Tony D

Commercial Turbos you get from Garrett and other manufacturers are set with "Containment" as a primary design criteria. They overspeed and break them to make sure they do NOT frag-out through the casings. If you saw what they did to those things during testing in the load cels you would be amazed. 45psi Surge, 45psi Surge, 45psi Surge....24/7 till failure. Heat soak tests where they get full exhaust temperature on the turbine wheel against a load for 1 minute to soak it, then immediately a valve switches to chilled air to heat-stress the thing, then back to hot...over and over 24/7 till it fails... Rarely is anything spectacular happening on the commercial turbos, the rpm indicator simply stops and you get an alarm to go in and check out what went 'poof'! Now the racing turbos....those have a metal shield and they watch them via video link from the cel at the REAR of the dyno room, about 25 feet from the operation console! LOL Those very same commercial turbo cartridges can be put into VERY sexy thinwall aluminum casings, with Titanium Turbine Housings for 'racing only' applications like CART or other uses, but they will not be available over the counter to regular buyers off the street. When they go, things from the inside usually end up on the outside, some distance away from the failure! I have seen Pallets of containment test turbos at the Garrett Facility in Lomita...they keep them around for loading up the Diesel Trucks for road testing under load. Nothing like a bed full of cast-iron turbo housings, and a car trailer full of crates of the same to put a load on the old 1-Ton Diesels! LOL

I gotta say, the TEC2 we had on the Bonneville car was a flawless starter. Even at 34 degrees in November with the big cam the thing would start on fast idle and warm up just fine. But it didn't like to get quick throttle inputs off idle till it was warmer... We would start it in the morning for the warm up with a twist of the key, while others were spraying fuel in the birdcatcher and jumping around because of flashback. Ahhh, the smell of Methanol and Nitromethane in the morning... Sometimes I wish we'd retained the TEC... I don't know if I still have the maps from that, but I could check. I was very happy with the way it cold-started.

O-Rings n Things in Fontana probably has a metric O-Ring that can adapt if you have inside and outside O-Ring diameter requirements. That would allow you to use your current pintile end (11mm) and simply get a 'fatter' O-Ring to seat against the 14mm holes. It's just an o-ring, you can probably get some teflon or PEEK backup rings as well to prevent any extrusion under higher boost pressures...but standard 75 Durometer O-Rings should hold up just fine at 50psi boost, even without backup rings.

One of the biggest hurdles I have when training people on centrifugal pump theory is that the impeller imparts flow. Pressure comes from slowing that flow, or impeding it...if you impart more flow without enlarging the slowing chamber a correspondingly, or removing restrictions you will get more pressure rise showing. Take a pump and run it free field and you will find you get a LOT of flow...but deminimis pressure. The thermostat opens, and you will see a drop in your block water pressure. When you are operating at higher pressure (higher rpms) and watch pump output pressure..and see it start fluctuating you know you are experiencing cavitation of the pump. Which is why a 16psi cap helps---more suction head to keep feeding the pump and preventing any cavitation (surge in a centrifugal air compressor). When you stop that flow during a cavitation episode, and that block water pressure instantaneously fluctuates, you can instantly form steam pockets. Usually when it cavitates it does so in rapid succession, so your steam pocket can get pretty big, pretty quickly. It used to be common on high load equipment to monitor bock water pressure. You can see the thing start misbehaving and then watch a corresponding spike in temperature. The actual mechanics of 'overheating' are pretty complex, not nearly as simple as many people would have you believe. If you can watch what is happening, you know which way to move to combat it. I think your issue is the formation of steam pockets over the top two hottest cylinders during episodes of either cavitation, or high heat production. In either case, giving those steam bubbles a place to IMMEDIATELY exit the area, instead of loiter and cause problems would aid in your heating issue. You have that steam in there acting as an insulator, and as a result the temps in those two cylinders start rising higher and higher, faster and faster. Put some more flow in there, and let ALL the cylinders vent steam/flow directly to the radiator (see the PM I sent about the FIA and LY cylinder head cooling manifold revisions) should help quite a bit. Once you know you are evacuating the water sufficiently, then you can start thinking maybe you are running 'too lean'. Of course reverse flowing the engine would put the coolest water into the hottest part of the engine like EVERY OTHER PROPERLY DESIGNED HEAT EXCHANGER ON THE FACE OF THE EARTH! What we have here is a holdover from Henry Ford's Ebuillent Cooling systems and the intimations from above of using simple head and thermal siphon actions to cool the engine in a 'total loss' cooling scenario. Since it was all set up to go that way to start, nobody thought about making it an efficient heat exchange under a pressurized scenario. When Chevrolet started doing high specific output engines (for the time, a whole 1HP per CID---oooooh! Wow!) they did some experiments on reverse-flowing the SBC. It was much more efficient and promoted less cylinder bore taper/wear. But they were tooled up for production and already had the stuff amortized. It wasn't until the engine went through a major platform redesign that this revelation (er...from 40 years earlier) was actually implemented. I mean, 'it worked good enough, why screw with it' does have a valid stance, but once you start talking about incremental redesigns, you may as well look at ALL the options.

