Bike engine for kit car
Discussion
I've been thinking about building a kit car for a while now and I've never really decided on an engine as I really dont know much about them so I'm looking for any advice/opinions. Does anyone know if there's a usual 'go to' engine, or if there are any good options? So far considerations are around reliability/cost/power in that kind of order.
Bike engines are fair expensive due to their popularity in kit cars. Probably 3k+ for a running engine/ECU etc.
You want as large displacement as possible due to lack of torque in bike engines;
ZZR 1400
Hayabusa 1300
ZX-12R
There are plenty of car engines that would be suitable for your car and cheaper. What car is it?
You want as large displacement as possible due to lack of torque in bike engines;
ZZR 1400
Hayabusa 1300
ZX-12R
There are plenty of car engines that would be suitable for your car and cheaper. What car is it?
A bike engine can be very suitable for a light car. A light 7 or similar will be much more responsive both to throttle and to steering without 150Kg of boat anchor car engine and gearbox.
As your car gets heavier, you'll have to change the final drive to reduce the gearing and increase torque at the wheels. Talk of the bike engine not having enough torque isn't quite right. True, they have less torque, but it's plenty for a light car. And what matters is torque at the wheels, not at the engine. The gearbox and final drive are torque multipliers.
I have a 2002 R1 engine (150bhp) in a sub 350Kg car. I'm geared so that 1st gear runs out at 60mph, which gives me a theoretical top speed of just over 140mph. For comparison, the bike weighed 200Kg and could do 90 something in first. My car accelerates from 3000rpm in any gear better than most sports cars, but the real performance doesn't come until >7Krpm.
On the downside, motorway cruising is buzzy.
So, is a BEC right for you?
It depends on the car you're looking at putting it into and what you want from it.
As your car gets heavier, you'll have to change the final drive to reduce the gearing and increase torque at the wheels. Talk of the bike engine not having enough torque isn't quite right. True, they have less torque, but it's plenty for a light car. And what matters is torque at the wheels, not at the engine. The gearbox and final drive are torque multipliers.
I have a 2002 R1 engine (150bhp) in a sub 350Kg car. I'm geared so that 1st gear runs out at 60mph, which gives me a theoretical top speed of just over 140mph. For comparison, the bike weighed 200Kg and could do 90 something in first. My car accelerates from 3000rpm in any gear better than most sports cars, but the real performance doesn't come until >7Krpm.
On the downside, motorway cruising is buzzy.
So, is a BEC right for you?
It depends on the car you're looking at putting it into and what you want from it.
"due to lack of torque in bike engines" - sorry, but that is rubbish, the engines you mention above all have torque well in excess of the vast majority of typically used car engines - everyone forgets the fact that there is a reduction gear on bike BEFORE the gearbox, so any torque figures you see quoted, which will be at the flywheel, should actually be multiplied by 1.5/to 1.6 (depending on the bike), hence the ZZR1400 mentioned above has usable torque of around 180ft/lbs
Yes, if you were talking about things like the early 'blade engine (the 893cc I think?) that was a little lacking in torque, but the much bigger problem was the peaky power output, coming on the cam only about 1500rpm b4 it ran out of steam, so you were constantly screaming the knackers off it!
If you look at any of the later 1000cc bike engines, the late CBR, R1, ZX10, GSX etc. all are great engines in a lightweight car & don't need the low diff ratios (high no.) that peeps were using with the earlier engines, hence nowhere near so revvy I have around 4750rpm at 70 mph, on a 3.2 diff I've driven plenty of small engined cars that don't do far from that!
Also, cost, yes, the 'Busa & ZZR1400 are £3k & more, but you can pickup a ZX12, ZX10, R1 etc for less than half that & it's ready to go, probably with a baffled sump. Any of the "cheap" car engines you mention aren't so cheap by the time you've put a fuel/ign management system on there along with throttle bodies/Webbers & maybe cams/head work to actually get any real performance out of them & they still weigh half as much again (at least) as a bike engine, so you're wasting power just dragging the engine off the starting blocks!
All IMHO of course
Yes, if you were talking about things like the early 'blade engine (the 893cc I think?) that was a little lacking in torque, but the much bigger problem was the peaky power output, coming on the cam only about 1500rpm b4 it ran out of steam, so you were constantly screaming the knackers off it!
