NS Dev
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 posted on 3/10/06 at 08:13 AM |
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Little numbers game!
Just out of interest, to satify my curiosity, everybody join in if you have a calculator and we'll rank the results on an engine by engine
basis.
Use rolling road/dyno results or std engine manufacturer data:
Multiply Power (in bhp or PS, they are close enough) by Torque (in lbft NOT Nm) then divide by swept volume in cc
(bhp x lbft)/cc = xyz
I'll kick off with mine:
Vauxhall XE 2.0 16v (204 x 169)/1998 = 17.26
Lets have the results from all engines on here, just as a little game!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Johnmor
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| posted on 3/10/06 at 08:26 AM |
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Alfa v6=
192x191/2993 = 12.25.
But maybe you should add MPG, standard engine and light car = 32mpg. so:
12.25 X32 = 392.
You said it was anumbers game!!!
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daviep
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| posted on 3/10/06 at 08:26 AM |
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Okay to satisfy your curiosity here goes for ZZR 1100
(147 x 76.9) / 1052 = 11.12
Now satisfy my curiosity, what does this formula show?
Cheers Davie
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whitestu
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| posted on 3/10/06 at 08:28 AM |
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Err...
1.8 CVH
88x108/1769 = bu@@er all.
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NS Dev
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| posted on 3/10/06 at 08:30 AM |
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just a crude measure of the overall "effectiveness" of an engine really, not very scientific, but basically enables a pretty direct
comparison of engines of all sizes and types, without getting into the "bike engine vs car engine" type debate.
You can compare engines in terms of their effectiveness at propelling a car quite well I think, feel free to disagree though!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Richard Quinn
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| posted on 3/10/06 at 08:38 AM |
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But wouldn't you need to divide by £'s spent on tuning? I'm guessing 204bhp isn't a standard XE 
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smart51
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| posted on 3/10/06 at 08:39 AM |
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1998 R1
150 * 80 / 998 = 12.0
Your formula misses out revs which is an important part of engine performance. (remember power is proportional to torque times revs)
a 100 BHP turbo diesel will beat a 100 BHP car engine which will beat a 100 BHP bike engine in your formula because your formual is torque x torque x
revs / cc.
What is it you're trying to prove?
I propose a different formula
torque x max revs / cc.
R1 = 80 *12000 / 998 = 961
XE = 169 * 7000 / 1998 = 592
1.8 CVH = 108*6000/1769 = 336
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daviep
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| posted on 3/10/06 at 08:42 AM |
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ME disagree!!! I'll certainly think about it
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Agriv8
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| posted on 3/10/06 at 08:46 AM |
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Rover V8 efficient OH well !!
Oh well here goes in Std form
(203x149)/4200 = 7.201 
and I am not starting on the MPG but it still scares grannies .
Regards
Agriv8
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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iank
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| posted on 3/10/06 at 08:50 AM |
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Would be interesting to see the average of the revs that give max bhp and ft/lb. Not that high or low values are inherently 'good'.
The formula doesn't really say much about how the car will act on the road/track, but so long as the thread doesn't degenerate into a
"my engine has better 'effectiveness' than yours" d*ck size war it should be interesting.
Finally for reference standard mini cooper S (classic)
(76 x 71) / 1275 = 4.23
Ave rev (5900+3000)/2 = 4450
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Volvorsport
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| posted on 3/10/06 at 09:00 AM |
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i like games
182x190/2316 = 14.9
BMEP or MEP - is the only way to compare engines efficiency . some results may scare you .
www.dbsmotorsport.co.uk
getting dirty under a bus
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NS Dev
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| posted on 3/10/06 at 09:02 AM |
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quote:
Originally posted by smart51
1998 R1
150 * 80 / 998 = 12.0
Your formula misses out revs which is an important part of engine performance. (remember power is proportional to torque times revs)
a 100 BHP turbo diesel will beat a 100 BHP car engine which will beat a 100 BHP bike engine in your formula because your formual is torque x torque x
revs / cc.
What is it you're trying to prove?
I propose a different formula
torque x max revs / cc.
R1 = 80 *12000 / 998 = 961
XE = 169 * 7000 / 1998 = 592
1.8 CVH = 108*6000/1769 = 336
Knew I would start a debate!
Disagree with your revs idea, because that is only relevant with regard to power curve. I can pull the rev limiter off my vauxhall and rev it a lot
harder (it's 8000 at the mo not 7000 and thats internally std) but it will only lose power at those higher revs.
I guess the point I was driving at, without getting into numbers that no-one will be able to find out, is that bike engines are not always the
winners, and neither are car engines.
The whole thing comes down to BMEP, which given a serviceable engine, is down to cylinder head breathing efficiency.
