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Discussion Starter #1 (Edited)
Later "early" European delivery Alfas, after the US got Spica in 1969, got Dellorto carbs, in addition to Solex and Weber according to parts manuals. They are pretty common on Euro post-1970 cars even into the mid-80's. Earlier, US experience is mostly, if not solely, with Webers so there is a shortage of knowledge and info (and parts) here. Since more post-70 Alfas are being imported, many Supers, they may have these Dellorto carbs. The "F" and after carbs were known as "low emissions" (and higher mileage) carbs. They have added features over earlier carbs and more complexity in tuning.

Two other recent threads elsewhere discuss distributor vacuum advance and where to take the vacuum feed and Dellortos came up there - LINK1 and LINK2. I have Dellorto DHLA40-H's on my 2L ca-81 Alfetta-engined 72 Super with a Bosch vacuum advance dizzy and OE Alfa EI and it performs superbly and gets 26-32 mpg. +/-. I thought I'd post some Dellorto carb info here as well.

PS: I am no carb expert at all so no tech questions for me, just passing along info.
 

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Oh Alfanuts, this is SO timely. My '73 Super was extensively modified in Holland before it ever came to the US and met me. Once a 1300, it now sports a hot 2000 from an Alfetta, has cams that look quite peaky, includes an aluminum flywheel, and has Dellorto 45s. For a variety of reasons, Nuvola sat for over a year waiting attention (oil pump rebuild, ignition system upgrade, and storage during a move), and when it arrived at the new home, is running overwhelmingly rich - fouls plugs if not driven like a race car. Before the car sat up, my only issue was that it did not like to drive at constant throttle and low revs in first gear - surged. Otherwise, it was a blast to drive.

I've taken the carbs off the car and given them to a SCCA racer who has a shop - he's going to clean the carbs, but he has no real experience with Dellortos. I'll put them back on the car and see if that helps - hope that it helps. If not, I'll have to trailer the car to someone who can resolve the issue I'm having.

So, I'll be watching this thread for any advice.

Mike
 

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Discussion Starter #3
Mine is a pretty stock ca-'81 Affetta 2L engine with tame stock 10548 cams and DHLA40"H" carbs (I have the jetting specs somewhere), a Bosch vacuum advance diazzy and period Alfetta EI. It runs like a dream. No stutter or surge. Gets 26-32 mpg and leaves no soot. Local wisdom is that 45's on a tame Nord engine can be problematic. We have one guy with Weber 45's on his 1600 Duetto and it took all sorts of fiddling.
 

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Wow, I get 20 mpg, it produces lots of soot when started, and it has plenty stutter and stutter in 1st or 2nd gear with constant throttle. I suspect I'll be doing a lot of fiddling. Or maybe I can sneak to my daughter's house and steal away with a pair of the Weber DCOE 40s my son-in-law has in his garage...LOL!

If cleaning the carbs doesn't make the car manageable to drive, there's a shop in Birmingham, AL, who are familiar with Dellortos. Just have to tow it there - only 2 hours, though.
 

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Discussion Starter #5 (Edited)
Funny that my stock '65 1600 with Weber 40DCOE24 carbs gets in the low 20's mpg. It seems the low emissions, high mileage carbs and vacuum advance and EI really makes a difference. The 24's stuttered off idle upon acceleration until we changed up the jetting per Jim Itin's recs. For a street car, I' d tend to find some 40's.
 

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My ‘72 GTV had Dellortos from the factory, it’s an Australian delivered RHD. A lot of the new 105’s of that era did like you say, although interestingly many of the early Alfetta’s reverted back to Webers. Hardly any Solex’s thankfully, if anyone acquired a car with them they were generally ripped off ASAP and replaced with one of the others.

The main reason people stuck with Webers back then was the availability of knowledge and spare parts, in particular jets. At least that’s my recollection after all these years. But by the mid 70’s we had emission rules in Australia that drive the factory to standardize on Dellortos for all the Alfetta’s and all the cars delivered after that, right through to the mid 80’s, had them. Even a 1985 Alfetta GTV 2.0 did. So there are still a lot of them around.
 

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I agree that 40s are more appropriate for a street 2L than 45s, but given that you have 45s you should just be able to choke them down to work properly, right? DLHA 45 chokes appear to be available down to 28mm, and if they're similar to Webers I'd think a 32 would work well on a 2L.

