HP improvement?
 

Just a thought. I'm about ready to put my engine together a few more items to purchase. $3500 later. Anybody have a ballpark figure of how much HP I will have improved. 1977 280Z FI. I am adding a 60mm throttlebody cold air induction, rising rate fuel regulator, header MSA, Twice Pipe exhaust(no cat)MSA. and paid to have the engine block and head completly rebuilt($1450)
Any other ideas for improvement not cam or block changes at this time?:icon_super:

All that put together, would up it maybe 15 - 20 hp max. The RR fuel pressure regulator won't do you much good as it's designed to increase fuel pressure on a "boost:fuel" ratio... since you don't have a turbocharger, the only benefit will be manually increasing the fuel pressure slightly.

The 60mm TB will increase throttle response & torque more and give a hp or two.

CAI & Header / exhaust... good! Let the mothah breathe!


A cam WOULD be a good thing to wake up that motor, especially now that you've done the other things & you can get a mild cam for 2 ta 3 bills... But also get a performance ignition unit & coil.

Put in flattop pistons and a 2mm head gasket when you get it rebuilt. That will bump up your compression to a little over 9:1 assuming you have a N47 head.

HP improvement
 

I have thought about the cam. I have a stock head( I haven't picked up the motor and can't remember the number. I've also heard some heads are better than others. Which is best to build, have ported and polished, new cam and parts and what is the best valves, Can't afford it now and want the Z back on the road(1 1/2 years without it)

another problem
 

I also have flat top pistons. Before I pulled the engine when it was running the idle every once in a while would jump to 2000 rpm for a while then back to normal. Could this be the cold start thermoswitch gone bad.?

Well From what research i've done about Z's i kno that the 280zx engine was the best built out of all of them and that the head on the F54 was the good one. since the stroke or soemthing is longer. and the diameter on the head is slightly bigger. But thats what i got from the internet sources i kno for a fact that the F54 is the "" best " " engine quote on quote.

The P90 (turbo) head also had the best combustion chamber design and had the best air flow characteristics of all the L series heads. Both the P79 (NA)and P90 used the larger size valves. But that all only applies to the 81+ F54 blocks. 79-80 used a different block/head. Both F54 block combos also had a higher power output then previous L28's.

e31 has the best combustion chamber but smaller valves. An N42 head would also be a good head to consider too

ok now what
 

I just got off the phone with the engine rebuilders and he says I have a N47 head with round ports with inserts. I thought N47 was square and now I'm confused.:confused:

N42 has the square exhaust ports. The exhaust liners in your N47 should not be a problem with a mild NA build. Make sure you use super unleaded if you do have flattops.

The N47 is a round port exhaust, and the flow rate on them is fine. If you want to port out the intakes a little, that wouldn't hurt, but the N47 head is totally fine for applications up to about 250 hp. Raising the compression by going to flat tops is a must, and then you will have to run super, making sure that it is not supergasahol, just straight super gas. Bore it out 1mm if you can afford it, use a stock headgasket, and have the engine balanced definently. Going to a hiperf cam is a must, add a header (6 into 1 and have it chromex'd), and a larger exhaust. A bigger throttle body is a total waste of money, and so is a rising rate regulator on a N/A engine. The cold air intake won't do anything except deflate your pocket book, it's not a Honda. Your car already has cold air intake on it stock. We have an awesome cam available that is our own design at 485 lift and 285 duration. It adds 1K rpm to your power band on a stock or semi-stock motor, but if you balance and put in hiperf valve springs, then you can spin it up to 7500 rpm.
Z man of Washington
www.zspecialties.com