Carb Choice on 1904

[hulbyw]

Have been gathering parts for my engine build for a 1968 Beetle. Wanting an easy to start and drive torquey daily driver. Was originally going to be a 1776 but I bought the 74mm crank in a moment of madness (so don't have to use)

New VW case
Mahle 90.5 (with Total Seal style rings)
74mm Crank
Scat C25 Cam
1.25 Rockers
CB HD aluminium pushrods
123 Dizzy with vacuum
Rebuilt OE rods
OE DP heads with standard valves, Berg HD springs, flowed and match ported to OE manifold ends
9.3 to 1 compression (easy access to 98 octane petrol)
Stock doghouse fan housing
Heater Boxes
Lightened flywheel
Full flow
VS Sport exhaust with provision for heat risers
Thermostat with flaps
Copy Berg equaliser
Stock rebuilt transaxle

I have a Weber 40DCN with heat riser manifold (was on a VW with unknown specs), 2 x 36mm Weber IDF's (off an Alfasud and not yet modified) and a stock 34 PICT 3 on the shelf.

For simplicity I am favouring one of the single carbs. Interested in engine builder's constructive opinions and if the PICT is a likely contender, what would I need to do to it to make it work (happy to get a CB centre section).
Cheers

[oprn]

What is it going into?
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)

[hulbyw]

Beetle

[Alstrup]

It really depends on which carb set up you decide on.
With the C25 & 1,25 rockers I´d say flow optimized dual 36 IDF´s. they are great little carbs that can relatively easy be modded to support more than that longblock has potential for.
Drop the sgl 40 DCN. Its never going to be really good.
Modified 34 mm Solex is right down my alley. In that case I´d say drop the cam and get one that suits such set up better. - I mean, the C25 will make the engine run, but the behaviure could be better. It depends on which engine behaviure you want. The very easy solution cam wise would be to use a CB 2280 or 2232 with 1,25´s. GOOD lower rpm power, not much above 4000.
I have been a little "around" after CB changed the duration of the 2239 cam, but I have sort of gone back to it, but on 110 LC. It simply is one of the best US cams for such a set up if you want good overall power and a good clean idle.
Last, the 123 vacum distributor ought to be swopped. The basic versions are for basic engines. You want a programmable, or you will almost be in a worse situation than if you chose a cheap 009. The 123 bluetooth is very popular because you can program it from your phone or a tablet or even an Ipad I believe.

Also, if you decide to use the Equalizer you should use a flywheel of no more than 13 lbs or the engine will be a dawg. Too much rotating mass and at too large a diamete will kill power big time...
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[oprn]

[hulbyw]

Thanks Alstrup. Should have said the 123 is bluetooth programmable.

Are there useful mods for the 34 PICT that I can do myself or get a local VW shop to do? Perhaps you sell modded 34 PICT 3 and can ship to Australia?

Unless it was a show stopper I would prefer not to have to drop the C25 as I already have it. Beetle will be used as a road car so no fuss, easy to drive with a bit more power and torque is the goal.

I will weigh my flywheel to check the weight before deciding on the Achiever.
Cheers

[hulbyw]

[Alstrup]

[Cusser]

I run an 1835cc DP engine with a 1976-purchased single Weber 40DCNF carb on it. Like it. Since 1976.

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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[Ohio Tom]

Agree with Al... 100%.

Anything less than the dual 36's, you defiantly need to drop the cam or you won't have a powerband at all really. The stock, and DCN carbs will be out of flow right when that cam is starting to work.
It will will be a depressing motor... Been there before.

You have all the parts listed to make the 36's the best choice.
When setup and tuned, it will run the best of all the choices, both light load and full throttle will be better...

[hulbyw]

Thanks for your input folks. Appreciated.
Cheers

[slalombuggy]

I have a 1904 in my buggy

Revmaster 40x35.5 heads as cast
9.3:1 compression
Engle 110
1.25 rockers
Stock flywheel
Pertronix billet distributor

Dual 40mm HPMX carbs

Absolutely the most fun engine I've ever built

[boxer74]

Kadrons?
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84 Westy

[Lingwendil]