coyoteboy
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posted on 4/8/10 at 11:00 AM |
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BEC engine lifespan
So with the bike engines being a lot lighter than car engines, and generally about the same price they're obviously an interesting proposal, but
the questions I have when considering the options are:
What's the lifespan of the engines/clutches when put into a BEC? I suspect the pain of dragging round half a ton of metal takes a toll on the
drivetrain. Are prices comparable to car engine parts? I know the car engine I was thinking of is a bombproof bit of kit and can be pushed massively,
drivetrain is good for 500lbft of torque etc, but it does weigh 200kg. If I strayed from the engine I was thinking and went the way of the BEC, what
are the pros and cons WRT a car engine? Is registering one harder? IVA? What emissions limits do I have to work to?
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alexcraiggtv
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posted on 4/8/10 at 11:17 AM |
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BEC Lifespan
I use my Blackbird Indy nearly every day for the past 18 months, goes no where slow and its mint! No clutch probs, engine issues what so ever
Not yet KATO!
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02GF74
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posted on 4/8/10 at 11:20 AM |
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oooh, BEC vs CEC
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coyoteboy
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posted on 4/8/10 at 11:24 AM |
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That is only 12 months though alex I used my road car every day and went nowhere slow (300hp) and the clutch lasted 90K miles until I shattered it
one fateful launch!
Not trying to start a war here but trying to assess whether a BEC will leave me repairing it every other weekend, or mean I'm struggling to do a
long trip without worrying.
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smart51
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posted on 4/8/10 at 11:29 AM |
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I did about 15,000 miles in my R1 bec on the clutch that came with the engine before selling the car on. Remember that the load on the clutch is the
torque produced by the engine, not the weight of the vehicle reacting that torque. Peak load on the clutch is therefore the same. The car, being
heavier than the bike, will take longer to accelerate. The load on the clutch during acceleration will last longer but will be no bigger.
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coyoteboy
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posted on 4/8/10 at 11:37 AM |
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Fair point, and one I've completely ignored, sometimes I'm a fool. I'd assume though that you'd spend more time slipping the
clutch by definition so as not to bog. What's the price of a set of clutch plates in something like an R1? Since they're a lot easier to
change the time/cost balance may be a lot closer than I'd thought.
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richardlee237
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posted on 4/8/10 at 12:22 PM |
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The torque transmitted through the transmission can be considerably higher than that developed by the engine.
If you dump the clutch then you not only have available the torque derived from the engine combustion but also the torque derived from the stored
kinetic energy in the engine flywheel and components as the loading tries to bring the engine to a standstill.
The inertia and mass of the car is greater than that of the bike so the car will require a greater torque loading for a longer period to accelerate
it.
Therefore the car will provide a greater stress on the system.
If you slip the clutch and don't let the revs change then the stored energy in the engine rotating components remains the same and the
combustion supplies the torque for acceleration hence less loading and longer life
Quote Lord Kelvin
“Large increases in cost with questionable increases in performance can be tolerated only in race horses and women.”
Quote Richard Lee
"and cars"
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Guinness
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posted on 4/8/10 at 12:27 PM |
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Don't forget that changing a clutch on a BEC is much easier than on a car.
Lift the front end of the car, remove clutch cover (12 allen bolts on mine).
Undo 6 further bolts, remove plates, fit new plates, re-fit springs (may upgrade at this point), re-fit 6 bolts.
Put cover back on (new gasket) and do up 12 allen bolts. Lower front end of car.
Job jobbed.
Gearboxes / big ends etc however are all another matter........
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adithorp
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posted on 4/8/10 at 12:37 PM |
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quote: Originally posted by richardlee237
The inertia and mass of the car is greater than that of the bike so the car will require a greater torque loading for a longer period to accelerate
it.
Therefore the car will provide a greater stress on the system.
But this is offset somewhat by the 25-30%lower gearing of the final drive (diff).
Clutches are quick and easy to replace on an R1.
With h/duty spring kit fitted they last OK. Not needed to change mine in 3 years. Clutch wear and general engine life will to a certain extent depend
on the quality of the driver and install.
I don't even think about whether its going to break down when I go out. I've done several 500mile days and a few multi thousand mile
trips. never had to change anything but the oil.
adrian
PS I'm sure someone will be along soon to tell you that they're made of chocolate!
