[john]

I just bought a 280zx motor that is a f54 block with a p-79 head. It has 60k miles on it. I have a 73 240z with a e-88/l24. It has 160k miles on it. I am definately going to put the l28 block in the car. I am just trying to decide wether to use the p-79 or the e-88 on the motor. The compression on the l24 in the car right now is low but went up when you put oil in the chambers. But on the fourth cylinder the compression did not raise. So I am assuming that there is a valve problem on that cylinder. My question is should I use the p-79 that needs no work, but buy a new header for $200, or should I use the e-88 on the l28, but fix the one valve? Also, how do I know if the valve seats are worn?

Thanks

 

[zbaron]

You should ask yourself whether you plan to use fuel injection or not and how much horse power you will want. The P79 head will breathe better (yields higher top end) but don't use that cam on a carbureted setup; the cam will give you fits so change it. I'd suggest going after market for a mild race cam.

> I just bought a 280zx motor that is a f54
> block with a p-79 head. It has 60k miles on
> it. I have a 73 240z with a e-88/l24. It has
> 160k miles on it. I am definately going to
> put the l28 block in the car. I am just
> trying to decide wether to use the p-79 or
> the e-88 on the motor. The compression on
> the l24 in the car right now is low but went
> up when you put oil in the chambers. But on
> the fourth cylinder the compression did not
> raise. So I am assuming that there is a
> valve problem on that cylinder. My question
> is should I use the p-79 that needs no work,
> but buy a new header for $200, or should I
> use the e-88 on the l28, but fix the one
> valve? Also, how do I know if the valve
> seats are worn?

> Thanks

 

[Chris]

I have a L28 in my carbed 240Z with a P-79 head, aftermarket cam from WebCam in Riverside, California, and have the square headers. It all works with no problems. When I originally bought the headers I had an E-31 head on there but the pistons were kissing the bottom of the surface so I had to replace it. I used a P-79, had the work done on it, slapped it on, prayed the headers would work, and now the thing runs like a champ. Compression went down from probably around 10:1 or higher to around 9:1 with no loss of power or torque. It runs strong. I couldn't tell the difference between the E-31 and the P-79 so I don't see why you would be able to tell the difference between the E-88 and the P-79 (I've also used an E-88 and no diff).

Just my two cents.

Chris