Engine/gearbox interchange info

Discussion in 'Mech Tech' started by Juneau, May 30, 2013.

  1. My current setup is a 1700 type4 engine with standard gearbox (1973).

    I plan to do a rebuild on the engine and gearbox over the winter and have a very basic question.

    Firstly, I'd like to increase the capacity (it's a heavy bus doing some high mileages). I have a spare 2 litre crank and will be replacing the barrels and heads so it will be over 2 litre when finished.

    My question is will my rebuilt existing gearbox take the increased torque OK? (I guess VW designed the six rib 2l gearbox for a reason).

    If not, what are my options for mating a 2l gearbox to my existing cases regading the cluth assembly, clutch bell housing etc, etc?

    Any advice appreciated.
  2. Moons

    Moons Moderator

    I run a boggo 3 rib box with a subaru engine and it seems happy enough - I think your issue (unless you are a revs the nuts off it and dump the clutch merchant) will be gearing.

    Mine needs a taller 4th for sure - and I think that's the major benefit of the 6 rib box.

    However, there are far more knowledgeable people here than I!
  3. The engine will be designed for maximum torque, road use only. It's a Westfalia (so quite heavy to start with) and our European round trips range from 2,000 to 3,000 miles, with four people onboard, plus loaded with camping gear. To be honest, the 1700 does really well (constant 70 to 80mph on the motorways) but she suffers on the hills. This years trip will be in Holland so nice and flat. However, next year will probably take us across the Alps.

    Not sure how the internals of the three and six rib differ. Is it mainly gear ratios or is everything stronger?
  4. Baysearcher

    Baysearcher [secret moderator]

    Think its the ratios, final drive, and the case itself is stronger.
  5. Also, I'm planning on using Stateside for the engine work and Bears for the gearbox. I've not used either before but talking to them they seem experts on their subjects.
  6. Baysearcher

    Baysearcher [secret moderator]

    Both über expensive, not that that's any real indicator!
  7. I've just been through a similar scenario myself, but slightly different set up
    1600 gear box CE code (oo2) and type 1 1776cc engine. Didn't notice any issues with gearing etc

    Then I fitted a 2110cc type 1 stroker engine, keeping the same 1600 gearbox. Now i run out of gears/ratios are all wrong so i'm replacing it with a new box with better ratios for the size of the engine. It is being fitted next week (hopefully).

    So type 1 2110cc engine with 1600 box didn't work for me. I was doing 50mph in 4th at 3,500 rpm.

    Most people told me to get a 2l gearbox (091, with 6 ribs), but they are mega money and you have no idea what condition they are in until it's too late. There is one on volkszone at the moment for £950!

    In the end I opted to get a brand new/rebuilt (002) gearbox from bears motorsport in Birmingham, but fitted with a the same final drive of 4.57:1 that is used in the 2l gearbox. So all the ratios are the same as my previous gearbox, but changing the final drive means all gears are slightly higher. Based on tyres of 185 65 15 i should now get 68.1mph at 3,500rpm.

    I decided that a very expensive, but possibly worn out 2nd hand 2l gearbox wasn't good value for money. One from Bears costs more but has been completely rebuilt with new bits and should last a long long time

    Sorry I can't help on mating clutches and bell housing.

    I hope this reply is of help

    Here is a thread to lots of useful ratio information

  8. I only saw this after i posted my reply.

    No experience of stateside, but good experience with Bears so far. I'll let you know once the new box has been installed, feel free to pm a reminder if i forget!
  9. Baysearcher

    Baysearcher [secret moderator]

    The £950 box on VZi was rebuilt though.
    How much was the bears re-build?
  10. oh yeah
    Vw type 2 2.0l 76-79 reconditioned gearbox for sale. 091 CP code 6 rib box. Reconditioned extensively with lots of new parts. Can be purchased outright for £995 or less if you have an exchange unit.

    You'll need to speak to Bears about exact pricing, mine was £950 plus vat and it was on an exchange basis. They are building me one with majority new parts and once it's fitted I'll give them my existing box. So i think that is a good deal compared to a unknown 2nd hand unit, even if it is reconditioned.

  11. I'm told the (091) 2l box is 8mm longer than a (002) 1600 box, which is important depending on engine and tin wear. The 091 is a 6 rib box which is apparently stronger than the 002 gear box case, however the 002 box is plenty strong enough for loads more horse power than any of us are ever likely to throw at it. Also told by a few people that they have never seen an 002 gearbox break!

    The info below on ratios was originally posted on prototype, in repsonse to a post i made that was similar to your original post.

  12. Baysearcher

    Baysearcher [secret moderator]

    Useful info there cheers! I've got a 5 rib from an 1800 so should be good for my new engine.
  13. I'm glad that re posting a reply I got from someone else can be helpful, especially as I'm not technically competent to post in a 'Mech tech' thread!
    Baysearcher likes this.
  14. Fantastic advice and data. Plenty for me think about. I've got a very lazy driving style so maybe a refurb on my existing box with a taller final drive would be the way to go.
  15. I have an prototype box and it's fine at all speeds.
    I don't want to slow the engine down as it's a T1 based engine and the cooling fan's only so big...
  16. sounds like a plan

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