I am the new owner of a 1980 Iron Duke banger that I am in the planning stages of rebuilding. It will be going into a T Speedster project. The engine came without an intake, and I have a pair of brand-new, never used, Carter-Weber DGEV 2BBL carbs complete with linkage, and considering fabricating a two-carb log intake. Would using both be overkill? I know they are popular with Chevy Stovebolts as a dual setup, but only being 2/3 the displacement, I wasn't sure if the Duke could handle the CFM. I know the 151 is not a powerhouse, but I do plan to use a "street performance" cam, about 255-260 duration. It has a cross-flow head, and I will be running headers. I have a couple of 40mm Mikuni motorcycle carbs (need rebuilt) laying around the shop somewhere...would those be a better choice?
I'd run just one Weber 32/36, or, if it has a really hot cam, one 38/38. I cannot comment on the Mikuni's, but other guys here have used motorcycle carbs on automobile engines. That would take a fabricated manifold, that accommodates hooking one carburetor to two cylinders, preferably that are not in sequence in the firing order. If I remember correctly, the firing order is 1-3-4-2. One carb would feed 1 and 4, the other 3 and 2, which might make for an odd look, but is functionally correct.
the bike carbs would work as you would have to put a balance tube between the carbs even if its 4 carbs , this is how its done on MGs ( and are a pain to synchronize ) and you have to make a longer ram tube , but I would stick with what gimpy says a single will be more than enough . remember the smaller it is the more sensitve it will be to tuning .
One thing to remember about the 2-barrel Webers is that a 32/36 is a progressive 2-barrel, and a 38/38 is a synchronous 2-barrel. With the 32/36, you will be on 1-barrel, unless there is a pedal and vacuum demand for the second one. I ran one for years on a Falcon 144. It kept good economy, but had a nice p***ing gear, when needed. If it is a street cruiser, I'd probably go with that one.
@ El Caballo: The Mercruiser 3.0 (and 2.5) engines are based on the 62-70 Chevy II 153 4-banger. A lot of parts interchange. It was also used in PRE-AMC Postal Jeeps. The "Iron Duke" is Pontiac's 151/2.5L that was produced starting in 77 or 78 that was used in Monzas, Fieros, Camaros, Firebirds, Jeep CJ5/7, AMC Eagle, S-10, and several other makes ad models. It is NOT the same engine as the Chevy II/Mercruiser, and VERY few parts can be swapped between the 151 and 153 without modifications. I've been told different stories about swapping a Mercruiser distributor into an Iron Duke: The Chevy II motor's (153)dizzy shared the gear on the cam with the oil pump at the front of the block, but the Duke's cam has separate gears for each, with the distributor towards the back of the block.....but later Mercs supposedly used separate gears with the dizzy moved back, and they will work in a 151. Can anyone verify this? I need to replace the dizzy on my Duke, and was wanting something with a smaller cap. The coil-in-cap HEI one I have now looks like a coffee can stuck on the side of the block (it needs replaced, anyway).
I had some very cool parts for a 151. I sold them a few years ago and I ran into the guy I sold them to. He still has them, doesn't know if he will use them or not. I can check with him if you are interested. The parts were a Super Duty cross flow head. I believe it had 1.94 intakes and 1.6 exhaust. It will take a 2.02 intake. It has been CC'd and the runners polished, new swirl polished stainless valves. Had dual Weber 45 side drafts, 1.75'' primary ****** header, hot hydraulic cam and the 2 piece aluminum valve cover.I will try to find some pics if I can. All these are brand new, only installed for mock up.
Ran 4 motor cycle carbs on a Pinto motor in a Karman Ghia with an adapter kit from Pinto beans. They were 4 mikuni dirt bike carbs.
I am running a 2.5 in my modified. I had flanges machined and TIGed to the manifold for two Carter YF one barrels. It has a header and reground cam. So far it idles ok, but has not yet been on the road. Hopefully next week.
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