If you look at any of the later 1000cc bike engines, the late CBR, R1, ZX10, GSX etc. all are great engines in a lightweight car & don't need the low diff ratios (high no.) that peeps were using with the earlier engines, hence nowhere near so revvy I have around 4750rpm at 70 mph, on a 3.2 diff I've driven plenty of small engined cars that don't do far from that!
Also, cost, yes, the 'Busa & ZZR1400 are £3k & more, but you can pickup a ZX12, ZX10, R1 etc for less than half that & it's ready to go, probably with a baffled sump. Any of the "cheap" car engines you mention aren't so cheap by the time you've put a fuel/ign management system on there along with throttle bodies/Webbers & maybe cams/head work to actually get any real performance out of them & they still weigh half as much again (at least) as a bike engine, so you're wasting power just dragging the engine off the starting blocks!
All IMHO of course
RussBost said:
"due to lack of torque in bike engines" - sorry, but that is rubbish, the engines you mention above all have torque well in excess of the vast majority of typically used car engines - everyone forgets the fact that there is a reduction gear on bike BEFORE the gearbox, so any torque figures you see quoted, which will be at the flywheel, should actually be multiplied by 1.5/to 1.6 (depending on the bike), hence the ZZR1400 mentioned above has usable torque of around 180ft/lbs
Yes, if you were talking about things like the early 'blade engine (the 893cc I think?) that was a little lacking in torque, but the much bigger problem was the peaky power output, coming on the cam only about 1500rpm b4 it ran out of steam, so you were constantly screaming the knackers off it!
If you look at any of the later 1000cc bike engines, the late CBR, R1, ZX10, GSX etc. all are great engines in a lightweight car & don't need the low diff ratios (high no.) that peeps were using with the earlier engines, hence nowhere near so revvy I have around 4750rpm at 70 mph, on a 3.2 diff I've driven plenty of small engined cars that don't do far from that!
Also, cost, yes, the 'Busa & ZZR1400 are £3k & more, but you can pickup a ZX12, ZX10, R1 etc for less than half that & it's ready to go, probably with a baffled sump. Any of the "cheap" car engines you mention aren't so cheap by the time you've put a fuel/ign management system on there along with throttle bodies/Webbers & maybe cams/head work to actually get any real performance out of them & they still weigh half as much again (at least) as a bike engine, so you're wasting power just dragging the engine off the starting blocks!
All IMHO of course
I've ridden all of those engines, in their original homes.Yes, if you were talking about things like the early 'blade engine (the 893cc I think?) that was a little lacking in torque, but the much bigger problem was the peaky power output, coming on the cam only about 1500rpm b4 it ran out of steam, so you were constantly screaming the knackers off it!
If you look at any of the later 1000cc bike engines, the late CBR, R1, ZX10, GSX etc. all are great engines in a lightweight car & don't need the low diff ratios (high no.) that peeps were using with the earlier engines, hence nowhere near so revvy I have around 4750rpm at 70 mph, on a 3.2 diff I've driven plenty of small engined cars that don't do far from that!
Also, cost, yes, the 'Busa & ZZR1400 are £3k & more, but you can pickup a ZX12, ZX10, R1 etc for less than half that & it's ready to go, probably with a baffled sump. Any of the "cheap" car engines you mention aren't so cheap by the time you've put a fuel/ign management system on there along with throttle bodies/Webbers & maybe cams/head work to actually get any real performance out of them & they still weigh half as much again (at least) as a bike engine, so you're wasting power just dragging the engine off the starting blocks!
All IMHO of course
You still have to rev them to get the performance. Even in a 200kg bike...
DanGPR said:
I've ridden all of those engines, in their original homes.
You still have to rev them to get the performance. Even in a 200kg bike...
That is true. I had a little play with an estate car about two months ago. I actually had to change down one gear to keep up with it. And when I'd done that, I still needed to use most of the throttle travel. The badge its rear read E63 S 4matic.You still have to rev them to get the performance. Even in a 200kg bike...
So yes, if you want to access all of the blistering - blow anything mainstream away - performance you do need to rev. That's not surprising with engines designed to rev to 11K + though is it? But you do not need to wring every last rev out for ordinary or even moderately sporty driving.
