PZG302

Here's a phot of mine in the 72 Nissan Fleet colour, also known as Hawthorn Green, can't fimd a code for it though. It is a fairly dark green, but not as black as a true BRG.

A little too exuberent out of the carosel and dropped the left rear off the tar turning me round and smacking the wall looking backwards. Only a small dent in the front gurad and a GT stripe front and rear from the armco. Was one of two to hit that bit of fence. A 323 Astina went straight in and smacked the front right, again only cosmetic damage for him. We also had a Porsche Boxter lose it in the kink and hit the tyre barriers on the inside of the tracl backwards breaking his rear bar and tail light. Better I did it in the MX than the Z

Well done on the fix and the improvement in times. Don't s'pose I'll see you at Noosa over the weekend? Heading up tomorrow (Friday) at sparrows to get everything sorted and have a good walk of the track. I should be around most of the day if you want to call in for a cool beverage.

For mine, The best con rods are custom made ones to get everything right. When you use existing new or second hand production rods there will always be compromises. From what I have read and been told, the best production rods are the L14, but from memory you have to get the correct L14 rods to use, and I believe they are getting rarer than rocking horse poo. As I stated above, if I didn't have a stroker fall into my lap, I wouldn't be bothering in building one. I would use a good L28, either N42 or F54, out to 89 or 90mm, depending on condition, using the standard L28 rods and oversize flat top pistons to suit. And get another N42 head prepped the way mine has been and run standard injection with Haltech computer. The L series bottom end doesn't any work as the factory tolerences were brilliant compared to the old red motors and 250's Holden and Ford threw together in the '70's, so they don't need the work that these anchors need to hold together at anything over 5500rpm. The stock bottom end will handle 7000rpm all day everyday if not abused.

Try JP Pistons in South Aus, they can custom make the pistons you want/need. Won't be cheap, but will be right. If you're looking at building a stroker DON'T skimp on anything. I'm only running a stroker because one fell into my lap at the very right price of not a lot. I will be keeping it for as long as I can, but if it goes bang and the bottom end is damaged beyond salvaging at a resonable cost, then I will go back to a standard bottom end and big bore to go to L29 as per a previous motor spec I raced with faiorly good results, ie 150hp at the wheels and plenty of torque, not quite as much as the stroker but still plenty. Personally for a good strong motor that will be liveable on the street and quite handy on the track and relatively cheap, here is what I would do. N42/F54 block, whichever you have. Get tested to determine safest over bore possible, be very happy if you can get a 89 or 90mm bore, it will be a good torquey motor. N42 head, clean up the ports and combustion chambers. The amount of work depends on budget. In reality not a lot is needed. Get the head serviced and new valves and valve springs as minimum, as well as seats. No real need to port the head, just clean up and don't polish, you want some turbulent flow. Cam, depends on what you want. I run the Nissan motor sports 76 degree grind in the race motor with injection and I could live with it on the street in this set up. It pulls from about 3500 to 6800 and I rev the motor to a max of 7200. Idles at about 800 - 1200 when warm. A more suitable grind for the street would be around the 72 degree grind, or I have used a 65-25 grind with good results for a streetable motor. Personally, I would run EFI, but get the right manifold. Do not use a L24E manifold, too small. If you can, run a NAPS manifold, or a 280ZX manifold. The 280ZX should have twin butterflies, this will work, but there are better. The N40, I think this is the right cast marking is a single 63mm butterfly and has slightly longer runners and better ploenum shape. Dat2Kman can give you a very thorough tutorial on the logs. The ultimate would be ITB, but only if the injectors are placed in the standard location at the head. The L series doesn't rev fast enough or pull enough air to really make the most of the injectors being away from the head as most aftermarket set ups are. The standard L28 injectors are fine for most NA applications. I run the standard injectors with a Haltech F9 computer and electronic dizzy. Other aftermarket computers will work just as well, and the standard L28 computer is quite goos and there are some tricks to be used with that one as well. My personal preference would be for Haltech or Motech, more exxy than some of the others but that's what I prefer. If you don't want injection, then triples or a good set of 2 to 2.5 inch Su's will work. Triples will be the most fun, but be prepared to spend money on them, my preference would be webers or Mikunis and buy new. Get the best linkages you can find and pay someone to set them and tune them right. This will see you only having to get them tuned every 12 months or so if you don't play with them, or worse yet let someone else play with them. Exhaust, a good set of extractors, if you can afford it get some made by someone who knows L series motors, not the bloke down the road who says he can, and then if it's a road motor, a good 2 1/2" system. This is only my personal opinion based on 20 years of racing L series motors in 4 and six cylinder form, using standard carbies, webbers and injection, for categories like Production Street Sedans, Improved production and Marque and Production Sports cars, plus being able to spend time around some of whom I believe to be the best people to play with L series motors over the last 30 to 40 years.