AIR Air Injection (Induction) Reduction (Reaction) System component, and was supplied on all L24 and L26 Cerburetted Engines subject to FEDERAL emissions laws (this is not a 'California only' emissions component). This is the same system that was installed on Domestic cars as early as 1966 in California (My 66 Cal Spec Chevrolet Corvair Monza had it, Federal Cars didn't). Most universally it was installed on just about EVERY car in 1973 to comply with the new regulations. This with only ONE injector functioning will clean up the exhaust on a properly adjusted 71 240Z with SU's to catalyzed 1983 specifications! The cleanup of post-burning excess HC's really helps scrub the exhaust. Today some vehicles use the AIR pumps to supply enough oxygen to let the Catalytic Converter function as there is not enough excess oxygen in the exhaust to sustain combustion. R&T (or one of them) did a test back in the day involving cutting off the long tubes to help flow while still retaining emissions compliance and they did notice a slight bump in HP or decrease in time to distance/speed by this modification. Most people are too young to remember HEADERS that were designed to ACCEPT these tubes. The law in CA formerly WAS that as long as all emissions devices were in place and functioning the modification (headers) were legal. Then the state found out they could force people to pay tribute and go through a TEST for which they pay a buttload of money to do, and if htey pass they are rewarded with the much acclaimed "CARB EO/LEGAL" sticker for their product. So now, those old 'Smog Legal' AIR Injection Tube headers aren't legal, technically, since they don't have a "CARB EO" Certification. I like how the out-of-state seller relies on myths to sell the part ("if you want to keep your car on the road in California you need this..." I won't argue that the part is becoming 'rarer' but last I checked (couple of years ago) Nissan still had the Air Gallery assembly in stock! BRAND NEW! Kinda Pricey for what it is, IMO. But if you need one for a 240Z to be 'correct' I guess you would pay that (it's for an early car, you can tell by the hot air snorkel on it...later cars '73-74' have a shorter more direct connection to the middle of the air cleaner instead of it's snorkel up front.)

Three Words: "Hard Tonneau Cover" The Pickup will probably be more 'safe' along the lines of 'more inertia and higher driver's position'... If you see him buying carpet padding and scrounding carpet remnants you can bet something else is going on under the Tonneau Cover than moving sacks of concrete for your sidewalk...

That's what I'm getting at! The car when driven correctly will move out O.K. No speed records being set, and not a danger to anybody else on the road, but it will keep up with traffic. My 69 beetle would do 75, just like VW said...but I found if I skipped a valve adjustment and let the valves go tight I could do 90...the education began. What you need is something that when wrung out will get to 50-65 reasonably quickly, yet not go much faster. Modern cars, alas, will do that. I mean Turbo Sprint, Geo Metro....eh...kinda small with all the SUV's out there IMO. The Beetle and old Bus was the perfect car to drive for me. Like stated above, no threat of speeding tickets (unless I was going 35 in a 25...) and really not enough top speed potential to get any serious tickets on the freeway (at the time Michigan still only gave 1 point for speeds above 55, and below 75 as that was the former speed limit...thank you national speed limit.) I learned a lot of valuable lessons driving and maintaining those VW's. I learned I HAVE to take care of my car, or it will not take care of me. I learned I HAVE to do procedures properly and not take short cuts or something WILL go wrong later. It kept me 'safe' while at the same time educating me on how to work on vehicles. That was just as important to learning to drive. To this day I find myself driving in 2nd gear to 25-30mph, not shifting out of third before 45, and not going into overdrive till well above 55. All left over from 'The Idiot Manual' explaining to me that if I shifted up too early, the engine WILL overheat.

