BRAAP

I’ll throw in my $.02 as well. Back in the mid ‘90’s one of our flag ship engine projects we built for Justin Boice and his unlimited class white water endurance race boat, (Wade was owner of the shop overseeing, planning, ordering parts, etc, for this project, I merely machined and assembled it). That engine was run only on 100LL Av-gas. This was a Twin Turbo, 540 CID Big Block, 10:1 static compression ratio, 12 lbs of boosts, water to air intercooler, (IAT after the intercooler was only 85 degrees), and on the engine dyno at Sunset Engine Development produced 1168 HP at 5800 RPM! Engine was not revved past 6200 RPM, (that is what we told Justin to keep it under, whether or not he did?) This engine would run at WOT for 80+% of the time during the race for stints exceeding an hour at times, set many records down and UP several rivers, (lower Rogue, Snake, etc), and would run a whole season between tear downs. I still have the pistons and Rods from the first season here in the shop. Pistons look great, under side shows no signs of coking, rings all show very little wear and could’ve easily ran another season, bearings look like new. That is one application where Av-Gas appeared to work. Also as a certified Aircraft and Power-plant technician and private pilot, I also know that Av-Gas is not formulated like auto gas, i.e., they are quite different. Av-Gas is formulated for longer shelf life as some air planes will sit for extended periods between fill ups. Av-Gas is also formulated to withstand the extreme temperatures of higher altitude and for many other factors that is not taken into account with auto gas. This different formulation alters Av-Gas so much that its specific Gravity is much less than that of Auto Gas. That means for given volume, there is actually less mass, (less dense, i.e., in a running engine, Av-gas burns leaner for a given jet size/injector pulse width compared to auto gas). With that means for us Auto guys, is that if you just switch to Av-Gas from auto gas, you will have to run slightly larger jets in the carb or slightly longer pulse widths for the injectors if the engine is fuel injected. You may have heard old timers talk about running Av-Gas in their cars, motorcycles, lawn mower, etc and mention that the Av-Gas is so much hotter that they burned a valve or melted a piston! Uh, yeah they burned the valves and melted pistons, but not from Av-gas being hotter. Av-Gas is NOT hotter, i.e. no more BTU in Av-gas vs Autogas, it is less dense, those bone heads didn’t compensate for that and as such, their engines were running too lean and THAT is what burned their valves and melted their pistons. Another attribute that Av-Gas has a slower burn rate, ie. flame speed. I have only read this in one other place, but the source was credible so I believe it to hold water. A slower flame speed could be a hindrance at elevated engine speeds as the rate at which pressure rises due to combustion is slower and therefore depending on the combustion chamber size, the engine could become less efficient at making power the higher it revs, i.e. burn event is not happening fast enough in the time available at high RPM. In summation; 1) Don’t mix Av-gas with auto gas. They are very much different. Use one or the other, but don’t mix unless you are a gasoline engineer and know what you are doing. Most of us just are not that savvy to know so we are better off not mixing. 2) Auto gas is known to work in auto engines as well as Air craft engines just fine. Av-Gas is for Air planes, (yet I have been know to run it in my … ) 3) If you plan to run Av-gas in a race car, I feel it is ok so long as it is not in a high revving engine with a large bore, but do not forget to tune for it, i.e. make darn sure the mixture is correct, do NOT just tune for auto gas then switch over to Av-Gas without retuning the fuel map. 4) Automotive Race gas works just fine and is actually formulated for high RPM, high compression auto engines, though it is generally more expensive. If Race gas is too expensive for you, then to be perfectly honest, racing in general is too expensive and you should just sell the car as the price of gas should NOT be the determining factor of whether or not you can race. That is my $.02 Paul ad... Very well said.

2savage, This process is called “eye-browing” the block. A practice used to relieve the block for oversize valves, or due to undersize bores , and also used to help unshroud the valves, if they open that far. I pulled these out of the archives; Eye-browing a block Somewhere in this thread Eye-browing is mentioned. Heads pg.4 OTM, As for the polishing pistons and chambers… Carbon will still stick to polished surfaces as well. Difference being, when you perform some form of “on a running engine” de-carbonization, (blown head gaskets do a great job of this), the carbon comes off little easier, i.e. doesn’t adhere as good do to smoother finish.

