Hi

The mission has begun to put a CBR600 head on a mini engine. ive been toying with timing belt ideas for a while and have decided its gonna be so much easier if i can use the original timing chain + sprockets. Id have to make the crank sprocket fit, but other than that would that be a problem to use?!

As the chain only spins the camshafts and doesnt have to pull the weight of the car i assume it should be ok?

or have i got it wrong?

cheers

Sorry, not able to help with this other than encouragement as it's nice to see someone try something different. I do remember reading about BMW bike heads being used with the mini.

I have to ask though, other than to be different, what is the benefit over, say, a bike engine? More power to weight? Just wondering what you'll get for all the expence/effort!

Cheers,
James

A chain would need correct tensioning and guide strips as well as enclosing fully to allow lubrication.A belt would just need tensioning and maybe a couple of guide rollers.
Paul

I'm with paulf - the enclosure required for the chain and guides would be a real PIA to make. A belt can be left exposed without issues.

On the other hand if the cams are meant to be chain driven (& the crank is too on an A series) then you're going to have to make something to mount a seal in to run on the shafts to use a belt.
Still mabye easier than making an oil tight timing case from scratch though! It's been done for the crank, I'm sure there are/were kits to use a timing belt on the A series, made cam timing changes much easier.

i still dont know why you'd do it/?

Do any of the stud holes and waterways line up? It sounds a bit of a pointless thread if they don't. The K series BMW bike head does line up, improves on the original mini design and has been well researched and carried out by a few people with documentation and pictures. The car cam chain and the bike cam chain are two completely different formats so you will have to make a sprocket for the crank or two for the camshafts.

the BMW head conversion is getting quite popular but its still expensive in kit form. The CBR head might not produce as much power but is definantly a cheaper alternative! its been done before, its just not a popular one.

im not an engineer or anything, i just wanted a project to tinker with that isnt gonna cost the earth but should be a huge improvement over the standard mini head. to have a spare engine sat in the garage i can play with for little cash works for me!

didnt think about an oil tight case but may have worked out a do-able (to my skills) pulley system, im sure time will tell if it works or not.

the stud holes and waterways dont line up, but they dont for the BMW head either! the valves fit in the bores for each head but you still need to redrill new holes, i dont know where peteff got that information from..... i only assume you mean the valves line up?

its just a bit of fun, if it works then great. if it doesnt its not like im spending thousands on it