Shane, Glad you had a ball at PI, even if the weekend did turn sour at the end. You must have been punishing the diff to get it to break like that, though I have never had a diff let go like that in my car The locker would have been nicer to allow you to just launch out of the slower corners, just that little bit better than the LSD would plus the better gearing would make a hell of a lot of difference as you were able to flow through the corners better and also better use the torque of the engine to drive out nicely, just where you make up most time. Also with the slightly more understeer setup the locker would induce, that may have helped in getting round the slower corners a bit better than with the LSD allowing a bit more oversteer, if you didn't change the suspension set up between diffs. Sounds like you may need to change the alternator pulley to a slightly larger one with the revs you were pulling. Mine used to have the same symptoms until we fitted a larger pulley to underdrive the alternator. The insides would spin themselves apart at the high revs, but still show it would charge in the pits. Took a little while to sort that one out. The only problem I have now is that I flatten the battery on hill climb events as the time spent at high revs isn't enough for the battery.

Not so much automotive, But in previous life have used Bentley Microstation, and Microstation with Focus, a HFC network design tool. When I was on the drafting boards have used Autocad and Land development Desktop in conjunction with specialist GPS and Surveying software packages associated with the Total stations I was using. Now mainly use MapInfo, and will more than likely be starting to use ESRI GIS products as more of my clients move from MapInfo to ESRI.

Thanks, Getting the Z ready for Noosa on the weekend, should be interesting to see where I am in realation to John Siddons, hopefully the extra power from the new head will get me back to where I was quite a few years ago when we ran the Aust. Hillclimb Chapionship at Bathurst, and wasn't that far behind him.

10 years for a race motor, that is very good reliability, well done on keeping it togther that long. Also good to to see the new front spoiler works, will have to put an undertray back on mine now....

Ok so what your saying, is keep a stock bottom end, with new main and rod bearings, from there flat top pistons. Yep, but get the block checked, it may need just a hone or it may need to be bored out. Once you what's what then pistons can be decided on, but flat tops would be the go for mine. Ok so the head then, port and polish, perhaps weld up a little to allow for hight compression, lightened fly wheel, lightened balancer. For the head, a good service, if needed, new valves and guides, and definately new valve springs. depending the head used, as to what work to do it. I'm not a believer of polishing ports as you need a slightly rough surface to keep the airflow turbulent to get the fuel in better. Decent set of extractors and now for fuel. yes and a well designed exhaust, my preference for a treet motor would be 2 1/4 or 2 1/2 inch system. i have always wanted a set of tipple webers, BUT, cost, the cheapest i can get a NEW set is $1500 with webers from Italy ($890) and a manifold with everything including soft mounts, linkages ect for $400 plus freight. Good price, but make sure the linkages are good quality with good balls for the rod ends, not the cheap plastic ones For the same price i can get a new set of SU 240 round tops like i have, or rebuild mine quite easily. Up to you, performance from the Su's is also quite good, not me experience as all my Zeds have had injection, and my 4 cylinder L series motors have used webers or the standard carbies. How much would going to a tripple weber benefit the car, VS keeping the 240 round tops. Again, need someone else to comment, but for mine a well set up set of Webers can't be beat for noise or the push in the back you get when they open up and the cam comes on.

Took the MX to Lakeside yesterday, got down to a 1:10.61, so happy with that. Not so happy with smacking the armco with the front and rear quarters of the left hand side coming out of the Karusel, trying too hard on road tyres. At least the damage was only cosmetic and will give me some panel beating practice.