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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dinosaurjuice
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posted on 4/8/10 at 01:10 PM |
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Was talking to a westfield owner with a fireblade engine, hes done 18,000miles but always carries a spare clutch. changed numerous times, simpe
procedure and only costs about £50. Its when gearboxes and pistons start vandalising themselves it gets expensive...
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coyoteboy
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posted on 4/8/10 at 02:14 PM |
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Well yes, kinda hoping that I won't go eating pistons regularly, but I do question the box etc. Of course the inertial load imposed by the fly
would be higher, but that's assuming you have no mechanical sympathy I guess, most of the time you don't drop the clutch at 10,000rpm.
Sometimes
I'm getting more tempted despite claiming I'd never go anywhere near the revvy noisy monsters.
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adithorp
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posted on 4/8/10 at 03:59 PM |
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Bottom line... If you want a quiet, comfortable, reliable car, buy a Lexus. If you want a fun car, get a kit and if you want a super fun car get a
BEC.
Registration is no different, except the low tax class (under 1500cc). Emmisions limits at IVA for a BEC are the same as a CEC. You'd need a cat
and power commander in most cases.
adrian
ps. have you been in a BEC?
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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coyoteboy
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posted on 4/8/10 at 04:09 PM |
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Certainly not interested in a comfy car, that was never the point - just don't want it to be the sole thing I drop my cash into (I've
another 2 cars that takes a percentage (one of which may be sacrificed), plus my sports and a house and girlfriend lol). I do, however, want to be
able to at least /reasonably/ trust a drivetrain not to die so regularly I have to buy a new engine/box every 2 years. I'm informed by my bikey
mates that they go through engines every 40-50K in a bike chassis, hence my concern that the car chassis would accelerate that death.
Never been in a BEC, specifically. I've spent some time working on Formula Student cars (600cc bike engine single seaters) but never driven
one.
Thanks for the info on the emissions. I'll read through the IVA documentation in more detail so I understand it.
[Edited on 4/8/10 by coyoteboy]
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JF
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posted on 4/8/10 at 05:32 PM |
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Well it really depends what kind of engine you got. In general a Honda will last longer then a Kawa. Although many claim to have had more fun on the
Kawa in the shorter time
Other important factor is yourself. Do you give the engine time to get up to temp and cool down. Or you go flat out 1 sec after starting etc. Always
top revs, or more moderate with an occansional top rev.
Do you use your clutch properly, or as a on/off switch. It's usually the monkey behind the wheel that breaks it...
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tandi
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posted on 4/8/10 at 06:09 PM |
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quote: Originally posted by adithorp
ps. have you been in a BEC?
I've had my Fury for nearly a year now, wasn't sure whether to go BEC or CEC until Jim took me for a spin in his R1 Fury... needless to
say the grin on my face said it all. You gotta love the smell, sound and performance. If I have to fix it every now on then it wouldn't bother
me!
ps Been 100% reliable to date
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adithorp
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posted on 4/8/10 at 07:24 PM |
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quote: Originally posted by coyoteboy
Never been in a BEC, specifically. I've spent some time working on Formula Student cars (600cc bike engine single seaters) but never driven
one.
[Edited on 4/8/10 by coyoteboy]
If you add your (rough) location to your profile you might get an offer of a ride.
Owning a BEC is a bit like a chain letter; Someone gives you a ride in one and you're converted and build/buy one. Then you're obliged to
convert more people by giving them rides.
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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Major Stare
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posted on 4/8/10 at 08:59 PM |
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Agreed, whats your location? Sure someone will let you have a ride.
Changed to a BEC last year and never looked back. Get a comfortable seat and you can drive it all day.
Jon "FISH"
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coyoteboy
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posted on 4/8/10 at 10:03 PM |
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Well I used to be not far from Manchester myself but I'm now in Glasgow (not ideal weather or roads for a kit lol) and only visit Manchester
area one a month or so these days. A quick ride along would be fun I think, might convert me as you say! I've been a low-down torque monster for
a long time.
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probablyleon
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posted on 5/8/10 at 06:43 AM |
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I blew up my BEC last week, was painful but I still feel the pros far outweigh the cons (by a mile). I had a fairly quick 2ltr se7en before my BEC and
would never consider going back, these things are fantastic! That said, I'm very impressed by the distances covered by some of the contributors
to this thread. For me, half an hour of scaring myself Sh**less is about all I can take before needing a break. Maybe avoid the Blackbird, tried and
tested routes seem to be R1 or Fireblade, that's where I'm going.
