MIKUNIS VS DELLORTOS VS WEBBERS

[benny]

Hey Guys,

 

One of my mates has a set of tripple Mikuni/solex 45 carbs whats the opinion on Mikunis vs the other carbs??

 

Thanks Guys

 

Ben

 

 

[Toecutter]

I think it's much of a muchness the only differences will be whether you go for 40's 44's or 45's re performance (although really dapends on how modified your engine is on potential gains by going bigger!?). Just keep in mind spares availabilities. I believe Webers are easiest as far as sourcing parts goes. I've got Dellortos on mine and I've been able to find all the jets I've needed although it can be a bit tough when it comes to finding stuff like certain emmulsion tubes, for example I got my hands on 5 off 7772.6 tubes for $50 and could'nt get my hands on a 6th so had to resort to paying $36 inc shipping to get one from Eurocarb.

 

I have'nt had much to do with Mikuni's but I imagine parts might be a little harder to find in Australia especially if you buy those early Solex carbs.

 

Dellorto's are usually cheaper than the Webers but I've heard they can require less upkeep re tuning than Webers although soemone with experience with both might have a better idea.

 

Sulio

[benny]

Thanks Sulio.. so in regards to 40,44,45 mm i presume 45 sucks more air the 40's??

 

Thanks

 

Ben

[Scoota G]

The biggest part about discovery in the engineering field is to throw everything out the window and be prepared to make mistakes.

There is no set formula for ANY engine or car and if one would think that they could do something as simple as join a forum and get all the Answers you need then think again.

The pioneers of motorsport had no one to ask and spent more money than the National Debt of all countries combined.

 

Try stuff and see what you can come up with. I think that if anyone here was an expert this forum would be locked down to a PDF on Z's

 

I could not think of anything more boring than that

 

My Bad

[NZeder]

Don't forget the Japanese OER carbs - ie SK replacements ie New Mikuni's with Weber jets and tubes. I believe a guy here in NZ has flow benched these vs new webers from spain and the OER flowed 63cfm more than the same size weber ie both 45 units. This is one of the reasons I had them on my late 240z road/race car.

[reverendzed]

Hey guys, without hijacking the forum, I'm not sure where Scootag is going...maybe he can elaborate!  I don't think Dzeyene was asking too much seeing that Sulio and others have already taken the triples route using a variety of carb setups.  It has always been my thinking that this forum/club has grown so well because of the desire of its members and adherants to freely share information so that people don't make the same mistakes and save money in the process.

Rev.

[Scoota G]

Yea i did rattle on a bit but to sum it all up what work for one application may noy work for another and i don't think with different manifolds, displacement, cylinder heads, emission and non emission carbs and even location that there can be a set formula to tune a car. What works on one car may not work as well on another

[Toecutter]

Thanks Sulio.. so in regards to 40,44,45 mm i presume 45 sucks more air the 40's??

 

Thanks

 

Ben

 

Hi Ben,

 

Before I go on I just want to say there are other people on this forum that know alot more about these carbs than I do but I will try to help as best I can. In response to your question the easy response is 40's are big enough for a stock L-series motor with alot of people installing 32mm chokes to maintain drivability down low. It's as much a question of what chokes you install as it is how big you go on the carbs, ie you can buy 45mm carbs but choke them down to say 34mm chokes or you could go the other way and buy 40mm carbs and install 34mm chokes getting a very similar result.

 

There is so much to be said on this topic that would go way beyond my knowledge base so I try and stick to the basics as I understand it based on research and trial and error.

 

With choke sizes just keep in mind that the size influences air velocity which means smaller chokes gives more air velocity pulled into the combustion chamber when inlet valve opens. If you have big carbs you will get slower velocity at low revs, these set ups are good for engines with hot cams that have a higher power band as with alot of track cars, (ie they spend most of the time at the 3500rpm and above range so works well for that sort of driving). When you have chosen the size of carbs you want then you will need to select the right size idle jets, for idle and progression, right size main jets and emulsion tubes for mid to upper range. I have prepared a spreadsheet based on my reading and set up, look in the carbs section, it's not going to tell you which carbs to buy but might help in starting.

 

I am pretty confident that I have a very good starting point for an L26 or L28 motor and that is:

 

Dellorto DHLA40's with:

32mm chokes

55 idles

40ish pump jets

125 to 130 mains

7772.6 (or .7) emulsion tubes

 

refer to the spread sheet in the carbs section for other details, ie main venturi, air bleed on transition circuit etc.

 

If you want to go down the Dellorto path send me a PM and Ill put you onto a guy in Italy who will sell you all three already rekitted for a really good price, (you will then need to buy manifold $300, linkage kit $200, soft mounts $75.00, velocity stacks $225 from memory and filters prolly about $150 for a set) . So before you start to tune them it will cost you about $1500 (+ all the new jets you will need as you tune). You can tune them yourself to a cetain degree. I must admit I'm pretty happy with how mine go, better than the SU's with no hesitation anywhere like some people have had issues with. It has cost many people I have spoken to around $2000 to $2500 all set up including tuning on a rolloing road.

 

Sulio