Rear Diff in Bike Engined Terrapins

[PHULL]

Gday guys hows it going, just been reading thru the forum and it's very impressive. I have bought the book a while ago

what I want to know about is how the people who have fitted bike engines couple the bike engine it's self to the back wheels.

what kind of diff do you use? is it some form of LSD
I know it has to be chain driven and I can see just fitting a locked differential as the easy way out, but it would handle like a dog.

do you guys bother fitting reverse to you cars


Thanks guys

[BigMark]

Hi Phil
I am not sure if any of the bike engine boys are on here yet but two options seem to be around, one is the Quaife chain drive diff (mucho mucho money) the other is to build your own version. I'm afraid as a newbie to this stuff I cant be too much help on the techy bits of doing that but I have been told on good authority that it is not that hard. I am sure someone on here will shed some light on it.
As for reverse I doubt very much if anyone would bother fitting a reverse to a Terrapin.
Cheers
Mark
PS this is a home made diff based on a Fiesta drive train

[twentyover]

Simplifying it-

1) Take a diff (either posi or open)
2) Remove Crownwheel
3) Bolt on sprocket

Of course, you'll want to seal lubricant in the diff section (those pesky tech inspector do have a problem with a diff drooling lube all over the course), maybe by building a cup or sleeve that covers the open spyder section. Remember you'll need to add (and change) lubricant, and vent it.

You'll also need to mount the dif in bearings (either pillow blocks, or bulid pillow blocks out of sealed bearings with the ID to fit your diff). This thing will probably not see more than 3000 rpm (if you use really teanie tires) , so you don't need to get too exotic on bearings

Yes, there is some design work in building the seal cup and venting, but don't make this tougher than it really is.

[Jawfish]

I'm interested in this for my next project.... a Super Terrapin,

I have to admit that I am mechaniccaly challenge in that area. I have a torsen form a 7.5GM diff, I get the idea of pillow block or bearings, the cap/sleeve for the diff fluids, but, my challenge is in the details. I'd really like to see a true exploded view of a set up and how you get about it. How do you build it ?

Hey there hope for me, since I did do my frame ;D

Fred

[Mr Locost]

This has been done with plenty of diffs. I have seen an Audi diff, Mini diff, Metro diff, Fiesta diff, escort diff and many others. The difficulty tends to be getting the sprocket straight.

Adam

[MiNiTiCi]

Hi Phil,
Your plea prompted me to update my web site to include some details of chain drive diffs.
Hope this may be of some use..
www.westhouse.plus.com/chaindrive1.htm
Doug.

[Jawfish]

Ask and you shall receive

Thanks Doug, this was what I was looking for, more details ;D

Fred

[Terrapin]

Great illustration Doug.

[PHULL]

Sensational page doug it gives me a heaps ideas.

what you think about BMW 323 lsd's? I don't know about you guys but they seem to go cheep round here
But I recon the clutch packs to rebuild them will be the killer last time I had to get one for a friend they were about $600 Aus

Ill keep an eye out for the Audi Torsen

[MiNiTiCi]

Hi Phil,
Re. BMW 323 lsd - I don't have any experience of them but having just looked at an M3 diff on e-bay, it looks a likely canditate for converting to chain drive.

Also - all you guys with Mini power or wanting a good strong basis for a chain drive, I also noticed a couple of Mini LSDs complete with outputs and 'S' couplings on e-Bay at the moment.
Doug.