Dellorto Vs Weber

[Zedrally]

Originally posted by Gav240z

Anyone had experience with tripple SU's on a 240z? Someone was asking me if I wanted a set but am unsure any suggestions?

Thanks

Gav,

There is a thread on 3x SU's, even though it sounds like a good idea, the results appear inconclusive.

This appears surprising as I had thought increasing the volumetric capacity would have corresponding increase in get up and go!

[Bruce Woolmore]

no they are not the same - pretty sure the carb mounts are, but that's it - jets, tubes etc all different and non-interchangeable.

[ozlime240z]

No they are not the same. They will mount to the same Intake Manifold, that part is standard, but little else is the same. They operate very simliarly tho.

Here is how I see the common carbie brands. This might not be 100% correct so guys correct me where you see I'm wrong.

- Dellortos were made in Italy, hence can be found on allot of italian machinery dating back to the 70's. Lancias, Alfa, Ferrari, Lambos. That sort of stuff.

- Webers were made in Germany (maybe elsewhere under license) and can be found on allot of German Machinery. Porsche, VW, Early BMW. And Also Ferrari / Lambo etc even tho they weren't German.

- Holleys were made in USA. Don't know what they came on originally but they where Huge after market. Still are.

- Mikunis were made in Japan ?? I think?? So they were the Jap performance Carbs. Found on the Jap performance cars of the era.

From a simplistic side of things, these four carbie manufacturers where very similar. They all had had side draft and down draft varieties and would bolt up with the same bolt pattern inlet manifold for their respective sizes (40's 45's etc) and type (side, down). Their operations where esentially similar (they mix fuel and air ) but I don't think any parts where interchangable.

But yes, an aftermarket triple carb inlet manifold will work with carbs from any of these 4 manufacturers. They bolt up the same.

OzLime240Z

[MicksZ]

I am a staunch Weber man myself - although they can be a pit hard to tune and can get expensive to get jets etc.

Mikuni & Dellorto Carb's are both Ok but I think you will find it harder to get jets etc for these in comparison to Weber carbs.

From experience Mikuni Carbs stay in tune a little better than webers though.

My 2 cents....

[Bruce Woolmore]

but Webers are as Italian as spaghetti!

also, did Holley ever make a side-draught? not with a weber bolt pattern, anyway!

[datfreak]

mmmmmmm spaghetti........

Just reliving a old post..

If someone bought webers/dellortos could he/she get the jet/tube etc sizes off someone else who has already got their set dyno tuned??? If the motors where similar- ie similar cam /head etc???

any thoughts??

Dyno tuning can be very expensive, and if everyone posted their tunes on here, perhaps we could make a database on the different states of engine tune VS weber/dellorto tune...

[Z 4 Z]

I can't tell you how great these carbs are to work on. They are pretty simple for the most part, with a sound that will turn heads. I have the Dellorto 40mm carbs on my 70 240 (L28) mated to a TWM intake manifold.

I was skeptical about the carbs when I fist got them, but I found that they were easier to adjust and more reliable than all of the other carbs.

I am by no means an expert on carbs, so I was pretty amazed that they were as easy to rebuild as people said. I am still working on the art of tuning, but they are balanced and they run like hell.

You can purchase the carb rebuild kits from CB performance (Superformance) out of California. This shop is fantastic. YOu can get just about anything you need.

Here's a pic of the dells on my ride:

<http://www.classicZcars.com/photopost/showphoto.php?photo=9419&password=&sort=7&thecat=500>

Good Luck!

Dan Zimmermann

[Handiman]

Gav,

There is a thread on 3x SU's, even though it sounds like a good idea, the results appear inconclusive.

This appears surprising as I had thought increasing the volumetric capacity would have corresponding increase in get up and go!

I'd thought of this myself but during research discovered that a triple SU setup simply won't work.

The reason appears to be realated to the firing order in as much as induction duration or pulse time is radically different between 1&2, 3&4 and 5&6.

Not a problem when using twin carbs/manifolds with a balance pipe but when you go to three inlet manifolds you just develop overwhelming fuel mixture variations between the three cylinder groups and even between cylinders in the same group as the airflow slows down and speeds up thus causing the fuel/air mixture to seperate out. This apparently because of inertia ie air molecules have less inertia than fuel molecules so accelerate quicker when the mixture is accelerated upon entering a new induction phase.

I guess this is why all the go mods opt for triple dual throat ie one throat per cylinder....all induction phases are then identical duration and timing.

Hope this helps