Close, but not over. That was the contention of the $1 bet John and I had running for years. The problem: (see aero forum) With a G-Nose, the speed potential will go up QUITE a bit. Our Bonneville car is not that powerful, only slightly more than 300 to the rear wheels, but the rake, G-Nose, etc on the car gets us what we need to go fast. At ElMirage, I watched a dual-quad 380CID chevy powered car go 155 against our 163 that very same day. Of course he was convinced his 'snowplow' front end was 'really really aerodynamic, he had someone design it for him'...and it looked like one of those big snowplows you see in the northern states, with a big scoop out front, flat front, and almost vertical front end with a totally closed radiator area. BIG block of plywood basically...and no headlight covers at all! Right now, there is a car (#236) that has a chopped roof and nice looking front end that looks like it should make some downforce...I think he has gone 170+ at ElMirage thusfar. Almost on par with the Opel GT he formerly had the driveline in (we are truly diseased)... This last shot was taken before he got the car painted, the first year after the Opel GT flat spinned and endoed three times in the same event. That pretty much did in that chassis...

Most people return turbo coolant to the inlet side of the water pump and in that capacity it functions as the 'external bypass line' that normally comes around the front of the block and returns to the suction side of the pump anyway. The system is designed for those two bypass routes (one internal, one external from the lower thermostat housing) without overheating---and as I discussed in the other thread are critical for proper pump operation and proper engine warmup before the thermostat cracks open to let coolant flow through the radiator. When you start the engine cold, that T-Stat is closed, the pressure built by the pump rotation has to go somewhere and that is through the two bypass channels mentioned. Later on the ZX's they added a 'poppett' valve on the 15mm line off the head to the heater for when the engine is revved to sky high rpms before the thermostat is opened...it dumps coolant in a shunt back to the pump inlet keeping the pump from cavitation...and shocks the system with a slug of water from the hottest part of the engine directly into the pump's inlet making it warm up all that much faster. Basically if you take a ZX and start it cold at the top of an onramp to the autobahn, and then immediately rocket down it to top speed and jsut keep going the poppet valve will open and recirculate a LARGE volume of hot coolant to the inlet to make the thermostat open faster as it will see hot water before the block is even fully up to temperature. The internal passages on the earlier cars were designed with the thought that people would take the time to properly warm up the engine before revving it up and taking on top speed runs. By the time the ZX came out---apparently it was realized this was not the case, and they changed the system.

Rev Limiter works for me. I had (in the dark ages) the keyswitch on the MSD 6 Box for dual RPM Pills. One was set at 2000, the other at 6700. When I would 'valet park' my shark car, they got it with the 2000rpm pill activated. MSD still sells all this stuff to run dual rev limiters. Frankly, I find in everyday driving I rarely need to go over 4000 to scoot in front of much traffic in a bone stock 260Z with a 3.7 gearset. With a five speed that will still get you a big ticket on the freeway! 3K would be where a 3.7 geared vehicle would likely keep the speed down to less than 80 on the freeways...but that's still fast. Get him involved in Auto-X and give him an outlet for his speed, and he will soon realize that playing around on the street is really just a joke by comparison. Once they hit 9 or 10/10'ths on the track they will realize most you could ever do on the street with other cars is so mundane by comparison that it 'isn't even worth it'---I know that is what did it for me! Every kid should be forced to learn how to drive in a 1200cc 62 VW Microbus. It gives you two things: Appreciation for power when you get it. most importantly: It teaches you patience. No matter WHAT you do in that vehicle, you WILL NOT get there any faster, so you may as well accept it and realize you get there when you get there.

Bo, I answered your questions in yoru other post, before I saw your PM. The heater hose is a direct shunt, and allows engines to potentially overheat. The flow answer is to tap above the head and return it directly to either the radiator, or the thermostat housing. The water pump imparts velocity to the water, and restriction along the way creates the pressure in the block and head. It is this increased pressure (up to 60 psi on the bottom side of the thermostat at higher rpms!!!) that keeps the nucleaic (give me a break on spelling---reference the grape ape racing document on cooling and how engines overheat for the correct spelling of the term) boiling from starting. It's not just the static pressure from the radiator cap. What the cap pressure does is insure there is sufficient NPSH at the pump inlet to operate correctly at variable speeds that can wing that thing up to VERY high speeds. One of the problems you get is pump cavitation, and a higher static pressure helps with that...but when the engine is cold you can cavitate when you rev high simply because no pressure is built up in the radiator yet, and the lower radiator hose can 'collapse' from the suction. Really, the only time there is real 'suction' at the water pump inlet is before warmup. Once the coolant expands and you build some static pressure against the cap, the pump in merely imparting flow to a system that gets pressure from restrictions along the way. Adding flow to one section may indeed rob flow from another...TimZ's post about the OEM Nissan LD28 pump (or was it JGKURZ...) as it has a larger impeller and fits our front cover.... So if you plan on modifying the flow on the head, I'd consider that upgrade as well. Take a look at what I wrote on the other post...feel free to copy and post to this thread if you feel it's appropriate. I'm jumping all over! BLaaaaah! Walla Walla Walla...

