# school me on running a single dellorto DHLA (1.5L 8v)



## brobs is back (Jan 22, 2008)

ok.. so i picked up a pair of DHLA's (matched and made in italy of course  )
together they were jetted for a 16v making around 150 whp..
since my 1.5L is basically stock and around 75hp i figure 1 should run on it pretty well.

anyways.. i have a single carb mani to go on (just need to drill/tap it for brake booster line)
also i was going to drill through the dividing wall to connect cyls 1/2 to 3/4 so there is no pulsing... right now they are divided.

i ordered a lotus style throttle lever and hopefully it fits the way i think.. right now my throttle cable "pulls" ... and on the dell it needs a "push"
so i believe this lever i ordered will put the pivot point at 180 degrees and hopefully will just swap out and will work with my current throttle cable setup.

if this doesn't work... what are the options for a single DHLA linkage? i found a couple on the internet that can be ordered from europe, but they seem fairly complex and i don't really want to rig up a way for the cable to attach to my pedal.. with my current setup (weber 36 TLP downdraft) i was able to simply cut off the end of an OEM cable so it still uses the OEM attachment on the pedal.

also what is a good baseline setting of mixture/idle on the DHLA? basically the same as with a weber?

sorry for all the questions/blabbering but i'm a sidedraft newb. any tips/links/info is appreciated.


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## B4S (Apr 16, 2003)

Cool, I ran one for a while on my 1.8, the jetting is in the All Carb Diet thread somewhere, lol.

The bad news is that if you're running emissions carbs (most Dells are), it's a bit tougher to jet because it's really not proper for that application . I had all sorts of issues that could have been jetted out, but it would have taken some time. They're mainly too lean at cruise, and under sudden acceleration, so you need to run a very large idle jet (which isn't proper for emissions DHLAs, but works), and an over-large pump jet (in my experience anyway).


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## brobs is back (Jan 22, 2008)

B4S said:


> Cool, I ran one for a while on my 1.8, the jetting is in the All Carb Diet thread somewhere, lol.
> 
> The bad news is that if you're running emissions carbs (most Dells are), it's a bit tougher to jet because it's really not proper for that application . I had all sorts of issues that could have been jetted out, but it would have taken some time. They're mainly too lean at cruise, and under sudden acceleration, so you need to run a very large idle jet (which isn't proper for emissions DHLAs, but works), and an over-large pump jet (in my experience anyway).


they are non-emissions models :thumbup:


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## brobs is back (Jan 22, 2008)

brobs is back said:


> they are non-emissions models :thumbup:


any more tips?

does it seem a good idea to connect the two intake banks? i would think it might help since i need to run a vacuum line off the one side for the brake booster... that way all the vacuum won't be being sucked out of only cylinders 3/4.

would a pic of my current setup and this sidedraft help in any way?

any word on linkage?? as that is my main concern really.. everything else i'll figure out  but i've never dealt with anything other than a straightforward linkage.

also.. is it tough to tune each barrel? i see there is a mixture screw for each one. i'm assuming you basically just tune them evenly?

http://www.dellorto.co.uk/merchandise/products.asp?CategoryID=8&PartsectionID=49
i believe i'm getting this linkage. 
what is the benefit of two throttle cables though? i may only use my 1.


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## jero (Apr 1, 2009)

B4S said:


> Cool, I ran one for a while on my 1.8, the jetting is in the All Carb Diet thread somewhere, lol.
> 
> The bad news is that if you're running emissions carbs (most Dells are), it's a bit tougher to jet because it's really not proper for that application . I had all sorts of issues that could have been jetted out, but it would have taken some time. They're mainly too lean at cruise, and under sudden acceleration, so you need to run a very large idle jet (which isn't proper for emissions DHLAs, but works), and an over-large pump jet (in my experience anyway).


hi any chance of posting your jetting for us including the emulsion tubes i think this would be a great help


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## brobs is back (Jan 22, 2008)

got the carb on.. runs like schit. 

was supposedly setup for 150hp on both carbs (for a 16v)

i figured running one would be fine at about 75 hp (on my 1.5L)

it runs.. but wants to die when i accelerate too fast and has no power in high rpms.
any help out there?


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## B4S (Apr 16, 2003)

Bigger mains, my last single side setup was jetted around 150-160, on a Mikuni PPH 40.

You sure they're non-emissions?  .

How's the idle/cruise?


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## brobs is back (Jan 22, 2008)

well i have no spark now wtf 

anyways.. pretty sure they are non-emissions.. how can i tell for sure?

they idled just fine when they were running. then i messed with the timing/mixture a bit.. it got worse then the car died. checking around now... i have no spark. which i think is just coincidence.

i tried a new (used) ignition control module.. no luck.. and tried a new (used) coil as well with the same result. i'm thinking possibly the hall sender took a crap? or the ignition switch? the ig switch is brand new :banghead:


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## brobs is back (Jan 22, 2008)

what about vacuum advance? i have no port for it on the carb so i ran it off the line going to the brake booster... before the check valve.


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## B4S (Apr 16, 2003)

If there's no port, then it's 75% likely they're non-emissions. If the nipple was broken off (had one of those), the hole would be plugged with some epoxy or something. If they only say DHLA40 on the top, with no letter afterwards, or have a C or E...then you're good to go. Any other letter will be emissions.

The vac advance on the dizzy needs a ported vac source, regular manifold vacuum (like at the brake booster) won't work. The timing curve would be waaaaaaaaaaaaay off, but the car would still run.