Light engines work well in light cars. Heavy engines do not.
mikeveal said:
That is true. I had a little play with an estate car about two months ago. I actually had to change down one gear to keep up with it. And when I'd done that, I still needed to use most of the throttle travel. The badge its rear read E63 S 4matic.
So yes, if you want to access all of the blistering - blow anything mainstream away - performance you do need to rev. That's not surprising with engines designed to rev to 11K + though is it? But you do not need to wring every last rev out for ordinary or even moderately sporty driving.
Light engines work well in light cars. Heavy engines do not.
Ok, so the E63 has around 563 bhp - more if it's the AMG version, it's not exactly a Morris Minor estate is it? & hardly surprising you might need to drop a gear to keep up with it, after all, you wouldn't expect to beat a Fezza or Lambo (or indeed my car) without at least trying a bit, I don't suppose the E63 was pottering along at 2000rpm in top gear!So yes, if you want to access all of the blistering - blow anything mainstream away - performance you do need to rev. That's not surprising with engines designed to rev to 11K + though is it? But you do not need to wring every last rev out for ordinary or even moderately sporty driving.
Light engines work well in light cars. Heavy engines do not.
The ZZR1400, which is the engine I know best hits max torque at 7,500 & max power at 9,500, but it already has figures well up there from long b4 that & that is obviously miles different to an early 'blade (max power & torque were both at 10,500 but it didn't really do much until 8,000 plus). Yes, if you want the last ounce of performance from it (the ZZR1400) obviously you have to wring it's neck, but unless you're going to drive something with a 10 litre diesel under the bonnet the same can be said of almost any engine. I can potter thro' town at 25 - 30mph in 6th gear & it will still accelerate quite happily from that point (that's around 17/1800 rpm IIRC) - will it blow your socks off? well no, but the suggestion was that bike engines have no torque which is just plain wrong
I would defo agree that light engines work well in light cars. Heavy engines do not
RussBost said:
Ok, so the E63 has around 563 bhp - more if it's the AMG version, it's not exactly a Morris Minor estate is it? & hardly surprising you might need to drop a gear to keep up with it, after all, you wouldn't expect to beat a Fezza or Lambo (or indeed my car) without at least trying a bit, I don't suppose the E63 was pottering along at 2000rpm in top gear!
The ZZR1400, which is the engine I know best hits max torque at 7,500 & max power at 9,500, but it already has figures well up there from long b4 that & that is obviously miles different to an early 'blade (max power & torque were both at 10,500 but it didn't really do much until 8,000 plus). Yes, if you want the last ounce of performance from it (the ZZR1400) obviously you have to wring it's neck, but unless you're going to drive something with a 10 litre diesel under the bonnet the same can be said of almost any engine. I can potter thro' town at 25 - 30mph in 6th gear & it will still accelerate quite happily from that point (that's around 17/1800 rpm IIRC) - will it blow your socks off? well no, but the suggestion was that bike engines have no torque which is just plain wrong
I would defo agree that light engines work well in light cars. Heavy engines do not
I read Mike's post as oozing with sarcasm, however as that is often my mode perhaps I see what I expect.The ZZR1400, which is the engine I know best hits max torque at 7,500 & max power at 9,500, but it already has figures well up there from long b4 that & that is obviously miles different to an early 'blade (max power & torque were both at 10,500 but it didn't really do much until 8,000 plus). Yes, if you want the last ounce of performance from it (the ZZR1400) obviously you have to wring it's neck, but unless you're going to drive something with a 10 litre diesel under the bonnet the same can be said of almost any engine. I can potter thro' town at 25 - 30mph in 6th gear & it will still accelerate quite happily from that point (that's around 17/1800 rpm IIRC) - will it blow your socks off? well no, but the suggestion was that bike engines have no torque which is just plain wrong
I would defo agree that light engines work well in light cars. Heavy engines do not
Yes it was the AMG, yes he wasn't poodling at 2krpm in top gear and yes, I was being sarcastic.
We are in complete agreement Russ.
If you really want every last ounce of performance from a bike engine, then yes, you'll have to rev. But to say the engines lack torque and to imply that you need to rev hard for normal driving really shows that the poster above hasn't driven a well set up bike engined car.
I was bloody surprised that I couldn't keep up with an estate car without dropping a cog though!
We are in complete agreement Russ.
