Lockjaw
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Posts posted by Lockjaw
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Here is a good philosophy. Do it right the first time, so you don't have to redo it. If you cannot afford to do it right, wait.
Look I am not bragging, I spent the 500 or so bucks to get forged pistons, had the rods prepped for floating pins, polished them, shotpeened them, and ran ARP bolts. You can easily spend 400 to 500 prepping the stock rods.
But guess what, I told every machinist that did my motor work, every person I talked to that I planned to flog the everloving crap out of my engine, and well, so far after 6 years the bottom end is still together. It has survived 3 different turbo's, multiple 1/4 mile passes at boost pressures of 20+ psi, and best I can tell, its still in good condition. It has seen less then 15 psi only long enough to get the boost jacked up there.
I guess we will see when I take the head off to replace the stock head gasket that finally let go.
If you are going to use a stock piston, you really need to use a turbo style one.
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Well putting his cam in a stock engine is pointless unless you do something with the rev limiter, its going to shut you down at 6400.
Also turning a stock engine to 8k would mean you have way more money then sense, they are not designed to go that high, you will need forged pistons, and a very good balance job, not to mention the BHJ balancer, and that is still a little high.
FWIW, I would run something a little milder. I have a little crower that is .428 lift, and 218 degrees duration at 50, with a 110 degree lobe center, and it pulls to 7k without issue. It also idles well.
James is running a web cam that is 254 duration, around .480 lift I believe, and he is currently the fastest L series guy on the board I know of.
Several of the guys are using ISKY.
Personally, I have heard both good and bad about Gude, but just because the guy has been doing cams for 20 years doesn't mean he's been doing them right.
If his cam pulls to 8k, and you get shut down at 6400, I can tell you right now, that is going to piss you off, since you will be hitting the limiter long before the engine feels like it is straining. You really don't need to turn one that tight.
Thats just one guys opinion. That and 35 cents will get you a phone call.
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Just put a damn bowtie in it and be done!!!
Bring your bowtie to race up Vail pass!
It'll bring ANY n/a to it's knees.
Give me an month and bring it down here, I will spot you a few LBS.
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I would have put a fuel pressure guage on it before replacing the pump, that would have saved you the money, but you will need the pump if you plan on further upgrades.
I can just tell you, I hate the stock injection since moving to the JWT stuff, and would encourage you to do the Z31 swap.
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Not this again...
I've seen ZERO evidence that the P90/P79 cc design offers *any* performance advantage. Where are the 255rwhp or 12.8x sec @ 107.x mph P90-headed' date=' pump-fuelled, NA cars?!
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We figured out it was cheaper and faster to go turbo. I mean my 3200 pound car is still 3 tenths and 7 mph faster, and it is only going to get worse the further we go. And it is only a 2.8, with a stock head, and that was on pump fuel, of the 93 octane variety. Stock cam too.
Somebody donate me a rolling 240 chasis, and I will make a P-series NA car to be reckoned with, and send all you N42 guys packing. And I won't need one of Sunbelts one off new funky do cams to do it.
The combustion chamber does make a difference too. Can you run 87 octane on a 10 to 1 motor with an N42 head and timing advanced beyond the stock setting without getting detonation? I did. Every day, in ALABAMA, where it gets hot.
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will do, but I hope you aren't in a hurry, I have't turned the first wrench yet.
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I always got away with 9 psi without an intercooler with no issue, 10 was asking for trouble. I would make sure I had a better fuel pump in there, and you should probably be using a rising rate FPR at that point as well.
Also, you do know if you have any oil getting into the combustion chamber, that can cause detonation, and using fuel injector cleaner will also lower your octance. So be careful.
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Well all I can say is you won't ever convince me the P90a is as good as a P90, much the same as you won't ever convince me a N42 is better then a p79.
And you are correct, I don't have hard numbers to always back up my claims, but I don't need them I was as big a skeptic as anyone about the relative merits of a p79, until I got to look at the back end of a car running one, and watch it continue to pull away.
I mean when you have the king Z car, and it followed all the comon logic of the hotrod Nissan books of the day, and someone comes in, tells you their smog head is the way to go, we laughed. We talked about that for months while the guy was working on his car. Junkyard 2.8 with a P79 milled 45 thous. He left me for dead, and my car wasn't slow.
