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Scoota and the three D's


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#1 Scoota G

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Posted 19 May 2008 - 03:04 PM

Right,

I finally got all the gear together for the triple Dellorto setup on my 75 2 seater.

1 X JDM Manifold with linkages
3 X 40mm Dellorto's (ex alfa running 145 main jets)
6 X 2.5" ram tubes
3 X soft mounts
1 How to power tune Weber / Dellorto book
1 Carb Sychronizer

Also i have some air cleaners on the way too.

Looking forward to this moment for a lot of years but i have a question......is it nessacary to run a return line to the tank?

Any advice would be welcome apart from the standard sell them to me instead reply  ;D.
Cheers
Mark K


#2 620Z

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Posted 19 May 2008 - 03:48 PM

Not mandatory to set up a return line to the tank. If I was you I would set the tripples up, tune them and drive it like that for a while. Later on you can look at the return line if you want to go down that road. That's my 2cents.

#3 modular9

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Posted 19 May 2008 - 03:56 PM

There is a thread from sulio about settings in the triple carburettor section of this very site. Plus other tips.

- Return fuel line is a dam fine idea. Ask sulio about the one he set up on his triple dello/datto beasty.

-Have you got the emissions dellortos or the non emission ones ? Eg what is the stamping DHLA40 H/g/c/d/e on the side of the dellorto. Dont take what the author says about emission based dellortos to heart. Some of us on here have DHLA40 H/G's and have been able overcome some of the problems.
- Also you dont need vaccum advance on your dizzy. I dont know if this is only for electronic ones or not. But every tuner i talk to says to lock off the advance mechanism.

Mick74 is a really knowledgeable guy when it comes to dellortos as well. I based most of my tune of what he told me and they working really well until my engine died in the butt.

#4 Scoota G

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Posted 19 May 2008 - 04:22 PM

Well thats the funny thing (not clown funny more like darwin award funny)
stamped on the side is DHLA40 but there is no letter on two of them.

But one has G stamped on it. I can only see 1 difference between the carbs.

#5 mick74

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Posted 19 May 2008 - 06:01 PM

Mark

There are 2 type of dellortos 1. With an adjustable idle circuit and 2. With a restricted idle circuit. If you remove the jet cover and see were the jets are,next to the idle jet there will be either a large rectangular hole which will indicate type 1 or 2 2mm diameter holes which indicate type 2, see photo below which is a type 2. For type 2 to work properly you will need to put a restrictor in it to close up the hole thus changing it to a close type 1.

Regards

Mick

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#6 Toecutter

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Posted 19 May 2008 - 08:45 PM

Yep Mick's the bloke for tripples advise. Helped me a heap. Scoota, I've attached a spread sheet that should help you set em up.

In regards to the return line you probably be able to run the car like that if it was a track car as you would use all the fuel coming to the engine but if you driving on the road the pump will pressurise the carbs and cause it to run rich and foul plugs really quickly as that is exactly what happened to me.

From memory these carbs only need about 2.5 psi fuel pressure and when they originally run on the Alphas they have a return line with no restriction at all. So if you run the original fuel rail open up the restrictor abit to about 3mm, (advise I got from a workshop that sets up Alfas for the track).

Cheers,
Sulio

PS. I've got 7772.6 emulsion tubes and 55 idle jets ready to go however it's running pretty good with the 7772.10 tubes and 60 idle jets. Would be good to get it onto a dyno. We might be able to organise a AusZcar dyno day after the next meeting in July but thats another story.

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#7 Zedman240®

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Posted 19 May 2008 - 09:16 PM

Oh Sulio, not 2.5 bar! should be 2.5 psi! 2.5 bar is around 30-40 psi.... With that pressure, you will have fuel running out of your interior air vents!

#8 Toecutter

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Posted 19 May 2008 - 09:21 PM

oops, my mistake 2.5psi, edited above also.

Thanks Dimitri!

Sulio

#9 modular9

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Posted 20 May 2008 - 09:24 AM

Toecutter : nah do the 2.5bar. would make a wicked youtube vid. Picturing fuel lines exploding , catching fire , owner crying. Perfect action movie in fact. You got the action you got the suspense and you even got the romantic soppy stuff for the ladies !  You would make a motza! :D :D

#10 Scoota G

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Posted 20 May 2008 - 10:34 AM

The fuel pump i have is one of those Facet pumps which run between 2-4 psi. Should suit the application well.
I do have the mechanical one still hanging around but it need a kit through it.

On another subject i just spied a 280zx with targas in main rd Ballarat, it has no plates and is sitting next to an old val which has a 4 sale sign on it. WOOooooOOOooo

#11 Toecutter

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Posted 20 May 2008 - 06:08 PM

On another subject i just spied a 280zx with targas in main rd Ballarat, it has no plates and is sitting next to an old val which has a 4 sale sign on it. WOOooooOOOooo


I'm picturing a wild life doco, the vulchars are circling. The poor 280ZX has'nt got a chance, it's about to be carved up!  :D :D :D


#12 Zedman240®

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Posted 20 May 2008 - 06:36 PM

If they are circling around in the air above the car, should make it easier to find! hehehe Should be a good parts car for someone or if the L28 is good,a spare motor.

#13 Scoota G

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Posted 27 May 2008 - 06:10 PM

Well,

I bolted the setup on today and just got it running.

The carbs are popping slightly through the Exhaust and it stutters up to about 2100 RPM and then they run clean and sound Friggin Awesome.

