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[Alfa_33_Veloce]

Im stuck. ive looked on the net every where to find out what carbs are on my UK '88 33 1.5ti veloce but have found nothing.

is there sumwhere on the carbs where i can find out what they are. i had a quick look but found nothing.

Please help??????
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** alfa 33 Veloce **

[Guest]

[Guest]

is there a way of telling exactly what they are. Im planning on fitting bolt on carb air filters and the shop needs to know exactly what they are. I cant take it to the shop because its miles away.

[Matt Stolton]

On the 1.5Ti, you will most probably have the Weber 36 IDF, or the Dellorto 36 equivalent. On some later S2 cars they did use up the stock of 40 IDF on smaller engines, with smaller chokes and mains, but as yours is an '88, you will almost certainly have the 36.

Either way, don't just bolt on filters to the top of the carbs. You must fit trumpets, otherwise you will screw up the quality of the air flow into your carb, loosing bottom end torque, and affecting top end power. If you take off the curved castings (which are just bent trumpets really) and just bolt on filters direct to the carbs, the air entering the carb has to get around a nasty right angle. This will lead to turbulence at the mouth of the venturi, and lead to bad gas speed and flow.

Trumpets for the 36s are hard to find, most only go as small as the 40s, but a 40 trumpet, with some light grinding/flaring of the entry into the 36 carb body would be preferential to having no trumpet at all.

Worst ways, the metal castings already attached to the top of the carbs are trumpets, if bent at right angles. If these are carefully polished, and any poor casting defects ground out, these are good enough for most applications. These will be streets ahead of just fitting filters to the carbs with no trumpets at all.

It is also worth considering a cold air feed to each filter. This will give some ram air effect at speed, but also tries to keep the inlet charge temperature as low as possible. By putting filters and trumpets at the top of the engine, you will be drawing in hot, thin air, which will make it a sod to drive around town. To get the best out of your engine, you need cold, dense air, as you can get bigger bangs in the pots with it, i.e. more power. Consider why the turbo boys spends so much on cooling the air post turbo, with there huge intercoolers. Cold dense air is more 'powerful' than thin wispy hot air.

You may be better off revising the existing air box. Lloyd at Clovertech showed me a 1.6 conversion he was doing. Basically from porting the air box and original trumpets/castings, and creating a funnel beside the radiater into the air box, you got nothing but cold air, through trumpets, nicely into your carbs, and it cost only time. Perhaps if you want to go mad, get a good replacement panel filter, but basically, you dont have to go too mad, and spend lots to get major inlet improvements.

You have to remind yourselves once in a while, that the alfa designers were not shite, unlike some of the compromises you see in other marques. Yesterday Lloyd was working on a 1.2 Clio (extended family type bollocks). It has a single injector working on a single 22mm bore. Your 1.5Ti has 4 mains, feeding into 4 36mm bores. You can see how the boxer can get so much more air and juice in compared with other cars.

The only downside of alfa, is build quality. If you carefully revise (grind) any poor castings and port here and there, you will surprised how good the original airbox is.
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Regards

Matt

Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!!

[Guest]

thanks for that, thats helped alot

[Edward]

Hello,

I had the same problem on a pair of carbs. Couldn't find identification marks anywhere. I expected to see some reasonable empossed markings as to what they were. On one set there was a little tab that told me what they were. Anyway, I would suggest the following, get some decent cleaner, I used Gunk as it was all I had around, clean the bottom flange where it bolts onto the block, just on the left hand front corner as you look at the carbs. So, if you were standing the carbs up, you want to clean the flange front as it faces you. There on mine I found a lightly stamped reference to the type of carbs they were. It was a little difficult to see but once I found it it was easy to find it on the other carb.
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The faster the better.