Which carbs do I want for 2x4 MR?

[ERA Chas]

Originally Posted by undy

Yea, I know .... unfortunately there's just no more hood room available for a taller filter. I'm already paranoid of renegade raised man-hole covers

Believe it or not it only lost 15 rwhp at peak over no filter at all.

Then try this for no loss over no filters:

[undy]

That sure looks like it provides a nice big gulp of cool air. It also looks like you have a little over an inch clearance than I do with my current setup. My hood would hit with filters that tall. I sure would like a 3" filter with the same setup I currently have though ...

Anyway, I'm well into the triple digits before it become a horsepower robbing deterrence. Those M/T drag radials sure do hook well when it's 90 degrees outside

Sorry for the side track El... back to regular programmed carb questions.

[ERA Chas]

In deference to El whose thread this is: Mine are custom 1850's which now flow 654 each on a tunnel wedge. Been bullet proof for 10 years, runs 11's and autocrosses too.

To finish a thought for undy: The K&N's are 2 1/4 x 9 and use offset brackets to fit in the scoop opening. We both use tunnel wedge however I don't know if LSC locates the engine where ERA does. The key for me is the pan which has a rolled flange at each carb and the filters sit flat on the pan. There's no height increase. May work for you if you want to play with it.

[elmariachi]

Originally Posted by undy

Sorry for the side track El... back to regular programmed carb questions.

Good info, as I know that once I get the carbs on, then I get to deal with the air cleaner issue as well.

[Argess]

I originaly used a pair of stock 1850s. Two mods are necessary.

#1 You need to connect the vacuum cans together. You can buy the kit, but what I did was to drill and tap the covers and install 90Deg grease fittings with the spring and balls removed. It was kind of neat as teh fittings faced each other, so a short rubber tube was all I needed.

#2 The idle circuit is designed for single carb use. You need to restrict the idle passage or you will probably wind up with all 4 idle mixture screws all the way in, which works satisfactorily.

Eventually, I had Pony Carbs fix me up a pair of new ones. They seem to work the same as what I had, but I do have more range adjustment on the idle screws and they wound up somewhere betwen 1/4 and 1/2 turn out.

[lovehamr]

Originally Posted by ERA Chas

In deference to El whose thread this is: Mine are custom 1850's which now flow 654 each on a tunnel wedge. Been bullet proof for 10 years, runs 11's and autocrosses too.

No stumbling in corners? How'd you do that?

Steve

[ERA Chas]

Vent whistles, .125 viton needles and the right float settings. Keeping the RPM elevated too.

[Argess]

Back to idle restrictions with twin carbs. The idle circuit is set by a fixed jet and is a rough setting. Fine tuning is possible by the adj screws. With twin carbs, it seems that even with the adj screws all the way in, the idle can be too rich. Carbs designed for 2x4 operation should have this taken care of, but if you purchase two carbs, each designed for single oepration, you can have a problem.

The answer is to have a carb shop replace the idle jets with smaller ones, or to insert a fine "V"-shaped wire into each of the jets to effectively reduce it.

Here's a bad pic from Dave Emanuel's book on Holleys:



I found stock carbs did run OK, but with the screws all the way in. I replaced them eventually with units from Pony Carburators and they must have done something to the jets as I can now run with all screws about 1/4 to 1/2 turn out.

[PANAVIA]

Didnt they have a dual carter AFB setup as well --or are my memory banks failing>?