Tips on installing 1700/1800 air-cooled into Vanagon...

[2mmBTDC]

Found a great 1700 Type 4 (Thanks Dan in Norwich CT!) for my wife's 1980 Westfalia, manual transmission. Here's what I had to do, to make the 1700 fit:

Note some later Vanagons have a different transaxle.

1) The most troublesome difference is that you have to keep the 1700 moustache bar (rear engine mount); this is because the 2000 moustache bar interferes with the 1700 alternator (for sure) and the 1700 heaterboxes (if memory serves). This is an issue, because the 2000 moustache bar mounts resist engine/transaxle rotation, whereas the 1700 moustache bar does not. The 1700 transaxle uses a mount at the upper rear of the transaxle, to resist engine/transaxle rotation. The Vanagon does not use this mount. The Vanagon transmission (at least the 1980) does have the 'ears' for the mount, on the transmission, but unlike the 1979 & older buses, in the Vanagon there is no heavy frame section above that part of the transmission to bolt the mount to.

I didn't realize this until I had the motor in. Rather than pulling the motor back out, I fabricated a bar, going from one of the 'ears' on the rear of the transaxle, to the frame to the side of the transaxle. I used rubber tubing, and rubber washers, on the bolt through the transaxle 'ear', for vibration damping. IMO, the preferred alternative would be to modify the 1700 moustache bar's mounting system, so that it's like the 2000 moustache bar mounting system, in order to resist engine/transaxle rotation.

The Vanagon frame rails are different, as well, so that the 1700 moustache bar will not bolt directly to them. I had to create 'ends' for the moustache bar, to connect between the bar & the Vanagon frame rails. Take some measurements & pictures beforehand, to make this easier for yourself. THIS IS IMPORTANT: the moustache bar controls the height, and side to side position, of the entire transaxle. So take measurements beforehand, so that you can position the rear of the engine at the same height, and side to side position, relative to the engine compartment. You want to position the motor/transaxle correctly, as it was stock, so that the orientation of your half-shafts, shift linkage, heater parts, etc won't be all messed-up.

2) Swap the 2000cc flywheel & clutch assembly over, to the 1700, so that the Vanagon transaxle throwout bearing & starter motor gear are in the right place. You will have to check your crank end play due to using a different flywheel; I used a dial indicator.

3) I am still working out which tin works best, on the hybrid installation. So far, 1700 everywhere, except 2000 tin in the front-most upper piece, next to the transaxle, where the throttle cable comes through. The heaterboxes also mount to that front-most upper 2000 piece.

4) Dipstick & oil filler. The 1700 dipstick & oil filler WILL work, inside the Vanagon engine compartment. They are a little awkward, but they work. You do have to use a flexible dipstick (like the 2000 dipstick) in place of the rigid 1700 dipstick. Alternately, you can do what I did: drill the top of the 1700 case, to allow use of the 2000 dipstick (2000 & Porsche 914 run the dipstick tube in the TOP of the motor, to the right of the oil breather). I would recommend sticking with the 1700 parts; I changed mine while the engine was out, because I wasn't sure the 1700 parts would fit in the Vanagon engine compartment.

5) The Vanagon engine compartment is lower than the engine compartment in the earlier buses. The 1700 motor I bought had one of those single Weber 2bbl carbs, in the center of the motor. The air cleaner on that setup apparently is OK in the earlier buses, but it is about 1.5-2 inches too high for the Vanagon. Recommend low-profile dual carbs.

6) External voltage regulator.

7) Keep in mind that the Vanagon runs a lower 4.57 ring & pinion ratio than what VW used with the 1700s & 1800s, because it came with that 2000cc torque motor. My 1700 pulls the 4.57 no problem, in a Westfalia, but don't be bashful about down-shifting early, leaving it in 3rd in town instead of putting it in 4th, or letting it wind out to the speedo marks, going through the gears if you're merging. Work with it, and you'll be fine.

That's all I remember. Please feel free to message, if any questions.

BTW, the air-cooled engines are a good alternative IF YOU MOUNT A CYLINDER HEAD TEMP GAUGE ON BOTH BANKS, just like every small airplane has. 90% of the problems with these air-cooled VWs are getting the heads too hot, then a chunk of cool air shrinks an intake valve seat in a hot head, the seat falls out, and away goes your motor. I have those cold-junction compensated "Mainline Sensor" brand ones from the UK (on eBay for 75 each); not intending a plug just giving an alternative.

GLTA

[MarkWard]

What did you do about the exhaust? Good info for others.
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[Alan Brase]

Wow, that seems like way more work than just fixing the 2.0 liter air cooled motor already in it.
Most air cooleds fail at the heads. I have never seen a set of OE pistons and cylinders badly worn.
Furthermore, the bottom ends are pretty strong. Many times one could just get the heads fixed and put in new rings and put the old motor back together.
What is REALLY important is taking care of all the details. FUEL LINES, sensors, wires, oil pressure switch, rubber seal around the tin and the tin itself.
Don't get me wrong- I like 17-1800's. Just put it in a 1972-1979 bus, where it fits well.
I think most anybody could fix an air cooled vanagon motor for $1000. Maybe a lot less if you are good at shopping for heads.
I DO HEARTILY agree with OP about the CHT sensors. I think High temps are caused by a variety of reasons, very often the failure of temp sensor I (in the AFM). but ya gotta know you have a problem before you know to fix it.
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Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home

[2mmBTDC]

Mark: The 1700 had an aftermarket (Empi) exhaust. That fit in the space allowed by the rest of the Vanagon, with no issues. I assume the stock 1700 VW system would fit the Vanagon (same block as the 2000, etc) but don't know for sure. As you probably know, the 2000cc Vanagon system won't bolt on to the 1700, because the exhaust ports are different.

[Wildthings]