Will webcam 142 work with an automatic transmission? (bus, 2.0L)

[[email protected]]

Hey humans,

I've acquired a '77 vw bus, automatic transmission, with the fuel-injected 2.0L. Engine code is SI 12; 004 101 101A. The cam is pretty worn, it looks like the previous owner mismatched the cam and lifters and the lifters wore into the cam. I'll be replacing the cam and lifters (hopefully reusing the cam gear), and after poking around on the threads I'm pretty convinced I'll be going with the webcam 142 and new solid lifters. This a a no-frills stock build, I'm just looking to get the bus back on the road. I've read that VW had different cams for automatic and manual transmissions, which begs the question, will webcam 142 work with an automatic '77 bus? All of the threads recommending this cam were referring to manual transmissions.

[raygreenwood]

[[email protected]]

Hey Ray, thanks for the info. I might post in the bay forum if I don't hear anything else here in the next day or two. I doubt a manual vs automatic transmission would make a big difference on cam selection anyway, I'm quite certain I'll end up ordering the webcam 142 (and matching lifters).

[BFB]

well, since this is here. what difference would it make what cam someone ran with an automatic?
_________________
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An interesting thing happens in forums where everyone starts parroting the same thing and "common knowledge" takes over.
Most experts aren't.

[raygreenwood]

[Takamotti]

There´s factory note TM84 from september 1972 called "engines with automatic transmission"

And this one is from TM80, august 1972 for manual transmission cars

[Takamotti]

And here are the later cams...

I have Schleicher 296 (degrees measured in German way, I guess it´s about 276 in US degrees) and later 090 automatic. I wouldn´t recommend this, peak power is at 5300-5500 and it feels ridiculous to rev the bus that high. But I think 142 (if it´s indeed stock 411/412/914 cam) peaks at 4900-5000 so it´s better.

[orwell84]

I went round and round trying to figure out what exact cam VW ran with their automatic transmissions.

I have run both the Web 142 and 73 with the early 003 automatic with vacuum modulator and a single progressive carb. I didn’t experience any issues with harsh shifting or unusual shift points. I was able to get a steady idle with both. I didn’t notice a huge difference performance wise between them. I think the 142 is plenty if cam for a stockish engine.

[Takamotti]

and by the way, the Webcam 142 I ordered doesn´t seem like very well made. Thrust surface is rough, I think it needs to be polished or it will kill the bearing. Also lobe edges were not rounded and look like they will destroy lifters.

[raygreenwood]

[Takamotti]

Ray, the TM80 is issued august 1972 so it's related to new engines built after that date. (But it also says this can be used as replacement cam for older 411/412). I just posted the two since there you can see automatics had slightly different cam, on buses on all markets. I don't know what exactly they used for d-jetronic.

[Takamotti]

and now that I actually read more of these endless notes (there´s hundreds of small changes to ignition timing etc) , in 1975 they started to use that lame automatic cam for everything

But since this is a performance thread... if you use that Webcam 142 your transmission will shift to higher gear too soon and you´ll never be on highest power. You can modify the governor by removing material from the counter weights but in my case it wasn´t necessary, I just adjusted the metal bar between transmission and carb linkage (dual dellortos) and now full throttle shifts are after 5000 rpm (my bus is from 77 but transmission is from late model Vanagon so it might not work for you, maybe early 090s are different)

[Takamotti]

Turns out I actually had saved some 411/412 files too, though I´ve never owned one. Factory file is called "technische daten 1.3", it´s from september 73.
So these are the same what Ray posted, the so called "passenger car" cams

[raygreenwood]

[Alstrup]

Yes, the 142 is basicly a 2 liter 914 cam. It will work with all the varius models of aut transmissions. So will the 73. One of the keys are compression. If you assemble the engine with either cam and keep the wimpy 7,5-1 CR you will get a runaround when adjusting the shift point, because the engine will effectively LOOSE lower rpm torque and vacum, so the transmission thinks you are on the loud pedal over a wider spectre. If you do a simple and decent 3 angle valve job on the stock valves 30/45/60 or even a 30/45/70 (on the intakes) along with raising the CR to at least 8-1 preferably 8,3 - 8,5 (with a tight deck) - AND increase idle and lower rpm timing (up to about 2200 rpm) with something like 3-4 degrees the engine will recover its lower rpm vacum and the transmission will work as normal and you dont have to rev it to the max to make it shift.

The D jet is slightly more picky, but its possible to make it work well. Even the now discontinued (I think) 9550 (Raby´s version of the #73) worked with D jet if the engine got some compression. 8,5-9 was good.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[raygreenwood]

[orwell84]

Btw, the 142 has a rougher finish because it is the billet cam that is used for all their type 4 grinds. They offered to clean it up for me when I pointed it out but I ended up doing it myself because it was quicker to just do it myself and not difficult. My 73 had a better finish but I still polished the thrust faces and put a nicer radius on the lobes.

[[email protected]]

Thanks for all of the excellent info everyone, especially Ray and Taka, I really appreciate the level of detail and all of the documents. I didn't even think about the compression ratio so I have some homework to do there. My main takeaway from all of this is webcam 142 (or 73) should be fine, but the transmission may shift a bit too soon due to lower vacuum pressure so I may have some tinkering to do once this is all set up; but, I'll have less tinkering to do if I get everything else right (compression ratio). Thanks for the great responses!

[raygreenwood]