Researching a Le Mans 260Z - Info appreciated

[acf321]

Hey Brabham (and others)

 

I seriously like the way you're thinking on this project, and I for One would be very very interested in seeing you getting this project done. If there is anything I can do, just give me a shout. This could be one hell of a car when done. Most of us guys are doing our own interpretations of what we like in a Zed for our own purposes, but your LeMans replica is a real gem, and as Alan points out is hugely unique, and holds a special significance in the history of the marque.

 

The fact that Nissan went head to head with the establishment, on their turf, and went to such lengths in terms of engineering, ie wheels, engine, aero and transmission is very interesting, and underpins the relevance of the 240 and 260Z and real sporting legends.

 

I would be very interested in some of the stats, Alan if you know such as; 1) transmission type and gearing ratios, 2) diff spec, what was the ratio, and was if LSD, 3) top speed, 4) peak HP, and RPM of that motor, 5) weight, and so on. Also, was that a metal car, or did it comprise many FRP, or other panels? 

 

Go for it I say Brabham, and as for one of those trick heads .. count me for one. We only need another 497 takers!

 

Thanks for the great read, and by all means let me know and i'll take you over to see the Hornet

 

Cheers

 

Adam

 

 

 

 

 

 

[Brabham]

The peak HP was 300 - they bolted this motor in on the Thursday just before the race which upped the output from 260 HP from the previous one. As to the other stats, I am not sure. The 240/260Z was such a versatile car being applied to the Safari Rally and circuit as well, special credit goes to it for making it into Le Mans given the nature of the circuit. It only just managed to qualify.

 

[HS30-H]

The peak HP was 300 - they bolted this motor in on the Thursday just before the race which upped the output from 260 HP from the previous one. As to the other stats, I am not sure. The 240/260Z was such a versatile car being applied to the Safari Rally and circuit as well, special credit goes to it for making it into Le Mans given the nature of the circuit. It only just managed to qualify.

 

More stories via the Autodiva forum ( commenting on gossip and stroke-pulling of the time ) that need to be taken with a big pinch of salt. One of the main contributors to that thread spent a long time a few years back pumping me for information and hard data about the car, and a few people have added press reports and other stuff into the mix. For me, the "300HP" engine-switch story just doesn't add up. Why? Well, the post-crash photos show the car still fitted with the 'Safari' FIA head and ECGI system ( not to mention the driver-controlled engine oil top-up reservoir system ) with all its dedicated plumbing and wiring, which is exactly the engine configuration that the car used in 1973 when the factory built it, and when it went to South Africa for the Springbok Series races. If there was an engine switch just before the '76 race, then what was installed in the meantime? I say its a smokescreen, and the clue is in the last line I quoted above....

 

They just managed to qualify in '75 ( they were lucky, as a dispute between some of the Ferrari-running teams and the ACO bumped them up from being reserves to actually taking part in the race ) and were slow. This probably as much due to driver quality ( no offence ) as to lack of proper preparation / equipment and the fact that the car was already getting old and was not necessarily suited to the Le Mans track. Remember that this was a car that had been built by the works in Japan, had raced / tested in Japan and then been sent to SA to race. It was left there - along with a limited kit of spares and data - in the hands of people who were not necessarily going to be fully familiar with it, and who did not have the factory mechanics to hand after their first race. With the cancellation of the Springbok Series, the car was eventually rescued from redundancy by the well-connected Schuller, and only got on the reserves list for the '75 Le Mans due to some clever lobbying / 'not-what-you-know-but-who-you-know' and some iffy paperwork. Having completed the '75 event ( not without some long stops ) and placed in class, they were automatically bumped up the queue for the '76 Le Mans, despite the protests and misgivings of other teams and drivers. Faced with all this lobbying, the team produce a story that they have switched their engine to some new demon tweeked '300ps/hp' unit ( from where?! ) and assure the ACO and their fellow competitors that they will be faster come the race. It's just a smokescreen, I'm certain of it. The engine was the same basic unit all along, and the '300ps/hp' is a nice round figure that appears rather conveniently....

