$150 for a 79ZX engine. Is it worth it?

[Arne]

I havent pulled apart a '79 ZX engine , specificly . But from what I have read the ZX engines that are NA all have flat toped pistons . That is all F-54 blocks.

Correct. The '79-80 280ZX all had the N42 block with dished pistons. The '81-83 280ZX all had the F54 block, dished pistons on the turbo, and flat topped pistons on the non-turbo.

When I talked about the price seeming high to me, yes, you do have to take into account the supply in your locale. Obviously you don't want to pay to ship one, and if that's a good price where you are, go for it.

[DatsunZsRule]

Hello all

forgive me as I haven't been here in a while but if memory serves me correctly, wasn't it you that made the mistake of NOT using a Cam Chain tensioner tool when you made an attempt to change out your Valve Seats in your current engine and lost your chain in the block which resulted in you having to remove the front cover???? And if I remember right I think you said that a neighbor was going to give you a hand putting it back togeather.

If I'm correct and you and your neighbor installed new valve seats and were able to get it put back togeather correctly then may I ask why are you looking for another motor??? If you just got finished doing the valve job and your motor is strong then I see no reason to spend $150.00 on another motor that is no different than the one you currently have. Yes, NO different. 1975-1980 Z/ZX L28 were all the same. #N42, Dished Pistons and all put out 135 HP NET. The N/A 81-83 ZX's (F54 flat top pistons, siamesed cylinders) put out 145 NET. Datsun had to make these improvements to carry the heavier ZX weight so if your looking to swap for better performance then your going to want to find the 81-83 L28.

Plus an engine not being ran since 1989 is not exactly a good thing either like Arne stated

Good luck with whatever you decide to do

[Hrududu]

Well, my plan for the engine isn't really set in stone yet. I don't know if I will put this in my car unless my current engine breaks and I need a new one. My thoughts are to get an extra engine to work on and possibly rebuild so I can get experience working on these motors. I ran into some terrible trouble changing my head gasket, and think it would be worth while for me to have some practice on a motor that isn't in my daily driver. As far as making it a performance motor, i don't think I will. As nice as that would be, I don't have the $$ for that kind of project right now.

[Hrududu]

Hello all

forgive me as I haven't been here in a while but if memory serves me correctly, wasn't it you that made the mistake of NOT using a Cam Chain tensioner tool when you made an attempt to change out your Valve Seats in your current engine and lost your chain in the block which resulted in you having to remove the front cover???? And if I remember right I think you said that a neighbor was going to give you a hand putting it back togeather.

If I'm correct and you and your neighbor installed new valve seats and were able to get it put back togeather correctly then may I ask why are you looking for another motor??? If you just got finished doing the valve job and your motor is strong then I see no reason to spend $150.00 on another motor that is no different than the one you currently have. Yes, NO different. 1975-1980 Z/ZX L28 were all the same. #N42, Dished Pistons and all put out 135 HP NET. The N/A 81-83 ZX's (F54 flat top pistons, siamesed cylinders) put out 145 NET. Datsun had to make these improvements to carry the heavier ZX weight so if your looking to swap for better performance then your going to want to find the 81-83 L28.

Plus an engine not being ran since 1989 is not exactly a good thing either like Arne stated

Good luck with whatever you decide to do

Ahh, yes. That would be me.

The project was changing the head gasket, but I never changed out the vavle seals. Now, I'm getting really confused here. I am getting mixed reports as to which engine has the flat pistons and which has the dished. My N42 appears to have flat pistons http://www.cardomain.com/member_pages/show_image.pl?bg=000000&image=http://memimage.cardomain.net/member_images/9/web/705000-705999/705202_74_full.jpg and I heard the F54 had dished to reduce compression for the turbos. So which one is actually better? Dished right? BTW, I still haven't finished putting my motor back together yet. :disappoin

[DatsunZsRule]

ALL 75-80 Z/ZX's had dished pistons Stock. If yours does not then it's got a 81-83 N/A

81-83 TURBO's on the other hand had dished like the 75-80 to lower compression.

"So which one is actually better? Dished right?" Well performance wise for a Non turbo actually the flattop pistons create a higher quench mixture and allow for higher performance combustion chambers so the flat top pistons are what you want if your looking for a performance upgrade. Dished were usually used to lower emissions.

[kenz240z]

To me, $150 doesn't sound too bad. And, like you say, it will give you the experience of working on it. Do a little research, there is plenty of information out there on rebuilding the Z engines. From mild to wild, you should be able to build the engine to achieve whatever performance level you want.

[DatsunZsRule]

I don't disagree on getting a motor to practice on however, your smart to put that $150.00 into your current motor that you say is not yet completed so you at least have a Z to drive then later on look for another L28 to "Practice" on.

Another thing I think would be best for you is if you don't have a Factory Service Manual then make that priority #1. You'll be lost without one. Then read it thoroughly first before you start tearing apart the motor to learn about the engine inside and out first. Just my opinion.

[Hrududu]

I don't disagree on getting a motor to practice on however, your smart to put that $150.00 into your current motor that you say is not yet completed so you at least have a Z to drive then later on look for another L28 to "Practice" on.

Another thing I think would be best for you is if you don't have a Factory Service Manual then make that priority #1. You'll be lost without one. Then read it thoroughly first before you start tearing apart the motor to learn about the engine inside and out first. Just my opinion.

Good plan. I'm on the lookout for one now. I think I have seen a few on ebay, and will get one soon.

[kenz240z]

Hey DZR, welcome back!

Hrududu, I definitely agree with DZR about getting a FSM and reading thoroughly. It is the best source of information for preparing you for tearing down the engine and rebuilding it.

[DatsunZsRule]

Thanks Kenny Glad to be back online with all you fellow Z Nuts

About the FSM, if you have a difficult time finding one in good shape, Courtesy Nissan sells them on CD ROM. Just thought I'd point that out as another alternative

[donald]

kind of new to this site but i have a couple of original motors all running in these cars at www.classiiczparts.blogspot.com

[Hrududu]

kind of new to this site but i have a couple of original motors all running in these cars at www.classiiczparts.blogspot.com

Where are they located at?