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280z engine swap


Tarheelz

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Hi Hybrid Z'ers so my engine block needs a complete rebuild as all of my plugs are pretty much soaked in oil.  I don't have the ability to do anything like this, SO I'd like to hear best options for an engine and 5 speed swap??  I'm sure this is a repeated question but would love some input.  Also, I would rather not spend more than $4 grand all in which cuts out some options I'm sure.  

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 Before you assume it needs a complete rebuild, know that these blocks last a long time. I've seen these engines with over 100,000 miles and the bore hone marks are still visible. A common cause of excess oil usage, aside from leaks, is bad valve guide seals. These can be replaced without removing the head or cam. Have you re-checked the valve lash and done a wet and dry compression test to confirm it needs a rebuild?

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Anything from 77 to 83 ZX will swap right in as far as 5 speed.  If you get a mid-80 to 83 5 speed you'll probably want the 3.9 diff also.  And a 76-78 propeller shaft.  Your 75 should have the unique bolt pattern diff flange and propeller shaft.

 

Any engine up to 1983 will swap in .  

 

I had good luck just buying a whole car that had been sitting for years.  If you have the space you can save a lot of money that way.

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On 11/8/2020 at 8:30 PM, bunkhouse said:

 Before you assume it needs a complete rebuild, know that these blocks last a long time. I've seen these engines with over 100,000 miles and the bore hone marks are still visible. A common cause of excess oil usage, aside from leaks, is bad valve guide seals. These can be replaced without removing the head or cam. Have you re-checked the valve lash and done a wet and dry compression test to confirm it needs a rebuild?

Hi, thank you for your reply!  Yes, I have checked and rechecked the lash multiple times.  Did a wet compression and went from 145-150ish to appx 160.  Thoughts on that?  

 

Also, I found someone that has a p79 head on f54 block.  Really good price what do you think about that combo?  Or I could drop my rebuilt N42 head onto the f54 block... 

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  A few more questions. Was the throttle wide open during the test? All the spark plugs out? Screw-in connection on the gauge or rubber cone?  Rubber hose used on the gauge and the length vs. metal tubing? Did you turn the engine over until the highest reading was obtained? I'd like to see it somewhere in the 165-170 range but 160ish is darned close and any, or a combination of the variables mentioned above could lower the readings slightly. Also I'm not an expert on all the compression ratios throughout the years.

 Were any of the cylinders considerably lower than the others is what you really want to know. If all the cylinders are within 10% of each other I'd look elsewhere for the oil consumption. The valve guide seals are notorious for going bad and fouling plugs.

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