 

About that '300ps/hp' figure: The car ( along with a sister car ) went to South Africa with data from the works team. The 'Safari' headed car ( running in Group 4 with local drivers ) was quoted at 262ps @ 7600rpm and 25.5kg-m @ 6000rpm, whilst the 'LY' crossflow headed sister car ( running in Group 5 with two Japanese works team drivers ) was quoted at 275ps @ 7200rpm and 29.8kg-m @ 5,600rpm. You can see that these are real endurance racing specced engines, designed to churn away lap after lap for hours and hours on end, with fuel stops to top up their 120 litre tanks. So the '300ps' quoted for the '76 Le Mans car - USING THE SAME ENGINE CONFIGURATION THAT WAS '262ps' ACCORDING TO THE WORKS TEAM - is more than that for its LY-headed sister, which went back to Japan after SA. Doesn't quite add up, does it?

 

I would not draw any conclusions from the lap times / top speeds of the car at Le Mans either in '75 or '76'. In the '76' event they at least had a couple of more capable drivers on board, but the car had not been built by the factory for Le Mans, was already old, and was running with limited resources by a team that was trying to punch well above its weight. To be blunt, they were out of their depth.

 

More on the car specs anon ( got some work to do here! ), but I just want to mention one thing, Brabham. Please bear in mind that the '76 car represents something that crashed with fatal consequences for its owner / driver. There's some baggage that comes with that. You might see it as a 'tribute' to build a replica / lookalike, but it may offend others - particularly if they were close to SION Auto / Haller or the others. Please bear that in mind.

 

And quite apart from that, the '76 Le Mans getup is bloody awful! A half-hearted and several years too late attempt at 'Pop Art' by somebody's well-meaning mate. The car looked its best in its factory colours / configuration ( '73 Fuji 100km / '73 Kyalami 9hrs ) in my opinion......

 

Cheers,

Alan T.       

 

 

[Brabham]

Thanks Alan,

 

this has all been incredibly interesting, have loved hearing the history of the car. Hope to hear more on the availability and sources of all the various bits and pieces.

 

I am conscious of the tragic history of the car and owner, and if I were to build a replica, it would be without the "Sionautos" livery and a few other changes here and there to the paint scheme so as to be sensitive about the history of the car. For me it is a beautiful looking car with a deep history, and the intention is not to offend anyone, it is a great shame the accident happened  :'(

 

If I were to build it it would be a loose replica given availabilty of parts is virtually non-existent and terrifyingly expensive. The FIA head looks cool, but I imagine the ECGR and oil top-up system are impossible to locate and a nightmare to setup and operate (mainly the ECGR).

 

Can LY crossflow heads still be found and did they run carbs or injection/throttle bodies? That would be a cool engine build to do. Also interested in potential bodywork suppliers.

 

Thanks and look forward to learning more from your next post. 

[NZeder]

Can LY crossflow heads still be found and did they run carbs or injection/throttle bodies?

You have a house to sell? If yes you might have a chance of getting hold of one - but first you must get the owner to part with it

 

I believe both carbs and injection was used on the LY heads. Alan can confirm.

[Brabham]

How much would an LY be worth if one could be found? Anyone ever seen one for sale?

 

Also anyone ever seen a set of those Kobe Seiko wheels for sale? eBay Japan?

 

Cheers.

[NZeder]

I found some pics of a real LY online - If you click the image you will redirect to the source - now if I could just my hands on one and see if kiwi-cylinder heads could remake a few.......(dreams are free - would have to get permission from Nissan I would guess as it is there IP after all)

 

 

[zedrally]

.....(dreams are free - would have to get permission from Nissan I would guess as it is there IP after all)

 

 

How would you go with the TC24-B1 Twin-cam crossflow head made by O.S.Giken ?

 

One question I have on this is is it the same head as the LY ?

[.]

I don't get how that sprocket could fit that setup....is there only one for two cams?......or is there two? and then how would thefit next to each other.......wowser!!

[PZG302]

The LY head was a 2 valve SOHC crossflow head.

[NZeder]

LY = Nissan 1970's (and early 70's at that) SOHC, 2 valves per cylinder Cross Flow FIA approved

 

TC24-B1 = OS Giken 1980's DOHC, 4 valves per cylinder cross flow - non FIA approved - I believe 12 made in the first batch, some more made later from different alloy = did not last. Currently 6 more getting reproduced with some improvements/modifications to the design of cam towers and like.

 

If you are going to remake a head an LY 100% replica would be the way to go as you can use this in classic racing/HTP/FIA group 4 or 5 replica.

[zedrally]

LY = Nissan 1970's (and early 70's at that) SOHC, 2 valves per cylinder Cross Flow FIA approved

 

 

Yep it is, but where does the Giken head fit into the overall picture ?

