E88 and P79 head talk

[rchrd989]

I currently have an E88 head on my N42 block. (Im not sure which E88 head I have) I have the oppurtunity to get a rebuilt P79 locally for a very good price. Im wondering if it would be worth it to replaced the E88's spray bar style valvetrain with the p79 internally oiled valvetrain, I looked at some specs http://www.atlanticz.ca/zclub/techtips/cam/index.htm and I see that there is some differences. What do you guys reccomend I do?

[Zmanco]

The P79 has a larger combustion chamber than the E88 so you will lower your compression ratio.

 

Is there something wrong with your current setup? If not, then there's nothing to be gained by swapping to the P79.

[rchrd989]

I would just be swapping the cam towers, camshaft rockers lash pads etc. the E88 head has a spray bar for oiling, even with the motosport high pressure oil spring i only yeild 15 psi of oil pressure at idle. the P79 cam is internally oiled

[naviathan]

Unless you swap the cam over, eliminating the spray bar will eliminate any oil to the lobes. You're best bet would be to buy an upgraded cam or have the one in the P79 reground, then call MSA and get the spray bar block off plates and you end up with the same internally oiled setup. Honestly I don't think your oil pressure problem is caused by your cam. I run both internally oiled cam with a spray bar and my oil pressure sits at the half mark of the gauge at idle after warm up.

[z-ya]

Try replacing the oil pressure gauge sender, they often read low when they get old.

[BRAAP]

I would just be swapping the cam towers, camshaft rockers lash pads etc. the E88 head has a spray bar for oiling, even with the motosport high pressure oil spring i only yeild 15 psi of oil pressure at idle. the P79 cam is internally oiled

 

 

 

There is a restrictor port at the head-to-block interface. You could remove the head completely, (if the engine would run that way), and your oil pressure gauge would still read within 5% of what it does now.

 

If you are only wanting to do this cam oiling swap based on a fear of inadequate oil pressure as indicated by the stock oil pressure gauge, (that is how I interpret your last post), just relax and forget about your cam oiling.

 

Lets get you on track here. The OE gauges are merely a reference that oil pressure exists and is NOT to be used as an indication of how much pressure exists. The OE Oil pressure gauges are actually worthless for the following reasons.

 

1) The do not indicate actual pressure.

 

2) The needles reacts and moves so slowly that if oil pressure did drop to zero at the bearings, the engine would have seized up completely before the gauge actually finally indicated 0 PSI. By the time you saw it on the gauge, the engine is spent.

 

3) Oil pressure is one of those items that if it is wrong, the driver should have immediate notification, such as an idiot light or loud buzzer. Can’t monitor a gauge 100% of the time AND drive, especially a very slow reacting/moving gauge.

 

4) Only after an oil pressure idiot light is installed, would a quality pressure gauge be of benefit so as to keep an occasional eye on actual pressure readings and let the idiot light warn you of immediate oil pressure failure.

 

In short, do not rely on the original Nissan oil pressure gauge for actual pressure readings. It is merely an indication that oil pressure is present, nothing more.

[Daeron]

In short, do not rely on the original Nissan oil pressure gauge for actual pressure readings. It is merely an indication that oil pressure is present, nothing more.

 

Thank you for putting that so wonderfully bluntly, and confirming an opinion I have had for quite some time.

 

It IS a rather nice indicator though.. adds to the atmosphere of the car IMO

[rchrd989]

cool thanks guys, Im thinking im not gonna worry about it for now.