I haven’t seen or heard of anyone doing that, though that is not to say it hasn’t been done. There is currently a Z-32 tranny adaptor for the L-6 engine. I have also heard and witnessed the Z-32 trannies holding up to big power, but having owned a couple Z-32's and driven a few of these trannies, I personally don’t like them, at all. They are known for soft/weak synchros and with some mileage on them, are quite crunchy in some gears, typically 4th and 5th, are the first synchros to go, then 1st. Mine currently has intermittent 5th gear crunch, even during very slow shifts, though other times works fine even for spirited up shifts?!?! My 4th gear shifts fine, for now any how, 2nd and 3rd are also just fine. My first gear is so bad I am just looking for an excuse to rip this POS tranny out of the car and put something else in its place. Wont down shift into 1st at all unless the car is not rolling, i.e at a complete stop! SUCKS for tight autcross tracks when you need to shift down to 1st, as this tranny wont! If I were I were to stick with a monster VG30DE/TT I would ditch this tranny in a heart beat and finding a way to get the T-56 to bolt up, and with any other big torque engine conversions, I wouldn’t hesitate in using the T-56 especially with the SBC and LS-x as it bolts right up, no special clutch etc, weighs “exactly” the same the Z-32 5 speed, is known to be bullet proof and isn’t prone to weak/soft synchros. Just my $.02

I second everything jmortensen stated above.

That would be a neat conversion for sure, (BMW Inline 6 in a Z car), boosted should be crazy. The BMW inline 6 has come up in a few bench racing sessions. I forget which BMW 6 cyl he felt would be a nice conversion from an initial cost perspective as well as future power potential, but there was one that he spoke fondly of. Hmmm….

Gollum, The 440 swap is indeed heavy on the nose, manual S-30 steering becomes much heavier than it already is. 440 cubes will roast the tires at will and it has “WOW” factor over the more common V-8 conversions we see. It will require hood modification. If you plan to EFI the 440 and build a custom TPI style low profile, forward facing throttle body manifold, it might be able to clear the stock hood. With Sanderson shorty headers it is a tight fit, but it does fit. For the purpose of WOW factor and it is different, I say go for it. For a street/strip straight liner project, definitely a fun project, do it. For a sports cars project that you want to carve corners with, it is a bit nose heavy, but could be made to still handle respectably, playing with different springs an sway bars, also might consider converting to Power steering. Mopar 440 with Torqueflite 727 trans, manual shift body in a '77 280-Z… Yours truly unleashing the torque...

WOW! Incredible work and the attention to detail is phenomenal! Nice work, thank you for sharing.

OMG!!!! Truly incredible discipline and fab skills involved here. In looking at these pics, it appears that every single part of this project is scratch built; from the U-jointed axles to even the gears look like they were scratch built! Are you a machinist? Do you have a mill and lathe at home, or doing this at work? Nice work…

I to recall that same exact story, can’t remember what book it came from though but that is exactly how I remember the story reading. In one of my other Z car history books I did find this regarding that Yamaha built Toyota and Goertz involvement with Datsun/Nissan. Book cover; Pg 42; Pg 43;

Welcome to HybridZ. Sounds like a very cool project. There is a member on this forum that has done an RB26DE in his Z-32. Here are a couple threads about his car… http://forums.hybridz.org/showthread.php?t=123023 http://forums.hybridz.org/showthread.php?t=119385

Percentage wise, based on the posts in this thread alone, (not counting the accounts of other Z-32 owners I have heard from that also agree with our sentiment of the Z-32 being finicky), that puts you in the minority. My first Z-32 was a clunker, price reflected such. I then set out knowing I was going to pay at least twice, if not more than I originally had paid for a decent Z-32. Found this one that I currently own. It is a VERY nice Z-32, reflecting price paid. Car was garaged, all maintenance and upkeep receipts since new, all factory maintenance kept up etc, yet still suffers from the “typical” Z-32 known issues as documented here. We could only wish that a higher percentage of US Z-32’s have the same consistent dependable reliability that you have witnessed, but in all my conversations with other owners and shops that maintain and modify these cars, the consensus is that the Z-32 is a finicky breed as stated by others in this thread.

