Type IV dual carb air cleaner-to-engine setup, linkage

[whc03grady]

Thanks for all the help being bestowed on me lately.

I'm making a trip to Brax Europarts (who knew that a tiny "town" in Montana was home to a big new and used ACVW parts warehouse?) on Friday and I'd really like to come home with all the stuff I need. I have what I think is the whole air cleaner set up: a horn to each carb, the box in the middle, and the funny little preheat box to the right front. But how does all this stuff fit to the engine itself? Certainly it doesn't just rest on top of the carbs. There're a couple clamps on the bottom of the cleaner box that clamp to something, but whatever it is I don't have it and can't find a picture of it. And is there another piece or something that makes the horns fit on the carbs with some degree of tightness? Some gasket or seal or boot or something?

Also, does the carb linkage really consist in: two pivot arms (one per carb, the right one having the screwy adjustment) and the big bar in the middle? And that just rests on the indentation in the air cleaner? And how/where does the idle mixture plumbing fit? Bentley is letting me down here.

(Where are detailed pictures of the Road Warrior's (r.i.p.) engine compartment when you need 'em?)

[satchmo]

Here is a pic of my 73 rebuild to get you started.

The blue tubing in the middle of the picture is the central idle system piping. The center of it has one tube going to each manifold, one leg going to the left (driver side) carb central idle port, one nipple for the famed 'Amskeptic reference tube" that connects to the right air horn, and one tube that used to connect to the smog pump (now blocked off with a bit of hose and a bolt for a plug).

Placed over the top of the central idle piping ("spider") are a couple black u-shaped stands for the air cleaner box. These bolt to the case with the same holes that the tinware uses and they provide a place for the clamps on the air cleaner to attach. Be careful as the 72 carb set-up used short stands for the oil bath air cleaner, while the 73-74 dual carb set-up used taller stands for the paper filter air cleaner.

Behind the oil pressure sender (round silver thing on the right side of the engine with the green wire attached) is the 'toilet seat.' This is the intake for the pre-heat system and the air filter box sets down into it.

The blue tube to the rear of the engine (behind the toilet seat) is the tubing for the EGR.

Not shown in this picture are the spring clamps on the carbs that keep the air horns from the air cleaner tight against the carb intake. I will see if I can locate a picture for you. I can also get you some pics of the throttle linkage, I think.

If you want this photograph annotated or labeled, send me your email address and I will send it to you.

Tim

[whc03grady]

That's gold, Satchmo! Gold! Thanks. I'd love to see any other pictures you have.
I see I'm missing the long tube that runs between the carbs, for the EGR; another item for the list. And I see I don't have those two long bolts connecting the fan housing halves. Hmmm.
My intake manifolds are different than yours. Well, one is anyway--it has a can with a nipple on it (no wisecracks). Do you (or anyone reading) know which side it goes on, and where the nipple leads?
What is that thing sticking out of the toward the right, under the right air-cleaner mount? It looks like a big plug-in.

[satchmo]

That's gold, Satchmo! Gold! Thanks. I'd love to see any other pictures you have.
I see I'm missing the long tube that runs between the carbs, for the EGR; another item for the list. And I see I don't have those two long bolts connecting the fan housing halves. Hmmm.
My intake manifolds are different than yours. Well, one is anyway--it has a can with a nipple on it (no wisecracks). Do you (or anyone reading) know which side it goes on, and where the nipple leads?
What is that thing sticking out of the toward the right, under the right air-cleaner mount? It looks like a big plug-in.

The EGR isn't necessary, but the tube between the manifolds is since it acts as a balance tube for the intakes. I plugged the port on that tube that went to the EGR on my engine, and removed the rest of the EGR plumbing.

Those two long bolts on the fan housing are leftover from where the smog pump mounted. They are only decorative at this point.

The manifolds for the 73 had the cans with the nipples on the side as part of the EGR system (I think). They were eliminated on the 74 manifolds. You can use them interchangeably as long as you block off the nipple and any other holes on the can.

The big tube under the right air cleaner mount is/was for the smog pump. It has a piece of hose with a hex bolt inserted to plug it off since without the smog pump it is no longer needed.

Tim

[Oregon72]

(Where are detailed pictures of the Road Warrior's (r.i.p.) engine compartment when you need 'em?)

My rebuild thread ('72 Type 4) is filled to the brim with photos - pages of them.

viewtopic.php?f=3&t=6815

Hope that helps.

[satchmo]

I take back the stuff I said about the blue pipe in the rear: that pipe is for the brake booster circuit. You can see it hooking into the brake booster elbow on the right manifold.

What was the EGR/balance pipe has been replaced by the stout gray fabric covered hose you see looping up and touching the firewall tin. It hooks into both manifolds via the stub ends of the original EGR pipe.

I apologize. It has been a while since I did this rebuild.

I know Oregon 72 has a lot of info and pics in his rebuild thread, but keep in mind that he has a 72 with the oil bath air cleaner, short air cleaner stands, short manifolds, a different central idle distribution pipe (spider) and the throttle linkage is quite a bit different than the 73-74 version.