I would NOT run that head line to the inlet---that IS raising your overall temperature of the engine by taking water from the hottest part of the engine and shunting it DIRECTLY to the inlet of the engine---where it mixes with the radiator return line and warms it considerably! This is a PRIME reason many 240's overheat. That mixing should be limited to the internal 8 or 10 mm passage, and the external 8mm bypass line from the lower thermostat housing. Think about this: The heater is a radiator and when the heater is 'on' and flowing water through it, it is cooling it therefore allowing NO increase in radiator water return temperature to the pump. When the heater is off, the bypass is OFF. NO FLOW! On the 280ZX's they incorporated a poppett-style valve to open at EXTREME high rpms when the thermostat is closed, as the two 8mm bypasses are not sufficient flow to prevent cavitation of the pump when revved cold. I would remove and plug that line IMMEDIATELY. Then, I would consider either taking the 15mm line off the plug side of the head and shunting it directly to the thermostat housing...but usually the flow increase holes are added directly over the combustion chambers to allow any steam produced to vent 'up and out' as well as increase flow in that area directly out to the radiator.

Yeah, let's make a quick and dirty plaster sand-casting of the thing and store the plaster postitives someplace. Then again, pourable high-durometer urethane would work better... Yeah yeah yeah, let's do that!

Normally the return line is up higher in the pickup well angled downward and tangential to any housing. This insures that air bubbles go UP and away from the lower pickup for the fuel pump. Looks like you are set up for a dual-feed setup. I think moving your return to the top of the surge tank in the cel and pointing it down and in will eliminate the possibility of air ingestion. If they (suction and return) are close to one another, or on the same level, any air bubbles coming down the return line can get ingested into the suction of the main pump. The #75 IMSA Car Millen drove had six pumps and two surge tanks, each 4" in diameter and almost the height of the car! Something like 42" tall...want to guess where the fuel return was on those tanks, in relation to the suction for the main fuel pump? About 40" vertically above the suction point!

Good Question, but my inclination is to say "no"... Honestly I can't remember what the door came from that I put onto my red 2+2, I am almost positive it was from a coupe, but can't positively recall. I could measure external dimensions I suppose. They're sitting next to one another right now...

You could get in contact (PM him here) with Frank280ZX, he is in Utrecht. He will have a container shipping to Rotterdam or Amsterdam late in June as I have been told. He's busy building his S130 for the Time Attack at Zanvoort first week in June. Matter of fact, I have to go UPS Red his bearing set to him right now...

The sticky is in my head...."there were two posts about rear cylinder cooling" LOL

Niiiiice!

Frankly, the term he was thinking of was 'integral' not really external. The pump on the L-Series is integral, as opposed to external. While it may be 'external' to the oil pan, it's most definately not an 'external' when you use the proper terminology of 'integral'---which is the differentiation between an integral pump and an external like a Dry-Sump setup that is belt driven. Even now, there are dry sumps being worked up to be integral to the sump, so they are integral with the block assembly, while not really 'external' in either of the previous interations. And the run of the L-Series pump goes a bit further than the NAPS-Z, check out your local KA engine....Why do you think 'high volume, high pressure' L-Series pumps are still in the pipeline while all the other parts wither on the vine?

I wondered where you were today... Maybe time to get some more coolant flow out to the back two cylinders. My CHT sensor (what I use on the MS) reads about 20 degrees hotter going down the road than the one in the thermostat housing . Didn't hear anything, did you! Damn it sucks when it goes like that. Better the head gasket than the pistons. And people called BS on me for a 2 hour unassisted head gasket change! LOL On the Octane Police, I know CA and MI have them. Matter of fact right now my standard stop, the Flying J in Frasier Park is on the hook for 4 engines at least after a load of bad gas. They had an announcement on the evening news (local) for anybody with engine problems after filling up there to notify the station for reimbursement if they can prove it happened after their fillup (not to hard, really). In Michigan, Sunoco sells (and I don't know who would buy this stuff) 84 Octane SUB-Regular! Talk about a big "D'OH!" on your turbo car if you mistakenly punch the wrong button on THAT pump!!!

