89 mm pistons

[lovemysan2]

http://cgi.ebay.com/ebaymotors...26523

Hey devious could these be used in a kajust curious

[deviousKA]

well they could if you had a low mileage ka block that had never been bored to get away with 89mm. The pin would have to be 21mm not oversize like many top end pistons are (.866/22mm full floating style for carrilo rods) in order for these to work with ka240sx rods only (trucks are press fit wont work). You could figure out the basic compression ht by figuring out what it would take to get 10.25:1 in l28, or else you would have to contact the guy and get the comp. ht to see if they are what you want for your ka.

email and ask about the pin size and compression ht, and make sure you can get away with 89mm on your block. if they are 21mm pin you would need to use 240sx rods.

Might be worth your time to check them out but there are other cheaper options available, the reserve is most likely high on those.

[TrunkMonkey]

those pistons won't work with oem KA rods without some work. KA rods are wider (thicker) than any and all of the L series rods and, iirc, the KA has one of (if not the) the tallest deck heights too. so even if you did get them to work with the oem rods, you would be lowering you compression height, thus lowering your compression ratio.

it would be so much easier just to buy aftermarket pistons.

-demetrius

*edit*

those pistons may be from a stroker kit offered through nissan motorsports, and iirc, the pistons would actually stick over the KAs deck at tdc. if so, you would have to mill them (more modifying) to make them work.

[deviousKA]

yes demcj is right, the ka pin journal is appox. .040" wider. This problem could easily be taken care of (just always make sure there is a minimum of .080" total slop side to side between rod and pistons).

They already have a couple cc's of volume in those valve reliefs, and like demcj said the ka pistons have one of the tallest comp. ht's of any nissan pistons. Look for something different.

[lovemysan2]

Well I'm not in the market anymore for pistons I was just curious about the compatability. I could have gotten away with just a hone on my block but I went with new higher compression motorsports pistons. I used my old rods the shop just pressed the pistons on. Motorsports informed me that my truck rods would need some machining to work. But the machinest just pressed them on no prob. Whats the deal?

[deviousKA]

the nissan motorsports 9.1:1 pistons aka early ka24e's? if so those are full floating style but use the same diameter pin as truck (21mm). Yes you can just press those on without machining, without using the pin retainers. It would have been better to use them with bushed 240sx rods.

[lovemysan2]

Yes "bushed" rods. What does that mean? I'm still not on my feet I just had nothing left to buy the 240sx rods with. So when he said he could handle it, I said have at it!

I went with the 1mm overbore pistons they claimed a slightly higher than 9.5 to 1 compression ratio. There supposedly the same as the 9.1s cept the extra overbore with the unchanged piston height gives the higher compression.

[TrunkMonkey]

Yes "bushed" rods. What does that mean?

it means that the rods have bushings in the small end where the piston pin goes through.

-demetrius

[lovemysan2]

Okay so it would be 21mm pin with a 1mm bushing in a 22 mm rod?

[deviousKA]

not exactly, im not sure of the pin diameter of the 240sx rod with bushing removed. Nissan does not use a 22mm pin, when a 240 rod is honed out to 22mm some of the bushing is left. The truck rods are all steel 21mm