 

It wasn't a competition part, it wasn't allowed in the US, yet it put out 15-20% more horsepower than the LY, yet there was no avenue for any vehicle with one fitted to run in that I can find, except for a rally spec 280ZX that ran in the US for a SCCA rally, which poses the question if it was allowed as a rally spec, why not for circuit ?

[NZeder]

Yep it is, but where does the Giken head fit into the overall picture ?

 

It wasn't a competition part, it wasn't allowed in the US, yet it put out 15-20% more horsepower than the LY, yet there was no avenue for any vehicle with one fitted to run in that I can find, except for a rally spec 280ZX that ran in the US for a SCCA rally, which poses the question if it was allowed as a rally spec, why not for circuit ?

I guess it comes down to what a circuit race organiser will permit - if you can convince someone who runs a race series to let an OS Giken head run then all good but that will be a hard road I bet, it is hard enough to get items listed on the sport option catalogue included let alone a very limited production non factory part.

 

At least with the LY - it was FIA approved for Group 4 and 5 Appendix J for the given period = you can build one up as an Appendix K HTP car - and that should not be turned away by anyone if the honour FIA Appendix K (for the given Appendix J period)

 

I have been reading a bit on the HTP stuff and Appendix K (for the given Appendix J period) and basically what is on the FIA papers or factory specs/options catalogues is what goes all other mods are out even if you can proof a car ran with an OS Giken head or other mods if the FIA does not have a homologation paper for a car with that mod you can't run it. Now my understanding is that back in period the US racing was not FIA approved ie SCCA, IMSA etc so all S30 or S130 mods that were done in the US in period are out as far as the FIA are concerned/HTP unless the same mod was listed on the FIA homologation papers - see where this is going....

 

Again if you were going to get a new head that is FIA period correct and (more to the point) legal then one of the FIA approved heads is the only option (be it rally head like that in the pics HS30-H posted or the LY shown in the pics above). Now depending on which class/group the car is build for in theory engine mods are also limited to stock/options catalogue parts  (however most, even FIA HTP papered cars, have bent these rules)

 

All of this stuff is a little off topic but sort of related to the Le Manns car as it was an event run under FIA rules so the cars were all meant to comply with the Appendix J rules of the day.

[peter mc]

NZeder did the ly req different pistons and did the head make good hp over a race L head . just curious..

[zedrally]

For some reason my reply has not appeared to NZders post.....

[HS30-H]

Brabham,

For a supplier of replica FRP panels like the ones on the '76 Le Mans car, try e-mailing Mori san at KAMEARI ENGINE WORKS, and tell him that you want the 5-piece G-Nose kit, the Works 'Type B' Overfender set, the Works 'Type B' front spoiler, and the Works 'Type B' three piece rear spoiler. He has a fibreglass supplier who makes decent enough quality for a relatively low budget. You could of course go to much more expensive suppliers ( high quality from the likes of Marugen Shokai does not come cheap ) but the end result will pretty much look the same if you spend enough time fettling it and fitting it.

 

However, isn't your car a 2+2? If so, I would not be on the rear Overfenders and rear spoiler fitting very well.....

 

 

[HS30-H]

About the 'LY' crossflow head:

 

In fact, the 'LY' was a complete package when built correctly. It wasn't sold as a kit to 'bolt on' to an already existing bottom end. To make use of the semi-hemi combustion chambers, special domed pistons were required with cutouts in the correct places, and these were used with high-strength conrods and a dedicated crank. The crank was made from a higher strength steel than the stock cranks, had narrower rod journals ( due to bigger radius at the ends of the bearing surfaces ) which required the special rods and brgs. This crank had a different flywheel bolt pattern ( more bolts ) so you needed to use the dedicated flywheel too. Lots of other dedicated parts too. The engine block was mounted at a different angle in the body to stock blocks, requiring special engine mounts and a dedicated bellhousing....

 

Replicating an LY would be a big undertaking. There's a lot there besides just the basic head casting: There's the inlet manifold, tappet cover and bellhousing to be cast too ( exhaust manifold could be fabricated ) but you need to think of the twin rocker shafts, the rockers themselves, the camshaft, cam pulley, cam chain, etc etc etc. Bear in mind too that the 'LY' ( like the FIA 'Safari' head ) was designed to be used with triple throttle bodied injection, and the angle of the inlet manifold on the 'LY' was not really ideal for carbs......

 

Power? Well, bear in mind why Nissan designed, built and homologated these heads and you have a large part of your answer. It wasn't all about power. Not to be cryptic, but it's a big subject.....

