sorealsosurreal Posted October 21, 2008 Share Posted October 21, 2008 so im building a stroker motor and am not sure what piston to use. im looking for a forged piston and plan on running a N/A high compression engine (10.5-11.5:1) not sure if all nissan ka24 pistons are forged but some of the pictures ive seen it looks that way. also before i buy a piston i need to know what headgasket to use. i was told that in doing a 3.1L stroker that the piston will rise above the deck surface .6mm so he encouraged me to use a 2mm head gasket. id perfer a 1mm if possible because its less likely to cause me trouble. anyways, advice on piston whether its oem or aftermarket (dont have money for custom) would be very helpful oh and the head i plan on using is an N42 if that helps at all. thanks everyone! Matt Quote Link to comment Share on other sites More sharing options...
Xnke Posted October 21, 2008 Share Posted October 21, 2008 There are no factory forged pistons for the KA24 engines, and unless you flycut the pistons, you'll have to run a 2mm headgasket anyway. Pretty much, your options are as such: $$$$$-Forgies: Anything you want, you can get, with enough cash. $$-Nissan Z24 piston: LD crank, L24 rods, N42 head, somewhere around 9.3:1 compression with a 1mm headgasket. (DISHED PISTON). Piston protrudes 0.65mm from the deck. stock piston protrudes 0.22mm from the deck, IIRC $$$-Nissan KA24E piston: LD crank, L24 rods, N42 head, somewhere around 11.5:1 compression with a 1mm headgasket, (FLAT-TOP PISTON) Piston protrudes 0.65mm from the deck. stock piston protrudes 0.22mm from the deck, IIRC $$$-Nissan KA24DE piston: LD crank, L24 rods, N42 head, somewhere around 9.3:1 compression with a 1mm headgasket. (DISHED PISTON). Piston protrudes 0.65mm from the deck. stock piston protrudes 0.22mm from the deck, IIRC Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 22, 2008 Author Share Posted October 22, 2008 so the piston isnt going to make contact with anything with a 1mm head gasket? Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted October 22, 2008 Share Posted October 22, 2008 so the piston isnt going to make contact with anything with a 1mm head gasket? I am building a 3.1L now as well and am in the same situation as you. I could only find a 1mm gasket awhile back. Since the pistons have a positive deck height of .6mm, I planned to take that much off of the top of the piston to give it a 0 deck height. I don't think its a good idea to leave it that close with only .4mm clearance. It would depend on how radical your cam is going to be as to eyebrowing your pistons. I am going with around 300 duration and .500 or better lift, so I think that I will need to put some relief eyebrows in the pistons as well. Check yours with some modeling clay to see how close you are. By the way, you can order these pistons directly from ITM at a really good price. They have a website. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted October 22, 2008 Share Posted October 22, 2008 And good luck finding the flattops. I searched and searched and searched to no avail. Even my machinist didn't have a listing for them. I ended up going with the dished piston that I got from 1 fast Z. He sells them in sets of 6 so you don't have to buy 2 sets. And BTW - according to the "How to Modify" book, negative deck height is when the piston sticks out of the bore above the block. 1 fast Z would argue that point too - there was a rather "spirited" thread about this a good while back. I dunno - I'm just a parrot, right? !! Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 23, 2008 Author Share Posted October 23, 2008 Ok so I think I'm going to go with a ka24de piston and then before I buy me head gasket make sure that there will be no clearance issues between piston and valves +1mm for the preferred head gasket and if so ill just go and buy a 2mm. Now if only some one made stock compression forged ka24de pistons (9.5cr). I searched the web and it seems even the 240sx guys couldn’t find them for their car! Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted October 23, 2008 Share Posted October 23, 2008 http://www.rhdjapan.com/ those guys have multiple thickness choices. No guarantees on CS/product quality, since I've never dealt with them (someone else linked me there for something at one point....twin turbo setup maybe? don't remember). http://www.rhdjapan.com/jdm-low/Tomei-Metal-Head-Gasket-L6-L24-L26-L30-BEAD-TYPE-11675 there you go. Once again, I've never dealt with them, so I can't tell you how they are with everything. Quote Link to comment Share on other sites More sharing options...
RisingSun Posted October 25, 2008 Share Posted October 25, 2008 I've got those KA24 pistons that I bought from 1 Fast Z, but didn't come with enough pin clips and he never sent them to me. I never installed them in my engine build. I recently found some pin clips at my local Nissan dealer that look good, but I am still a couple short. They are ITM brand. I can send you some pictures and if you like what you see, make me an offer. This is what I went with instead. They are ceramic coated, but I will have to find out from the builder what brand they are. If you like how they look I will find out where he got them and pass that info on to you. Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 25, 2008 Author Share Posted October 25, 2008 yeah, let me know what those ones are and from where, im guessing they ar 89mm? did you deck your block? Quote Link to comment Share on other sites More sharing options...