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## brobs is back (Jan 22, 2008)

so what should i do about the vacuum advance? 

it just says DHLA no letter afterwards


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## B4S (Apr 16, 2003)

Leave the advance unplugged. It'll still advance on it's own, there is a centrifugal part of it that will allow for a basic ignition curve, but you'll lack the cruising and part throttle advance. Your fuel economy will drop a bit, but there isn't much you can do about it . Even going to an MSD setup won't help, because it's also only a 2D curve. You'd need to either run emissions carbs (to get the vac port), or an electronic ignition that allows for MAP or TPS-based mapping (megajolt, electromotive, etc). CIS-E Knockbox ignition will work fine with manifold vacuum however, so it's a cheap option .

You've got non-emissions, definitely. What are the jets/tubes/chokes, etc?


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## brobs is back (Jan 22, 2008)

i have no idea at all.. where should i look on them for the info?

and the 2nd carb has a vacuum port on it.. perhaps i should have used that one :banghead:

i can snap a pic tonight


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## B4S (Apr 16, 2003)

Wait...the other carb has a vac port on it? Is it coming out of the side or the top?

Does it say DHLA40 on it with no number? Emissions carbs have ports...non-emissions carbs don't...

I sure hope you don't have a mixed set .


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## brobs is back (Jan 22, 2008)

the serial numbers are one right after the other.. so not a mismatched set.
and yes.. it says 

the vac port is coming out the side by the throttle rod. i will snap a pic to show you.. might make more sense. 

i don't even think it says DHLA40 just DHLA


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## brobs is back (Jan 22, 2008)

*sorry this took so long. the car sat in the street with no spark for weeks. finally got that sorted with a new distributor and got it running again. *

ok well i was wrong.. 
i was told when i bought this set that they were non-emissions models. 









it appears they are DHLA 40 N (the N is stamped so lightly i didn't see it before... i figured it would be cast like the rest of that part)

so i got it running/driving... occasionally when i go to WOT from idle it wants to fall flat on its face... and when i get under load it has no power.

here is the jetting:

the engine is a stock 1.5L with open 2" exhaust and a 1.6L head/cam (slightly hotter cam)









stamped "62"









bottom stamped "160"









top stamped "195"









stamped "80"

any help would be appreciated. i'm pretty much lost at this point.

i figure i'll swap on this carb that has the vacuum port so i can run the stock vacuum advance on the distributor. but i still need help on the jetting :banghead:


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## B4S (Apr 16, 2003)

Ok, at first glance, they seem to be jetted reasonably well for single-use. The issue with emissions carbs is that they are really not meant to be used as such, so jetting them is going to be interesting. I managed to make it work on my car, to the point where it was reasonably driveable.

Emissions carbs have a large flatspot at the transition point from idle/cruise to WOT, so you'll have to tune around that. The 62 idles are obviously someone's way of tuning that flat-spot out (it's a common emissions-carb mod, although not the best way to do it, as it then defeats the benefits of the emissions-body). I can't remember exactly what idles I ended up running, but I can tell you that it was always a compromise between half-decent cruise and eliminating that flatspot. The 162 mains with 195 airs are pretty close to what I ran on a high-comp 1.8, so maybe you've got too much fuel at WOT?

A wideband is a really important tuning tool for someone working with emissions carbs, IMO. It's very tricky, especially in a single-use. What emulsion tubes are those? If they are not .8, .9, .10, or .11s...then it's pointless to try to tune them because the other tubes won't work properly. I had good luck with .11s, and the .10s start a teeny bit earlier (but do essentially the same thing as the .11s).

That jet marked 80 is the starter jet, don't worry about that one, since it's only active when the cold-start choke is operating.

[edit] I was running .11 tubes, 60-65 idles, 160 mains, 34mm chokes, 42 pumps, and 170-180 airs.


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## brobs is back (Jan 22, 2008)

i believe the last digits on the emulsion tubes were stamped "11"

what is the "42 pumps" ?

i wonder if most of my issue is from not having the timing vacuum advanced under throttle?

i would believe it was rich, because it smells like gas when it's running.


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## B4S (Apr 16, 2003)

42 pumps refers to the size 42 pump jets. These are where the engine gets its fuel from when you make sudden sharp changes in throttle position. Acceleration fueling, by a different name.

.11 tubes is a good thing, one less variable to worry about.

If there was vac advance, you'd have a bit less of a bog in transition, but it wouldn't be that much different than running the way you are now. 90% of the modded carbed cars out there (and MANY aircooled cars) all run without vac advance. A lot of the aircooled cars never even came with it (although that's why the fuel economy sucked  ). The Bosch 009 dizzy is a prime example of this. It's one of the 'standard' dizzies that the air guys love...but has no vac portion. The bog is always going to be there, due to the emissions carb, but it can be minimized. I'd start by getting a slightly smaller main jet, try a 155 first IMO. That might sort out the top end gutlessness, and then you'll have an easier time sorting out the lag between cruise and WOT.

Wideband?


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## brobs is back (Jan 22, 2008)

found the pump jets.. they are 42.

where would i hook in a wideband?


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## B4S (Apr 16, 2003)

In your exhaust, after (or in) the downpipe.


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## brobs is back (Jan 22, 2008)

right.. but i don't have anywhere to do so in the system.


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## brobs is back (Jan 22, 2008)

so what would you do without a wideband?

am i stuck buying a bunch of jets and just trying them out?

i really wish that this carb wasn't emissions like i was told when i bought it :banghead:


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## B4S (Apr 16, 2003)

I'm confused, you don't have room for a wideband in your exhaust? :what:

Without a wideband, you will have to tune it the old fashioned way: Plug cuts, plug color, and seat of the pants. This is going to mean a LOT of extra jets, or some really small ones that you can drill out until you find the right size.


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