 

Cheers,

Alan T.

 

 

 

[zedrally]

About the 'LY' crossflow head:

 

snip

 

Power? Well, bear in mind why Nissan designed, built and homologated these heads and you have a large part of your answer. It wasn't all about power. Not to be cryptic, but it's a big subject.....

 

Cheers,

Alan T.

 

Wonderful explanation, but you've now opened the can of worms. Can you continue with your reply on the above paragraph and add any information that you're aware of regarding the Giken head, still not sure how it fit's into the big picture ?  Unless the simple answer is that the L series was unable to be developed any more with the lessons from it's development being applied to the RB series..

If the mods think this is off topic (which  it is now), can you split it into a new thread please....

[Brabham]

Thanks Alan for the info.

 

Are there any other suppliers of the body kit that you know of? I would have a look at all of them before buying one.

 

I would need to buy a 2 seater for this project, have to finish my 2+2 first . Perhaps a 260Z 2-seater would be a bit better than a 240Z as the shell is a bit stronger after 1974? However would the body kit fit a 260Z 2-seater (are the external dimensions the same?)

 

Replicating either an LY or FIA setup appears to be a near impossibility. So a modified and carburetted L28 may be the go here.

 

Stevo may want to add the info on heads to his sticky if he is watching this.

 

Thanks for all the info - very interesting

[Brabham]

Does Marugen Shokei have a website? I could not find one. I will also send an email to Mori San - thanks for this contact. Cheers

[HS30-H]

Does Marugen Shokei have a website? I could not find one.

 

Marugen Shokai's main page:

 

http://home.att.ne.jp/sky/FairladyZ/ZG/ZGmain.htm

 

Note that he doesn't make or sell the 'Type B' Overfenders and/or spoilers. The best replicas of the OEM G-Nose in the business though.....

 

Alternative suppliers of replica works 'Type B' parts include the likes of 'RS Start' and 'City Auto'. Mike pointed out 'Arita Speed' before, and they do make their own replicas of the works parts, as well as all sorts of other derivatives.

 

However, you may find that several retailers buy from the same manufacturer - and the manufacturer does not sell direct to the public. That's probably a good thing, as - in my experience - most FRP moulders are as mad as march hares. Must be the fumes...... 

[HS30-H]

Wonderful explanation, but you've now opened the can of worms. Can you continue with your reply on the above paragraph and add any information that you're aware of regarding the Giken head, still not sure how it fit's into the big picture ?  Unless the simple answer is that the L series was unable to be developed any more with the lessons from it's development being applied to the RB series..

If the mods think this is off topic (which  it is now), can you split it into a new thread please....

 

I don't really want to get drawn into a discussion of the merits and/or drawbacks of the OSG TC24. I've talked about my ( limited ) personal experience of it on other forums, and it always seems to end up with some bright sparks quoting spurious figures for the opposition, talking up the power that can be got from a modified 'stock' head, and just generally taking the piss out of it. Depressing.

 

But I think - for a small private engineering firm - it was a really brave, clever and interesting project, and they got a good bit of publicity out of it ( still do! ). However, it was built too late in my opinion. If they had designed and built it ten years earlier it might have had a chance to be better received, further developed and produced in greater quantity ( because demand would have been greater ). It was also never properly homologated, so you can't use it on an early car in FIA sanctioned events, as Mike has already pointed out. So it's an interesting side bar to Nissan L-Gata engine history and aftermarket tuning, but suffers from unicorn syndrome. 

 

About Nissan's FIA race heads ( the 'Safari' and the 'LY' ): Like I said, I'd prefer not to be drawn into a discussion / comparison that's just about quoted power and torque figures. Soon as you start getting into such a discussion, people start quoting figures from the likes of BRE, BSR, Rebello, Wako, Kameari and/or their own pet tuner, and it all means very little ( especially when the "BRE taught Nissan how to build race engines..." crowd walk through the door ). However, as I kind of hinted at before, such heads were not designed, built and then homologated solely with higher power figures in mind. These parts were built with endurance racing in mind, as well as Nissan's target of winning the East African Safari Rally, Monte Carlo Rallye and RAC Rally. On an event such as the old Safari, hand grenade buzz bomb engines that give high power on a dyno and had lives timed in hours were no use to anybody. Quite often crews would be forced to use local fuel with low octane ratings, and who knows what else in it, for an event covering thousands of miles with limits in servicing. These FIA heads were conceived as being useful in such circumstances, but such development was cut short by the 'Oil Shock', when racing took such a hard hit in Japan. Nissan also won the Safari in '71 ( quite apart from the success of previous years ) with the Z, proving that the 'normal' L-Gata could do the job anyway ( although it was hardly a stock engine in the car ), and did it again in '73. 

