Nissan_Boy85 Posted January 3, 2010 Report Share Posted January 3, 2010 Are there any specific markings on the rods or pistons that would identify them as Z24, Z20, KA, etc. or is there a way to tell with measurements or something? Quote Link to comment
ggzilla Posted January 3, 2010 Report Share Posted January 3, 2010 No, so measure: 1) the diameter 2) height from center of pin to top. Post your results here. Quote Link to comment
datzenmike Posted January 3, 2010 Report Share Posted January 3, 2010 The length between the center line of the big and small ends will identify them. Take the rod cap off and stand the rod up on a flat surface and measure up to the center of the piston pin hole. You should easily be able to measure within a mm or two. The Z20 came in two lengths 152.5mm and 149.5mm (same as the L20B rod) The Z24 and the KA24E were the same length at 165mm. But the piston pin end of the KA rod * has a bronze? insert to allow a floating piston pin, plus there is an oil hole in the top*. See below: (*applies to car motors only) KA24E rod on left and Z24 rod on right. Note the Z24 rod is thicker and stronger looking. Quote Link to comment
Nissan_Boy85 Posted January 3, 2010 Author Report Share Posted January 3, 2010 Diameter: 89mm Center of pin to top of piston: 33mm Shortest part of skirt to top of piston: 54.5mm Longest part of skirt to top of piston: 70.5mm *All measurements are approximate. Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 If 89mm and marked STD, they should be KA pistons. 20b are 85, Z22 are 87. Pretty sure I remember KAs being 89mm. Could also be Z24. Take a picture, post it up, probably will be easy to tell by casting differences. Quote Link to comment
datzenmike Posted January 3, 2010 Report Share Posted January 3, 2010 KA and Z24 pistons are virtually the same having only the piston dish different. The KA24E dish is 2.8cc of volume. The Z24 dish is 15cc volume. Left to right Z24, Z22(S), Z20E, L20B pistons. A KA has almost no dish in the top. Quote Link to comment
Nissan_Boy85 Posted January 3, 2010 Author Report Share Posted January 3, 2010 I think they are Z24 looking at the pictures and comparing. It just that I havent found a set of rings that work so I was beginning to question if they were or not. Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 Look like Z24 to me, but hold on, I have a set of Z24 and KAs in the garage. Let me get the camera, back in a second. [EDIT] Sorry, forgot to scale them down for a second! Okay, here we go: KA pistons: Z24 pistons: Quote Link to comment
ggzilla Posted January 3, 2010 Report Share Posted January 3, 2010 They are stamped 30W in two different places. 30W is the "Applied Model" code for 12100-30W00 ROD COMPL-CONNECTING 0985-0488 Z24 engine alternate 12100-03G10 Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 Nice ggzilla! It looks like those pistons have been polished, there isn't any webbing on the sides. I'm thinking someone did that afterwards, that it wasn't a stock finish for a Z24 piston? Quote Link to comment
Nissan_Boy85 Posted January 3, 2010 Author Report Share Posted January 3, 2010 Right, I went out and did the same thing, compated my KA to my Z24. I think they are Z24 but why can't I find a set of rings then? Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 They look like a standard 2,2,4 to me? 2mm compression 4mm oil control. What about the rings aren't working? Not fitting in the lands? Too wide? Too small? Quote Link to comment
datzenmike Posted January 3, 2010 Report Share Posted January 3, 2010 NOT a KA piston. There are no 'C' clips holding the piston pin in. Could be Z24.. Mmm don't see the 'C' clip here either. Matt??? Nevermind, the truck KA didn't have the floating pins. These are D-21 pistons. The 240sx had the 'C'clips. Did not know. :D Quote Link to comment
ggzilla Posted January 3, 2010 Report Share Posted January 3, 2010 Type up above. 30W is the "Applied Model" code for (i think) 720 4-wheel drive. This doesn't mean the rods are for 4WD, only that it was first used in that model. Can't find piston rings? 1. Nissan dealer PN 12033-30W10 (STD, tell the dealer if you want oversize) 2. RockAuto.com Quote Link to comment
Nissan_Boy85 Posted January 3, 2010 Author Report Share Posted January 3, 2010 The lower compression ring will not fit. I've gotten 2 sets and in both sets the lower compression has not fit. Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 Hmm, it's possible the ring lands are screwed up. Have you tried rolling the edge of the ring all around the outside to see if it drops in on some spots, and not on others? One of the pistons I had in my overheated Z22 had that happen. The ring was actually trapped in the lands. It would spin, but had to be yanked out. Mike: Yep, don't have any car stuff, only D21 stuff. Didn't know that about the pins, though. Quote Link to comment
Nissan_Boy85 Posted January 3, 2010 Author Report Share Posted January 3, 2010 Just went and did that. Same gap all the way around. I said the lower compression ring earlier, I ment upper. Quote Link to comment
datzenmike Posted January 3, 2010 Report Share Posted January 3, 2010 Hmm, it's possible the ring lands are screwed up. Have you tried rolling the edge of the ring all around the outside to see if it drops in on some spots, and not on others? One of the pistons I had in my overheated Z22 had that happen. The ring was actually trapped in the lands. It would spin, but had to be yanked out. Mike: Yep, don't have any car stuff, only D21 stuff. Didn't know that about the pins, though. Hah, I love it! Always nice to learn something. Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 Not a day goes by I don't learn something! Nissanboy, take a pair of dial calipers and measure that gap. Wait a minute, I'm just remembering isn't the 20b ring land 2,2,4 and the Z pistons 1.5,1.5,4? I think that's right. Anyway, measure that top ring land and see what you come up with. For mm 25.4 mm = 1 inch. Quote Link to comment
Nissan_Boy85 Posted January 3, 2010 Author Report Share Posted January 3, 2010 Or use a par of digital calipers that can display in mm :P I got 1.5 and the ring is 2. Quote Link to comment
datzenmike Posted January 3, 2010 Report Share Posted January 3, 2010 Can't find piston rings? 1. Nissan dealer PN 12033-30W10 (STD, tell the dealer if you want oversize) 2. RockAuto.com I checked and 12033 33W10 is true for up to '85 Z24 pistons. For '85 and up use 12033 83W00 for a standard set. Quote Link to comment
ggzilla Posted January 3, 2010 Report Share Posted January 3, 2010 Does the pistons have any casting numbers inside? way up on the inside? If not just call a custom piston company and tell them the dimensions of the diameter and the lands. They can sell you the right set. NAPA could problem figure it out from the their book. Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 Damn, I don't have our engine parts catalog at home. I have a bunch of others, but those are the few that usually aren't tossed out. When you say 1.5 and 2, do you mean the top compression ring is 1.5 and the lower 2? Then 4 for the oil control? If so, that's rather odd. Quote Link to comment
Kujo720kittyD21 Posted August 1, 2021 Report Share Posted August 1, 2021 Question ❓ 85 86 Nissan z24 engine,. Pulled the head off one ,. Had the numbers 83w stamped one one side an the number stamped on the other. What would this indicate Quote Link to comment
Kujo720kittyD21 Posted August 2, 2021 Report Share Posted August 2, 2021 On 1/2/2010 at 11:05 PM, datzenmike said: I checked and 12033 33W10 is true for up to '85 Z24 pistons. For '85 and up use 12033 83W00 for a standard set. Okay thank you. So they are stock. That's for the info Quote Link to comment
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