Vanagon automatic in a bay?

[alaskadan]

Ok thanks. My friends budget likely will barely cover the suby conversion let alone the buffoonery of swapping to an auto. Just didnt want to get done and find that gearing for highway driving was ridiculous . Will have first hand experience with both by end of winter. Doing a 78 auto riviera 2.5 conversion and a 74 stick westy 2.2 conversion after that. Thanks for the help sambanistas.

[Mr. Unpopular]

[WhirledTraveller]

Fwiw I was wrong about the manuals and automatics having the same top gear ratio. And your 74 will be shorter geared. Should be 0.89 in 4th and 4.857 in the final drive, overall ratio 4.32

A later bus (2.0 liter) has the same 0.89 4th gear but a 4.57 final drive. Overall 4.06

A later automatic has a 1.0 3rd gear and 4.09 final drive, overall 4.09

If you plug those numbers into a calculator assuming 25.7 inches tire height, you get 3671, 3450, and 3476 rpm at 65 mph respectively. To keep your same transmission but get the same top gear ratio as the latter bus, you need to upgrade to a tire with a 27.1 inch height.

Edit, mr unpopular posted as I was typing. The auto's do have a 1:1 top gear. And as I've shown a very similar final ratio as the manuals. Not sure about slippage but I'm sure there is some.
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1977 Westy, Automatic. Big Valve heads, CS Cam.

[Mr. Unpopular]

Again, you aren't accounting for converter slippage with the auto.
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"In any racing engine, the nearer you are to it disintegrating, the better it's performance will be"
-Keith Duckworth, creator of the Ford/Cosworth DFV

[WhirledTraveller]

I have an automatic bus and turn about 3600 rpm at 65 mph so I don't think the slippage is very much.
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1977 Westy, Automatic. Big Valve heads, CS Cam.

[Wildthings]

The Subaru engine will run nice and quiet at 4000+ rpms and to get the maximum benefit from the conversion you might as well let it spin. I don't think I would start thinking about a change in gear ratio until the displacement of the conversion engine got up better than 2500cc's and maybe larger.

[alaskadan]

Cool. Ive drive a syncro with a 2.5 in it and that sounds comparable. Which i dont mind those rpms at 65. Anyhow how fast do i need to go in a van. Will proceed thanks.

[WestyPop]

[alaskadan]

Little update here. We got the 2.2 with a smallcar adapter and a 87 vanagon auto hung in the 78 riviera. Used sc engine mounts and a vanagon mustache bar with modified ends to bolt to the frame. We removed the trans cooler and are going to loop it for now. So obviously we are using the bay trans mount on the front. Looking at it further if one was to make a mounting plate to allow the use of the vanagon trans mount on the front ( which looks doable) it would move engine and trans rearward about 2 inches. Then the bellhousing mounts could bolt onto the backside of their respective hangers instead of inbetween . This would allow ample room for intake . Of course linkages and cables need tobe lengthened. Mustache bar brackets are already custom. It all seems very doable. Would there be any concerns with the axles being "swept" rearward? I dont think an approximate 2" move rearward would be an issue for the length of the axle, just wondering if creating compound angles would be a problem for cvs? Just a thought.

[Wildthings]

[WhirledTraveller]

Delayed update here... I did install the Vanagon automatic into my Bay. The actual swap was a piece of cake although there was some drama with the condition my "good used" transmission.

Photos for those who want to follow in my footsteps. Firstly, a brief overview of the differences.

The Vanagon transmission has cooler inlet/outlets on the "front" of the transmission (front meaning towards the front of the bus).

In order to understand how the flow works, it's helpful to know how the ATF system work. The oil pump is in the front of the case, spun by a hollow impeller shaft drive driven by the torque converter. It pulls ATF from the pan, pumps it, and sends it back down to the pressure regulator in the valve body. The pressure regulator sends regulated pressure to the hydraulic valve system and controls the transmission. The *excess* fluid from the pressure regulator is sent back up in the direction of the oil pump, and in a bus transmission is routed directly to the center bore where it travels down the impeller shaft and into the torque converter. In this way the torque converter fluid is refreshed. In a Vanagon transmission this flow is diverted so that is goes through the cooler first and then back into the impeller shaft towards the torque converter. This is done by blocking the return passage, and opening up an alternate passage out of the case.

This is a Bus transmission case with the guts removed.

And this is a Vanagon:

And the return gallery for bus:

And for the Vanagon:

So you can see that it should be possible to modify a bus transmission by just doing something similar, drilling and tapping the two holes and blocking the return galley with a plug. The only problem is that the Vanagon transmission has more case material there to support the drilled and tapped holes. I still think it should be possible.

Anyway from there it's pretty straightforward. You need to grind/cut away a little bit of the forward engine mount to make room for the outlet hose. I run to a magnefine filter:

Then to a thermostat and passive dual-row cooler:

The return goes through a 90 degree AN6 fitting over the top of the crossbeam:

To a Banjo bolt:

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1977 Westy, Automatic. Big Valve heads, CS Cam.

[alaskadan]

So ive been putting some miles on the 78 riviera the past couple weeks while i put some finishing touches on the van for the owners. 2001 2.2 suby with an 87 auto from a vanagon. We looped the cooler ports. Drives nicely. It has 205/70 R15 tires on it. It could be a little taller geared. A 2.2 is a nice amount of power for a bay. It is the more powerful single port .

[Wasted youth]

WhirledTraveller, nice follow up! Very interesting differences noted on the fluid path between the bus and Vanagons.