Lockjaw

Header and exhaust. Mill the head, open element air cleaner, mild cam, bigger throttle body.

Ross Racing 68 each, plus 110 for trick tapered chromoly piston pin's. Turbo pistons, flat top, with all the tricks.

I can do cams too.

OK you got me on that one James, I forgot the shimming of the cam towers, but if they are shimmed 80 thous, which is the same as the additional valve length, and the springs are shimmed too, then you should not need to change lash pads. So I guess I kind of get to smack talk you back. Dan, if I ran an E88, isn't that the same as an N42 except the N 42 has the slots cut for the injectors? If so, then I have N42 experience by association. I think I have also clearly demonstrated that I have the tuning proficency with webers, so I don't buy your retort about webers slowing down a car in response to my claim of an E88 slowing me down versus a p79, which incidentally had a bent valve, and still outperformed the E88. ( I found out about the valve later ) At least not on my engine, perhaps on someone else's engine. That said, I am going to defer to Bob H's assessment, with one caveat. He has a hydraulic P90A, and I know from personal experience that a P90 head worked better for me on my turbo engine than a P90A. I would bet his car to that a P90 with the same work done to it as his P90A would outperform it. HEHE. Bobs post also reminded me of one other thing the Z doc people were claiming, which was that the P series heads had some work done on them to enhance low lift flow. Anyway, I had enjoyed the debate, and if you haven't figured out by now, I happen to be a touch on the pig headed side. I hope one of these days to see you have finally caved and tried one just to see what the deal is. I am sure you will not be disapointed. You guys are some of the best folks too. Just wanted to let you know.

Actually, there are lawyers out there that have convinced juries that people are that freakin' stupid. I heard those the other day on the radio or something.

Almost all turbine housings are cracked. Where specifically is yours cracked?

We could do NA cams.

Thanks Bob, I knew you would come around. Oh and I think I am enjoying this every bit as much as Sean, and I like all of you. Now we need to have a group hug.

Daw I neglected to deal with that head you mentioned, but I have thought about it. It seems to me like it would be worth a shot if not for anything else, then to simplify the process for techically challenged folks. Dan, have you ever actually run a P series head? Serioulsy, have you every gone to the trouble to mill one, shim it, and put it on a car? I have run just about every head out there, except the N47 and N42 ( although I used an E88 with the same combustion chamber as the N42. I went from a P79 to an E88 and lost power on a flat top 280ZX bottom end. Nothing changed but the head, and I had the E 88 milled 30 thousandths to boot. My buddy went from an E88 to an uncut P79 on his high compression 3 liter, and picked up power. My other friend went from a seriously milled E88 with the E31 style combustion chambers to a cut P79 and picked up power. On all three of these engines, the only thing that was changed was the head. Yeah no hard numbers, but they all ran better. Now I am sure there are variables that can factor into that and make some differences, but the bottom line is on every engine we have done something with, when we went from any series head to a P series, we gained power. We just weren't very scientific about things back then, and to be honest, we did not care as long as it made our cars faster. Bring your Z on down here. I would like to see what it is all about. On a road course, you can have your way with me, but on the strip, that turbo will make you long for some NOS. Now if I put all that over into my 260Z, then you better look out. Dan for what it is worth, I was like you. When my friend who is a pal of the Z doc boys up in VA came in with his "smogged" 2.8 with a p79 on it, and told us the Z doc guys said it was the head to run, we laughed our heads off. We actually got off to the side and made fun of him. He put up with our ribbing for a long time. But when he put the engine in his car, with the head milled a mere 45 thou, and ran a cam I had run in my many different heads that never was spactacular, and took me for a ride, well I was shocked. I raced him that night in my 240. I had a 2.4 with a cam, header, light flywheel and 3 two's, and I never had run across a Z that could handle mine from a low speed kick, but his did. He pulled out on me and kept on going. From that point on, we believed. Dumb story I know. Short of hard numbers from someone, there is no way anyone will ever convince me that the open chamber N42 is superior to a closed chamber P series head. Oh and on the subject of compression ratio's, a full point in compression is supposed to be worth 4 percent more power, so half a point would theoretically be 2 percent. On a 130 hp engine, a half point compression would theoretically bump its output up to a tire shredding 132.6 hp. I believe Yo would be correct that the factory did show an increase of 10 hp going from the N42 to the F54 engine. Just for comparison, a pound of boost is supposed to be worth a 7 percent increase in power. But that is another thread.

So what are you trying to say, exactly ? Damn, now I am going to have to come up with a co-helper to prove this point. I don't see what is so tough about somebody making a concession that perhaps the P series could be better. Why would Nissan make a change, and make it for the worst? How hard would it have been for them to just make the combustion chamber a little bigger on the N42, and use the same dished piston as in an N42 block, and turbo it? Why did they feel the need to completely redesign the heads? Dan I am not belittling what you have accomplished with what you have done either. I think the power outputs you are getting are impressive, and there may not be huge differences between the N and P series, but if there is a 10 hp difference, to me, on an NA engine making 235 hp to the wheels, that is significant. Also, if you will note, all of the high performance aftermarket heads now use the smaller closed combustion chamber.

Heh Heh Heh He said masturbation.