 

So the FIA heads were not just about power figures. They were about giving high revs, stable and even temps, and decent power for hours on end, and not just in 'ideal' conditions. They can and will give high power, when built with that target in mind.

 

 

Cheers,

Alan T. 

[NZeder]

I was at the track in the weekend so missed some of these posts as they came through.

 

First thank you Alan for informing of more "type B" flare vendors and for the info on the Safari and LY and their purpose. I am interested in the FIA heads for the reason you state - changes to the design for endurance/improved cooling. The L-Gata engines really are impressive given the non cross-flow of the stock heads, these can still produce good strong HP. It is the "LY" as a package that is interesting - different crank, rods, pistons, head, intake and exhaust setups all different - and like so many other race or work engines it is the whole package that makes up the engine and it performance/endurance

 

Reading back there was a question about how much a LY head would be and if anyone had seen one on a Japanese Auction site. Well I have never seen a LY head listed but I have seen a LY crank and it was in the order of $4000 for a second hand crank that needed some bearing work. So that should give you an idea on what the cost of a LY package will end up coming in at - I would say think BDA cost then some or in the order of a genuine Abarth 2000/Simca DOHC engine and you would be close (ie 38,000 EU for the Abarth) and that is if you can find someone who want to sell a LY.

 

I am sure Alan will correct me but most LY that are in existence are either in cars Nissan ownership or private collectors who would not part with them for any amount of money.

 

Many seem to forget these are Japanese cars and they were raced in Japan, it was just during the period (1970's) little was known about the domestic racing series in Japan (which ran under JAF rules which is the FIA approved motorsport association for Japan, which is unlike SCCA or IMSA) which is a shame as the cars would have raced under a FIA standard (ie Appendix J) of the day. It is always the other series that seem to get the interest when building replicas ie BRE (SCCA) etc.

 

For the reading I have done one of the issues with the with the S30 is the class/group in which it must run. FYI see here for FIA Appendix J info

 

• Group 1: series-production touring cars (5,000)
  
• Group 2: touring cars (1,000)
  
• Group 3: grand touring cars (1000)
  
• Group 4: sports cars (500)
  
• Group 5: special touring cars
  
• Group 6: prototype-sports cars
  

 

Now it would be nice if the S30 could run under group 1 but it can't as the rules state for 2+2 model as does group 2. The 260z/280z 2+2 was FIA approved for group 1 but the 2 seater version can't run under group 1 or 2 as they don't fit the 4 seats requirement.

 

So that put the 240z in Group 3 and 4 and it therefore completes against much more exotic cars with more technology or larger engines. The zed does do a good job in this group but like the Le Mann 260z - it was really out classed by these exotics and as stated was lucky to even make the start line.

 

The zed was successful in the US which ran under different rules and those mods are hard to get past a FIA body ie CAMS 

 

So this puts the zed into Group 3 in stock form (see mod permitted in Group 1 as the same applies to Group 3) and it is usually handicapped vs other models that were in group 3 also (one example is a 427 Camaro which was group 3 the 350 Camaro was group 1, another example is the 7000cc Vette of the same period and in long high HP tracks a stock zed will never bet that)

[Brabham]

More good info thanks Alan and N Zeder. Alan could I please get the website for city auto? I found the website for RS Start. I am now wishing my Japanese was a whole lot better as the google translator offers questionable interpretations. Thanks for the suppliers, I will give Marugen Shokei a miss as not sure if their G-nose will fit in with the front spoiler and overfenders from other manufacturers. That leaves me with Arita, potentially City Auto, Kameari and RS Start so that is pretty good. Will get in touch with all these guys, hopefully can get a complete set from one of them. I will also need a G-nose bonnet hinge set too will I not? Do they come with torsion bars or do I use the torsion bars from an existing set of normal hinges?

 

On the wheels Alan, where would I be likely to source a set and how many were produced? Also would it be advisable to use them on a track now or are they likely to fall apart? Cheers.

[Zedman240®]

When you fit a Gnose, you can actually modify the original hinges to work with the new front. If you have a glass bonnet, I wouldn't install the springs...