Dual carb air cleaner clearance

[911pickup]

I've decided to ditch my old, stock carb and replace it with a set of dual 40 Webers.
Before I took the body off the pan I noticed that there was not a whole lot of 'head space' where a dual carb setup would go. So, I'm wondering what sort of clearance you guys, with dual carb setups, have?
I'm thinking there is a good chance the stock air cleaners on a set of Webers won't fit under the body.

I guess I won't really be sure until I fit the body back on the pan.

[YDBD]

here you see the engine with dual double EMPI's with standard filters that fit pretty well. There are brackets that hold the body out, especially on the right side as the cylinders are offset more towards the rear of the car. My tail lights are also inset into the body so more clearance problems.

I thing you should be OK with the VW Bug tail lights

I can go measure if you need, as the body looks the nearly the same.

[wythac]

I have a set of Berg DCNF 42s on my car, but since I have a 3" lift they fit fine..but when installing the motor the linkage mounted near the top of the shroud needs to be depressed to get it past the rear lip on the body, and I install the carbs and intakes after the motor is in. I'd look for a system that uses linkage at the belt line of the carbs and intakes rather than up top.

I guess to figure out an application to your car, see if you can find someone here who runs duals that you like that can measure for you the height of the carb,intake and air cleaners above the engine tin on each side. Should be a big help.

I can measure the height of mine for you if you'd like but my kit is a little unusual so I'm not sure that info would tell you much that would be useful. PM me if you'd like me to measure and send that info.

[YDBD]

From the cylinder shroud flat at the center of the intake measures 13 inches to the top of the filters. From the center of the filter to the back edge is 3.5 inches.

Hope this helps.

[911pickup]

Thanks for the responses. I plan on installing the 40 Webers now, but I won't be putting the body back on the pan for another month or two.
I'm lucky I have a hoist, so I can put the body on the lift, roll the pan underneath the body and slow drop the body onto the pan. It will be easy to check for clearances and I'll be able to lift the body back up if I have any issues.

[joemama]

When I had dual 40 idf on my almost exact Manx clone, I needed a 2" body lift, as well as shorter manifolds. My buggy had led tail lights, like you see on semi's, held in the body by rubber grommets, and I had to pop out the lights to get to the screws holding the top of the air filters on. On the passenger side, I had to massage the gauze style filter to get over the velocity stacks, and the drop the top of the filter housing on, and it just barely fit, within 1/4" of the body. I should clarify that I used full size velocity stacks inside the filters. If you use short velocity stacks, you can use a shorter filter. I went back to a single center mounted Zenith, got tired of clogged idle jets, but do miss the performance.

[911pickup]

I suspect at the very least I'll have to go with shorter air cleaners.

I've had three sets of Webers on my air cooled engines over the years (1 set of 40s and two sets of 44s). I had problems with clogged idle jets on all three.

I was considering going with dual singles, but John, at Aircooled.net recommended dual Weber 40s instead.
Way back in the 1970s I put a set of Kardons on my 1970 VW Beetle. I drove that car all through my university years (over 50,000 miles) and never had any problems with the carbs.
I cleaned the filters and did minor adjustments once a year. That's it.

[andk5591]

Take a look at K&N filters web site. They have a universal application section where you can find a filter to work for almost any application. Like the ones I use on our buggy are actually for a snowmobile (conical, offset, angled base). They have almost anything you can imagine.
_________________
D-Dubya Manx clone - 63 Short pan,1914.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Cindy's daily driver.
Max - 73 standard Beetle hearse project - For sale
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[oprn]

My Manx copy came with dual Kadrons and the air filters were nearly impossible to service in place. That became very evident when I pulled the engine to clean up oil leaks and found the air cleaners not properly sealed and fastened and a coating of road dust inside the carbs bores.
Yes a compression test revealed the rings are indeed dusted!

[911pickup]

I had a similar clearance problem with my old Porsche 356 replica. I ended up having to take the velocity stacks and large filters off and install 1.5" high air filters from CB.

Another question: How do you buggy owners sync your carbs? I imagine in most cases there isn't enough room to put the syncronizing tool over the top of the carb.

[wythac]

I use few tools to sync mine:

1) Screwdriver

2.) Chair pulled up to the back of the car

3.) Two ears

4.) Patience


A roundabout way of saying that I use less than scientific methods. 30 years ago when I bought my Berg 42 kit I asked a friend of mine who was an ACVW mechanic and drag racer to show me how to set them up. At that time I had them installed in my bus and it was a PITA to stick my head into the engine well to tweak them. Fortunately it wasnt often necessary. Much easier process with those same carburetors installed in a buggy.

