Difference between Flat top pistons

[78 280zcar]

Is there a big difference between 1980 flat top pistons and 81', I looked up piston rings for both years and there is a difference between the rings. The 80' one uses the same rings as a 78, but the 81' uses the same rings as an 82'. The reason I ask is because I am buying some flat tops off of someone on this site but am not sure if they are 80' or 81' flattops. I was hoping to use the same rings from the rebuild I have already done but am not sure if I can. Thanks

[78 280zcar]

I just figured out that this is a pretty much dumb question.:stupid: Does the 78-80 use the same pistons? What years did flat tops come in the picture? And what years Zx's came with the F54 block?

[78 280zcar]

That brings me to another question. Will F54 pistons and rods fit into an L28 if they are standard?

[COZY Z COLE]

Check this link out.....http://www.geocities.com/zgarage2001/engine.html

LARRY

[78 280zcar]

Thanks for the info. But will the pistons and rods from an F54 fit into an L28, I just dont want to have to change the block

[Mat M]

Thanks for the info. But will the pistons and rods from an F54 fit into an L28, I just dont want to have to change the block

From the link provided by Cozy Z Cole, I would have to assume that you would only have to swap out the head in order to have flat top pistons on a regular (non F4) block.

[78 280zcar]

I have a P79 head thats why I was wondering, from what I have found is that if I put flat tops with a P79 head my compression will go up to 8.71:1.

With the way it was before with an N47 and dished pistons it was only 8.47:1. Thanks for the info guys

[=Enigma=]

Thanks for the info. But will the pistons and rods from an F54 fit into an L28, I just dont want to have to change the block

First of all an F54 IS an L28. Everything I've read indicates that F54/P79 combos came with flat top pistons. I'm no expert here but it seems to me you're asking the wrong questions or just asking the wrong way. Perhaps that's the reason for the lack of knowledgable answers.

As for what pistons will fit your F54, my answer would be be the right one for the bore. Any piston for an L28 should fit in any L28 block, but it has to be one that fits whatever you current bore is. It may have been bored over at some point, or it may need to be to get rid of uneven cylinder wear, ridges, or scoring.

According to the lengine.exe program, an L28 with a stock bore, an unshaved head, and a standard head gasket will yield the following compression ratios with the listed heads and pistons:

L28 block + N47 head + dished pistons = 8.29/1

L28 block + N47 head + flat pistons = 9.82/1

L28 block + P79 head + flat pistons = 8.52/1

I am still learning all this stuff myself, but it seems to me that it might be worth your while to purchase a copy of How to Rebuilt Your Nissan/Datsun OHC Engine or How to Modify Your Nissan&Datsun: Ohc Engine. I've got a copy of the latter on the way.

I hope this helps some but like i said, I'm no expert.

[78 280zcar]

I have one of the How to rebuild your nissan/datsun engine books. But it doesnt have anything about changing to different pistons. The above compression #'s came from lengine.exe, but with a felpro gasket. I have an L28 block from a 78' but I was just wondering if F54 standard size pistons and rods would fit into a standard bore L28 or if anyone has ever tried it. Thanks

[78 280zcar]

I just read this again and realized how stupid I am. I meant to say will standard F54 flat top pistons fit into an N42 standard bore block:rolleyes:

[=Enigma=]

Correction to my post above. Apparently the F54 came with both flat top and dished pistons according to this:

http://www.geocities.com/zgarage2001/z.html

[Arne]

I just read this again and realized how stupid I am. I meant to say will standard F54 flat top pistons fit into an N42 standard bore block:rolleyes:

I believe so, yes.

Are you planning to use a P79 head?