No need to spend money on the bottom end for a street motor, the standard L series bottom end will handle 6800 to 7200 all day, this is what I have revved my street Lseries powwered cars to for many years. Also not many cams will be making power after 6800 any way unless you go for a custom grind, and then they will be making power that far up you won't have any torque in the mid range making the motor an absolute pig to drive. Unless you spend big dollars on getting the bottom end right by someone who knows L series motors inside out, and I would say there are only a handful of people in the country who do know what they are doing with an L series, don't touch it. I have seen a lot of L series motors brewak cranks and rods because the builder thought they knew what they were doing. I have never touched the bottom ends in any of my motors and not one of them has ever had a problem with crank or rods. I have only ever had one motor, and L22, 4 pot, spin a bearing because it was being used for qualifying for a race meeting with only about 15 minutes run time on it, and the builder rebuilt under warranty as I wasn't given any time to run it in. Jason, Dat2kman has spent a fortune on his L28 to get it to rev to what he needs to be competitive in Group Sc against all the Porsches. He should be able to enlighten you on the costs when he's back from Sandown.

Depending on who's dyno you use 200rwhp will be being optimistic. My motors only see around 140-160 rwhp, but I build them for plenty of torque and don't need to rev them past 7200. This is in my circuit racer. For a road motor you want something that is tractable form down low and works well from about 2500-6500. Personally, I would opt for a N42 head with a little bit of work to the ports, just clean them up, and from talking to different people and how I have set my ports up for injection, don't polish them, the rough surface will help the fuel stay atomised with the turbulence introduced in the air flow. The carbies sound on the money, but don't dismiss injection, the standard L28 injection can work quite welland there are a few tricks you can play to get the computer to work really well. Decent extractors, if you can afford it some custom built ones, that send the gas out through a 2 1/2 inch system. As for cam, for something that's a bit of fun a 65-25 grind will give you good torque, but a 72 degree cam will give a little more top end without being a pig on the road. The revs you are aiming for a little high for mine, my race motor develops max power at about 6800, with a broad torque curve from 3500. You only need to rev an L series to around 6500 for the street too much higher build costs go up to keep it all together, having said that the standard bottom end doesn't need to be touched as Nissan had pretty good tolerances at the factory, nothing like the eqyivalent red motor and old 250 from Fraud in the 70's. Realistically a good road motor that doesn't cost a fortune will put out a realistic 120-140 rwhp, but a good dyno operator will get you 200 if you really want, and maybe a bit more

Easy fix then....... Get rid of the booster and get a firmer pedal with much better feel. I run an unboosted 1" m/c and it's no problems at all to use, just has so much better feel than a boosted pedal.

Use a modern injection system like Motech and hide it somewhere and show the scrutineers the standard computer if they ask, plus you know most of the tricks to the L28 computer computer anyway....... I know when you're chasing big horsepower with plenty of restrictions it becomes expensive. I know who's motor would owe them the least in dollars and I wouldn't be that far behind in power, especially on a kW/$ basis. Only problem I have is the car is pretty much a circuit racing orphan now, though will be intersting to see how far John Siddons is in front of me at Noosa. Plus you forgot all the fibreglass bits that are homologated for the Z for both standard and ZG panels

So a lot of work for not a lot of gain...... I still reckon for ease of build and availability the N42 is the way to go for a good torquey NA L28, L29 or L31.

Bugger, I only have a 3.9 as a spare. Might also be worth chasing up 4WD wreckers for a 720 front diff, I know the diesels are 4.875 and most petrol are 4.6, but there were also a few 4.4 front diffs as well.

Touche and well said!!! Hope you don't have to wait long to find the right car. I could be tempted to sell mine, but from the sounds of it you aren't after a track pig.

My engine builder and a couple of others found that the N42 head was a better unit for a higher compression NA motor, and can be made to work quite well with not a lot of work. The motor that my current head was built for originally had a P90 head, but we found with what I wanted and the budget available to me the N42 was a better head and needed less work to get the flow and susbequent torque I was after. I now have a few N42 heads as spare as they are also a lot easier to get a hold of than the P90 head.

The cam I'm running is a Nissan motorsport 76 degree grind, don't have the specs here with me, but is an off the shelf grind. I am still using an AFM, what I believe to be the standard one that was fitted to my inlet log, made a mistake in the first post, the casting number is N47 on the log. I believe it is a turbo log of some description and has a single throttle with the butterfly at 63mm in diameter. The only modification to the AFM is to enable me to run the Haltech F9 computer that I have used since about 1994 with no problems. If you're in Brisbane you're always welcome to wander around to have a look.