Really Randy? I thought you were a Ford Tech. Are you doing motor pool work, or something else. "PM me" you have piqued my curiosity...

Yeah, I guess the 'proper answer to the question' is that the 10K tachs were in the Z432's. Thanks for the manual Eric! Now I know all the gadgets in my 71 as well! Curiously, the 'flash to pass' button they show in the '432' section was in my 'mystery car' S30-110661, a 240-Style Body with all the "PZR" floors, flash to pass light on the signal switch, but no 'PS30' as the chassis code says it should have.... That switch is now in my current 71 Fairlady Z. "Flash to pass" in an early S30 is soooooo cool!

This is my 'Freeze Plug'... Using a larger turbo generally results in a higher Boost Threshold, meaning full boost will not be realized until a higher rpm. This is not the same thing as 'lag'! Lag is the time it takes for the compressor, once given a WOT situation, to come onto full boost. This time is so quick in modern turbos as to be almost immeasurable (if that is a word). People get conditioned to drive 'on the cam'---and this is supposed to be acceptable in an N/A engine. Yet when you go WOT on a cammed engine at idle you get soggy response (V8's included). Run it up so you are 'on the cam' and go WOT and you get instantaneous response. It's well known you have to drive a Cammed N/A engine 'on the cam' for proper response. This is no different than a TURBO engine. Yet, apparently slapping a hairblower onto a car is supposed to magically transform the engine into an 'all rpm performer' and ignore the basic laws of physics. Drive a turbo car properly, and there will never be an instant where you will notice 'lag'---that went away well before the 70's were done and the 80's came along. Now, having been in JeffP's car, I can say his engine runs like a much larger CID simply because his engine breathes so well. Sure, you only get 3psi at WOT from 1000rpms, but the dyno will show it pulls linearly from there on up. Sure, you feel the torque peak pull harder at 4500, just like any cammed engine, but you really don't feel a surge at 3400 rpm when the boost goes like a switch from 3 to 20psi. You wouldn't think the curve would stay as flat as it does with boost jumping so quickly, but it does. The current generation of turbos are not what terms like 'Lag' were meant for... Maybe I'm missing something, or misinterpreting it, but "lag" from the above quote looks like a mis-driven old-school turbo setup. Drive even an old school turbo setup properly, and 'lag' really isn't an issure either. And driving it properly means keeping the r's above boost threshold, same as when you drive a heavily cammed engine. As for the detonation issue, I agree. I don't know what 'drivability' issues you were having with the stock P90, but raising the compression probably didn't accomplish much other than giving you another headache. I run a Non-US N42 and have run that to 17psi, but that's not with dished pistons. I think you messed with a working combination and learned the hard way theory sometimes does not work in the real world. Did your 'drivability' issues get any better after the head swap. Did you feel the difference you thought you would? If not, that's a good indicator to go back the way you were. It's only a couple of hours work and another couple of gaskets. Sucks when experiments don't work out.

Depending on the size of the I/C, as long as your keeping the discharge of the I/C above 120F, you can spray quite a bit into the inlet and not worry about precipitation post-cooler. But with the injection, the I/C usually becomes redundant as the latent heat from the vaporisation of the anti-detonant performs a similar fucntion as cooling the airflow with mechanical/physical means.

Regarding Daeron's comments on page 12. I would agree that 'flow straighteners' would be a technically more correct term to use. When I originally saw 'vortex generators' I read this as generating a vortex as in their design. This is why definition of terms is so important and semantics more than a pedantic exercise. If people don't understand what you are trying to say, then you all loose a lot of time chasing stuff because of misunderstandings that need not be. Similarly misapplying a term can lead to similar things...Technically the items Monzster put into the manifold are decidely not vortex generators. I forget the proper aerodynamic term, 'strake' or something other. VG's are generally at an oblique angle meant to disrupt airflow over a wing, not really to channel and straighten it. VG's are used to great effect in general aviation aircraft in lowering speeds the aircraft can fly with stability with higher angles of attack on the main wing surface. Splitting hairs? It's exactly why definition of terms is always the first section in any technical paper...