Bob_H

I'll be your sense of reason here. Anything over about 89-90mm will not really be possible. The whole "diesel liner" thing is a myth. The LD28 block had a 84.5mm bore. Those that have actually taken the LD block and tried to get a "larger" bore than the L28 block were only successful in getting it out to about 88-89mm, or nearly identical to the L28 blocks capabilities. Now they may be talking about general liners for a generic diesel block... So unless I'm missing something, your still only going to get out to about 89-90mm. If you take a whole bunch more out,(there are posts which indicate about how much is left when they did some sonic bore testing on 89 and 90mm bore blocks) - and ad a liner back in, you are about the same overall size, maybe just a mm or two bigger. I guess you could push it out to 90+mm, and there is one guy I know that did run 91mm, (had the block originally bored to 89.5, they messed it up and did it at 90, then he screwed up the block and had to get it bored out again). He ran it for a while, but it never made much power as the walls were so thin, it was assumed that they were deforming under power and allowing a lot of blow-by, i.e. not good sealing. Remember, thin is a relative term here..... I have never heard of a 3.5L kit for our motors and I did a lot of research before I built mine and wrote the Datsun workshop,(which is somewhat dated now). plenty of 3.1 and 3.2L, but not much beyond that. Food for thought. -Bob Hanvey

Was it a modified pan, or just the stock RB25 pan? Did it include a pickup or will you have to modifiy that yourself? Just trying to find other options for all those that ask me about mine. -Bob

Ok, so I puruse the forums and take a look at your progress - great work! I do have a question for you. On your intake - how did you do that initial aluminum/steel tube bend? )the one that goes around the strut housing? I have some similar problems with the RB26. Of course I have to combine two intakes into one, but similar issues. And the way you excecuted the intercooler gave me a great idea on some things as I was set to the mindset of having the pipes at the top and the intake below - this gives me some more options. Like I said, it looks great - I have the same fuel cell, and would like to see how you hooked it up, specifically the filler hose/bend. -Bob Hanvey

Thanks. The wheels pictured are the 17's. -Bob

I am a fan of tha color - my other Z is that color. But since I already have a green car, I think I'll pass on another green one. Blue is nice. How did you do it so fast? Any chance of seeing a silver-ish color? Bring 'em on if you have more colors! -Bob

Take a look at my webpage for more shots: http://www.geocities.com/row4navy/rb26swap/72Datsun.html So noone can tackle the silver paint job? -Bob

Cleve won't know- I asked him. He bought the car almost 6 years ago with the body already complete. He then did the suspension/cage, etc.. Bottom line - I have no answer to your questions. -Bob

There is nothing subtle about this car. I am pretty sure the entire car is an IMSA kit with a G-nose front. None of it is John's stuff, but they did do quality work. -Bob

While that is a cool color - no way, no how. I am not a fan of purple. And as long as it remains purple - it will still be Cleve's car, not mine. I figure a new paint job, my engine, and some of my touches, and then it will truely be mine. -Bob

Ok, some of you followed the short photoshop thread in off topic here: http://www.hybridz.org/phpBB2/viewtopic.php?t=30252 I am still trying to get a silver color on the car, but to no luck so far. With the base of purple,(the real color), I just can't photoshop a lighter silver, such as BMW's Titanium silver, or some of the silvers with blues in them. Here is the original: And the first attempt at Copper: And the hybridz work from redruM,(shows the Copper better): I am undecided between the Copper, a Silver, or a Silver/Blue such as on the Nissan Sentra Spec V or the new EVO VIII. My problem with photoshop, other than my being completely inept with it, is that I can't get the lighter colors, i.e. silver, to show well. The purple dominates the picture. I think using the first copper example might allow a graft of silver better - but at this point, I am photoshopped out, not to mention I can't even come close to getting the paints to look like these two. So my question? What color would you choose? If you feel so inclined, go for it with photoshop and bring your best. I would really, really, really like to see a silver on the car. I am leaving for a 6 month deployment tommorow,(tuesday morn). I will still have access to the internet, but at a reduced bandwith/opportunity. So if I could be so bold as to ask if you do a photoshop job, esp. in silver - could you also send a copy to the following e-mail address: hanveyre@vaw121.navy.mil That way I can see it sooner as we have what roughly amounts to a dsl modem,(about 700k), for the entire Aircraft Carrier. Thanks guys. And today I'll try to answer whatever questions you have about the car. -Bob

