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View Full Version : 99-00 Altima Pistons in Ka24de rwd block



SxMachine
06-16-2005, 07:33 AM
Just wondering if its been proven to work without rod/ crank clearance problems. Its already been proven that the rings will work with oem ka(s14) but altima pistons? I'm rebuilding my ka for my 510 and just looking 4 alternatives to forged pistons. Mild amounts of boost on oem parts can only handle but so much, i understand.This topic was searched before with inclomplete results by the way. Anyone with updated progress

insndrvr
06-16-2005, 10:29 AM
They should fit, it's essentially the same motor. The main thing to keep in mind if you are reusing old pistons from one motor to another is the piston grade. There were 3 grades of pistons from the factory. The grade is basically the three size tolerances. If you go to big, you risk pistons siezing, and if you go too small you may get piston slap. I can't imagine that the Altima pistons are any better for boost than the 240 pistons.

llll
06-16-2005, 11:02 AM
Not sure about the pistons, but use 1998 Altima piston rings. JWT says there stronger than most aftermarket rings.

gunluvS14
06-16-2005, 12:02 PM
just curious, what makes the 98's item different from the others?

insndrvr
06-16-2005, 02:28 PM
Upgrading the rings is rather pointless unless you are going with stronger pistons. If you have to rehone or bore the block and install new rings, you might as well use those. But just to put Altima rings in with stock pistons to have the stronger rings is useless. The rings will hold up a lot better than the stock pistons.

flip240
06-16-2005, 08:05 PM
^ I have to agree with that. The rings on my DOHC were fine when I blew it up. Its the ring lands (the part of the piston that the rings sit on) that are prone to breaking.. I dunno if the Altima ring lands are thicker, but if they are, I'd say go for it.

SxMachine
06-17-2005, 05:35 AM
^ I have to agree with that. The rings on my DOHC were fine when I blew it up. Its the ring lands (the part of the piston that the rings sit on) that are prone to breaking.. I dunno if the Altima ring lands are thicker, but if they are, I'd say go for it.


Thats what i'm wondering. If Nissan improved the piston ringlands for the Altima. Its just a temporary, low boost (at the most 7-9 psi on stock internals) project engine 4 my 510 like i said.

cesar
06-17-2005, 08:49 AM
for 7-9 psi don't even bother changing the pistons; stock ones will do just fine.

There's plenty of people that are running ~12 psi daily with stock internals with no problems. it's all about tunning bro.

llll
06-17-2005, 09:03 AM
just to put Altima rings in with stock pistons to have the stronger rings is useless.

I understand that. KA ringlands give out long before anything else.

I was just saying that since he's rebuilding his KA he should use 1998 Altima rings. Not sure why, but thats the year that JWT says to use.

From what Ive read over on KA-T, S14 KA pistons are stronger than S13's.

insndrvr
06-17-2005, 10:47 AM
What I was saying was that unless he is planning on rehoning the cylinders and using new rings, he shouldn't bother with the altima rings. Keep the stock rings in there respective locations unless it's not holding compression.

JimStinksAtDorifto
06-17-2005, 11:43 AM
to summarize...

If the motor has good compression and leakdown, you don't need to do anything internally as it will take that smount of boost like a champ, with proper fuel of course.

If you are going to refresh the motor for low boost, then just reuse stock pistons and use 98 Altima rings while you're in there just as a safety measure.

Unless someone has the 240sx pistons side by side with the Altima ones and there is a difference in the ringland, there should be no need to use new pistons.

cesar
06-17-2005, 04:29 PM
From what Ive read over on KA-T, S14 KA pistons are stronger than S13's.



That's just a myth dude, there's plenty of internally stock S13's making a lot of power with no issues, look at Phatka-t's S13 project car; it made 404 RWHP and 409 RWTQ when it was internally stock, and when it blew up it was because of a bent rod, not a piston or ring land.

SxMachine
06-17-2005, 04:34 PM
to summarize...

If the motor has good compression and leakdown, you don't need to do anything internally as it will take that smount of boost like a champ, with proper fuel of course.

If you are going to refresh the motor for low boost, then just reuse stock pistons and use 98 Altima rings while you're in there just as a safety measure.

Unless someone has the 240sx pistons side by side with the Altima ones and there is a difference in the ringland, there should be no need to use new pistons.




Thats all i was lookin 4. Like i said i'm keepin the set up inexpensive, quick (somewhat), simple and safe. Belive me i fully understand the consequences of a half-assed rebuild, I just gotta get the Dat runnin asap. While the Ka is outta the car i'll do what my money says i can do. If i blow it, I blow it. One day proper build an boost will come.

turtl631
06-17-2005, 09:22 PM
look at Phatka-t's S13 project car; it made 404 RWHP and 409 RWTQ when it was internally stock, and when it blew up it was because of a bent rod, not a piston or ring land.



That's not true, the stock block S13 started losing compression because the ring lands were going. This was after a bunch of dyno pulls and some 1/4 mile runs, but still, it happened, even with a great setup and tuning. The stock rods went around 500 whp after Ivan added forged pistons, but I believe there was a small boost spike involved, so 500 whp may be okay for stock rods and perfect tuning.
The problem is, the real world is seldom perfect, so if you tune to the ragged edge, eventually you're gonna blow up when somehting goes wrong.

insndrvr
06-18-2005, 07:00 AM
As far as confirmable facts go between s13 and s14 KA pistons, the only thing I can say for sure is they are different. They internal casting marks are different. The company logo on the inside of the piston skirt is different, and the texture of the casting is much rougher on S14 pistons. Wether or not the pistons are actually made different is hard to say. Maybe they cooled the castings at different rates. I would like to get some altima pistons as well to compare to the KA's. I am not really sure there is a way to compare strength without breaking the pistons with some sort of reliable test.

mattmartindrift
06-18-2005, 08:30 AM
I had an S14 ka in my car, w/ turbo, it took a week to take out ring lands, I had an S13 ka after that, it took 4 months, both on the exact same setup. The S13 had more miles. I'm not sure what other variables could have also been involved, but same tune, same supporting mods and all the peripherals were the same.

llll
06-18-2005, 02:59 PM
I had an S14 ka in my car, w/ turbo, it took a week to take out ring lands, I had an S13 ka after that, it took 4 months, both on the exact same setup. The S13 had more miles.

What turbo/psi?

SxMachine
06-18-2005, 07:44 PM
Well maybe since i'm buying new stock ka pistons anyway, i might as well buy Altima pistons. This project is somewhat sacrificial anyway.

flip240
06-19-2005, 02:15 AM
I had an S14 ka in my car, w/ turbo, it took a week to take out ring lands, I had an S13 ka after that, it took 4 months, both on the exact same setup. The S13 had more miles. I'm not sure what other variables could have also been involved, but same tune, same supporting mods and all the peripherals were the same.


Sorry, but that proves nothing. http://forums.freshalloy.com/images/graemlins/frown.gif

rn240sx
06-19-2005, 08:11 PM
We tried to use Frontier Pistons which are 8.5 compression with 99 altima rings cause they are "suppositly" stronger, but after speaking with 4 nissan dealers and tech's, it cannot be done.