Triple Michunis...

[justaZcarguy]

Hey,

Sorry 'bout the spelling. :stupid:

Anyway, anyone had luck with Triple Mikunis? I bought a parts '73 and low and behold it has a built 260z motor in it. Nice suprise...

Was looking for some feedback on these.

And, nice talking to you the other day Beandip...:classic:

Thanks and have a great Wednesday.

Z ya l8r.

[ZmeFly]

but i did have dell ortos really nice carburetor easy to adjust and work on and much smoother them webers

[HS30-H]

I have used both 40 and 44PHH Mikunis, as well as both 40 and 45 DCOE Webers on the L-series sixes.

The Mikunis need a bit more educated fiddling to get the "transition" right on each particular engine ( thats the transition between the Accelerator Pump circuit and the Main circuit ) - as each engine is going to have individual characteristics based on compression, valve size, cam etc. The accelerator pump stroke is adjustable - but most people just bolt them on and expect them to work perfectly..........

Nissan would not have offered them as a Sports Option part if they did not think that they were any good. They also fitted them to the Works circuit race and Rally cars when carburettors were used - all the others had the ECGI Fuel Injection systems.

All of these types of sidedraught carburettors ( Weber, Mikuni, Dell'orto, SK, etc etc ) are totally tuneable for each individual application. If they don't work right, its down to the person who fitted them either cutting corners on jetting and venturi sizes, or not having enough experience to know what is needed.

In the carburettor beauty contest, the Dell'orto has to come out as the Miss Piggy of the bunch. Sorry, but that is one ugly carburettor...............

Alan T.

[Cuong Nguyen]

Hi all,

a good friend of mine has a triple Mikuni set up for sale, I'm not sure if they are the 40mm or the 44mm, I'll have to check.

These are mounted on an SK intake manifold and have all the linkages between them, they are in very good condition, I'll get some photos of the set up soon.

[dohc]

Hey Cuong,

How much does he want for the triples? Also while on this topic, do the triples go out of tune heaps faster than twins or is it about the same?

I had a mate with triple carbs on an XU1 Torana (202ci, )and he was forever having them tuned..... They also chewed through fuel like a 20b rotary Now I know that the Aussie 202 is a pretty hungry engine, but it was getting ridiculus by the end....

Is this normal or was his set up wrong?

Thanks for any input.

R.

BTW Alan, What is the race history of tripple carbs on Datsuns? Were the Mikunis used exclusivly or where delorto's used as well? Ta.

[HS30-H]

What's up dohc?

The factory used the Mikunis on all their race cars unless otherwise fitted with the ECGI Fuel Injection. My interest only goes up to around 1975 ( or even 1976 with a little pinch of salt ) and then picks up again about 1989 / 1990 when I saw the Group A R32 Skylines racing in Japan ( wow....... ) - so I can't vouch for the gap in between, and it hardly matters anyway.

There were a few honourable exceptions to the dross of the post "Oil Shock" period - notably the "Silhouette" series race cars, which were mad - but they were all injected anyway.

Prince used some race engines that they married up with Weber carburettors - notably the GR8, and some of these survived the transition between the last days of Prince proper and when they were taken over by Nissan. The Prince Skyline S54 GT-B was fitted with 40DCOE Webers from the factory ( and was the precursor to the C10 series GT-R ). A few semi-Works / privateer teams used Webers on their Skyline and Z race cars - but the proper Works cars always had Mikunis.

Like me, they probably thought the Dell'ortos were too ugly to love...............

If ANY sidedraught carbs don't work right its probably the owner / fitter's fault. If they go out of tune ( after having been IN tune ) then its probably down to having a crap linkage. These things don't change their settings on their own.

Happy twiddling,

Alan T.

[dohc]

Thanks for that Alan, I really wish you had all your knowledge written down somewhere! It would make one hell of a read....

Just one last question though; Which year did Nissan/Datsun swap from carbs (twin or triple) to the ECGI injection? I know in Aus we had twin carb 260z up until 1979 I think, when the 280zx came in.

It is my understanding that the 260z was injected in other countries but I'm interested in which year this injection came in?

Thanks again Alan,

Ross.

[HS30-H]

Aw shucks Ross, you're such a flatterer.....

As far as the Carbs to ECGI changeover goes - I can only tell you about the situation with the race cars. The swapover to Injection on the road cars ( and they did not use their own ECGI system ) is a mystery to me as it falls somewhere outside my area of interest - sorry. I tend to wear blinkers and only take notice of things that interest me ( selfish, isn't it? ).

Mind you, I bet you any money that Nissan once again had no clearly defined switchover point from Carbs to Injection on the Z. They probably tried it in certain markets first and then gradually blended it in. I know that carburetted versions were being sold alongside Injected versions at one point in Japan, and this was possible because Japan always had several different models of Z to choose from on the Home market. Just about everybody else outside Japan got one particular model / spec. for their particular market.

On the race cars, Nissan were also using the ECGI Injection on cars contemporaneously with Carburetted versions. They started out injecting their Sports racers ( like the evolutions of the R380 series and up; for example the GR12 was a bloody fantastic engine - big inch V12 with double overhead cams and whacking great injection trumpets ) and then they were injecting the S20 sixes in the GT-R before the Z even came out. Even "lowly" Sunnies got injected in race trim. The Z432-R racers sometimes got the ECGI and the 240ZR was used with both too. In most cases, the Injected cars went to the "Ace" drivers or were used on the cars where the most power was required. The Works Rally cars used them both on the "normal" L-series sixes as well as the LY "Crossflow" engines, with the first instances of injection being used in around late 1971. The Circuit racers had them a bit earlier.

Sorry I can't help with the date for the introduction of Injection on the Aus market road cars.

All the best,

Alan T.

[dohc]

Thanks again Alan, you've answered my question beautifully. I'll be able to move on with that.

The reason that I asked is that I'm at a cross road of going for triple carbs or injection.... It's good to hear that they were using EFi in competition so early, I was a bit worried that they didn't use it until the late '70's.

Hmmmmm, I recon I'll head for injection after all :classic:

Oh and we're glad your so selfish, it means you've got a depth of knowledge on the early nissan's that we all envy

Cheers,

Ross

[Z-point]

complete with linkage, headshield and manifold. Did not run for a couple of years, so tell me what to do.

Clean the outside perhaps the inside.....with what?

can I take every thing apart or is that dangerous for a newby?

[Z-point]

picture

[Cuong Nguyen]

Hi all,

the triple Mikuni and SK manifold set up got sold for AUD$1200!!!

I really wanted to get it but unfortunately didn't have money at the time! They were 44mm Mikunis and a Sanyo Kiki intake manifold all complete with linkages etc.

The set up is going into a car that is being built for Targa Tasmania (the world's greatest tarmac rally). I will get picks of the car once it goes together.

BTW does anyone know a source for SK manifolds?