I don't need hard numbers when someone is whipping my butt. You know what I am saying too.
Bottom line is, the solid lifters don't have problems, ever. To me, you need no other reason to run a solid head then that. Whatever series you want, if it makes you all warm and fuzzy to use an N42 have at it, personally, there won't ever be one on my car. But then I can handle setting up a P series to deal with the timing chain slack and all that from milling, others cannot.
In fact, on my turbo engine, there would be a P79 there long before an N42. Thats how much I believe. When someone comes up with some hard numbers I can look at, then I may change my mind.
Oh and my friends NA car, every bit a match for my pals turbo car, which ran 13.1's @109 or so, if memory serves. So it wasn't just an 1/8th mile wonder. I am telling you, I have never ridden in an NA datsun that ran like that one. It pulled to 8k and sounded like it was turning 6k.
Of course it was really cool when he went to a 3 inch exhaust and flowmaster. Now that baby would talk to ya. Turbo's are fast, there is no dening that, but to me, there is something about a high compression L6 with a big cam, header and exhaust. If there is a finer sound on this earth, I haven't heard it.
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I have the same problem with my engine, and suspected the turbo due to oil in the compressor housing. I replaced the turbo, and still have it.
Now with a blown head gasket, I am going to have the head worked, and ALL the valve guides replaced. I talked with a guy at Rebello, and he says the turbo engines routinely have to have exhaust valve guides replaced, hardly ever on the intake.
So that is what I am going to do. I have good compression, no smoke except when boosting and then shift gears. If the guides don't solve it, then the turbo is going to FP for a rebuild and compressor upgrade, and if that doesn't work, then the engine is coming out.
I got no oil anywhere right now. No intake, PCV, none dripping from the turbo that I can find.
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120 overbore is to much. Personally I would go with a P90 or 79, and have it milled, it has the best combustion chamber design. The Maxima N47 head is another appealing option if you ask me.
I know from talking to Rebello that even on the turbo heads (p90) they port the exhaust side, the intake flows good. So in an NA application it is far more important to get it in there, the engine will get it out. IMO.
There is alot of debate on this board between me and a few others, but I have seen a P79 run better on every engine we have ever installed one on, keeping everything else the same. The high swirl design of the combustion chamber aids in detonation resistence, which allows more compression, and hence more power.
The E88 is not a good choice unless it has the E31 combustion chamber design, which looks similar to the p79. The fact that most all hipo heads now days are a closed combustion chamber to me speaks volumes about avoiding the E88 and N42 head.
So I am sure you will see someone take issue with me, but my friends 240 ran 8.40's in the 1/8th mile on a stock 2.8 liter engine with a milled P79 and bolt ons.
And I also believe this, if nissan went to all the trouble to redesign the combustion chamber, there must be a good reason for that. See if you can find DAW and he can fill you in on the Maxima head. I would go there first.
Good luck.
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Bob you still neglect to notice what I said, long freeways runs. Guess what, a turbo Z car, with a stock oil cooled turbo, and no oil cooler is going to heat the oil and thin it, hence the ticking. I in no way said the head had bad lifters, but the fact remains, I did not like the racket it made with a stock cam, it should have been silent. Now its ulitimate condition, well who knows, it was a 98k mile engine that was about 10 years old at the time. But hot thin oil means lower oil pressure, so you figure that one out, maybe there was some trash in one of the lifters.
I do know this. My turbo engine was in a 240Z, and thru the 1/8th mile, I could not beat my friend, who owned the 83 ZXT I now own, and his was stock, with a P90 ( and way more mileage). Now it doesn't take much common sense to figure out a 240Z with the same engine and turbo as a ZXT that is loaded, well that should not have been much of a race. But it was, until I swapped the head.
I also went from having to run down mustang GT's, at the time, our favorite victims, to pulling them from a dead stop, so the power gain was more then noticeable.
David, I really don't care what you have done to your head, the bottom line is you bench race, and have as of yet been able to step up the plate and demonstrate your car runs well. Still no answer to the question of what does your car run? So if you think its name calling to describe what you are doing, so be it, but if I was going to call you a name, I would probably chose something a little more colorful then bench racer. Just so you know.