The power is up and it now gets up to 80 Kays really quick. I am going to put a fuel pressure thing to restrict the flow and modify the linkages for the accelerator is not traveling a long way to open/close.

Does it sound right about the fuel pressure?..... I think that is what is throwing the idle off.
Can't wait to show someone... anyone..  :P

#14 Toecutter

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Posted 27 May 2008 - 06:41 PM

What size idle jets and pump jets are you runnning? It might be the cause of your hesitation. Also need to make sure that batterflies are correctly positioned because if they are letting too much fuel to be pulled through from the main jets it might explain why it hesitates down low. You need to be drawing fuel from the idle circuit at idle and when they open have the pumps jets give a squirt and then mains kick in howevere if your already drawing offf the mains it could be an issue.

Mick74 is well versed and can probably correct anything I might have got wrong but this is one thing I would check before further tuning.

Can you give us a complete break down of all components you are using?

ie choke size, mains, idles, emmulsion tubes, air correctors etc etc?

Sulio

#15 Scoota G

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Posted 27 May 2008 - 07:54 PM

Ok here are the sizes

2 Carbs are running 145 Main jets / 7772.8 Emulsion tubes / 52 Idle jets / 210 Air correction

The DHLA g Carb is running 145 Main Jets / 7772.10 Emulsion tubes / 55 Idle Jets / 240 Air correction

Thats all i have for the minute




#16 Toecutter

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Posted 27 May 2008 - 09:20 PM

Ok here are the sizes

2 Carbs are running 145 Main jets / 7772.8 Emulsion tubes / 52 Idle jets / 210 Air correction

The DHLA g Carb is running 145 Main Jets / 7772.10 Emulsion tubes / 55 Idle Jets / 240 Air correction

Thats all i have for the minute


I'd match that DHLA G emmision carb up to the other two for starters. These are the two e-bay sellers I use for parts. The QLD supplier, (RECARB), is a carb shop, pretty well priced and quick. The Italian fella is very good to deal with but obviously shipping can be slower. I've only used EUROCARB once, they are expensive but they do have the parts that are hard to find, (ie I managed to find 5 x 7772.6 emmulsion tubes locally and resorted to getting the 6th one from them).

http://stores.ebay.c...ORS-PARTS-STORE

http://stores.ebay.c...RB-carburettors

http://stores.ebay.c...rto-Weber-Carbs

Sulio

In regards to the G carb (emmision type), you need to match up fixed air bleed to the IDLE JET HOLER (AIR BLEED) on the other two carbs. Refer to info I gathered below for correct size. The ones I have are all 0.9mm size.

This is the "Air Bleed" located on the Idle Jet Holder when looking at the performance universal DHLA40, so with these the actual holder as the hole '(s) in it and acts as the IdelJet Air Corrector. Normally numbered 7850.1 (equal to 1.4mm), 7850.2 (equal to 1.2mm), 7850.6, 7850.7, 7850.8 (equal to 4 x 0.55mm holes). NOTE: with the emmission carbs this "Air Bleed" or "Air Corrector" is a fixed 2.00mm "Jet" located in the "Idle Circuit". There are actually 2 of them in each circuit. Recommendation by the book are to have 1.2mm brass sleeves made up to be inserted to reduce these. I have heard people using 0.9mm for L seires motors.

Sulio



#17 modular9

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Posted 28 May 2008 - 09:16 AM

2 things that helped my idle and up to about 2300 or so

1. vacuum advance off the dizzy. Found it was fluffing about. I dont know if this is because my dizzy is fubar'ed or not.

2. Soft mounts !  ;D Frothy fuel is not good for the carb and idiot that I was I didnt have any on my setup. Great to see the engine shaking its arse off but the carbs being nice and insulated. Gemparts on ebay has softmounts. Made a big difference to the point that the engines condition was the limiting factor in idle rather than the carbs.

Also you will have more luck in finding 55 idle jets than you will finding 52's locally .( eurocarb has 52's i think but exxy ).

Sulio aka "dellorto-king" has this pdf which is real handy . I am sure you got it but he has just updated it.

#18 Scoota G

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Posted 28 May 2008 - 04:40 PM

It can be amazing the difference one day can make.

The D's are running fine as it turn out to be just slight adjustments in linkage and idle mixture. It does hesitate down low but get past 2 grand and hang on.

The sound they make is just Bloody Awesome and the extra power is very noticible.
(But no good if you work afternoon shift at Coles and have trouble with roundabouts ;D)
Anyway many thanks to you guyz and Sulio for all the intel. I just need to keep tuning and they will be 100%.

I posted a pic to   8)


#19 Toecutter

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Posted 28 May 2008 - 06:13 PM

Sulio aka "dellorto-king" has this pdf which is real handy . I am sure you got it but he has just updated it. 


I hope that sheet helps, ah "Dellorto King"!? maybe Mick74 but certainly not me but they sure are great fun hey!

(But no good if you work afternoon shift at Coles and have trouble with roundabouts )


Just to explain to anybody reading this post and scratching their heads, I had a few beers with Scoota the other night at a pool joint as i was in Ballarat and as we were leaving we saw a bloke take out a give way sign and blow a tyre on a round about. We earned some karma browny points getting him going again as he looked like he was in a bit of shock. hmmm...are'nt we nice people, remind myself of that Scienfeld episode with the Pakistani restaurant.

Sulio



#20 Scoota G

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Posted 28 May 2008 - 11:08 PM

ROFL :) ;) :D ;D >:( :( :o 8) ??? ::) :P :-[ :-X :-\ :-* :'(




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