Huh? Well I partially agree. It does have, “another purpose other just than being big”. It corrals and directs air to the cylinders as it was designed to do. The point still stands though, compared to most/all other intake manifolds, it is expansive and literally physically covers the entire top of the engine, from strut tower to strut tower, radiator to firewall, making it rather difficult to reach/tend to items below it, i.e. the rest of the engine and its ancillaries. FWIW, there is another OE Nissan intake manifold that “might” be low profile enough to fit under the hood of the Z-32 that came on the VG30DE engine that doesn’t cover the entire engine. Came on the VG30DET. Here is that intake manifold; I am pretty sure I gave the brakes good grades from an OE standpoint. Of course, all OE production brakes can stand an upgrade when being used aggressively/abusively. Yeeup. I like the Z-32 brakes. Hodo, With all due respect, your post comes across as a Motor Trend write up, as such your post reads as you are merely quoting those Motor Trend articles from the ‘90’s. It doesn’t seem that you have much if any actual seat time, city, freeway, or in the context of this discussion, any competition seat time in either the C-4 or Z-32. Having had the opportunity to not only track an ’85 C-4 that was prepped for national level Solo-II competition and also drive that same C-4 on the street to and from work on more than a few occasions, I can tell you without doubt, it is demanding of the drivers attention, yet when playing at above 7-8 tenths the C-4 rewards the driver with stern, yet communicative feedback and response that is indicative of a race car. Just as Ron and Team Nissan stated, if the driver is not paying 100% attention to the C-4 while driving it, the C-4 can and will bite you at anything above city street driving. The Z-32 on the other hand is fun, taught, nimble for its obese weight, but definitely not a race car by any stretch of the imagination. My Q-45 was softer, but just as easy to drive. The C-4 is much closer to a race car than the Z-32 ever thought of being, whether it is Road Racing, and especially Auto crossing. Compared to an Altima, Maxima, Camry, Accord, the Z-32 handling is stellar, but compared to the serious sport cars on the market, it is merely ok. Want more proof? Ok, here ye go.. SCCA Solo-II national events. The Super-Bowl of Autocross competition where only the best of the best come to compete to prove to each other and the world who is the best driver with best car in a tight transitional racing environment, i.e. who can make their car dance faster than the next guy. In looking over the archives, from years past, the hands down WINNINGEST car of all cars that ever competed in the SOLO-II nats is the C-4/C-5 Corvette! The 240-Z placed a few times amongst the Vettes, but NOT “one” Z-32 among every car ever offered in the states, that showed up to compete at the National SOLO-II events has yet to take a win, though there are literally hundreds of Vette wins! Starting on page 249 of the link below is the archived winning results of the SCCA SOLO-II national events. I’m sure similar results can be found in many other forms of racing of comparably prepared C-4’s vs Z-32. SCCA SOLO nats archive results... In short, Motor Trend lies, actual race results don’t. The Z-32 is fun and spirited, no one argues against that. Is the Z-32 a Vette killer on the track or freeway? Stock for stock, mod for comparable mod, not even close. Is the Z-32 easier to live with as a daily driver vs the C-4? Very much a two thumbs up vote for the Z-32. What does that have to do with the price of Tea in China? Your reasoning on that flies like a lead balloon. Using your logic, what is your reasoning on why we don’t see many Datsun 510’s or early 240-Z's on the road any more? Again, reads like some ‘90’s Motor Trend article, not from a true performance sports car enthusiast. Sorry Hodo, but most of your comments come across as not making sense and/or is written with little to no experience to support such claims. Regards, Paul

As far as I know, this manifold has been in production for quite a while. It is basically a recasting of the street tunnel ram with 8 injector bosses cast in the bottom of the base and a plenum box similar the TPI plenum that bolts on to the top. Recently the base has been cast/machined for the GM Vortec intake ports and bolt pattern.

Guys, gals, and Larry, My father is building another SBC, not for a Z this time, sorry. Any how, he has a pair of Vortec Iron heads that I waved my magic wand over in the bowl area and now he is knee deep in an EFI conversion and has his sights fixed on the Stealth Ram manifold. Rumor has it, there is a composite/plastic version of this manifold in testing, soon to be released. Seal between the upper plenum an the base, and supposedly the base to the cylinder heads utilizes O-rings! Anyone know anymore about this composite/plastic version? Doc, Larry, Grumpy? Any one?

I’m struggling to see the “sense” in this post? Username, of Crispy Chicken?.. by chance a reference to a crack/drug addiction? I mean honestly, joke or not, why would you say that in this thread? ...Back-ground check anyone?....

If your pistons are the OE or OE replacement cast flat pistons, at TDC, those pistons pop up above the block deck between .020”-.025”, which limits how thin of a head gasket you can use, i.e. the pistons come real close to contacting the head! The OE type head gaskets, Felpro, ROC, HKS/NISMO 1mm steel shim variety, etc, are all about as thin as you would want to go with the OE flat top pistons. Weld up the chambers on both sides of the spark bolt to reduce chamber volume is an option, but will require the chamber to final shaped, (unshroud the valves while you are at it), and all the valve seats then “should” be replaced as the heat introduced in the chambers will distort the chambers surrounding the valve seats which could relax the press fit, subsequently dropping a valve seat! Not pretty. Custom pistons with a dome that matches the chamber shape is also an option, but I am positive that you wont find ANY cast pistons in this arrangement. That will have to be a Forging. JE, Ross, etc are all good sources for custom L-series pistons.

