Dual carb on a 79

[bradartigue]

What is it about the 1608 that makes it work well with the IDFs? After so many years of horror stories about dual carbs, I've been amazed at how well my (Euro) 1608 runs. The IDFs have really been "set it and forget it". Apart from a tiny hiccup through 3000 rpm on part throttle, they pull cleanly and strongly, I average about 27 mpg (US), they sound great and posted quite good values on the last emissions test.

Mainly because the 40IDF was designed for an engine of about 1600cc, the motor revs up and down quickly, and the cam profile is different. 40IDFs run well on both the 1438 and the 1608. On the other motors I'd rather fuel injection or a single carburetor.

[BEEK]

having done about every carb combination on a fiat twin cam, and having raced them too.
i loved the 40idf on my 1608, the 2.0l cars i have built have doine the 40idf, the 45 dcoe, and 40 and 42 dcnf's, the all out race motors on 45 dcoe were very good, but my favorite was the single 40dfi, that carb rocks on a built fiat twin cam. you do have to relearn how to drive, because it is on and off, there is no subtle acceleration, but it cruses well. just my .02

[So Cal Mark]

we've done a few of the 38dges carbs on 2L motors, and there is a slight learning curve on how the get the best acceleration but they have a monster top end

[BEEK]

i am assuming a 38dges and a 40dfi would behave the same way, just have never used the dges.

[RoyBatty]

I too am wondering if I am just one of the lucky ones.
My idf clones are running great on an 1800 in my 75. No internal mods to the engine. Just a 4-2-1 exhaust and pertronix module.
I can go outside in 30 degree weather, pump the accelerator 3 times and the car starts up fine and I set a high idle with the hand throttle cable. No chokes. I drive it easy until temps come up, which doesn't take long at all, and then off we go.
I fully expect to have to fiddle with them every now and then as linkage wears. But for the benefit of the experience of driving them and the way they livened the car up, it is a small price to pay. And worth it to me. I love to go and tweak and fiddle without having to use a multimeter and test light, or a computer code tester.
By the way, now that I have the jetting and such dialed in, should I expect to have to go a bit leaner when the temps here climb back into the high 90's?

What is it about the 1608 that makes it work well with the IDFs? After so many years of horror stories about dual carbs, I've been amazed at how well my (Euro) 1608 runs. The IDFs have really been "set it and forget it". Apart from a tiny hiccup through 3000 rpm on part throttle, they pull cleanly and strongly, I average about 27 mpg (US), they sound great and posted quite good values on the last emissions test.

[So Cal Mark]

lean mixtures and high temps don't make big power

[RoyBatty]

I understand that Mark,
Based on my experience with aviation, hot days require a leaning of the mixture even at ground level as compared to cold dry air in the winter.
I was wondering if the IDF's are that finicky to seasonal atmospheric changes?