Are all F54 blocks and P79 heads the same?

[=Enigma=]

I have an opportunity to purchase a complete L28 F54/P79 motor from an '82 280ZX for $250 + the cost of a rental trailer to get it home and my time. The odometer on the car it's in reads 260K+ mi. I pulled the plugs and turned it over via the crank pulley bolt and it's definitely not seized, but lying under it I can hear what I believe to me compressed air leaking past the rings into the crankcase with the plugs put back in. Based on the miles this is no surprise to me.

The upside is that the motor is still in the car and hasn't been directly exposed to the elements like another I am looking at from I believe a Maxima, which brings me to my questions.

Base on the mileage, is this still a good deal, and should I grab the 5 speed tranny as well?

Or...should i go with the element exposed engine of undetermined mileage which I can probably get for $100 less?

And finally, was the F54/P79 found in Maximas, and if so, are they basically the same from the standpoint of stroke, cam timing and valve size?

[=Enigma=]

Anyone?.......

[montoya_fan01]

It would be normal to hear air like you describe when rotating an engine by hand. Just rebuilt my L24 last summer and as I adjusted the valves before even starting the engine the first time I could hear that. Checked compression after a few hundred miles and all cyls read 175-180.

Maybe you could bring a fresh charged battery to the engine/car and do a compression test to ease your fears?

PS Grab the 5 speed if the price is right.

[Fun_in_my_z]

Buy the car sell what you dont want and make your money back.

[=Enigma=]

Unfortunately, the car is in a junk yard and the starter is missing. That's why I was cranking it by hand. Since I was planning on rebuilding it I guess the high miles don't matter much. The block and head both look solid and it's not frozen. Any idea what a typical rebuild with a mild cam and a rebuilt head would cost if I did the assembly after honing, tanking and anything else that should be done? $1000, $2000..more..less?

So that hissing sound is normal eh Montoya? Wierd. I would think on a fresh rebuild you shouldn't be leaking any pressure from the cylinders in any direction unless something was wrong. Could it simply be the pressure changin in the crankcase due to th movement of the pistons, and the hissing sound is actually coming from the crankcase breather?

[montoya_fan01]

mine cost close to $2K

It seems to me to be normal. My engine is running just fine and I heard what I believe was the same sounds that you heard.

[sblake01]

....................................And finally, was the F54/P79 found in Maximas, and if so, are they basically the same from the standpoint of stroke, cam timing and valve size?

No. The 810 and 910 (Maxima) used an L24E. They are front sump engines and would require machine work, and the oil pan and pickup from a Z in order to fit them in a Z.

[=Enigma=]

No. The 810 and 910 (Maxima) used an L24E. They are front sump engines and would require machine work, and the oil pan and pickup from a Z in order to fit them in a Z.

Hmm....I found an F54/P79 combo in a junkyard, and the guy swears it's from a Maxima. He also swore up and down that the only Z motor he ever had was from an early 240Z. However, I managed to find 10 L6 engines. A few were definitely from Maximas but I also found one early L24 with SUs, 2 L26s w/Flat Tops, as well as a couple L28s w/F54 blocks and various heads.