I changed your subject line as “Did I do this wrong?” is too vague. Thank you. Paul Ruschman HybridZ staff

C’mon guys. This guy has a hand in building Darius’s car, he asks a very simple valid question and the very first reply starts in with BMW Purism? You all are members of a very well established anti purism high performance automotive forum, aka HybridZ, where everything from inline four cylinders to V-12’s and diesels stuffed under the hoods of old Datsun’s is acceptable, and you question this guys engine conversion? I'm ashamed for you as we all know better than that. He did not ask anyone’s opinion about the whether or not the OE BMW engine should be removed for an LSx, he asked about Forums dedicated to Hybrid Bimmers. It may not be a Z car, but it is a Hybrid, regardless of the badge on the hood! Please show the same respect to him that you would want concerning your hybrid Z car. The "no purism allowed" drum has been beat...

Bo, just curious, what boost level corresponds to what percentage of load, i.e. what Load percentage is atmospheric pressure, 10 PSI, 15 PSI, etc?

Jeff, Very cool. Thank you for sharing this publicly. Just curious as to what moving the slot to the outside of the plenum might accomplish? I.e. opposite wall of the runner inlet vs dumping in the middle of the plenum in this design? Here is very crude MS-paint rendering… *** edit *** Looking a little closer at the Audio pictures above, it almost looks like they are dumping the air into the plenum near the runner inlet…

Boy oh boy was Ron all tuned up over this one as he just received that half price haggle yesterday. I haven't seen Ron that spun-out in a very long time. Anyone here that has been out to the shop and seen or ridden/driven Rons dime knows this 2 door dime is quite clean, complete, interior is fully intact and in great condition other than the drivers seat, especially considering its age. Engine has the small SU’s, (SSS or roadster...) elect ign, the “good” exhaust manifold, and a few other niceties. Any how he was so spun out over this "half price haggler" that today he dug his heels in and repaired the popped HG! When he was finished after burping the cooling system he took me for ride and now he seems abit calmer. The car also runs smoother/stronger than it ever has! It is actually a very nice mostly stock Datsun 510. To be honest, the car is worth $2500+ right now as it sits. To the half price hagglers...

Tyson, Not sure if this helps or not, but if you try to reply to a thread that is locked, i.e. most threads in the tool shed, you’ll get that error message. Also, the Member’s projects forum as the only person that can reply to those posts is the original poster. Another situation that happens on rare occasions is if you open a thread and try to reply to it, and one of the admins either locks that thread or moves that thread before you click the “submit” button, you’ll get that error message. Paul Ruschman HybridZ staff

Well it sounds like you have a butt-load of research ahead of you. Regarding the L-series, or any engine for that matter, there is no “magical” special combination of short stroke big bore or vice versa that offers ANY sort special magical mystical performance, real or perceived. Torque comes from displacement, HP comes from said torque AND RPM. The higher in the RPM range the engine makes torque, the more power it will make. Then it is the fine tune that will extract the maximum output from that engine build combination making it stand out from the rest of the cookie cutter builds. With that, always build the engine with as much displacement as your budget can afford. That will be your basis for building tire shredding torque, (A small block Chevy bolts in the car with very little mods and adds only small amount of overall weight considering how much more displacement you gain, i.e. 350 doubles the displacement of the L-28 at approx 150# lbs weight gain with iron heads etc! Aluminum heads and several other weight saving measures can bring a V-8 conversion to less overall weight than the L-28! Now I’m not saying swap in a V-8, but that extra displacement does bring forth quite a bit of fun factor when the loud pedal is mashed.) Then depending on how you intend to drive/use the car, that will dictate how you go about building the upper end, i.e induction, exhaust, cam etc. That will dictate how much HP the engine will produce and how it produces that HP. Add a hair dryer or two and now you have an entirely different monster which can produce torque and HP on par and even more than the naturally aspirated V-8’s. Here are a few threads for you to read regarding making power with the L-series. This should keep you busy for a while… L-6 internal dimensions.. The Big BORE stroked L-6 L-series cylinder heads, big and nasty head work for big power. ***edit*** Daeron beat me to the first link…