RisingSun Posted October 27, 2008 Share Posted October 27, 2008 I talked to the guy that found the pistons for me....he couldn't remember the source. Yeah, the block and head were resurfaced for a good gasket seal. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted October 27, 2008 Share Posted October 27, 2008 I dont remember a customer that didnt recieve enough clips, Hmmm, interesting. How long ago was it? Send me a bill on what you had to pay to get some more, and Ill re-emburse you. BTW, .6mm=.023". They are not that if you actually measure them. With a 1mm head gasket, it comes out to the perfect, .025" or so. I would NOT repeat NOT run a 2mm head gasket and loose all quench. Unless your going with an N42 or other OPEN chamber non qhench head, then you can do whatever you like with head gasket thickness. Yes in all my calculations, and building, negative is piston above deck, but everyone argues with me on that point so I just keep it to myself Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 28, 2008 Author Share Posted October 28, 2008 i actually do plan the n42 head, but im glad to know a 1mm gasket thikness is alright, i looked at your site and it said that you dont supply the std bore anymore (89.mm) can i ask why? Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted October 28, 2008 Share Posted October 28, 2008 Yes in all my calculations, and building, negative is piston above deck, but everyone argues with me on that point so I just keep it to myself It's in the "How to Modify" book by Frank Honsowetz - I just read that section the other day. But - who the hell knows! As long as you say - the piston is sticking up above the block - most folks (hopefully) can get the picture. So Bryan, are you saying on my stroker with an MN47 head, that I should have used a 1mm HG instead of a 2mm? How much performance could I potentially lose? Damn gasket cost a freakin' bundle....AND my motor is together already. Shux..... Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 28, 2008 Author Share Posted October 28, 2008 for piston pins how many of you are using full floating pins compared to press fit pins. i was told to use a full floating pin by boring the rod and throwing a bushing into the rod, advice anyone? Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted October 28, 2008 Share Posted October 28, 2008 I'm using press fit with the ITM's I bought from Bryan, as recommended by my machinist. Not sure of the advantages one way or another to either configuration. Hoping someone will chime in and enlighten me/us! Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 28, 2008 Author Share Posted October 28, 2008 ok so to use a press fit, did you just use the pin from the 240 rod and press it into the ka24 piston and there yeah go or what? im going to order from a company called EPWI (my school has a deal with them) and the pistons i will be getting from them are the ITM pistons or another brand that i cant think of at the moment Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted October 28, 2008 Share Posted October 28, 2008 I used the pins that I got with the pistons. They are sized (at least with Bryan's kit) to be press fit in the rods, but the piston bore for the pin is just a hair larger, making the piston a floater. The pistons came with the circlips, but we opted not to use them and just press fit the pin into the rod. It fit.... The pin is centered on the rod through the piston, so it (the piston) can still "float" a little bit either way, it is held rigid by the pin being pressed in to the small end of the rod - meaning, it's got a little play either way when the piston is mounted, but the pin is rigid in the rod. Does this explain it correctly? Not sure how to convey it, other than the pin does not float in the rod, but the piston floats a bit on the pin when mounted on the rod. Had the small end of the rod been bored out and bushed, I would have had to use the circlips, but since the pin is a press fit, when you grab the piston and move it left and right on axis, the pin does not (and cannot) stick outside the pin bore of the piston. Somebody help me explain this better - I know what I mean to say, but not how to say it! Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 29, 2008 Author Share Posted October 29, 2008 i think i get what yor saying, the pin is pressed into the rod as in stuck and wont move on the rod but the piston itself isnt pressed but floating and can move a little back and forth on the pin but cant move enough to cause damage because the pin is still stuck on the rod. let me know if i get what your saying. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted October 29, 2008 Share Posted October 29, 2008 You get the prize for saying the most in the least amount of words. That is exactly what I'm saying. Good on you! Quote Link to comment Share on other sites More sharing options...
sorealsosurreal Posted October 30, 2008 Author Share Posted October 30, 2008 woohoo! ok so lets see if you get this one. to make it a full floating piston and rod setup i would have to bore the l24 rod then press a bushing into the rod and then bore the bushing to the same diameter size on the small end of the ka24 rod then use the ka24 piston and then im full floating? i have no idea how but that would make the most sense in my mind. Quote Link to comment Share on other sites More sharing options...
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