Carb upgrade options

[SubGothius]

I've long been wondering about the most feasible and cost-effective carb upgrade options for my Zagato ('79 2L w/ 30/32DHTA aka "Cali garrote") -- sure, we'd all love to have a special manifold with twin 40s, but I just can't afford to go whole hog like that, at least not right away. FWIW, I don't live in CA and prolly won't in the foreseeable future, and the only local emissions test applicable for my car seems to be tailpipe wanding for CO content. Some obvious, affordable upgrade candidates include: 34DATR/DMTR -- this seems the most widely recommended and available for transverse FIAT/Lancia applications (tho' prolly better suited for the smaller X1/9/128/Yugo SOHC engines?), rarely available used so a bit spendy for brand-new; 38 or 32/36DGV/DFV/DGAV/DFAV/DGEV/DFEV -- seems the most modern carb still widely available and supported, is occasionally mentioned as an upgrade for Lancias, but how well/ill suited are these for our transverse engines? Would I want the DF*V or DG*V (they're mirror images of each other)? Holley 5200/5210/5220 -- Holley's licensed clone of the Weber DG*V (or DF*V?), widely and cheaply available in junkyards everywhere (used on many US 4-bangers), but are there any particular concerns to be aware of with one of these (beyond generic concerns with the DG*V/DF*V design)? 40DCNF (single) -- what about getting a single 40DCNF to bolt onto the stock manifold (will it?), so I could at least start upgrading partway towards dual 40s instead of buying a transitional carb I can't use later? Any other possibilities?

[Shant Fabricatorian]

Yes, I take an interest in this topic too. My stock 34 is leaking from the linkage between the cable mechanism and the carb itself, and while it's not really a big issue at the moment (after tightening it up the leak isn't too serious) long-term it will require a new carb. Only I have the added problem of using mine everyday and stopping at every petrol station I go past is not on...

[SubGothius]

Hrm, sorry to see nobody's jumped in with actual advice on this yet... :( FWIW, I've gathered from reading elsewhere that a single 40DCNF on a stock plenum-manifold would prolly not work well, as carbs used in multi-carb setups (e.g., DCNF, DCOE, IDF, etc.) are intended for one-throat-per-cylinder operation, rather than blending the carb throats' output into a common intake plenum.

However, Shant's mention of his stock 34 has me thinking... Since we Stateside Lancisti only ever got 32s at best or, even worse, 30/32s (!) like mine, I would actually be rather pleased to get a non-US-spec stock 34 on my car as, I'm sure, would others here not taking the dual-Weber or FI plunge. Indeed, I'd suspect quite a few stock 34s are sitting around gathering dust in garages abroad, having been replaced by gutsier single or dual setups or FI conversons, non?

From Brian Long's Lancia Beta retrospective book, I gather that carb'd non-US 2000s (and 1800s? Can't remember now...) came with Weber 34DATR2 or, on later models, a 34DAT2 (what difference does the "R" signify?), or Solex 34CIC variants (prolly less desirable by now due to rarity of parts?), and 1600s came with a Weber 34DATR1 (what does the "1" signify, and would the difference make this unsuitable/untuneable for a 2000 engine?). Given that the only widely-available/-recommended single-carb upgrade offered by major vendors here, short of going whole-hog to dual-40s, is the 34DMTR (same as the 34DATR but sans water choke) also sold for X1/9 upgrades, perhaps we might well make good use of all the perfectly good, still tunable and rebuildable, non-US stock 34DATRs currently sitting neglected abroad?

Anyone have a stock Weber 34DATR2 sitting around that they wouldn't mind seeing in a new and loving home? :D

[Tony K]

I've been mulling the same thoughts around in my head for a while, just didn't get around to writing it.

I, too, would be interested in a stock Monte carb as a slight upgrade over my Scorpion's stock carb. So if anyone across the pond has a good used one to sell, put me in line behind Tye. Really, any suitable upgrade with an automatic choke similar to the stock one will do.

I would also like to know the distinctions between the various carbs mentioned. . . .

Thanks,

[Zagato78]

Me .02. Do the single 40 DCNF. I recently upgraded from the single to twins. The single 40 is THE carb setup for these engines. You will not be disappointed with the power. It frankly, was unbelievable.

You will need to mod your intake manifold. I still have my single that was mod'd. I'll post pics for you if you like. The other carbs are just too small. Combine the carb is a lighter flywheel and enjoy! :P

Dan

[Tony K]

Dan,

Please do post pictures!

Thanks,

[SubGothius]

I would also like to know the distinctions between the various carbs mentioned...Although the meaning of Weber's carb designations are the subject of much lore and speculation but even more puzzlement, a few known/likely interpretations are: D=Dual-barrel;
I=Independent/Individual barrel;
M=Manual choke;
A=Automatic choke (coolant-sensitive);
E=Electric choke (temp. sensor);
O=hOrizontal (side-draft);
N=vertical (dowN-draft);
V=Vertical (down-draft);
T=Transverse (fore-aft barrel configuration with front-/rear-hinged float(s) in narrow bowl(s) when mounted on transverse engines)...
...Do the single 40 DCNF... You will need to mod your intake manifold. I still have my single that was mod'd. I'll post pics for you if you like...Yes, please do post those pics -- perhaps in your Lancisti gallery, to share with the rest of the class for posterity? ;) While you're at it, details regarding jetting/venturi sizes you used and on what displacement engine with what other mods, etc. would be helpful as well -- at least to get us in the ballpark for fine tuning (presuming 1800s would need slightly different tuning than 2000s, likewise for higher compression or hotter cams?). I'm guessing the mod involves some sort of baffle to divide the stock one-for-all plenum into a quasi-dual-plane configuration, porting one carb barrel to cyls 1 & 4, and the other barrel to 2 & 3? 8)

[Tony K]

Thanks, Tye!