Now Bob I know you don't like car comparisons, but you have to deal with some things that happened over a decade ago, and you know, starving college students won't drive from Auburn Alabama to Birmingham or atlanta to dyno a car. We did not care enough to go that distance. And we would have rather spent the money on some secret mod our friends did not know about.
However, you show me an NA guy on this board who runs or ran 8.40's thru the 1/8th mile with a 2.8 that was stock except for a cam, header & exhaust, and sidedrafts. There is no disputing the car ran what I ran, I double checked with my pal, and he has never lied to me. I drove it with SU's, and it was positively brutal above 3500 rpms.
Who wants to spend money on a p90a, then spend a bunch of time and money modding the lifters, pay what sunbelt wants for one of their one off cams, and still not be assured the head is going to make as much power as a solid head? Not me. And if by chance you happen to be out messing around and one of those one off lifters takes a dump, then where are you, running like crap as you have already said. Maybe worse, eating a lobe on your expensive one off cam. And I would be curious to see what head sunbelt recommends for their cams too. Maybe JWT as well.
No thanks, I will stick with a solid lifter head, and know beyond a shadow of a doubt that my 'lifters" won't go bad, that my valve geometry will be consistent, and that I will always make more power then someone with a hydro head.
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So what you are saying is oil is not any more or less compressable then metal?
Sorry Bob, but there is not any way you can convince me that the hydraulic lifter doesn't compress some. I mean I have worked on V-8's and you can surely compress the hydraulic lifter with a pushrod.
I hated my head when I had it to. Long runs on the interstate and then coming into city traffic always resulted in lifter tick at idle, which I despise. I considered replacing them all with new ones, which I could get at the time, but they we 36 bucks each, at cost , which works out to 432 bucks, versus the 250 I paid for a solid head.
And it certainly seems to me that if there was no performance advantage of solid over hydraulic, that all the cam manufacturers would have somehow managed to figure that out by now, and quit offering solid lifters, since a hydraulic is obviously easier to deal with. (sarcasm added)
The bottom line is no one has stepped up with a hydraulic and run good numbers, you are pretty limited with the stock cam to a powerband that keels over about 5500, and I guarantee you the solid head is way more forgiving as far as setting up with an aftermarket cam.
The bottom line is you can spend a bunch of time and effort and money one a haed that might make as much power as a solid, or you can just get the solid head and be done with it. Seems like common sense to me.
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I decided not to reply to Lockjaw because anything i say he stomps his foot until he is right.
I just don't like bench racing, which is what you are doing. You don't have to like my opinion, I don't have to like yours, but I have a basis for mine, where is yours?
Oh and what does your car run? I missed that somewhere.
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Well Bob your point is somewhat valid with one exception, when I did all of this, there weren't dynojets in every city, so we tried our best to make valid comparisons using cars and eliminating as many variables as possible. So while not completely scientific, it still does lend credence to the fact that I did in fact run both heads, and did in fact make more power with the solid head.
At least I have made a swap and have some basis to comment, rather then doing "research" and saying something is a fact. You can call it what you want to, I call that bench racing, and don't really care for it, and my real world results tend to discredit the "research".
You have made an aftermarket cam work, congratulations. I think I could manage that feat myself, but I chose not to play with a head in which I have found less power.
As for the P79, well we have been down that road, but none the less, my freind ran 8.40's in the 1/8th mile in his 240 with one, and he was using a square port header, which would be like a turbo exhaust manifold, so it seems the P79 would work in a turbo application, and Yo2001 was using one on his car he just sold, and put down some pretty decent numbers for a 2.6, running moderate boost.
Again, I have some factual basis for what I say. I dare say, there are not to many NA guys running 8.40's on this board today, and this was 10 years ago, on a 2.8, not some tricked out 3 liter or larger, and no port work.
So I guess it all boils down to those who actually do comparisons in the real world, versus those who just like to crunch numbers. Sorry they did not have dynojets back then, we did have a vericom, and it said my freinds 240Z was making 240 or so hp, wether that is true or not, I don't know, all I know is it ran 8.40's in the 1/8th mile, and would spin well past 7k with little trouble or drama. And he spanked the mess out of a lot of people, including some guy with a souped up stripped out vette with a 454 in it.
