Jetting Recommendations for Weber 44s

Post by **Sluggo** » Tue Oct 10, 2006 8:59 pm

My main jets were flooding the Webers and causing bogging. Without looking at what they were i ordered new idle, Main & A/C Jets according to the Weber Guide for 2000cc Type 4 engines. The idle that came was smaller but the Main & A/C were bigger. I tried em anyway. Now I get more bogging. Right now it's running Idle - .60 / Main - 1.55 & A/C - 2.0. It was Idle - .65 / Main - 1.35 & A/C 1.75.

What would a good jetting setup be for Weber 44s on a 2 liter Type 4 in a 72 Bus? I'm looking for fuel economy.

chitwnvw · Post by **chitwnvw** » Tue Oct 10, 2006 9:54 pm

Call John at Aircooled.net, you could pose a prospective buyer, but I bet he'd help you out regardless.

Maybe you should have bought the 40's!

fido · Post by **fido** » Wed Oct 11, 2006 1:54 pm

all depends on the size of the venturis.

you will want 30mm venturis on a stock 2L with stock heads. 60 idles will be fine. your air correctors should be OK at 2.00, but the 1.55 mains are fat. plug the 1.35s back in and you'll be closer to the mark.

as a rough guide, the main jets want to be around 4 X the venturi size (or slightly bigger).

Emulsion tubes will also effect this, so you need to check on those too. The weber book sold by CB performance has lots of tables in with all this stuff - its only about 15 dollars. Well worth an investment.... Unfortunately I swapped my copy for a DCOE / DHLA book so cant dictate straight from the horses mouth....

Post by **Sluggo** » Wed Oct 11, 2006 8:40 pm

These are what Jake just recommended to me.

44s are a bit healthy for a Bus

This works well

32Vent
130 main
200 air
60 idle
F7

My venturis are 36. Jake recommended 32. Emulsion tube is a fat F11.

This is not a stock 2liter. 1800 converted to 2000 with big valve 1800 heads. I put the 135s back in and it helped some. I'll be ordering some new jets & venturis from CB Performance tomorrow.

chitwnvw · Post by **chitwnvw** » Thu Oct 12, 2006 8:17 am

Really? Jake thinks the 44s are a bit much for a bus!?!?

Post by **Sluggo** » Thu Oct 12, 2006 8:42 pm

chitwnvw wrote:Really? Jake thinks the 44s are a bit much for a bus!?!?

Yep.

Colin teased me too much with his FI comment in my Fuel Pump thread. I'm seriously considering it. If I can find a decent affordable set up (hint hint [-o<). All the new jets & venturis are gonna cost $120 before shipping. And I already paid $35 for the few I just got.

Post by **Amskeptic** » Fri Oct 13, 2006 8:28 am

Sluggo wrote:
chitwnvw wrote: Really? Jake thinks the 44s are a bit much for a bus!?!?
Yep.

Colin teased me too much with his FI comment in my Fuel Pump thread. I'm seriously considering it. If I can find a decent affordable set up (hint hint [-o<). All the new jets & venturis are gonna cost $120 before shipping. And I already paid $35 for the few I just got.

chitwnvw,
It is a dick-sizing issue with valve and venturi and exhaust header sizes. When a honking 44 is feeding two little cylinders, you can bet that velocity drops precipitously at low speeds. This is a common mistake in the performance section of this hobby. You see people complain about low power when what they are really feeling is low TORQUE, and they open up the engine some more which makes it worse. If the engine dies away above 5,000 rpm, that is a restriction symptom.

Sluggo, ask Velokid1 in a couple of weeks how he likes his FI. It was a mostly trouble-free installation with just a couple of "creative workarounds" and some wiring. . . .

Colin

Post by **Sluggo** » Fri Oct 13, 2006 9:29 am

Amskeptic wrote:Sluggo, ask Velokid1 in a couple of weeks how he likes his FI. It was a mostly trouble-free installation with just a couple of "creative workarounds" and some wiring. . . .
Colin

I've been inspecting Busses for a few buyers in the UK (saved one guy from making a huge mistake). On Wednesday I checked out a nice brown with orange stripes '79 with FI. Even with it's tired original engine, there was still a lot of pep once you got moving. I had to finesse the FI a little to get it to work right & idle. I had never touched a Bus FI setup before. But it was actually pretty easy. All those threads I read started flooding back to me. Now I'm hooked on the idea.

chitwnvw · Post by **chitwnvw** » Fri Oct 13, 2006 10:28 am

I've got a 79 rustbucket, but the engine mechanicals are fine. Be the perfect donor. I guess I'll wait and see how velokid likes his over the long haul. Also, I wouldn't know where to start, so a write up or something to get me pointed in the right direction.[-o<

As for the 44's isn't that what John at Aircooled recommends? And then Raby saying it was a bit much really surprised me. Are the 40's smaller, better suited for this task? I'd pm'd adventurewagen about his and he's seems pretty happy with the carbs themselves, not so with the linkage and whatnot that he got with them....

Post by **Sluggo** » Wed Oct 18, 2006 7:50 pm

Back on topic (although I do enjoy seeing threads drift into all these interesting exchanges). I put in my new Jets, Venturis and E-Tubes today.