My new-to-me GTV was similarly modified in Belgium and has an Alfetta engine with Dellortos (though they're DLHA 40s and the cams are stock Spica.) So coming from the Weber world I'm figuring out the Dellorto thing as well, though so far it seems fairly straightforward.
 

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But Mad North-Northwest
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I'll also add that if it was running okay-ish when you parked it and now isn't, your main problem likely isn't jetting or chokes. For rich running I'd start by checking your float levels: maybe the needle valve is gummed up and not closing or something.
 

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I'll also add that if it was running okay-ish when you parked it and now isn't, your main problem likely isn't jetting or chokes. For rich running I'd start by checking your float levels: maybe the needle valve is gummed up and not closing or something.
That was my thought too, so I've pulled the carbs and have given them to a SCCA racer who has a restoration shop. He doesn't have parts, but he's going to take them apart and clean them. I'm hoping that is the solution. While he's got them, I'll be cleaning 3 sets of nearly new NGK plugs.
 

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Wow, I get 20 mpg, it produces lots of soot when started, and it has plenty stutter and stutter in 1st or 2nd gear with constant throttle. I suspect I'll be doing a lot of fiddling. Or maybe I can sneak to my daughter's house and steal away with a pair of the Weber DCOE 40s my son-in-law has in his garage...LOL!

If cleaning the carbs doesn't make the car manageable to drive, there's a shop in Birmingham, AL, who are familiar with Dellortos. Just have to tow it there - only 2 hours, though.
[/QUOTE]


Actually, with an engine in this state of tune, 20 mpg ain't all that bad. 45's use gas. Also, keep in mind that Alfanuts/Bruce's car has a vacuum advance distributor on a basically stock Alfetta engine slotted into a Super.

Rather than send the whole car to Birmangham, if the shop knows Dellortos, I think I'd just send the carbs down to them.
 

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Discussion Starter #11 (Edited)
Also, keep in mind that Alfanuts/Bruce's car has a vacuum advance distributor on a basically stock Alfetta engine slotted into a Super.
I have a feeling it's the whole package with carbs, vacuum advance dizzy, mild 10548 cams and EI.

PS: The "Zaagmans" fellow on the ABB knows a lot about these carbs, is passionate about them and indicates he has stores of parts. I imagine there are others in Y'urp who know them well since there are so many there on later Alfas (>'70 or so).
 

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It seems the low emissions, high mileage carbs and vacuum advance and EI really makes a difference.
I replaced classic Webers with the same size emissions Webers on a GTV and immediately gained 4 mpg. When I sold the car the new owner drove it from Charlotte NC to Ontario, Canada and averaged 30 mpg and it had C&B cams and a non-vacuum distributor. I know little about Dellorto's but the big difference between classic and emissions Webers is in the plumbing of the idle/progression circuit and the emulsion tubes.
 

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Discussion Starter #13
On highway driving I get 28-32+ mpg, usually loaded down on a road trip and going fast on an Autodstrada/route/via/bahn.


The articles posted discuss the different plumbing, and, hence, the different tuning of the F+ Dellorto carbs.
 

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The articles posted discuss the different plumbing, and, hence, the different tuning of the F+ Dellorto carbs.
It is important to know that if you are going to tune the carbs.
 

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Discussion Starter #17
Saw this on a FB for sale post: the "N's" have a TPS apparently. He's selling some G's. "I have these N series which are also very cool. With throttle position sensor."
 

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Saw this on a FB for sale post: the "N's" have a TPS apparently. He's selling some G's. "I have these N series which are also very cool. With throttle position sensor."
Hi there, that would be me. And yes, I have multiple sets (Dellorto, Weber and Solex) in stock. Completely restored, factory specs, using only original parts.
 

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If looking for a set of dellorto's try and find a set of dhla WITHOUT any prefix ie: dhla f dhla h dhla g. If you have a modified engine Any alfa dollorto's with a prefix have a fixed air corrector on the idle circuit making it difficult/impossible to tune transition from the idle circuit. Common dhla dellort's with no prefix have a idle jet and air corrector on the idle circuit making it easy to tune the transition phase from the idle to the main circuit. If you have stock or very mild cams the dhla g/h/f all work well.
I hope that makes sense.
Also nearly all dhla dellorto's have compensating screws (as well as mixture and balance between the two carbs) which can be adjusted when using a balancing tool to obtain a smoother idle.

The 'how to power tune' book on dellorto's may be more clear than my late night post lol
 
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