Which engine for a 77’ 280z

[Av8ferg]

Okay, I think the turbo is a no go. I don’t need more trouble and this will be my first engine rebuild.   So help with the heads, pistons and compression for a strong street car. 

P90 Head was for turbos.  Came with dished pistons and lower Compression Ration to accommodate for the boost. 

P79 was the NA turbo ZX engine with flat top pistons.  This will yield a higher compression ration.  

ZH...copy all on my N47 in my car now an be used.  There are 3 non-turbos at different places in my area.  One is an 1980 and others are 82’s.  Two of the places want a core charge....one $100 the other $200.  That’s silly.  

I agree...look for the cleanest engine that seems less abused and with least miles and least rust and old leaks.   P79 is the Head I want corrrect?  This way I may not have to buy replacement flat top  pistons as I would if I went with the P90 Head engine.  Unless someone swapped them before which we’ll assume for this discussion....didn’t happen. 

 

[Reptoid Overlords]

It's my understanding that if you use the 1980 N47 head with the '82 F 54 block(with flat tops) you get somewhere around 10:1 compression ratio. Perhaps someone will correct me, as I've been meaning to ask about that for some time, and I'll learn something from this thread too.

I'm putting some of the finishing touches on an '82 F54/P79 build. It's my first one.

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[Av8ferg]

Cool, didn’t know that. So my N47 head in that 82’ block could yield higher CR than the P79 head. This begs the question, when you do stuff like this are you changing the way the engine runs. I’m not looking to drive an engine that runs like crap. I see this happen with guys who build muscle car engines and put cams etc on them. Sure they’re powerful but also run and idle like crap. I want a smooth engine.


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[siteunseen]

I would try and find a cheap borscope that uses your phone for the display to stick down the plug holes to look at the piston tops. You want flat for sure but also no small holes from corrosion or pre-detonation. The smoothest tops. Harbor freight or amazon has them. Someone was talking about one not too long ago but i can't remember where the bought it. Seems like it worked with bluetooth?

[wal280z]

1 hour ago, siteunseen said:

I would try and find a cheap borscope that uses your phone for the display to stick down the plug holes to look at the piston tops. You want flat for sure but also no small holes from corrosion or pre-detonation. The smoothest tops. Harbor freight or amazon has them. Someone was talking about one not too long ago but i can't remember where the bought it. Seems like it worked with bluetooth?

Good idea Cliff - as we know, even the newest L28's (other than those slated for other use, i.e. forklift, marine use) are now over 35 years - I know I've changed a bunch in my engine - it certainly isn't what came out of the factory, so who knows who did what to an engine that is sitting in the junkyard... especially if it is wrecked - at least  you know it "ran when parked"

John - I assume they will pull the engine for you? Whatever, if you need an open bed truck to transport it to the barn, let me know.

Wayne

Edited February 14, 2019 by wal280z
clarification in bold

[siteunseen]

Probably said this before but the best money i spent was Tom Monroe's "how to rebuild datsun/nissan L motors". $20 from Amazon.

Bought parts i knew i would need every chance i could. retailmenot.com had 30% coupon codes for Advance Auto. Buy online and pick up in store, no shipping. Starter, alternator, chemicals like aviation gasket sealant and anti seize. Assembly lube etc. and a felpro gasket set. I reused my bolts but now you can buy stainless whole car kit from zcardepot.

[siteunseen]

Ferg does your n47 have a spray bar and an oiler cam? My 9/76 build date did. You want a turbo oil pump either way i think. The nissan turbo head bolts too.

I'm getting the horse ahead of the cart now so I'll quit. Get you a notebook and start making your to do list then parts needed.

I ended up enjoying working on mine rather than driving them. Keeps me busy and the mileage down. 

[wal280z]

5 hours ago, Av8ferg said:

...I drove a turbo once in like 1989. It was a peppy little car and fun to drive....

 

4 hours ago, Av8ferg said:

...Turbo mean lots of tuning work and extra stuff to do.

For me, a turbo was just something ELSE to break down..... Never have been a fan of them.

[grannyknot]

Turbo's are cheating,  there, I've said it and can never take it back.  Here's the sound turbos love to make

[wal280z]

4 minutes ago, grannyknot said:

Turbo's are cheating,  there, I've said it and can never take it back.  Here's the sound turbos love to make

Chris, I whole-heartedly agree.... Coming of age in the 70's, turbo's were the rage back then, but now, as I grow older, I realize that turbo's were installed in under achieving engines to save money and add a big profit to the mfr. bottom line. Well, maybe not that much, I mean, Chrysler was bailed out in the '80's... Welcome the K-car....

Wayne

[Patcon]

I agree with your not going turbo. There are lots of issues going turbo. I have 2 turbo motors here at the house and may go that way some day but you really have to go aftermarket EFI and intercooler to make it worth while. It's lots of work and programming.

I think if I were going to approach this, I would go with the better of the 2 P90 engines. If you don't use the head, sell it. They bring pretty good money. Supposedly they are one of the better breathing heads though. I would go triple webers like Blue said with about 10:1 compression and a good ignition system. Maybe a 123 ignition system. Should run really well and not be overly finicky. I might bore as much as I could to get a little larger engine. Play with the engine calculator some... @240260280

Make sure the engine you buy will turn freely by hand. The boroscope is a good idea!

8 minutes ago, grannyknot said:

Turbo's are cheating,  there, I've said it and can never take it back.  Here's the sound turbos love to make

So are biting and low blows but if I end up in a fight all options are open. ?

[Av8ferg]

Cliff, my N47 has a spray bar only I believe. I didn’t see holes in the cam lobes for oil purposes. Good idea on the notebook.

So, I’m going with the general consensus that the 82’ NA is the way to go. I think it has a P79 not the P90 the P90 was in the turbo engine. I’m surprised no one voted for the N42 head engine in the 76’.
Good advice on making sure it turns by hand and getting a Bluetooth borescope. Buying the rebuild book tonight on Amazon.
Wayne, yes that’s pulled. I’m going to look at two of the engines tomorrow, the third is 2 hrs away (near where we went last time) and will have to wait a week or so. The plan is to bring it to my house and start tearing it down here and drive my wife nuts. I’m hoping it will fit in then back of my 4Runner on a pallet. I need to think this part through as it probably weighs in excess of 450#s. May need to borrow a truck or a small trailer...may need your help! Good thing I just had shoulder surgery 2 weeks ago! Supposed the be on light duty for 4-6 weeks. I imagine my doctor would be opposed to me trying to lift engines alone.


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