Ok, I know there was a great thread recently that had a link to a site that re-did cars, and had a tutorial. I can't find it and would appreciate any help. I tried photoshop, adobe photoshop, and tutorial in the search page to no avail. Anyways, I am trying a few different colors on my Z to see what to paint it. Currently my choice is the brand new orange available through chevy for their 2004 avalance. (see their site for colors). The color of this mclaren is very close to the pictures below- Here is a link with the pictures for more hi-res shots: http://www.highresautoimages.com/mclaren/f1.html And a driveway shot: http://forums.s2ki.com/imagecatalog/customimageview/49157/ And the image: Let me see if I can get a shot of my car here: More shots are in the hybridz gallery - the other side rear and a front shot. What I am trying to do is put the McLaren color on my Z to see what it will look like. And to answer the questions ahead of time - Yes, I bought the car recently - yes it was the one at SEZ event - Yes it was fast as hell before I blew the motor,(20 psi compression on the front cylinder when it was dyno'd and when I bought it) My RB26 is going into it after I get back from deployment. So I took my few months away as a perfect opportunity to fix some minor problems on the car and get it painted a color I wanted. My choices were pretty much narrowed down to a few silvers that had blue tints in them. A 2001 Nissan Sentra Spec-V color called I believe Silver Mist - the new 2003 EVO VIII silver color, and possibly the BMW M5 color silverstone - but that was really too much blue for me. Then I saw the McLaren, and the Chevy commercial with the new avalanche,(has the guy singing the "I feel like woman" song) which had the same color. I am seriously leaning towards this as I love the copper color. I just want to see it on my Z first. I am a photoshop newbie and have never tried to swap colors. Any help is greatly appreciated. -Bob

Possibly. But we don't know what "effective" lash of the hydraulic heads was compared to the non-hydraulic heads. I do know the grinds are different when ordering aftermarket cams - but I can't remember the difference they told me. It is also possible that the 4 degree advance was an overall change for the turbo's and was in Datsuns mind, a change for more performance? Who really knows. But a valid point you brought up earlier as well. -Bob

I most certainly did read what you wrote. P-90A heads just don't tick after long freeway runs unless they are bad. Hot thin oil does NOT make a lifter tick. Poor oil pressure, inadequate oil pressure/flow, and bad lifters cause lifters to tick. The viscosity on oil doesn't change that much, and that in the end makes little to no difference - oil is still incompressible once the check valve closes - whether it is 10 wt or 80 wt. Don't assume just because I don't like the way you compare cars that I think everyone MUST dyno a car for any comparison to be valid -for even those are not accurate car to car in different locations. I am just very against slamming something from one single experience, esp. when you don't know everything about that head, correction, all the condtions about the head. As you said: Maybe? Maybe? Maybe the lifters were trash. Maybe it was perfect - we'll never know. So it is useless to use it as a baseline for all other P-90A's. At NO time did I ever doubt the numbers you put forth. At no time did I say they were crap. At no time did I not think they were GREAT numbers to run for a turbo or a NA car. Never. What I still have a problem with, and will continue to have a problem with - is there are FAR too many variables to reasonably compare those cars with ones elsewhere, much less with head swaps, etc... But you an I came to an agreement on that last year. That trying to compare your 2.8 experience with say mine is not accurate. Some guys rock at the 1/8 and 1/4 mi. Your friend, Norm, etc.. Others suck. My bottom line, as it will ALWAYS be - the P-90 is really no different from the P-90A. The sad thing about all this is everyone who has had a bad experience with a P-90A head, assumes they are trash and useless for performance. Bullshit. Your head was trash. You did gain power by switching. You did go faster with a new head. It had nothing to do with the hydraulic head being inherently bad - it had to do with your head being bad. As is the case with nearly every person who had bad experience with the P-90A head. And the name calling - trash talking whatever you call it, is really not good for hybridz. No matter how much you disagree. There is nothing inherently wrong or inaccurate with David's statements. But you don't agree with his statements, so he is benchracing in your mind, or whatever you want to label it. What crap. Fundamentally, some of the things you said are inaccurate - had he countered them, as did I. They were the basis of your stand/arguement. Even with the record set straight on how lifters bleed down or why, you will still not like the P-90A or think it is good for performance. But your reasoning was wrong initially. My guess is you just have different reasoning now - and that is fine. I'm not sure why I am even covering this. I guess it is because I have respect for both of you. And I see this as only eroding that - and that is not good. Just me though... We can all agree to disagree - nicely. -Bob