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gixermark
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posted on 5/8/10 at 09:00 AM |
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depends ultimately how many miles you want/expect to get out of a bike engine ? most don;t build/buy with any real intent of trying to get say 30k
miles out of the engine.. but no doubt many do !!
part of the appeal is the simple nature of changing engine and the cheap supply - say £500-£1500 for the entire plant
The only way I would change to a CEC would be for a highly tuned 2.0 - say 225+hp to make it worthwhile.. I've been in mild 160/170hp CEC sevens
that don;t inspire me personally... Problem is, to get that 225hp+ you'd be into similar/more money for the engine/box alone than what woudl
build an entire BEC kit car..
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coyoteboy
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posted on 5/8/10 at 09:12 AM |
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I've every intention of using the car, I'm a bit masochistic - the idea of having to concentrate hard for a 4 hour trip to see my friends
doesn't scare me, in fact I find it rather inviting after years of driving my slow diesel commuter while the fun car is off the road In fact
I'd consider using it daily to brighten up my country-lane commute. I'd happily replace engines every 30K if they were £500 a pop, but it
seems that even the oldest and least powerful R1 on fleabay is £600. That said, I suppose at ~5K a year that probably works out under a hundred quid a
year for a consumable engine.
If I were going to be going CEC I'd be throwing in a 300hp/300lbft 3S-GTE, atom-style rear engine. I can source these for ~500-750 inc gearbox
at 200hp standard and do the few mild modifications required to get to 300 for another few hundred. I know I could make that engine last for a decade
without effort, using it as a daily commuter. With a BEC I'd been putting the R1 first (I'm used to working with the R6 engine in a single
seat racer) and I'm no stranger to BE's anyway, I've taken a carb'd 4pot bike engine and megasquirted 'n' sparked
it, so really my concerns are solely lifespan/running costs versus versus a fairly fit and forget car engine. Of course the car engine would be approx
3x the weight of the bike engine, require much more space and stiffer chassis.
I'm going to be designing my own from scratch (again, masochistic tendencies) so I can pick placement/layout etc myself. I've already been
developing an electronic paddle shift for the fun of it and I have people around me that are used to designing race car chassis and suspension systems
so it seems the sensible way to go.
[Edited on 5/8/10 by coyoteboy]
[Edited on 5/8/10 by coyoteboy]
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Rocket_Rabbit
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posted on 5/8/10 at 10:07 AM |
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quote: Originally posted by coyoteboy
Of course the car engine would be approx 3x the weight of the bike engine, require much more space and stiffer chassis.
This was my dilemma.
I have a modified S2000 and was thinking about breaking it, but keeping the vital components to stick in a CEC.
After some good research, even though the engine is amazing, the weight simply put me off.
After speaking to a guy who has done this to an MNR Vortx, he came back with reports that the car weighed in at 690kg?!?!?!
~200kg weight penalty of a BEC
That was enough for me to say no.
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coyoteboy
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posted on 5/8/10 at 11:59 AM |
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But on thinking about it, a 300hp CEC at 700kg is ~430hp/ton, 300lb ft @3500rpm.
A 500kg BEC with an R1 engine is only 300hp/ton, 20lbft at 10Krpm .
The tradeoff in that sense is a no-brainer. I suppose in corners and stopping the extra weight is a penalty, but the donor car copes admirably 1400kg
so I suspect that a well-designed chassis and suspension would deal with that extra pendulus weight and keep the power to the tarmac - it seems bike
engine cars spin for 50% of their acceleration!
[Edited on 5/8/10 by coyoteboy]
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adithorp
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posted on 5/8/10 at 03:38 PM |
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The donor car is a barge in comparison to a BEC. You need to get a ride in one to understand the point... and even then you don't get a true
impression of what it's like with just the driver. Comparing the numbers means very little. Ride in one and you'll either have to have one
or you'll never go near one again. It took about 30secs to convert me.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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adithorp
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posted on 5/8/10 at 03:41 PM |
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quote: Originally posted by coyoteboy
Well I used to be not far from Manchester myself but I'm now in Glasgow (not ideal weather or roads for a kit lol) and only visit Manchester
area one a month or so these days. A quick ride along would be fun I think, might convert me as you say! I've been a low-down torque monster for
a long time.
I'd be happy to oblige. Let me know when you're next here and weather and work permitting we'll arrange something.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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