Mine only really need to be tweaked when I have changed something significant, such as when I installed a different cam and heads, which I haven't done for awhile.

Experience has shown me that the most common "balance" issue is in the linkage. I usually have to make minor adjustments each time I reinstall the engine after working on it. Once I went with thicker intake gasket material. Just that one change required a few adjustments.

I always set the idle with the linkage disconnected. Then I hook up the linkage. If the rpms change, I disconnect one side at a time to tell me which side is "ahead" of the other and adjust the linkage as required.

Hope that helps. Good luck with your project.

[oprn]

With the Kadrons there was no way to get a snail on top the carbs never mind get your head in there to read it. Like the last poster I just tweaked and listened, not entirely satisfactory!

This time around with the Webers I will drill and tap the intake manifolds on each cylinder so that I can use the bottle method the motorcycle guys use or an accurate digital vacuum gauge.

[andk5591]

Just posted this on another thread and have done it on Kads and just remembered that I did it on Webbers once.

I have posted quite a few times about my homemade manometer. Works great as long as you have a port that you can pull vacuum from on each carb. On Kads, you use the balance tube ports....
_________________
D-Dubya Manx clone - 63 Short pan,1914.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Cindy's daily driver.
Max - 73 standard Beetle hearse project - For sale
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[oprn]

Just an update on the air filters/dual Kadron/Manx copy issue. I just put the engine back in and proved that it is actually impossible to put the air cleaners back no. I had to take the intake manifold with the carbs off the engine, install the air cleaners and then wrestle and wiggle the whole assembly back into place!

Both sides!

With the left being the worst!

Took me 3 hours!

Just to put the air cleaners on!

This is insane!!

I am so not looking forward to the dual Weber install I have planed for this buggy!

Surely someone somewhere has marketed a remote air cleaner set up for these dual carbs?

[wythac]

I doubt anyone has. Too small a number of potential customers.

Necessity is the mother of invention though. I recently built a remote filter system. For different reasons than clearance however; I needed a better filter for offroad, one that wasn't sitting on carbs right behind two large dust producing tires.

I purchased a Donaldson filter recommended by another offroad buggy builder on this forum. They are used on industrial equipment like forklifts.

A short experiment with hot rod air cleaner ducts failed before it got off the ground...not enough room and the connection hardware was expensive and not flexible enough material for the job. I sent it back.

I went to the hardware store and found 2" ABS pipe and fittings worked well as ducting between where the air cleaner is mounted at the rear of the car and the metal "boxes" that I made to replace the filter elements on each carb. Works great and other than the purchase of the Donaldson filter, cheap.

I don't have pics but can shoot some if you'd like...not sure they would do you much good because of the offroad application. I share this info more to maybe get you thinking of a way to create something on your own with available local materials at low cost.

[oprn]

Really all I need is some sort of fairly compact banjo fitting for the top of the carb. The rest as you say is pretty easy to fabricate and and number of stock and after market air cleaners could be used.

I wonder what the blow through turbo guys are using.

[andygere]

Here are a few ideas. Note that the base assumption is that you are already planning to use shorty manifolds.

1) Super low profile air cleaners. These will probably need more regular servicing, but if space is tight it might get you that extra inch. https://www.racetep.com/manufacturer/carbs-and-inj...ilter.html

Another version: https://vwparts.aircooled.net/CB-1-1-2-Tall-Aluminum-Air-Filter-CB3260-p/cb3260.htm

2) Low profile plenum and remote air cleaners. This may not get you the clearance you need, but it provides the right idea. A lower profile unit would work with the shorter velocity stacks.

Here's the way CB Performance does it on their Turbo builds:

This expired ad shows how one builder mounted the air cleaners inside the buggy. On the Manxter, this was probably done to provide cleaner air for off road use.

http://dsb.yuku.com/topic/3297/Meyers-Manxter-Camarillo#.WVFC0NyQy6J[/url]

[oprn]

Thanks for the ideas!

The first one I would not trust as it could not handle the dust involved with a rear engine car without being too restrictive.

I was not aware there was a short manifold option available for either the Kadrons on a type 1 or Weber 40s on a type 4. All the short manifolds I have found are fro Webers on a type 1.