...Dan -- would still love to see the single DCNF/manifold pictures!


Next question: forgive my not knowing my own car (haven't had much experience with the mechanicals yet) - but does my 100% stock original 1800 Scorpion have an electric or water choke?

I don't know carburetors very well - have worked with Dellorto and Weber side drafts, all with manual chokes, and that's the extent of my experience..

Thanks,

Tony

[SubGothius]

I'm under the impression, last I'd read, that the first-series 1800s only came with DMTRs, meaning a manual choke (my earlier hazy comment about 1800s with DATRs notwithstanding)... If yours doesn't have a manual choke, then it would prolly be a water choke, as electric chokes were a later development.

Edit: D'oh, I was thinking FWD 1800s re: stock DMTRs, my bad -- 1800 Scorpions may well have come with stock DATR/DATRA (not sure what the final "A" means) using a water choke.

[badboyboogzy]

well my two cents worth is this they are different from ozz and england to the usa if any usa guys want em we have a box of about 25 34/36 datr nd dmtr which are very similar not sure how they will most all need kitting but they are there if anyone wants them im in australia about half are useable as is

renay
bbb

[SubGothius]

Oo! 8O 34/36DATRs? As in, DATR with a 34mm primary and 36mm secondary barrels? :twisted: Hm, that's a mite better than straight 34s, and still fairly thrifty on fuel (esp. in light of rising costs lately)... I may be interested soon; wha'd ye want for one, anything beyond postage/shipping costs? I could even consider taking on the lot for redistribution, or you might consider just eBaying them to Stateside buyers yourself (i.e., on ebay.com not ebay.com.au) if ye have the time to bother?

The single-40DCNF option still sounds appealing as an eventuality, but I'd yet need to afford the carb itself, and DCNFs still fetch a pretty penny even well-used on eBay, and would likely need at least retuning/tinkering to work properly (not to mention whatever manifold mods would be necessary). Also, does the 40DCNF even come with a cold-start choke at all, let alone any provision/option for automatic-choke operation? (Not that cold-start provisions are really critical in local weather, but still as a matter of principle... :roll: )

At this stage, I'm mostly keen on finding the highest ratio of benefit:cost, so if I can get an Oz-spec 34/36DATR on the cheap for now (and with auto water choke to boot!), that appears to be the leading candidate for meeting my own objectives. 8)

BTW/FYI, the earlier-mentioned Weber DGV/DFV/Holley 5200 design appears suboptimal for our transverse-engine application, as Will Holding attests here (http://lancisti.org/forum/viewtopic.php?t=1425#7488) re: his experience with a DGV.

[Tony K]

bbb - I, too, would be interested in a useable DATR, especially one with an automatic choke, for my Scorpion. I had never heard of 34/36 DATR before(?) - Are this lot of carburetors you are referring to the standard 34 DATR ones from Betas?

If you have a good working one, email me with price, more info, etc. at racing_nut_1@yahoo.com

Thanks,

[chrisc]

Hmm. I think my 1500 x1/9 had a 34 datr fitted as standard?

[SubGothius]

...I had never heard of 34/36 DATR before(?) - Are this lot of carburetors you are referring to the standard 34 DATR ones from Betas?...I'd never heard of a progressive D*TR Weber before, either, and had been presuming Betas in Oz had the same spec (34DATR) as their European counterparts, but bbb seems to be saying that at least some Oz-spec Betas had these progressive carbs instead (mebbe as an option or a popular upgrade)?

Euro-spec X1/9s may well have had 34D?TRs; we only ever got 32s or worse Stateside... Only the '74 FIAT 124s ever came with a stock Weber 34, tho' earlier 124s apparently had 28/36s (now that's progressive -- can only imagine the perceptible shift from relaxed, miserly cruising mode when one really dipped into those throttles!), and of course some earlier, pre-Lampredi DOHC models had 34s-36s or the like...

[badboyboogzy]

yip stock as a rock from 1800 and 2000 betas here they also have dmtrs or damtrs or supthin like it on the imports but the most commen is datr i think and i think one other but my 1600 has a dat 34/36 and its and import i rekocn they used whatever was leftover from prvious models ill check out prices as for the 8 that i have they are all in peices and the others ill have to check on but most every beta guy here would hve a least one datr or datra or dmtr or dmtra or some bloody thing i will get what hthey all are there is about 20 25 in a box so i will check themout and let eveyone know but its anzac weekend so dont expect anythim=ng for two days or so pubic hols and such
bbb

[lampinenracing]

Hello.
I have had in two ocassions a serious leak in the carb, seems that with the time and heat the alloy don't stay plane around the front left part of the carb body.
I think that a cheap option about a carb replacement is the 36 dcnvh or 36 dcnva (the same with auto choke) from the Talbot (Horizon, Solara...) and Peugeot 205 (Simca-Talbot 1600 engined).
This carb is very similar to the dcnf and easier and cheaper to find, and could give better performance than the very restrictive dmtr or dat original ones. (it is a two corp simultaneous carb).
Also is a lot of simpler to clean and rebuild (the 34dat have a lot of membranes!)
I was thinking about fitting this one, but at last I am going to fit two 40dcoe carbs from a Alfa 75 in a Guy Croft manifold.
I think that is necessary a very little of machining to fit the 36dcnvh to the original manifold and I am interested in listen if somebody have fited this carb, or opinions about it.

You can view this carb at:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=9886&item=7968642352&rd=1

http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&category=79069&item=7969349106&rd=1

[junior]

If you are wanting a 34 D*TR maybe you would like to view the one on ebay at the moment:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=43120&item=7970557284&rd=1&ssPageName=WDVW

Regards