That can be found on the following page: http://www.adtdl.army.mil/cgi-bin/atdl.dll/fm/1-509/Ch1.htm So lets not confuse the two issues. A worn lifter WILL bleed down and cause a loss of performance. And from your own words showing the lifters on YOUR head were bad, (excessive ticking after driving, etc..), I would also expect a SIGNIFICANT increase in power with changing to ANY other cylinder head with the same camshaft! The devil is in the details here! I would also expect the same increase with new lifters,(yes, expensive and no longer available), or going through the same process that David and awd92gsx have gone through, i.e. thoroughly cleaning the lifters. But you did neither, you just swapped out your head for a solid head, and now generalize your personal experience with a WORN LIFTER head into all P-90A's. Come on - you are better than that. I will state ABSOLUTELY that a P-90A head in 100% conditon and a P-90 head will produce the ALMOST IDENTICAL power within the margin of error, or a percent or two, assuming ALL condtions can remain the same. If it really produced less power, then Datsun would likely have changed the power rating when they came out with the P-90A.... Not saying a manafacturer is perfect, but a 20hp loss is significant... I get wound up when people generalize their individual experience with a BAD LIFTER head and say all P-90A's are crap for performance. They most certainly are not. Yes, they do require some different,(not more, different), attention than non hydraulic heads. It has been shown by more than two members of this board that they can be cleaned and put back in service. I have personally run a high performance cam with stronger aftermarket springs on a P-90A. And with Sunbelts new line of camshafts that require less spring pressure than stock on a .600 lift/300 duration cam, you can now run any size cam on the P-90A. Details folks, details... -Bob

First, yes, I am on Active duty - leaving for a 6 month deployment next Tuesday. And Family day cruises are awesome. It is the one time the rest of you can see exactly what goes on around an Aircraft Carrier - the launching, landing, and an airshow with no rules! As far as ticking lifters after autox runs? The problem in my BMW M Coupe, and other E36 M3's had to do with oil - specifically not enough. With just a normal fill of oil, coupled with hard driving, the oil would foam a bit, and the pickup would be uncovered, or be drawing from aerated oil. When you can't supply oil to the lifter when it is not under pressure from the camshaft/follower, it bleeds down. You then get the ticking. I can't say that is the case with the KA24's and VG30's, but was with the BMW S52's. Or possibly with a poorly designed system,(talking general here, not specific motors), the oil pump just can't keep up with the requirements, or the lifters are poorly designed to refresh the pressure in the lifter. If you start up a hydraulic head car, and then pop the valve cover, the lifters are pumped up. They take anywhere from 2-5 min to bleed back down. So to properly check the cam timing of a hydraulic head, you must start the car,(or at least turn it over and build oil pressure), then shut it off and quickly remove the valve cover. Makes for a fun time.... -Bob

I'm somewhat afraid to respond again as this topic has finally quieted down. But a quick referesher on the "how to" of the hyd. lifters: First, they are pressurized into the "up" position by oil pressure. This end supports the end of the follower or 'rocker' as commonly called that is not touching the valve. As the camshaft comes around and begins to exert pressure on the follower, an internal check valve in the lifter seats and doesn't allow any further oil to escape the lifter. In essence, since a fluid is incompressible, it is the same as a solid lifter. The advantage is the oil pressure sets your "lash" for you and keeps the cam from hitting the follower abruptly each revolution. And to say that "none" of the fast turbo guys run the P-90A is a misnomer as we only know a few that post here.... There is nothing inherent in the P-90A head that keeps it from performing well on a high horsepower motor - I did it for 3+ years and it is still going. The key is good lifters - without them the head sucks. That is the most common reason people don't use the P-90A. The second most common reason is they think that a performance cam cannot be used with it - which it can. And with Sunbelts new camshaft designs that utilize less spring pressures than stock, any size cam can now be run with the P-90A. There is merit to racing and putting down actual numbers - but to completely discredit something else purely on your own experience is limiting at best. My experience points completely opposite. But we both succeded. You already know how I feel about comparing your cars with other cars we know nothing about - that was covered well in the first P-90 vs P-79 thread. Lets please not go there again - it doesn't help our arguements. Bottom line - this is all worth what we paid for it - nothing. apples to oranges. -Bob

And Jon, I haven't forgotten about you - I will respond to your last e-mail when I get back up in Norfolk tomorrow. -Bob

