Rick

I have a 240Z with 2.8 mechanicals and 71 SU type carbs. I keep thinking that I should change the SU's for 3 Webers. However the engine will rev to 6500RPM and does not run out of breath so obviously the carbs are doing the job. My 240Z will potter around in traffic and will keep up with any of the triple weber cars on sprint day. I know there is more that can be done to the engine as I am currently getting 140 HP at the wheels as per dyno report. However you have to have a balance between a road and race car.

Some say the 4.6 ratio is too low, others say it will be OK for sprints but too low for the track. The only way to find out is to try it. Had to take the diff to a diff shop to change over the halfshafts form the 240Z to the 720 diff. Also had to change planetories. Next event is a hillclimb so it should be beneficial in this event. And biker you will know whether the change over is beneficial as I will be right up your---------. Have picture of your car at Leyburn but lost your email address. Rick

I have owned my 71 240Z now for 18months and probably done about 10 race events consisting of 1 km sprints on street circuits, 20 km sprints on race tracks and various hill climbs. The cars suspension was set up to try and cater for all types of on road conditions and has proved to be very good. The engine is basically standard with mild cam, extractors, electronic distributor and N42 head giving 134BHP on the Dyno at the rear wheels. Wheels are 16" x 7" with 205 x 50 series Falken ZE 326 tyres. Doing the 1km sprints I have had difficulties with the huge gap between 2nd and 3rd gear and was 1 - 2 secs slower than other guys in my class. Investigation showed that my 240Z was originally an automatic with a 3.5 to 1 diff. The guys at the local Z Club advised me to source a higher ratio. I recently sourced a 4.6 to 1 front diff from a Nissan 720 4 wheel drive ute. The problem I have is that the flanged drive shafts into the diff are different to the standard flanges on the diff in my 240Z. I took off the back cover on the new diff to see how these flanges come off but cannot work out how you remove them. Does anybody out there know how I can remove them to replace with my existing type flange assembly?

Engine no for HS 300 1224 is L2405 4278. Is this the original engine? Rick

Hope you know I am in Brisbane, Australia! Still for sale at Aus$200.00 for set plus freight.

I want Aus $200.00 for the 4 hubcaps plus freight. Rick

As I said before I have aset of four "D" hubcaps available.

Hi Ivan, There was a stock standard 240Z being dyno tested after mine which was great as a comparison. Although a standard 240z is rated 150HP at the flywheel they could barely get 100Hp at the rear wheels. Brisbane Turbo and Tuning is owned by John Whittaker who has a 547Hp twin turbo 2.5 skyline motor in his Z and his son has a single turbo 250 HP L28 motor in his Z. He seems to know what he is talking about. However I am open to any further info from the gallery.

Sorry my mistake. Actual torque is 282 nm between 3500 and 4000RPM. HP at flywheel is 168HP at 109kmph I found out that: HP at the flywheel is - HP at the rear wheels plus one third. ie. 126 + 42 = 168HP So my Z has good torque and power where I need it most for roadwork and would need a different cam for serious competition work.

No the Z is not standard. I was not sure of the engine mods that is why I got the car dyno checked. From the outside the car has an N42 head, extractors and uses the standard round topped SU's. By the idle sound it has a fast road cam. So 126 HP at rear wheels is OK as the motor has 575 NM of torque at 90 kmph. Yes I was at Niagra Falls 2 years ago and have seen how the falls freeze up some years. Brisbane is sitting at about 30 degrees C at this time of the year. I like snow but only to ski in.

Does anybody know the ratio of HP at the flywheel to HP at the rear wheels. I recently had the engine run up on a Dyno to establish motor HP and was given a printout of 126HP at the rear wheels at 4900 RPM. I want to calculate the HP at the flywheel!

Heh Nigel, I have the original wheels and trims for 71 240Z right here in Brisbane Australia. I was going to take my car back to original but I am having too much fun racing the beast. If you want me to email pics contact me. Can phone on 07 33251145 Rick.

