GearBox Upgrade

[six]

Hi

im currently building a 74x90.5 engine for my bus and very aware that the gearbox will no do much more than 65 staying in the stock rpm range..

So my options are to get a 091 late bay 2ltr box or modify my ca code box.

Whats the options on modifing the box? any one make some final drives to re gear it etc..

your thoughts pls

thanks
6

 

[Guest]

Bears seem to be the best place for this type of work, i think easy had his gearbox sorted by them?

theres a 2L 091 in the forsale section for £350 i think? http://forum.earlybay.com/viewtopic.php?f=27&t=21327" onclick="window.open(this.href);return false;

definitely cheaper option as i think getting your gearbox reworked with cost around £700 all in depending on its condition.

 

[Trikky2]

You can interchange the final drives from the 1.6, 1.8 and 2 litre gearboxes. The gear ratios are pretty much the same - the only one you notice slightly is 4th ratio of the 1.6 is a bit higher than on the 2 litre.

Heres the relevant data :-

1.6 litre and 1.7 litre

1st 3.80
2nd 2.06
3rd 1.26
4th 0.89
final drive 5.375
Overall in top 4.407

1.8 litre

1st 3.78
2nd 2.06
3rd 1.26
4th 0.89
Final drive 4.86

2 litre

1st 3.78
2nd 2.06
3rd 1.26
Top 0.88
final drive 4.57
Overall in top 4.02

The only disadvantage of the high 2 litre diff is that at 30 mph you have to stay in third because in top the engines doing under 1500 rpm.


If you go non stock tyres and or wheels it will also affect gearing so you can check out here to see how much it would would change :-

http://www.tyresave.co.uk/tyresize.html" onclick="window.open(this.href);return false;

 

[six]

nice one chaps.. yeah tbh i'm thinking finding a 091 2ltr box.. the 3.88 'flyer boxes i think are too much for my planned mild small stroker. best get looking for something close..

thanks again

 

[mattp]

I've just had a gearbox built for me and the advice I was given is that you need upwards a 1.8L engine to push a bus with 2L box. For under 1.8L a std box with taller 4th is fine.

I got a box in which is 1/2 way between 1.6 and 2l boxes and then swap out when the new engine arrives next year

2L boxes seem to go for £250 to £350

 

[easy]

Go with Bears dood, let them know all the specs of your engine and any print outs (rolling road etc) and they will sort you out a box of dreams for your bus 8)

 

[six]

yeah any idea how much one of them would cost though.. im currently erring to the 091 side as its alot cheaper.. plus the torque with a 76x90.5 on some 38's would be plenty to push the bus along nicely.. but would love to know.. however ive found cogbox and other box builders not really up for jsut a chat on the phone..

 

[mattp]

yeah any idea how much one of them would cost though

Second hand for a 2.0box is £250-£450
Getting you old 1.6box reconditioned with a new R+P would give you something similar ratio wise in a 3 rib box for say £600-£700
A re-con 2.0 box from outright is best part of £1k

As a box builder explained to me, the cheapest way to get a gearbox reconditioned with 2.0 ratios is to get my old 1.6 box re-build with new R+P and gears/bearing replaced as necessary.

plus the torque with a 76x90.5 on some 38's would be plenty to push the bus along nicely

May be an 1.8 box is best. I've just had a 1.8 box built for me and also a 2.0 box for my pet project. After some further consideration I think that even the 1.8 box needs 1.8litres up pushing in and the 2.0box 2 litres upwards

however ive found cogbox and other box builders not really up for jsut a chat on the phone..

Because they have a business to run -a chap I know has just bought an all singing all dancing box for erm.....over £3k and I guess this is what get box builders excited

Bears seem a very good place to go and are good on price -they are friendly too.