1835cc and 6rib tranny in a 68 baywindow

[brently88]

Hi there,
Just purchased a 68 bay window that came with a 3rib tranny and no motor. I'm planning on getting a 1835cc motor and a 6rib tranny. My question is would it take any extra supports other than the moustache bar since everything is bigger, and has anyone had any experience with this?

[Brian]

Weld in some supports on the frame for the "ears"

The transmission is the only thing that will be heavier.
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[airschooled]

The weight of the engine is nothing compared to the force of the torque that the engine/transaxle assembly applies to the wheels and rear mounts. Think about Newton's third law; every force has an equal and opposite force. Consider the strength required to accelerate a bus from a dead stop? That amount of force, (more or less depending on gear selection,) is working on whatever mounting system is holding your power-train in place.

The shift rod length might have to be compensated for due to the engine/trans combo being a different length that what either the bus or transaxle came with.

Robbie
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[brently88]

I'm completely new to the air-cooled scene, thank you guys for your input. Would it be a bad idea to run a 3rib with the 1835cc?

[Jeff Geisen]

Late transaxle into upright engine - don't neglect the input shaft length, the late one is too long and will eliminate crankshaft end play in the upright engine if not exchanged/shortened.

IMHO, the weight difference between the two transaxles is negligable, the weight difference between T I/T IV engines is the reason for the bell housing's "ears".
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[Tcash]

Who's installed an 091 Transmission in an early Bay?

[richparker]

[Randy in Maine]

I would also keep the stock transmission. A 091 will gear you up too much and you won't have the torque to make it work well.

[brently88]

Would I need anymore support other than the mustache bar since the engine is larger, or since I'm not upgrading the tranny would it suffice?

[Randy in Maine]

Just make sure the moustache bar is helping support the engine in the rear and you will be fine.

[aeromech]

I installed a 091 into a 1968 bus but it was matched to a 2007cc engine which is very close to what VW did originally with the 091. If you want to do it here's some pics and just read the link that was posted above. Ask if you have any questions.

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[aeromech]

Swap the bell housing from the 091 to the 002

Swap the input shaft from the 091 to the 002 (or cut it like I did)

Swap the nose cone so you can use the old style forward mount
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[sodbuster]

My school of thought on all this is that VW put allot of time and money figuring out gear ratios for these buses. they must have been doing something right.

For the bay window buses VW offered three basic ring and pinion ratios over it's production lifespan. the 002 3 and 5 rib transaxles came with 5.375 to 1 for the 3 rib and 4.86 to 1 for the 5 rib. The 6 rib 091 came with a 4.57 to 1 ring and pinion ratio.

these changes reflected the increases in engine type, size and displacement through the years. Buses with the 1600cc single and duel port motors and the early 1700cc type IV motors used the three rib 002 with the 5.375 to 1 ratio. once the horsepower and displacement started going up room for improvement was needed.

This led to the new and improved 002 transaxle also known as the "5 rib" or "pyramid" transaxle. It came with the 4.86 to 1 ring and pinion ratio. along with the new ratio came improvements to the shafts gears and case. these transaxles came in buses with the 1700cc and 1800cc solid lifter motors but mainly designed to handle the 1800cc motor.

but the larger displacements kept coming as wel as body safety improvements and added options that kept adding weight to these puppies.
VW had the 2000cc hydraulic lifter motor coming down the pipeline but was still using the 1800cc fuel injected motors when it introduced the 091 transaxle with the 4.57 to 1 ring and pinion ratio. though used in models with the 1800cc motors it was ultimately designed for the 2000cc motor.

I know I know. Whats my point? My point it this. VW took the time to carefully match the ratios of it's transaxles to the displacement of it motors. when I went through my bus I did so too. I couldn't be happier with the results. All of the ratios I have been talking about are all available in the aftermarket for the 002 transaxles. IMO your early 002 in it's stock form will have no problem handleing the 1835cc motor but the motor itself would be mutch happier in it's powerband with the 4.86 to 1 ratio as opposed to the stock 5.375 or the 091 with it's 4.57 to 1 ratio.

Mi dos centavos.

P.S. for the record, 71 westy 1776cc 002 transaxle 4.86 R+P.

[sambabus]

The 3 rib 002 is good for about 200 hp. The 1835 usually makes less than 100 hp. Why are you going with an 1835, because that's what you have?
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1970 convertible bug, 1835cc, single 40IDF, disks.
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[skills@eurocarsplus]

[brently88]

The guy who I'm getting the rebuilt longblock from said he could do a 1835 for the same price as a 1776 so I figured I might as well get a little extra power.

[dawie]

Do not forget that there are differences in 4th gear ratios as well.

Generally, the 3 rib boxes have 0.82:1 4th gear. (Wide gap between 3rd and 4th).
The 5-rib and 6-rib usually came with 0.89:1 4th gear. However there were some conflicting info published by VW on these ratios.
"Vanagon" 2L had 0.85:1 4th.

In simple terms:
3-Rib ring & pinion is 10% shorter than that of 5-rib. (Roughly). But:
3-Rib also has 8% taller 4th gear. (Compared to 5 & 6 rib).

So 3 rib's overall gearing in 4th gear is only 2% shorter than 5 rib, but it's first 3 gears are 10 % shorter overall.

2L bay's 6-Rib 091 have roughly 6% taller gearing in all gears compared to 1800- "5-rib".

[brently88]

Decided to stick with the 3 rib tranny and go with an 1835cc. I even went and got the tranny checked out, and he said the tranny looked like it was in great condition after sticking a wire camera through it. Let's hope it shifts just as well.

[Brian]

screw it get a 2110
But good choice. 1835 isn't a stroker so a 002 with a 5.375 I imagine is ideal.
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Wash your hands

'69 Bug
'68 Baja Truck
'71 Bug
'68 Camper

Only losers litter

[Tcash]

Tranny Refresh..... how far to go?