If you really want every last ounce of performance from a bike engine, then yes, you'll have to rev. But to say the engines lack torque and to imply that you need to rev hard for normal driving really shows that the poster above hasn't driven a well set up bike engined car.
I was bloody surprised that I couldn't keep up with an estate car without dropping a cog though!
Having built a Megabusa Westfield (Hayabusa engine) and having driven a Westfield with a 2.0 VX Red Top and a Westfield with a 300bhp Rover V8, as well as owning a Fisher Fury 1.6 Sigma engine (190bhp) and a Sylva Stylus with a 2.0 VX Red Top, I have some experience of this!
Bike engines are great fun - howling to 10,500rpm, sequential gears etc - but they're at their best on a track day. On the road, the issue is gearing (which is entirely dependent on the diff ratio and you struggle to get anything high enough) and mine was doing about 7000rpm at motorway speeds. Which drove you mad. If you need a reverse gear it's also problematic - I broke several reverse gearboxes before switching to an electric reverse system (better but not great). The lack of torque stuff is not relevant in a light car, but I did find that a passenger really affected performance in a BEC.
If you do little road mileage and want a track car, then a bike engine is fun. But if you like spirited drives on A-roads - and trips to Le Mans - then a car engine is a lot easier to live with. In something like a seven I'd also avoid V8s: the Westfield V8 my mate had was very fast, but it didn't really suit the character of the car (plus with side exit exhausts it doesn't sound like a V8 when you drive it - more like a big VW Beetle!).
I'd go for any modern rev four-cylinder engine in a light kit car. The Ford 1.6 Zetec is a great choice as it's so light - only about 70kg - and can be made to really rev with head work (mine could rev to 8,500rpm!). Plus easy to mate up to a Type 9 gearbox.
If you're building a larger slightly heavier kit car then it has to be a V8; I currently have a Gardner Douglas T70 and it will really pull your face off with the torque of the 6.2-litre LS3.
Bike engines are great fun - howling to 10,500rpm, sequential gears etc - but they're at their best on a track day. On the road, the issue is gearing (which is entirely dependent on the diff ratio and you struggle to get anything high enough) and mine was doing about 7000rpm at motorway speeds. Which drove you mad. If you need a reverse gear it's also problematic - I broke several reverse gearboxes before switching to an electric reverse system (better but not great). The lack of torque stuff is not relevant in a light car, but I did find that a passenger really affected performance in a BEC.
If you do little road mileage and want a track car, then a bike engine is fun. But if you like spirited drives on A-roads - and trips to Le Mans - then a car engine is a lot easier to live with. In something like a seven I'd also avoid V8s: the Westfield V8 my mate had was very fast, but it didn't really suit the character of the car (plus with side exit exhausts it doesn't sound like a V8 when you drive it - more like a big VW Beetle!).
I'd go for any modern rev four-cylinder engine in a light kit car. The Ford 1.6 Zetec is a great choice as it's so light - only about 70kg - and can be made to really rev with head work (mine could rev to 8,500rpm!). Plus easy to mate up to a Type 9 gearbox.
If you're building a larger slightly heavier kit car then it has to be a V8; I currently have a Gardner Douglas T70 and it will really pull your face off with the torque of the 6.2-litre LS3.
DanGPR said:
Bike engines are fair expensive due to their popularity in kit cars. Probably 3k+ for a running engine/ECU etc.
You want as large displacement as possible due to lack of torque in bike engines;
ZZR 1400
Hayabusa 1300
ZX-12R
There are plenty of car engines that would be suitable for your car and cheaper. What car is it?
£3k for a decent engine and ECU setup seems reasonable and roughly what I was expecting. Thanks for the suggestions, I'll start looking at those. No car in particular, it's something I want to design from scratch. You want as large displacement as possible due to lack of torque in bike engines;
ZZR 1400
Hayabusa 1300
ZX-12R
There are plenty of car engines that would be suitable for your car and cheaper. What car is it?
annodomini2 said:
Fwd, Front rear or mid rear?
Mid rearmikeveal said:
Yes it was the AMG, yes he wasn't poodling at 2krpm in top gear and yes, I was being sarcastic.
We are in complete agreement Russ.
If you really want every last ounce of performance from a bike engine, then yes, you'll have to rev. But to say the engines lack torque and to imply that you need to rev hard for normal driving really shows that the poster above hasn't driven a well set up bike engined car.
