Discussion
A Caterham with an ordinary four-cylinder engine weighs around 1100 lbs.
The four, with its gearbox and clutch, weighs around 275 lbs.
This leaves the car less engine/box at around 825.
I'm thinking about building one with a Honda XR650 air-cooled single. That weighs around 85 lbs including its gearbox, putting me at 910 before even considering any of the other savings this engine offers - tiny battery, no radiator or water, narrow tires, some weight off the exhaust, the ability to select the lightest-duty axle and some narrow tires, a smaller gas tank, etc.
The disadvantage, of course, is power - the most I could get from a streetable, durable XR650 would be 50 hp, which would fall to 45 or less on a hot day. I'd end up with around 120 bhp/ton empty/cool which would fall to around 90 bhp/ton with me in it and the engine running hot.
Has anyone driven a low-powered Se7en regularly? Is it still fun on the road and fast enough to keep up with traffic?
The four, with its gearbox and clutch, weighs around 275 lbs.
This leaves the car less engine/box at around 825.
I'm thinking about building one with a Honda XR650 air-cooled single. That weighs around 85 lbs including its gearbox, putting me at 910 before even considering any of the other savings this engine offers - tiny battery, no radiator or water, narrow tires, some weight off the exhaust, the ability to select the lightest-duty axle and some narrow tires, a smaller gas tank, etc.
The disadvantage, of course, is power - the most I could get from a streetable, durable XR650 would be 50 hp, which would fall to 45 or less on a hot day. I'd end up with around 120 bhp/ton empty/cool which would fall to around 90 bhp/ton with me in it and the engine running hot.
Has anyone driven a low-powered Se7en regularly? Is it still fun on the road and fast enough to keep up with traffic?
I think this is an interesting idea but given the lack of power from a single agree that it's just not going to be quick enough even at that weight.
Does anyone know if a 7 has been built with a V twin engine? I was thinking of something from Ducati or possibly a Honda VTR100, these give decent power and should be very light weight compared to a car engine. Obviously a Harley engine is out of the question as given their weight and feeble power output these are only suitable for agricultural applications.
Does anyone know if a 7 has been built with a V twin engine? I was thinking of something from Ducati or possibly a Honda VTR100, these give decent power and should be very light weight compared to a car engine. Obviously a Harley engine is out of the question as given their weight and feeble power output these are only suitable for agricultural applications.
Vlad the Imp said:
Does anyone know if a 7 has been built with a V twin engine? I was thinking of something from Ducati or possibly a Honda VTR100...
Not a Caterham, but I know of several 'Sevenesque' cars that have been built with Vee twins. See this thread for further discussion and examples.http://www.locostbuilders.co.uk/viewthread.php?tid...
This guys fitted a VTR engine to his seven type car, when you read down it tells you about it all. ITs quick as well, i remember him doing Croft in a 1.36 which is megagrad time.
This guys fitted a VTR engine to his seven type car, when you read down it tells you about it all. ITs quick as well, i remember him doing Croft in a 1.36 which is megagrad time.
Arrrghhh, metric and imperial in the same post = Engineer pain!!!
Seriously though, a 120bhp/tonne (metric) Caterham is going to be a bit steady. I'd say 180-190bhp/tonne is the minimum you want
Now what would impress me is if someone stuck a chunky (150bhp+) air cooled two stroke in a Caterham... THAT would be cool. Knowing nothing about bikes and their engines, are there any candidates?
Seriously though, a 120bhp/tonne (metric) Caterham is going to be a bit steady. I'd say 180-190bhp/tonne is the minimum you want
Now what would impress me is if someone stuck a chunky (150bhp+) air cooled two stroke in a Caterham... THAT would be cool. Knowing nothing about bikes and their engines, are there any candidates?
That would be a lot of money in custom bits for...a pretty slow car. Have to wonder about the cooling and gearing too. Assume live axle, so you are somewhat limited.
Interesting, but there are probably easier ways of getting about.
Ian at Stuart Taylor experimented with lots of bike engines, some more successfully that others (he blew up quite a few gixxers !!) as you can see from Sam's link.
If you are looking at an S3 imperial Caterham chassis, then there isn't much room in there. A v-twin, particularly a 90degree one, is going to be tricky a) to fit under the bonnet b) to get at the right angle for the propshaft to go down the tunnel.
Not impossible, and the characteristics could make for a great fun car. Lovely noise, and good torque spread if you can get the gearing right.
Boring I know
but a one litre 4 cylinder bike engine is going to be a lot easier to get parts for in the US. There is a very well populated bike engined race series that use them.
Interesting, but there are probably easier ways of getting about.
Ian at Stuart Taylor experimented with lots of bike engines, some more successfully that others (he blew up quite a few gixxers !!) as you can see from Sam's link.
If you are looking at an S3 imperial Caterham chassis, then there isn't much room in there. A v-twin, particularly a 90degree one, is going to be tricky a) to fit under the bonnet b) to get at the right angle for the propshaft to go down the tunnel.
Not impossible, and the characteristics could make for a great fun car. Lovely noise, and good torque spread if you can get the gearing right.
Boring I know
but a one litre 4 cylinder bike engine is going to be a lot easier to get parts for in the US. There is a very well populated bike engined race series that use them.Gassing Station | Caterham | Top of Page | What's New | My Stuff