I'll address this tomorrow, but in essence, your assumption is completely wrong. Fluid is not compressible any more than a solid metal is compressible,(i.e. they will all "give" a little, but for all purposes they are incompressible). And the pressure of the oil has nothing to do with what the lifter sees. Once the check valve seats, the pressure is significantly higher,(an order of magnitude) than the seat pressure or it wouldn't stay pressurized - but that gets into the theory of how it works. There is a lot more to this....but I will have more time tomorrow afternoon. -Bob

That was so uncalled for. Not again. I am getting ready to go on a 6 month deployment so I can't run this topic for 5 pages again. Lets lay some ground work first. In pintoz's original post, he was asking about the P-90 vs the P-79 while he was waiting for his new turbo...... So that leads me to believe that this is a turbo car he is asking about. If that is the case - the P-79 is out of the question. With its exhaust liners, they will run very hot, not a desireable trait in a turbo car which already has very hot exhaust. Second, it doesn't really match the turbo exhaust manifold. Turbo = no P-79. So the discussion is somewhat moot from the original post. But we went through this last time. All you proved was that for your combination, it was better - and we have no guarunteed that you kept ALL, and I mean ALL condtions exactly the same for the comparision. Therefore it is as good as comparing oranges to wrenches. And to claim that the hydraulic head made less power leaves so many issues unanswered. Were your lifters even in good shape? Did you have bad oil pressure? How would you even know? Back up your "factual statements" - I know your better than that. For anything under 250hp, I would be my car it is less than a few hp difference at best - if that. And please don't say " I ran 9.xx with the xx head and 8.xx with the xx head". There are far too many variables in that comparison as well. Arguing for arguing is pointless which is largely what is going on here. That is my job. Actually, I only argued about the subject. Anyways.... The P-90A can and will make good power up through 7000 rpm as I did on my car. It can be set up to work with an aftermarket cam - you just have to watch a few parameters. And what in the operation of the cylinder head could you possibly point out that would cause a significant power loss, i.e. the hydraulic head requires more power to operate,(to turn things over, etc..)? In some respects it is better, in others worse - it all depends on your application and what shape the lifters are in. -Bob P.S. - and oh by the way - I have run an aftermarket cam in my hydraulic head so it most certainly can be done. It ran for about 15k miles before I sold it and it is still going.

Part of my suggestion to turn the tip down also includes ensuring it is far enough away from the car to be in that energized airflow. If you stop the exhaust tip at the rear valance, you are assured of having problems as that is a very stagnant area of airflow around the car. So a tip pointed down that still doesn't clear the end of the bumper will likely still have a problem. I wasn't clear about that in my first post. Sorry. -Bob

A couple of thoughts. First, the hole in the later 280z cars rear lower valence. In the early Z's, airflow would build up behind that panel under the car, and on many you will notice the center of that lower panel bows out a little. They put those "vents" in that lower valence to help relieve some of that built up pressure. And in my experiementing, which is backed up by Metalicar, extending the exhaust tip helps significantly. It is a very turbulent area of the body behind the hatch, and if the exhaust is dumping into that area, it will just stick in that area. In the previously linked post, it was covered fairly well about the discussion about the airflow flowing up along the C pillar to the window area - but who really knows if that is the case. No real answer for you, but the one I have seen work every time is to get a downward facing tip, i.e. it goes down at about a 45 degree angle, putting the exhaust into the high energy air leaving the bottom of the car. Or at least have a squared off tip vice a 45 degree cut that goes up,(which most of us have because it looks best). -Bob

I can't take full credit for that. Phantom gave the same answer I did, just in a slightly different way. Yes, they do shoot odd things from cats. In the initial testing, they shoot a lead sled,(actually a weighted sled). I think it is a 5000lb sled, but can't recall exactly. And more recently, They shot an old plymouth or something like that from one of the operational carriers. So you can shoot cars, and they have. If I recall, it went a few hundred feet. The carrier was barely moving at the time so no, it didn't run it over... I expect the end speed was around 80-100 mph. -Bob

As a "current" Nasal radiator,(Naval aviator..) Phantom hit it on the head. The weight is merely a part of the equation. Depending on the plane being launched, the end speed is anywhere from 135ish for a S-3 to about 160ish for a F/A-18. BTW, that is Knots, so add a few for MPH. If they compute it wrong, and say they think they are shooting a 50,000 lb load but are actually shooting a 15,000lb load, they will likely break the cat at the end of the shot. The water brake at the end can only take so much force. To give you and idea, you can feel the ship shake when the catapult hits the end of the shot. And the Carrier is over 1000 feet long and displaces over 95,000 tons.... Whoops, see others now covered it. -Bob

Go ahead Jeff. -Bob