Which is the best reverse box?

[Rob Bailey]

There are a number of reverse boxes for BEC on the market. I like the quaife box as it is straight through and does not have any of those pesky chains. It weighs 6.5kgs.

 

Are there any other decent options that I should consider?

 

Any help greatly appreciated!

[lancelot]

Try the following:

 

 

locost builders BEC forum

 

seventorque BEC forum

 

yahoo.com bike-engined-cars

 

Probably much more info on these as they are bike-engined only...

 

What are you building?

 

Edited by - lancelot on 4 May 2005 17:19:03

[ChrisG]

You will likely get the answers either "don't bother - get the missus to push" or "electric" 😬.

A good mechanical reverse box seems to be a tricky beast to manufacture, many have tried and failed to get them reliable. I think the Quaife ones now are probably OK (you'd hope so considering their overall experience) and possibly one or two other designs, although not many seem to buy reverse boxes now because of all the problems with them over the years, so either go electric or don't bother.

 

Edited by - ChrisG on 4 May 2005 17:27:02

[blade_runner]

I have the old chain box made by Nova transmissions, My box and car was used for the reversing speed record of 102 mph, as long as u remember the chain is a service item, and does need to be changed then you should have no problems with it, the chain failures in early boxes like mine were usually due to a poor quality chain being sourced, but this seems to have been sorted, I know of another 2 Caterham Fireblades locally using the same method, and we have each changed the chain once each, and between us we must have covered over 10k, mind you we have all added a breather to our boxes and the standard design seems to allow the box to pressurise and then it forever leaks oil, a simple drilled, tapped hole with a pipe fitting screwed in and a length of washer hose up under the scuttle works fine, I will prob change my chain every winter, even if it doesnt need it, it can be done easily in 2 hours and I paid around £30 for two chains from Nova, so its not expensive. my car has had a very hard life, being the demo fireblade car and then raced by the second owner, and apart from chain wear the rest of the internals of the reverser box are fine. there are some photos of the internals of the reverser and a chain change on my webshots site under overhauls and up grades... Just click 'pinky pics' down there

 

'Pinky Pics' here

[Rob Bailey]

I am building a Caterham Hayabusa, I was going electrice reverse route (RACMSA rules state that it must have a reverse) but all the pumps for the dry sump seem to be getting in the way and it won't fit.

 

Therefore I am now resigned to a mechanical reverse. Nova and Quaife boxes are about the same price, the Nova box uses a chain that I am not too keen on and I have heard that the quiafe is a noisy beast.

 

Is it true about the quaife?

[blade_runner]

I cant speak for the Quaife box, I have never used one or know of anybody that has one, however I did look over the quaife at the Last autosport show and it did look from the outside a well put together piece of kit, but to as how it performs... I have no idea 🤔 In mine I can sometimes hear the Nova box in the back ground but its not overly noisy, unless the chain is badly worn, the main problem with the nova box is it has no tensioner on the chain so thats the noise you hear. its a measured fixed length of chain so you get slack on the unloaded side of the chain between the sprockets. as I had posted earlier, it works ok for me, but if i was building a new car I would explore other boxes, they must all have pros and cons.

 

'Pinky Pics' here

[caligarinet]

I have the Quaife reversing box fitted, haven't found it generating any noise at all?

 

Only problem I have had is that the mechanic that fitted it didn't mount it to the chassis very tight, so vibrated lose, easily resolved, only for the bolts holding on the prop-shaft to come lose, as the mechanic hadn't threadlocked the bolts.

 

At present it is working well.

 

The car initially had an electric reverse mounted in the passenger seat, which was kind of impractical for me, as I do want to be able to fit a passenger seat when needed.

 

 

[blade_runner]

Have you tried to speaking to Z cars? they specialise in bike engine conversions and may have a reverser box design all of there own? may be worth a call?

Z cars website here

 

'Pinky Pics' here

[steve_m]

The weight saving of not using one isn't that great as you'll still need a centre bearing and some other form of reverse - you might save at most 1.5 Kg.

 

Mine vibrated but Quaife fixed it, one of the dog rings wasn't perfectly round. It also leaked oil from the selector shaft oil seal but again Quaife have fixed it, all free of charge. Their support is very good.

 

In forward gear it's 1:1 dog engagement with no gears so doesn't really sap much power and will handle whatever power you put through it, there are 400bhp turbo busas using them with no problems. The bearings are apparantly pretty big for what they are asked to do so it shouldn't cause any problems.

 

The oil filler/breather cap needs to be replaced with a breather pipe and small catch tank at least 30-40cm above the box. I also change the oil in mine every 3000 miles although I don't think this is technically required. Takes about 250ml or so of fully synthetic gear oil, I use Redline lightweight shockproof as that's what's in the diff.

 

[Irrelevant]

robertb: I have almost completed a Caterham Hayabusa turbo.....so I have been through the dialemma you are facing. I'll tell you what influenced my decision......there is no right or wrong though, everything's a compromise.

 

If you want the engined mounted as far back as possible and at the 'correct' angle, you will not have space for an electric reverser up front and there is no space at the rear of the tranny tunnel.

If you want a starter motor type reverser (like Blackbird Motorsport built cars) then you will have to mount your engine a bit squint and relatively far forward so there is space for the starter in the front of the tranny tunnel. Andy Griffith's 1500cc Busa is built this way and he doesn't have any problems so there's nothing wrong in doing it that way.

Being an anal perfectionist git, I decided I wanted the motor as far back as possible and a also wanted the engine mounted 'correctly' - i.e. with the output sprocket at right angles to the body.

I ended up getting a Quaife reverse box as they will take the big torque that I'll have and they are very compact. I'd heard loads about problems with the Quaife boxes but I think they changed the design and the new boxes are supposedly OK.

 

Suffering serious sprint cold-turkey. Must get this finished

[Rob Bailey]

Z-cars are doing the installation of the engine for me and I can assure you they do not have a solution to the reverse problem. I am really desperate to get the car on the road right now. Thanks for all your input guys, Mr Quaife is getting the order. I let you know how it goes when she is installed and running...

 

Thanks again,

 

Rob

[Irrelevant]

robertb: Have you committed to having Z-Cars do it?

 

Suffering serious sprint cold-turkey. Must get this finished

[Rob Bailey]

Adam,

 

Yep, they have already installed the engine and they have tried to fit an electric reverse. I should be picking the car up within the next 2 weeks fingers crossed.

 

Here is hoping,

 

Rob