Autolites vs. Webers for Offy

[Anonymous]

Possible hood clearance issues aside, what are the pros and cons for each?

On Carbs. Unlimited's website, they say that the Weber 34 ICH will work for up to 2.0L engines and only flows around 150 CFM, which is a good deal less than a stock Autolite for a 200. It doesn't seem like this would be such a good choice for the primary carb, would it?

I've thought about having an Autolite 1101 as the center carb and two Autolite 1100s for the outers. That seems like it would give good performance while running the middle carb.

One more question, would an Offy be an improvement even if the stock cam was used?

 

[CobraSix]

I'm running all Autolite 1100s on my Offy right now. Autolites are lower profile then the other carbs, but the down side is they tend to be longer, so I had to remove the autochokes on all three carbs to get it to work properly.

I personally would keep them all the same, just for tuning reasons. I did put a Pony Carb 1100 on the center since it was my best running carb.

Slade

 

[Anonymous]

Hi Falco64,

While 150cfm may sound small for a 200, remember that as rpm move up, and flow requirements increase, you will have two move carb comming on line. By the time you need WOT flow, the Webers will be flowing 450cfm in aggregate. More than you need.

I have some concern about running the autolites. They have not proven to be good performance carbs. Idle circuit is poor. Require constant tunning. I think I would go with the Webers. More money, but better carb. I think CobraSix used the 1100's so as to be able to use his very nice, custom, air cleaner. The Weber's will fit under the hood with the air cleaner designed to be used with them. Not as sexy, but not as fussy either.

Just my opinion - Steve

 

[Anonymous]

Actually, the Webers aren't that expensive. New 34 ICH carbs can be had for $125, very close to the 1100 once you add the core charge.

I have 2 more questions:

1) Is it still beneficial to use the Offy with a stock cam?

2) Can a '68-73 dual advance dist. be used or would one with mechanical advance only have to be used?

 

[Anonymous]

Are you looking for more CFM or less? If more is what you're after, why not check a Holley 5200 or a Weber 32/36 (the weber flows 32/36 and has 320 CFM rating). The holley was installed on the older Mercury Marquis 6 cylinders so you can actually buy them from Advanced auto parts or Auto zone. The weber you can find (lot of people use them on Jeeps) at weber.com or webercarbs.com or sometimes on ebay (I got a brand new 32/36 on ebay for $75).

 

[Anonymous]

If I do a major carb. swap, it will be using the Offy. setup instead of the 2 bbl. swap. I was just wondering if the CFM was large enough for the primary carb.

But I still have two unanswered questions here:

1) Is it still beneficial to use the Offy with a stock cam?

2) Can a '68-73 dual advance dist. be used or would one with mechanical advance only have to be used? (If a dual adv. can be used, where would you get the vacuum from: manifold or throttle?)

 

[CobraSix]

1) even with a stock cam, you should feel a difference. Now granted, I higher lift cam will be more noticable (my 260H is great with the Offy). If you wanted to increase the lift without messing with a cam replacement, consider the 1.6:1 roller rockers AzCoupe sells. They will increase the lift of your valves allowing even more air into the cylinders, making better use of the Offy's flow potential.

2) I'm currently using a vacuum/mechanical advance distributor. It works okay, but I would not recommend it. It tends to make the timing incorrect at higher RPMs and I occasionally have back fires through the carbs. One actually caused a very bad vacuum leak I had to fix. I'm in the process of replacing the distributor. If you want cheap, Duraspark 2 is a good replacement. Plug the vacuum port and change the spring and you effectively have a mechanical advance distributor. For more information, do a search for "Offy tuning". There was a long string regarding many Offy tuning questions and the distributor question was one of them.

Another idea, though much more expensive, is an MSD set up. I saw in Jeg's today a timing computer that you can adjust the advance curve and actually get rid of the need for any vacuum or mechanical advance. That set up is expensive, as it requires a MSD 6 ($150) and the timing computer ($100 for fixed, $170 for adjustable) but give you more precise control other then springs. That is what I'm going to do eventually with a DS2 ignition.

Slade

 

[Anonymous]

Hey Falcon64,

The mechanical only set up is the way to go with the triple carbs. You can convert either the dual advance DSII or the 68-73 dual advance dizzy. I used the 68-73 dizzy with Pertronix and I am very happy with the results. The conversion is very easy to do and the performance is excellent. I can send you complete details if you go this way. I think you will be very happy with the triple webers and the mechanical dizzy with the stock cam. As Slade recommended, high lift rockers would be a plus. However, I think the roller is overkill on a stock head. You can't use the rpm potential and you done have a milling / decking valve geometry problem to overcome. You can purchase a 1.6 adjustable rocker assembly with a set of new push rods from Rocker Arm Specialties for $175. I did this upgrade. You can feel the difference.

Good luck - Steve