole through your block

[95_NISMO_HB]

OK... so I have 20 (nothing special) - 40 and now 60 over... At what point do I need to sleeve the block? hahaha:crazy:

[jdoe44]

These are all very minor bores, for standard rebuilds. They are not really a performance upgrade.

stock engine = 89mm bore x 96mm stroke = 2389cc

(3.14159 x (89/2)^2 x 96 x4cyl = 2389cc)

20 over -> 89.5mm bore x 96mm stroke = 2415cc

(3.14159 x (89.5/2)^2 x 96 x4cyl = 2415cc)

40 over -> 90mm bore x 96mm stroke = 2442cc

(3.14159 x (90/2)^2 x 98 x4cyl = 2442cc)

[89miNISSAN808]

^^stroke will still be the same...are there stroker kits?

[91hrdbdy]

yea i found them on the web 2900.00 for a long block. Im looking in to some similar things.

[95_NISMO_HB]

For $2900... you might as well do an RB25 skyline swap... LOL

[jdoe44]

Yeah... I fucked up on the stroke on the last one.. .I still computed it at 96 though.

The point remains the same though... 1mm or .040" over gets you 53cc's which is the equivalent of 1.8 fluid ounces.