I haven't started the Bus yet though. I'm gonna wait till I get my new exhaust tomorrow. I'll post the results. From what I understand, I should see a decent boost in performance & mileage (because I won't be flooding out the carbs at 1/4 throttle and the engine will actually be able to exhale). And also steadier readings. I've read a few post at other forums where people mentioned how hard it was to keep the engine tuned with that crappy exhaust.

I love this smiley!

Wish I could find that chicken catcher one again.

DurocShark · Post by **DurocShark** » Thu Oct 19, 2006 9:46 am

Sluggo wrote: Wish I could find that chicken catcher one again.

Can't help you with that, but I made a Stingray one...

Post by **Sluggo** » Thu Oct 19, 2006 10:14 am

DurocShark wrote:
Sluggo wrote: Wish I could find that chicken catcher one again.
Can't help you with that, but I made a Stingray one...

Wasn't there a Steve Irwin thread on here? That would be appropriate yet inappropriate at the same time.

fido · Post by **fido** » Thu Oct 19, 2006 3:28 pm

The engine will behave better, but it will still be difficult to control at low revs - those 44mm butterflys let alot of air/mixture through.... even when cracked open only a little bit. That was what Jake was on about. Great for 6000 rpm. Not great for controlling 1000-1500 rpm taking off in a heavy bus.

Hope it all works out. The new exhaust will help higher rpm, but wont help the low rpm problem.

Fuel injection will be better at everything on a bus.

Post by **Sluggo** » Fri Oct 20, 2006 11:10 am

Installed the new muffler yesterday with the help of Bottomend. The muffler I got was a Dansk. (This ties into the carb jetting problem as the crappy EMPI made the carbs close to impossible to tune correctly).

Complaint #1: The welds between the ports & flanges were pretty sloppy. Had to grind em smooth to ensure a good seal.

Complaint #2: Muffler kit was missing the 3 studs, washers and nuts for the tailpipe flange.

Complaint #3: There are two dents in the back of the muffler. One for the Rear Shroud Tin and one for the Oil Fill Tube.The dent to accomodate the Oil Fill was half an inch off. It pushed on the Oil Fill and caused a decent leak. The dent should be exactly one foot from the right edge (we measured Bottomends German Stock muffler). The Dansk is 1 foot 1 inch from the edge. First we tried a clamp to widen the dent but it was pushing in on the wrong side. Bottomend had the brilliant idea of driving to this secluded area he knew of (so as not to disturb my tenants) and hammering the dent out to add a 1/2 an inch. Worked out great. Bus sounded like a "big Singer sewing machine" as Bottomend described. Better sound and smoother idle right off the bat. My Vacuum jumped from the crappy 10 PSI to the Healthy 18 PSI I was looking for. The engine ran about 50* cooler. The oil temps ran about 75* cooler.

I went with Jakes recommendations on the Jets & Venturis.

Went for a drive to La Crescenta with the Wife & Kid. Bottomend came along too. Drivabilty improved by 200%. I can actually accelerate and it only took about a minut to get up to 65 rather than the 20 it took before. Have to get used to giving it more than 1/4 throttle (all I could give it with the old jetting without serious bucking and almost stalling).

But all was not perfect. Bus stalled out on the freeway on ramp on the way back at 11pm with an unhappy wife and a sleeping baby boy in the back. Mixture was pretty lean. Even out the Air Adjusters to 1/2 a turn out each and we got her going again. Still some bogging.

1st - Little to no bog.
2nd - Bogs a little around 2500-3000 RPM at 1/2 throttle. Picks up at 3/4 but still slightly sluggish.
3rd - Same as second
4th - Have to keep it above 3500 and still a little bog with a few small pops.

I'm gonna do some fine tuning today and maybe change out the 60 idles for 65's (Bottomend feels it may be slightly lean with the smaller mains, idles, vents & e-tubes but bigger A/Cs).

Any other suggestions?

vdubyah73 · Post by **vdubyah73** » Fri Oct 20, 2006 4:05 pm

Close the air adjusters. They are used to synchronize the barrels on each carb. They really have nothing to do with jetting. Go with what Jake recommended. I'm running 44 IDF's on a 2275 type one with 55 idles. Can't remember what my mains are, 155's or 160's, but my air correction jets are 200's. Jetting is more about the carb than the engine for initial jetting. I think if you close the air adjusters and start over with your mixture screws you'll get closer.

The engine needs to be fully warmed up for fiddling about with carbs, really warmed up. your linkage geometry may be off too. The adjustable down links need to be as close to straight up and down from left to rite as possible this !------!
not this /-------\ . Fore and aft is important also thats why the linkage kits have a little spacer for one side's throttle lever, it's to correct the offset of the cylinder heads when you set up the hex bar to be straight across between the carbs. If your linkage isn't right, one carb can be ahead of the other at one throttle position and then behind at another position. Gives you bogs and pops and other drivability issues. Did all that make sense? It took me quite some time to figure out on my own about 6 years ago without the internet and no hotrod VW's around my neck of the woods to guide me.

Bill

Went back and re read the thread I have 36 vents in my 44's so disregard what my jets are.

Itinerant Air-Cooled

Itinerant Air-Cooled

Jetting Recommendations for Weber 44s

Jetting Recommendations for Weber 44s