Hi Biker, Well done on your excellent find in Sportscar and Racer magazine. I need to find which newsagent sells them to check out the real thing. Attached some more pics of Leyburn. Rick

OK Biker, You must explain to the members that your green 240Z has a 260 lump in it and has more power than the yellow 240Z which is stock standard! When is the next sprint event at Willowbank which being a flat circuit may be better suited to the yellow 240Z with less power? As I said before the yellow Z now handles well but is short of the necessary horsies needed to get up with the front runners. You need grunt in hillclimbs which is where the better torque of your motor shows in the results. The Leyburn digital photo was scanned off a picture taken by Marshall Cass photographers. See you at the next event. Rick

Hey Biker, Just because you beat me at the Noosa hillclimb does not make you an authority on tuning. Richard Blundell

Thanks Guys you have been most helpful with the dating process. Next time I need to find a good looking chick I will post an enquiry as you are a wealth of information, or is this only on Z's? And I was wondering whether Alan was a professor of Japanese history because he lost me somewhere between the emporers.

I have read many articles on modifications to increase horsepower for the 240Z. Nobody seems to offer a scale of suitable mods showing horsepower gained with the level of modifications done. I run my car in hillclimbs and sprint events but also like to use it on weekend runs. I apparently have an L24 motor with N42 head, SU type, round top carbs and 6 into 2 extractors with 2 and half inch straight through exhaust.( I have not opened the motor to check the internals yet) This engine revs to 6500 rpm before running out of breath. Torque seems to be in an even band from 2500rpm. The addition of an electric fuel pump has helped deliver fuel. Does any one know what the next level of tuning should be? I have not had this engine dyno tuned so do not know what it currently produces.does anyone know what the next level of tuning should be?

I am trying to ascertain when my Z was manufactured. It was first registered in Australia in Oct 71 but has a chassis no of HS30 01224 which would indicate it was built well before this date as Datsun first produced the 240Z in Oct 69. Does anyone know what 240 Z chassis no's were built in 69. 70. 71?

So does anyone know where i can get a good LSD for my 71 Z.

Can anybody tell me what mods I should make to my L240 motor to take me up a stage or two in engine horsepower. I am currently using the car for club sprints and hillclimbs. All suspension mods are complete and it handles exceptionally well. Unfortunately I get my arse kicked powering out of corners and down long straights. The motor was rebuilt before I got the car a few years ago using pretty much standard parts except for the addition of the N42 big valve head and a decent set of extractors. I fitted a two and a half inch street legal straight through exaust. Limited funds at the moment prevent me from taking the car to an engine tuner. I am quite capable of doing all the assembly work myself.

The 240z was born to race. I wanted a car that could be used for a Sunday run or be used to do sprints and hillclimbs. I did not want to purchase a thrashed car so I bought a standard 1971 240Z and decided to work on handling before worrying about increasing horsepower. Fitted progessive springs with Koni skocks, 26mm front sway bar and 14mm rear. Braced struts front and rear and fitted 16"x 7" wheels with good Falken road tyres, fitted better seats and 4 point harnesses. The car already had the big valved N42 head and extractors so a good tuning was carried out and I have since done 1 round the houses event, 1 track event and 1 hillclimb. This car handles like it is on rails and I am not too far behind cars that have 3 litre motors and triple webers. The secret, get the handling right first and then boost horspower. Car runs out of breath at about 6500 rpm but is a great all round fun toy. Next expense is all weather race tyres which should give me another 3 secs advantage before venturing into getting more "horsies" out of motor. The 240 Z is a great first time racer capable of keeping up with modern cars 10 times the price.

Alan stean of Z car Workshop in Brisbane can help with bonnet, boot and door reproductions in fibreglass which they use in their rally cars. Contact info is: zcar@iprimus.com.au www.zcarworkshop.com.au tel 07 3808 2755