And in a purely mechanical sense, the hydraulic lifter is supported by oil pressure, and oil is compressable, a solid rocker shaft is not, and I will go even further and say the seat pressure on the valve spring is indeed higer then the oil pressure on most Z engines, so it would seem, at least to me, that the place of give in the valvetrain of a P90a would be the lifter itself, which could not be a performance benefit, if you ask me.
But again, what do I know? I am just some guy who counts money for a living, and has spent the last 16 years fooling with Z cars. I think the fact that none of the fast turbo guys run a P90A speaks volumes about what the consensus is on the head.
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Judging by the yawn, there must not be much under the hood.
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Give it up. You know what you need to say, you have to say it to your wives all the time.
LJ got the low down on the heads.
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That is the kind of intake I used that I picked up boost switching from.
You picked up boost?!!? That implies more restriction.
In other words, when I went from the tapered manifold to the turbo one, my boost pressure in the manifold increased, all else being the same. More boost equals more power, so I felt like it was a good thing.
Maybe we are looking at it from a different perspective, I likened it to pressure drop across the intercooler decreasing, thus increasing the amount of boost I was seeing in the intake.
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I was going to send mine to swaintec for thermal coating anyway.
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That is the kind of intake I used that I picked up boost switching from.
I like your TT set-up though, those headers are trick, and you have some plumbing nightmares it appears.
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The springs are all the same, but, is this one of the funky P90A's without hydraulic lifters?
Hydraulic lifter heads don't use the springs.
You are referring to the springs that go on the back side of the rocker arm, and connect on either side of the rocker pedestal, right?
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Yeah I guess your real world experience proves my actual facts wrong. HUH?
And it is quite impossible to go back in time, I do know that I raced a car before and after the swap, and he made no changes, I made one, a head swap, and well lets just say the results proved what I say, the P90 is better.
And tell me Mr Expert. What have you actually PROVEN with your hours and hours of research? I actually did the swap, you haven't even done that yet.
And what does your car run with its hydraulic head? And why is it the fastest turbo Z guys on this board all run the P90?
All you have proven is you spend an inordiate amount of time, with a head every one agree's is not as good as a solid lifter head, and you have had to MODIFY it from its stock configuration, and you still haven't proven it EQUAL to the solid lifter head.
Argue all you want. The bottom line is, I have run both heads, and the solid head made more power. And I KNOW I can run an aftermarket cam in my solid head, you haven't even PROVEN you can do that in you MODIFIED hydraulic. See I have seen someone run one of the Nissan L9 grinds in a hydraulic head, with the nissan specified retainers, and lash pads, and guess what, it ate it.
You just want to argue, go out and prove it. I don't have to prove it, the facts are, I have seen it first hand, and the fastest turbo cars on the board all run the solid head.
You go do research, we will keep running our fast times.
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It will make you spill your drink if you don't watch it.
Mine on the JWT ecu is much nicer.
Oh and I had a 280ZXT box that would go over 7k without hitting the limiter, but usually only when I changed out the cap and rotor. Never could figure that one out.
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well we ran a 500 lift cam on a P79 milled 110 thousandths on a flat top 280ZX engine with no issue's, so I wouldn't be scared unless the cam is way bigger then that.
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You would have to get swing valve assembly that fits and they generally use 3 bolts to attach the exhaust. Or the new style uses 4 bolts and you have to have an external.
Seriously, use your turbine housing, they can bore it out for a bigger turbine wheel. It can be made into a hybrid too.
Mine is a nissan one, and it was a royal pain to go from a Ford (garrett) style turbine housing to the nissan.
And the Nissan swing valve won't bolt up to the garrett housing either.
VAPOR LOCK SOLUTIONS FOR I/C'd 280ZX
in Fuel Delivery
Posted
You should not have vaporlock issues with a fuel injected car. Chances are, you have a bad connection at one of the sensors, you have a leaking injector(s), or possibly the CAS in the dizz is going bad.
I don't run the injector fan, never have.
Run some STP fuel injector cleaner thru it, check, your timing to make sure it is not retarded, and clean all the connections at the ecu, and the sensors for the ecu. Then see if you still have a problem. Also make sure your head temp sensor is staying connected. Mine comes off from time to time, but JWT in their infinite wisdom fixed that so its not so bad, like a stock one.