Well I had an interesting day on the dyno getting my motor finally set up for fuel with the computer. Basic specs are: L28 stroker to L31 N42 head - some tidy up of chambers and ports for flow Haltech F9 computer and L28 electronic dizzy L28 N42 cast turbo log maifold and standard injectors After a few false starts due to not enough time and niggly things like throttle linkages not lining up with the new inlet manifold I finally got the old girl onto the dyno to get the fuel sorted with putting my old race head on the stroker bottom end. Previously this motor ran a E88 head with standard 280ZX manifold and recorded a dyno figure of 142 rwhp on a dyno dynamics dyno in shootout mode with points dizzy and 125 rwhp on the dyno used by Powertorque engines up here in Brisbane with an electronic dizzy. The rebuild of the car this year saw my old N42 go on the bottom end and a turbo log manifold with 63mm diameter single throttle body replacing the standard L28E manifold. Standard injecors are still being used as they can comfortably supply enough fuel. As previously stated the throttle linkages were a drama. This is due to the runners on the new manifold being about 1/2 inch longer than the old manifold and only giving me about 1/4 throttle, not good for any motor. A day or so of mucking around had the linkages adjusted correctly to give me full throttle. Off to the workshop today for the final tune so I can have a play at Lakeside in a fortnight and then onto the Noosa Hillclimb in mid November. More dramas, the motor is as the mechanic said - "breathing heavier than a peodophile at a wiggles concert", this maybe due to the fact that it was originally built with the crankcase breather blocked off and all breathing through the top end, or the bottom end needs a freshen up. When revving hard under load the amount of smoke out of the catch can is not pretty. It looks like I will be up for a bottom end rebiuld in the new year :-\ The good news is that when geeting the fuel right I saw 131 rwhp at just under 5k and plenty of torque. 6hp more and 2k less I'm impressed. Looks like this will motor would show an honest 150 or so if we did a power run, which would equate to about 160-165 rwhp on a dyno dynamics shootout run. Very happy about this especially as the torque curve will be as flat as before . I like my motors like me - fat and lazy Now I will be running its first event in three years at Noosa as the mechanic was not confident it will last a track day. This will be fun learning the car again, and the MX gets another flogging on the track :-\ Finding out a little more of the history of the motor tonight it looks like that it is overdue for a bottom end freshen up and while it could cope with the E88 head the much better N42 head is now causing the bottom end some grief. A fair bit more fuel has been added to the maps with the better flow. Best get the spare blocks ready to be bought into service if this one is shot!!! Jason, hope you're not going away over Christmas I can see a rebuild happening!!!!!

Ash, if you need help in finding out its history I have a good friend in Tassie who would be able to help. he was involeved with a JWS in the 80's, in fact jot him into a lot of trouble when he set a speed record on the F4 west of Sydney with it

Jason, Haven't had any problems with mine running 18x8" rims -2.6 offset with slicks, or the 15x7" rims with toyos, with backspace of about 110mm. Come round and have a look, I haven't had to do anything special yet to the struts other than drop spring seats to lower static ride height and keep the full travel of spring and damper. Neg camber is at about 2 deg without having to worry about bending struts yet, and no problems with bump steer.

If you can find one, and you can't have mine , an N42 cast number turbo log manifold flows pretty well. The runners are about 1/2 inch longer than the standard L28E manifold and the log itself is less tapered than the standard 280ZX log. That should be a lot cheaper than going the ITb set up plus the injectoras are at the port where they work best and not stuck way ou tin the middle of nowhere where they just don't work as well as on a low revving motor, <9k

Why do want the P90 head specifically??? In my experience, unless your planning to put a hair dryer on, the N42 can give better results for a lot less work. I had a P90 head on my first race motor but we had to take a fair bit off it to get the compression we wanted and then a fair bit of work to getthe porting to suit as well. At the time I was running L28 out to 2.9 running standard injection and using the standard L28 computer with a couple of tricks to double pulse the injectors for more fuel. My last L29 used an N42 head with better results for less dollars and this head is now on my stroker L31. Now a story in it's own right. The spec for that motor was L28 out to 2.9 with N42 head, standard single butterfly log of 280ZX and Haltech F9 computer. Good for about 130-140 hp at the wheels with points dizzy, but more importantly plenty of torque to pull out of corners. One big advantage of the N42 head is that they are a lot easier to find and need less work to get flowing nicely.