You gonna run an E31 or N42 on your turbo engine? I forsee a huge "KABOOM" in your future my friend. OK I will give you that for the mechanically challenged, an N42 would be the simpliest choice. But, see all the developement work by electromotive on the L series ceased when the VG engines came out, so they never really got to play with either P series head. Had they, I think you would find they would have surpassed what the N series heads did. James, we are only talking about 2 mm difference on the valve length, and I know when I was setting my cam up in my p79 that is was protruding well beyond the rim of the combustion chamber and I had to get the head up off the bench to finish installing rocker arms. I also think it head was designed that way to make the mixture come out and "swirl" which is where the P series heads are vastly superior to the other designs. Not to mention the P series heads are much more detonation proof than the open chamber N series. Also for you guys, if you recall, the valves out of the N42 head can be put in the P series and you just shim the springs up two mm, and then you maintain your valve geometry. That is what the Z doc guys were doing. Yes it is a little more expensive, but if you already have the N42 and pick up a P series for a hundred bucks, you are set, except for buying the shims. I don't understand why everyone thinks that getting the geometry right on the camshaft is so hard to do. It is really very simple. At least I think so. Now I have 3 people on my side.

If you have an electric fuel pump, you could wire it manually and shut it off. If the car is an auto, shutting it off in drive would solve your problem too. I am a little befudled by the whole thing. I just don't recall ever having a problem like that. Maybe you just got a bad tank of gas?????? I suppose you could dump a bottle of octane boost in there and see if that helps.

Is that for all 12?

Geez man, even Bob agree'd with me. On the premise that I am allowed to run gas out of a pump from my local amoco station, I may take you up on your challenge. What about headwork? What is allowed versus what is disallowed? What about the engine? Does it have to be 2.8 liters, or can it be any sized L6 up to 3.1 L? BTW, what does an 8.40 in the 1/8th work out to in the quarter mile? Using the 1.57 factor I have always heard produces a 13.2, and that was a stock engine with an unported head. P79 head. Yeah I know the conversion is sort of bench racing and all that, but we did not have a quartermile track around us then. There are a lot of variables. What about transmissions and rear end gearing. I have to know this stuff, because I don't want to be accused of cheating, and I will say I subscribe to the Smokey Yunick method of determining what is allowed, if it doesn't specifically say I can't do it, then it must be ok. Any camshaft limitations? How long does the motor have to last? Does it have to be streetable? Use Carbs? Etc. The only thing that sucks about this is it will distract me from playing with my turbo car, and nothing I do to the NA engine will make it as stout as more boost on the turbo. I need a partner in crime, anybody game? Maybe I need to check with my pal Ira and see what he thinks. This could be fun. And Dan, I love you too, we just disagree on this particular subject. Oh and my eye's are brown.

Yes we do disagree but aren't you running a P90a? Actually that thread had a lot of good info in it. What we really need to do is take all the heads, put them on the same motor, and dyno them all. Of course, I think we should make the combustion chambers all the same CC, that way we could eliminate compression differences. If we did that, I am confident that the P series heads would thoroughly trounce the other ones. But that is just one guy's opinion. Sorry Bob, had to do it. For those who don't know, the P79 is essentially a P90 with exhaust liners cast in the exhaust runners. See sometimes we agree.

The one that goes in the 300ZXTT is a good one too.

Have you checked the cam timing yet? I have never had a dieseling issue, no matter what cam I have run, and I bet I have run 7 or 8 different one's, not counting the stock one's.

No sense searching, Bob H will weigh in after while and back me up.

Are you getting spark from the coil? I would check that. Also, check the plugs and make sure they are not wet now. Finally, you need to choke the SU's to make the car start. SU's are tempermental in that regard. Adjust the needles via the adjustment knob on the bottom, and adjust that from fully closed to 2.5 turns out. That should get you in the ballpark.

Scottie I think it depends on the turbine wheel what the housing is bored out to. Mine is 2.25 with the stage III wheel, but I opened it up a little with the dremel. Whatver size it is, use the absolute shortest piece of largest diameter that will work, and tranistion to 3 inches ASAP. That will make some nice power.

The GN one won't bolt up either, it has a 3 bolt triangular flange. The hybrid is the best way to go for ease of installation versus power output. The E trim is a little more efficient at higher boost levels, the B is better at lower one's. A V trim B or a 50 trim E would be good places to start. Get the stage III turbine wheel with a .63 ar housing. You can use your nissan turbine housing and have the turbo upgraded if you would like.

I always liked the reponse if you have to ask you can't afford it, which means I can't afford anything, becuase I always ask. What made the biggest differences. Lets see. A big hybrid, intercooler, JWT ecu upgrade. But the best bang for the buck I got was the 3 inch mandrel exhaust with a straight thru muffler. That change alone dropped me 6 tenths of a second. I have alot tied up in mine. It has forged pistons, and very good machine work, which together was probably 2 grand. I had a 3 angle only done on the head, it is port matched and that is it. Has ARP rod bolts. I am probably close to 5k, counting buying everything except the car.

I will accept morgans numbers. I was close. Do his include flywheel and clutch and all that jazz?

P90 is the best. No matter what anyone else says, a P90 is the best. Repeat that 100 times.