I was bloody surprised that I couldn't keep up with an estate car without dropping a cog though!
To be fair, I wasn't planning on some AMG slaying machine, just something thats a bit of fun to drive and is something thats a bit unique. People drop £20k on sports cars all the time so this is just the beginning of me thinking that I might be able to design and build something pretty quick and unique for the same money. Engines are my weak point and I don't really have a lot of time to do the research at the moment.We are in complete agreement Russ.
If you really want every last ounce of performance from a bike engine, then yes, you'll have to rev. But to say the engines lack torque and to imply that you need to rev hard for normal driving really shows that the poster above hasn't driven a well set up bike engined car.
I was bloody surprised that I couldn't keep up with an estate car without dropping a cog though!
peterrosey1 said:
If you do little road mileage and want a track car, then a bike engine is fun. But if you like spirited drives on A-roads - and trips to Le Mans - then a car engine is a lot easier to live with. In something like a seven I'd also avoid V8s: the Westfield V8 my mate had was very fast, but it didn't really suit the character of the car (plus with side exit exhausts it doesn't sound like a V8 when you drive it - more like a big VW Beetle!).
I'd go for any modern rev four-cylinder engine in a light kit car. The Ford 1.6 Zetec is a great choice as it's so light - only about 70kg - and can be made to really rev with head work (mine could rev to 8,500rpm!). Plus easy to mate up to a Type 9 gearbox.
If you're building a larger slightly heavier kit car then it has to be a V8; I currently have a Gardner Douglas T70 and it will really pull your face off with the torque of the 6.2-litre LS3.
Interesting, I'd definitely like it to be usable for spirited A roads. What power is the Zetec with the headwork? I'm aiming for a reasonable bph per tonne, for a 600-800kg car. Although this target weight is just something I've pulled from thin air for now.I'd go for any modern rev four-cylinder engine in a light kit car. The Ford 1.6 Zetec is a great choice as it's so light - only about 70kg - and can be made to really rev with head work (mine could rev to 8,500rpm!). Plus easy to mate up to a Type 9 gearbox.
If you're building a larger slightly heavier kit car then it has to be a V8; I currently have a Gardner Douglas T70 and it will really pull your face off with the torque of the 6.2-litre LS3.
Duncanpainter said:
I'm aiming for a reasonable bph per tonne, for a 600-800kg car. Although this target weight is just something I've pulled from thin air for now.
If I were you I'd be looking at aiming for 400-500kgs. You're really going to feel the extra weight on pulling away and you won't really get the benefit of the revvy engine with a heavier car. They work well in light cars because you can keep the cornering speed reasonably high and the revs up. If you're having to scrub off a lot of speed for each corner, then you'll struggle to build it back up again.
Ambleton said:
Duncanpainter said:
I'm aiming for a reasonable bph per tonne, for a 600-800kg car. Although this target weight is just something I've pulled from thin air for now.
If I were you I'd be looking at aiming for 400-500kgs. You're really going to feel the extra weight on pulling away and you won't really get the benefit of the revvy engine with a heavier car. They work well in light cars because you can keep the cornering speed reasonably high and the revs up. If you're having to scrub off a lot of speed for each corner, then you'll struggle to build it back up again.
A 7-esque bike engined car can, without too much effort, be under 550Kg. Of that bike engine and gearbox is 60 to 70Kg. If you're thinking about something with a roof, it's likely to be heavier & a car engine may be better suited.
As for twisty A roads. There is no problem with a BEC on A roads. You do not need to wring it's neck to get " much better than production car" performance. A well set up BEC should leave you smiling for the rest of the day.
BECs aren't fun for motorway cruising. The high revs become wearing on the soul. But that's not what the car is for.
Ambleton said:
If I were you I'd be looking at aiming for 400-500kgs. You're really going to feel the extra weight on pulling away and you won't really get the benefit of the revvy engine with a heavier car.
They work well in light cars because you can keep the cornering speed reasonably high and the revs up. If you're having to scrub off a lot of speed for each corner, then you'll struggle to build it back up again.
This is correct. FYI my Spire Gt3 RGB car is 580kg inc driver (minimum weight for the formula). They work well in light cars because you can keep the cornering speed reasonably high and the revs up. If you're having to scrub off a lot of speed for each corner, then you'll struggle to build it back up again.
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