Progressive Weber carbs. Options

[JoeSharp]

Last weekend at The Roar in Daytona I saw a 914 with 2 progressive Weber carbs. Not that I haven't seen that before. This one was done by using 2 of the single manifold plenums with tubing for a spacer in the middle. This guys name is John and I told him about this board.
Sorry, no pics. I cary my camera now so that won't happen again.

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[veekry9]

6 banger?

[JoeSharp]

No, the 4.

[Dave_Darling]

Someone posted a scan from an ad for such a setup a while back. I think the ad was in one of the VW magazines back in the 70s or early 80s.

--DD

[SirAndy]

Someone posted a scan from an ad for such a setup a while back. I think the ad was in one of the VW magazines back in the 70s or early 80s.

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I remember seeing that too ...
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[URY914]

I remember the ad also. VW & Porsche was the mag I believe.

[IronHillRestorations]

I have a parts car in my barn (4 cyl) with two progressives on it.

I've always wondered how that set up would perform. With the correct jet and venture package, I'd think you should be able to get good fuel economy and good wide open power.

[Eric_Shea]

That guys on Facebook Joe...

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[maf914]

Last weekend at The Roar in Daytona I saw a 914 with 2 progressive Weber carbs. Not that I haven't seen that before. This one was done by using 2 of the single manifold plenums with tubing for a spacer in the middle. This guys name is John and I told him about this board.
Sorry, no pics. I cary my camera now so that won't happen again.

(IMG:style_emoticons/default/thisthreadisworthlesswithoutpics.gif)

I saw this 914 and its unusual carb set up at the Roar last year (Jan 2014). I briefly talked to the owner who was a bit busy with another group, so I didn't get a chance to quiz him about the dual carbs. The arrangement was as you describe.

I thought I saw his car (medium blue) again this year parked near the infield grandstand at the east horseshoe turn, but we were on the way to the paddock and I didn't stop to check it out. Same with the black 914 in the Porsche park. Then, on the way out of the paddock heading for the west horseshoe, I forgot to stop. (IMG:style_emoticons/default/confused24.gif)

[mrholland2]

Sooo, this idea is using two of the (normally crappy, center mounted) Webber progressives mounted where the (not crappy, variety) carbs would be with the short intakes?? This sounds interesting . . especially with the idea that the primary would be small and economical, especially at steady cruising and the secondary could open to kick it in the pants.

How would this work? Are there short intakes that would line up?

[monkeyboy]

Sooo, this idea is using two of the (normally crappy, center mounted) Webber progressives mounted where the (not crappy, variety) carbs would be with the short intakes?? This sounds interesting . . especially with the idea that the primary would be small and economical, especially at steady cruising and the secondary could open to kick it in the pants.

How would this work? Are there short intakes that would line up?

Yes, It's not necessarily the carbs are crappy, but the placement in the center is crappy. Anything you put there won't run well. Moving them outboard solves that.

[DBCooper]

You're probably thinking of this:

(IMG:http://www.914world.com/bbs2/uploads_offsite/i379.photobucket.com-2618-1421203120.1.jpg)

They weren't bad but the Weber/Dellortos were better. More info in a thread here: http://www.914world.com/bbs2/index.php?showtopic=224951

[veekry9]

The same Chuck Beck I would guess.He's an innovative guy,all kinds of great ideas for as long as I can remember.Since the '60s and 70s.

http://www.beck904.com/
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https://www.google.ca/#q=chuck+beck

https://www.google.ca/#q=progressive+5200+carburetor

https://www.youtube.com/watch?v=j4qflAXIsZE

[ThePaintedMan]

So basically that's the same type of manifold that the dual ICTs use, with the same problems - Racer Chris has explained this to me before, but the firing order of the Type IV is such that sharing the same intake plenum is sub-optimal. However I'm sure this is better than a single Weber Progressive, if not much harder to tune.

Weber IDFs all the way.

[DBCooper]

Yup. In the T1 and T4 engines each head fires both cylinders (4-3, then 2-1) so you have the carburetor on one side of the engine supplying fuel to two cylinders in succession, then sitting and waiting while the cylinders on the other side of the engine fire. That means you have the first cylinder affecting the flow of the second one beside it, not best for flow. At idle you can actually see it as a standing wave right above the carb throat, called "the inversion effect". It's not the carb that's the problem, they're actually pretty good carbs, just not on a flat four. It's really the problem of two cylinders sharing a single carburetor and short runners. In any case dual progressives died, just like dual ICT's (or Kadrons)

The problem of any center carb on a flat four with unheated manifolds is different. Again it's not the carb, it's the extended length of a cold intake runner to the head.