Upgrade help (contemplating swap to bike engine)
Discussion
Hi.
Tax on my CVH-propelled Mojo2 expires next month, so I'm thinking of declaring it SORN and giving it a proper overhaul for spring '08.
Since the mojo is so light (<550kg wet), and has the mid/rear layout, I think perhaps a bike engine transplant would be a worthwhile endeavour.
I hope to do most of the work myself with a budget of about £3k (say, a cheap fireblade 893/900 unit ~ £500).
With the above in mind, I've got a couple of questions:
What differential set ups do people on a budget use? I understand you can contrive to slap a sprocket on the end of a freelander diff, which apparently has a suitable final drive ratio, and then just chain drive it. Is it really that simple?
Will I run into trouble with the dvla? I've been told that it's just a matter of filling in a form and declaring the change of capacity/engine serial No. I presume it must have to be inspected too. Is this an expensive/difficult process? Is it as strict as SVA?
Thanks
Tax on my CVH-propelled Mojo2 expires next month, so I'm thinking of declaring it SORN and giving it a proper overhaul for spring '08.
Since the mojo is so light (<550kg wet), and has the mid/rear layout, I think perhaps a bike engine transplant would be a worthwhile endeavour.
I hope to do most of the work myself with a budget of about £3k (say, a cheap fireblade 893/900 unit ~ £500).
With the above in mind, I've got a couple of questions:
What differential set ups do people on a budget use? I understand you can contrive to slap a sprocket on the end of a freelander diff, which apparently has a suitable final drive ratio, and then just chain drive it. Is it really that simple?
Will I run into trouble with the dvla? I've been told that it's just a matter of filling in a form and declaring the change of capacity/engine serial No. I presume it must have to be inspected too. Is this an expensive/difficult process? Is it as strict as SVA?
Thanks
That's the trouble with the mojo. There's so few of them out there, and they're mostly 4age or cvh powered - still, I find it hard to believe that it can accomodate a CVH + gearbox + twin sidedraughts (okay, fairly compact) but not a bike engine.
I've not seen any concrete evidence of a b/e mojo, but there's a youtube vid of what is described as a cbr600 powered one. Time to nip to the bike breakers with a tape measure, methinks.
Does the chain drive diff require that much space? The engine bay is quite tall to accomodate the engine+gearbox.
I've not seen any concrete evidence of a b/e mojo, but there's a youtube vid of what is described as a cbr600 powered one. Time to nip to the bike breakers with a tape measure, methinks.
Does the chain drive diff require that much space? The engine bay is quite tall to accomodate the engine+gearbox.
Capt.Sadness said:
I understand you can contrive to slap a sprocket on the end of a freelander diff, which apparently has a suitable final drive ratio, and then just chain drive it. Is it really that simple?
I doubt that will work, if you mean attaching a sprocket to the diffs input flange? If so that would mean mounting the bike engine longitudinaly rather than transversely.Most mid engined BECs I have seen use the internals from a sierra/landrover diff, with a sprocket mounted in place of the crown wheel and a custom made cradle to mount eh bearings on etc. You have to work out a way of keeping oil inside the now open diff.
How about putting the money towards a Rotrex supercharger conversion?
Edited by Mr2Mike on Thursday 26th July 08:55
Hi,
You're right, that seems to be the solution in the sylva riot - it uses the fiesta diff (which i'm already using in my car) with a chain sprocket in the middle - which of course makes more sense than a freelander diff, which must be for f/r arrangements, unless, as you say, one were to twizzle the engine around.
I've emailed sylva to see if they know of anyone who has managed to mount a bike engine in a mojo.
You're right, that seems to be the solution in the sylva riot - it uses the fiesta diff (which i'm already using in my car) with a chain sprocket in the middle - which of course makes more sense than a freelander diff, which must be for f/r arrangements, unless, as you say, one were to twizzle the engine around.
I've emailed sylva to see if they know of anyone who has managed to mount a bike engine in a mojo.
I don't know, as I've got a Phoenix, but I thought that the reason JP had to redesign the Mojo ( to become the riot) was to allow the bike engine to sit in the car with the same configuration as it had on the bike, offset, so the final sprocket aligned with the diff, allowing the chain drive, and saving a lot of money on the final drive, at least that is my impression from reading the stingray site. If you mount the engine the 'wrong' way, as in a bike engine striker, then surly you can get the engine in the Mojo, it must be half the size of the CHV.
I have no idea about what this car looks like, however if you are trying to put a bike engine in the rear, I would suggest that you get in contact with one of the universities that is participating in the Formula Student Automotive Engineering Competition (FSAE) as this is basically how they do it. You might even find that they have the parts you need lying around, of an earlier prototype or last years car. They have to design and build a new car every year.
If you find the engineering building and ask around at either admin or piston heads type people they will probably point you in the right direction. If you talk to admin just pretend your looking to sponsor the project, i.e. have cash for old parts. Last team I was involved in had three different diff adaptations lying around, each with different lSD’s inside a machined housing. This held the oil and mounted the sprockets on the outside. Also allowed the engine to sit central in the car and equal length drive shafts. Later developments were focused around making it lighter. I think the dif was out of a Subaru front transaxle. The GT had clutch type, STI viscous, and a custom torsion was also made to fit.
If you find the engineering building and ask around at either admin or piston heads type people they will probably point you in the right direction. If you talk to admin just pretend your looking to sponsor the project, i.e. have cash for old parts. Last team I was involved in had three different diff adaptations lying around, each with different lSD’s inside a machined housing. This held the oil and mounted the sprockets on the outside. Also allowed the engine to sit central in the car and equal length drive shafts. Later developments were focused around making it lighter. I think the dif was out of a Subaru front transaxle. The GT had clutch type, STI viscous, and a custom torsion was also made to fit.
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