1776 engine and gearbox / transmission upgrade for my 69 Westy

[mabbo]

Hi,

I have a 69 Westy with a 3 rib 002 gearbox and a 1600 twin port. My gearbox needs a rebuild and Im planning on having the ring and pinion changed for better gearing on the motorway. I assume it will be the same, or similar gearing to a 6 rib?

Anyway, I was planning on rebuilding the 1600 at the same time to help with the longer gearing. Im hoping a very mild 1776 will be enough? Id like to keep everything stock - the cam, and heads etc all stock, just a balanced crank assembly. Id also like to keep a single vacuum advance distributor, 34 pict 3 and stock exhaust.

Will this be enough to cope with the gearing? Or would I need a small cam, twin 36 DRLA or IDFs, and a better exhaust?

Cheers
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[SGKent]

I upgraded to a later gear ratio in my 1971 and it was a huge mistake.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[aeromech]

I can see that just like me you have preconceived ideas about what you think will work best in your bus.
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VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
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[mabbo]

[mabbo]

[SGKent]

[richparker]

Don’t change the R&P of the transaxle, just like the others have stated you will regret it. I have a ‘71 Westy with a 2275cc and the stock 3 rib 002 transaxle, which was rebuilt. It’s a great combo. Plenty of torque to push a heavy loaded bus and it is able to maintain speeds a lot better.

Building a 1776 seems silly to me. If you are gonna pay a machinist to open your case, why not have it opened to accept 94 pistons and build a 1914. It’s not like the price is going to be higher. A 1914 with a PICT34 (with an enlarged Venturi) and a Engle 90 cam is a real stump puller.
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[aeromech]

I think his preconceived notion involves Porsche speeds as opposed to stump puller torque.

Seems to me you need to keep your stock tranny. Then build a slightly larger, well balanced, high RPM engine. Being able to run all day long at 4500 rpm would get you the highway speed you want. You’ll need all the rotating engine parts balanced as well as a welded and balanced generator fan that can handle the rpm.
_________________
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

[Wildthings]

Try going to larger diameter tires to begin with. 27x8.5r14's will effectively give you 5% longer gearing than the stock 185r14 tires, and make is easy and cheap to go back to stock if you want.

For what it's worth, on a 4-5% grade my empty bus with an aged 1800, late 002 gearing, 27x8.5R14 tires, and a progressive carb will out pull my empty Thing with a 1600, 185r14 tires, Bug gearing and stock carburetion.

[richparker]

I agree with the 27x8.5 tires, but you gotta have the engine to push them.
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’71 Westy build
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[mabbo]

[mabbo]

[mabbo]

[richparker]

[mabbo]

[SGKent]

I am an old man now and my math isn't nearly as good as when I was younger. But I believe that a 2L has a 94mm bore. That means the surface area is 6940 sq mm. A 1600 has a 85.5mm bore. That is 5,741 sq mm. The 2l has almost 20% more surface area on the piston. That is essentially 20% more push when the cylinder fires. The stroke affects how long that push is and the angles involved, but in general the shorter the stroke the more frequent the engine can fire, and the faster it can spin. To get max push you want the larger bore, assuming that the case, crank, clutch, rods can handle the forces. A longer stroke engine of the same bore will have more torque, but the top end speed won't really be all that faster. I proved that back when I built racing engines by building smaller displacement engines (same bore but shorter stroke) that went faster down the straightaway than longer stroke engines. The shorter stroke engines reved faster and higher. A longer stroke will generally be more efficient as it will harness more of the heat that pushes it. A 1776 is a bore of 90.5 mm so it will be about half the power gain of a 2L over a 1600. A 2L T4 is 1970 cc. A 1600 is 1584 cc.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[skills@eurocarsplus]

it's all in the combo

i'd play with tire size to shed a couple hundred RPM's but a 1776 is a warmed up 1600 imho.

i have a 1904 in my 71 with stock gearing. it will do 75 at about 3800-4k all day.

if you liked the late bay, copy the power and gearing of that. these engines scream because they need to keep the fan speed up for cooling.
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[aeromech]

"Ideally was looking for real world experience of doing the same as what I had planned rather than just opinions."

"I understand its an old bus and cant be compared to a modern SUV but I loved how my old late bay with the 6 rib and 2 litre drove. Ideally Id like to get a little closer to that."

Okay, real world experience. In order to get what you want the following is what I did for a customer with deep pockets. His was a 1968 bus with stock engine and tranny. Here are pics of what it became. Apologies to all you guys that have seen this before.

2007cc engine with dual Dellortos
Engle 100 cam
Sidewinder exhaust

091 Six rib

Power drum brakes

_________________
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

[dub_crazee]

Cool pic of your servo bro.


Ultimately if you’ve got 100 hp + you’ll have enough power for a longer 4th and lower rpm cruising. Talk to you transmission builder; tyre sizes, power and use of vehicle will all make a difference to what he recommends.

You know the score Mabbo
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69 Beetle
71 Bay
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[richparker]

Please show me your 100hp rear wheel HP bus build, I’d love to see it.

In the real world I dynoed my 2175cc on a Mustang Dyno in Tucson, Az. 75 HP with 107 FPT.

Unless you show your bus on a rear wheel dyno with “real” numbers, all your calculations mean nothing!


Link

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