44IDFs on a 1438

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bartigue
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44IDFs on a 1438

Post by bartigue » Fri May 17, 2019 6:17 pm

44IDFs on a 1438

Discuss. I know the "they're too big" argument already. My thought is that a small venturi - 28 or 30 - will create enough air velocity to make them work, and they'll be jetted down some, but if it works should increase the torque and just be a lot of fun.
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Brad Artigue
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friedman
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Re: 44IDFs on a 1438

Post by friedman » Sat May 18, 2019 8:32 am

Sounds to me like you already have the 44s and want to justify the purchase! Do you have a proper 44 intake manifold? I can't really ad anything technical to the discussion but will note the Brits seem to stick 45 DCOEs on everything including motors under 2L.

Not sure what you gain if you are going to choke down on the venturis.
Carl in Virginia
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miker
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Re: 44IDFs on a 1438

Post by miker » Sat May 18, 2019 9:18 am

Not to point out the obvious but if they could never work they would not make them. Pierce Manifolds sells 28s. I would start with 115 main jets.
MikeR (mirafiori.com since 1995)


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Re: 44IDFs on a 1438

Post by bartigue » Sat May 18, 2019 9:32 am

Carl - Absolutely trying to justify having them, plus Andy hogged out a waffle top for them, making them hard to resist. The venturis are choked down to increase air velocity, which needs to be high when using a large carburetor on a smaller engine.

Mike - I agree. Even ancient posts on Mirafiori reflect use of 48's on 1608cc engines, so a 44 on a 1438 doesn't seem that nutty. The 912 guys put 44's on small VW engines, so I'm not totally nuts yet.
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Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
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Re: 44IDFs on a 1438

Post by miker » Sat May 18, 2019 10:19 am

Some interesting discussion of throttle plate angle in the 44s with small venturis vs. smaller carb with same size venturis. That may be where the tradeoff is. https://www.thesamba.com/vw/forum/archi ... index.html
MikeR (mirafiori.com since 1995)


1977 Fiat 124 Spider
Previously owned:
2012 Fiat 500 Prima Edizione #236 (now owned by my son David)
'86 Bertone X1/9
'81 Fiat Spider 2000 #236
'78 Fiat 131 four door
'76 Fiat 128 4 door
'74 Fiat 128 4 door
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Re: 44IDFs on a 1438

Post by davedecker4 » Sat May 18, 2019 12:38 pm

It only makes sense if you're going to run a totally built engine of the race type variety starting with examples from CG book. I'm not quite sure if that's your style. I would likely put them on a built 1800 or 2L and put either a larger single carb or dual 40's on the 1400 with mild build focusing on porting and balance with some compression. You might be a little happier with that. Especially so after getting initial setup dialed in. You may be able to find someone to trade so they can move up to more power. Might keep you both happy while spending less money. Just a thought.
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Re: 44IDFs on a 1438

Post by friedman » Sat May 18, 2019 5:29 pm

Of course the only real way to know is to slap those babies on and see what happens. When I got my first IDFs, there were a lot of guys who said they would not work on a stock spider motor...…..that was clearly not the case for me and I have been enjoying twin IDFs ever since....I even put them on my 128s and a pair will go on my X (if I can get a replacement motor for it).
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Re: 44IDFs on a 1438

Post by davedecker4 » Sun May 19, 2019 1:20 am

Wouldn't DCNF fit the X and 128 better? They work well in the Scorpion. Perhaps the Dino crowd could expound on the relevance of carb to engine direction.
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Re: 44IDFs on a 1438

Post by friedman » Sun May 19, 2019 8:15 am

Agreed but I like IDFs, they are my comfort zone.
Carl in Virginia
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