Good luck, Tim

[whc03grady]

So we've got four pipes composing the spider (or half-spider, if you will).

The pipe at the NW position on the spider, it looks like it goes up, get some hose attached to it, and then jumps over the front of the upper tin. That's not for the brake booster?

The pipes at the West and East positions basically connect the manifolds, okay.

The pipe at the SE position formerly went to the air pump and has been mercifully plugged.

The long blue pipe not obviously attached to the spider looks to simply connect the manifolds, much like the big lazy hose forming the bell curve: that pipe is somehow worked into the brake booster?

[satchmo]

So we've got four pipes composing the spider (or half-spider, if you will).

The pipe at the NW position on the spider, it looks like it goes up, get some hose attached to it, and then jumps over the front of the upper tin. That's not for the brake booster?

The pipes at the West and East positions basically connect the manifolds, okay.

The pipe at the SE position formerly went to the air pump and has been mercifully plugged.

The long blue pipe not obviously attached to the spider looks to simply connect the manifolds, much like the big lazy hose forming the bell curve: that pipe is somehow worked into the brake booster?

I'm going to post another few pictures in my gallery that may clarify matters since the photo above isn't too good because things overlap a bit. But no, that pipe in the NW position has a hose on the end that connects to the big pipe on the top of the left carb, which is not in the picture. It ends right there rather than wrap over or around the tin. This is where the air/fuel mixture comes into the spider from the central idle portion of the left hand carb. The air/fuel mixture then goes down to the center part, then heads to each manifold.

The long blue pipe in back is indeed the brake booster circuit. Look closely just to the right of the right manifold. You can see a bit of blue just above the black 90 degree rubber elbow that hooks into the brake booster vacuum port on the lower part of the manifold. It does the same thing on the left side, and also has a small extension that goes through the firewall tin and connects to the hose going to the one way valve for the brake booster. I know it isn't real clear where the pipes end in the picture.

Originally, there was a metal pipe of the same diameter of the blue pipe that went between both manifolds (note the attachment points on the upper rear of your manifolds - small port with two 6 or 8 mm threaded holes) and it had a screw type fitting for the pipe going to the EGR filter. I got rid of the EGR filter, and thought I didn't need that pipe between the carbs anymore, so I threw it away. Colin let me know that the pipe between the manifolds was still necessary because the cylinder firing order creates pulses in the carb and manifold creating something called 'stand-off', where the fuel mixture isn't sucked into the manifold very well. Keeping a connection between the upper part of the manifolds evens out the pulses in the intake and prevents stand off (at least that is the theory). Since I didn't have the original pipe, I fashioned some metal elbows for each manifold, then connected them with that big gray/tan hose. The picture above doesn't make it clear where the hose ends because it ends behind each manifold.

I will post some other pics in a few minutes. I hope that will clear things up.

Tim

[Amskeptic]

So we've got?

Read through this, Mitch and look at the pictures to help fill you in:


http://itinerant-air-cooled.com/viewtop ... =50&t=7767

[whc03grady]

Okay, you guys are giving me the goods with these pictures and diagrams. I'm missing the dashpot and associated works. That's a left-carb only item, yes?
I have to ask:
Do I need the EGR vacuum valve? And the 4th-gear only vacuum advance valve?

[BumbleBus]

I'm making a trip to Brax Europarts

If you bring your camera along and snap photos for your blog or whatever I'd love to see what the place looks like and get your impressions. The '72 I'm trying to restore has a lot of receipts from Brax and they seem to do good work from what I can tell. I was thinking of road tripping down there myself this summer to check it out and to show the lady I bought my bus from the progress since she lives close to there. Thx and best of luck with Ludwig's motor!

[satchmo]

Okay, you guys are giving me the goods with these pictures and diagrams. I'm missing the dashpot and associated works. That's a left-carb only item, yes?
I have to ask:
Do I need the EGR vacuum valve? And the 4th-gear only vacuum advance valve?

No. You will get along fine without them. Unless you are going for a perfect stock restoration, anything to do with the smog pump or EGR system can either be removed or plugged.

And yes, the dashpot is only on the left carb.

Tim

[whc03grady]

I got most of the stuff I needed, but when I got home and cleaned up the air cleaner stands they had the same part number, ending with 'B'. This implies to me that there was an 'A'. Now the question is, are there two different parts one needs, a right and a left, an A and a B? Or is it a year thing; earlier stands were a pair of As, later they were a pair of Bs?

[dtrumbo]

I don't know the answer to your specific situation, but generally speaking, don't get mired in the 'A' & 'B', etc. designations. Typically, the letter suffix is a revision to a specific part, just as the numeral after the 'dot' in a software version. A left vs. right is, from what I've seen, a completely different part number not just a letter-suffix. Of course if the left part is the same part as the right part then it's... the same.

Am I still helping?

[whc03grady]

That seems right, thanks.