If you compare BMEP's for bike engines and car engines (good, comparable ones!) then you will find the car engines are just as good.
The Vauxhall engine's SPECIFIC torque, which is how well it breathes, and thus it's power potential, is very good. Sorry to keep quoting
that engine but I know more about it than others and it makes the numbers!!
As I said, just a numbers game, keep playing and lets see what we get, cos I think there are plenty of bike engines that will beat the vauxhall
anyway, so let it keep going!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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NS Dev
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| posted on 3/10/06 at 09:03 AM |
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quote:
Originally posted by Volvorsport
i like games
182x190/2316 = 14.9
BMEP or MEP - is the only way to compare engines efficiency . some results may scare you .
LOL looks like we overlapped on the BMEP statement!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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NS Dev
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| posted on 3/10/06 at 09:06 AM |
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quote:
Originally posted by Agriv8
Rover V8 efficient OH well !!
Oh well here goes in Std form
(203x149)/4200 = 7.201
and I am not starting on the MPG but it still scares grannies .
Regards
Agriv8
heh heh I think for the next game "granny scare factor" might have to be added!!!!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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smart51
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| posted on 3/10/06 at 09:24 AM |
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BMEP (brake mean effective pressure) is a measure of how much force acts on the piston. Which is very nice. What makes a car go forwards is the
torque that the engine produces, and not at the flywheel but at the road wheels. BMEP, Max Torque, Max Power etc are all some way removed from what
actually matters.
I was just pointing out that your formula is biased for peak torque when I believe that there is more to it than that. Perhaps I suspect that you
have an ulterior motive
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NS Dev
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| posted on 3/10/06 at 09:41 AM |
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heh heh I do have the motive of comparing all engines, and perhaps "quietening" some of the pro-BEC banter, but equally I have no axe to
grind, if I didn't have the vauxhall stuff already I would have used a Busa mylself!
That is also the reason I added the "divide by cc" bit, if I were just trying to poo-poo bike engines I would just have gone for peak
torque alone!
You can gear a car for all the torque at the wheels that you need, you just fit a crawler gearbox from a tractor, so I am afraid that's not the
answer either!!!! LOL
I am just trying to get as close as I can to a BMEP survey but bearing in mind that nobody will know their BMEP!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Coose
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| posted on 3/10/06 at 10:08 AM |
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Should you not factor in weight also?
<opens another can of worms to add to the pile which is ever-growing!>
Spin 'er off Well...
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Volvorsport
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| posted on 3/10/06 at 10:11 AM |
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ok with this in mind
http://www.locostbuilders.co.uk/viewthread.php?tid=52746
578x520/2316 = 129
we have a winnar !!!
www.dbsmotorsport.co.uk
getting dirty under a bus
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Gav
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| posted on 3/10/06 at 10:15 AM |
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VAG 1.8T
(220*230) / 1781 = 28.411
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Agriv8
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| posted on 3/10/06 at 10:20 AM |
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Quote NSDEV .... is down to cylinder head breathing efficiency....
Oh bu**er - rover v8's - breathes as will as an asmatic 65 year old that smokes 60 a day. 
Of course I could just remorgage the house for a set of Wildcat heads. when the lottery numbers drop LS6 with tremac 6 speed MMMMMmmmmm Nice.
Note to everyone
This is about statistics at the end of the day the ability to reference one engine againt another using a calculation and yes we all understand that
the calculation is not the most accurate but lets keep it POLITE please. ( PS my D*ck is bigger than everyones )
Agriv8
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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NS Dev
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| posted on 3/10/06 at 10:28 AM |
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quote:
Originally posted by Volvorsport
ok with this in mind
http://www.locostbuilders.co.uk/viewthread.php?tid=52746
578x520/2316 = 129
we have a winnar !!!
Cripes!!!! didn't see that post!!!!!!
Will have a look at the vid tonight, can't really look at work!
Just as with the VAG 1.8t, forced induction certainly is a winner on the efficiency!!
Just can't bring myself to use one of those 1.8t things, just a bit "white goods" for me and power too many faceless cars.
certainly stump up the goods though, torque curve like a diesel!
Interestingly though it seems the 5 valves have nowt to do with it, nat asp versions built for competition are behind many modern 4 valve engine
designs in terms of flow and BMEP.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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ned
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| posted on 3/10/06 at 10:54 AM |
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bit late here but..
219x169/2092=17.69
beware, I've got yellow skin
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Guinness
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| posted on 3/10/06 at 11:00 AM |
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I'm loving that Manta, but it sounds all wrong, more like a turbine engine than a 4 stroke.
Cheers
Mike
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NS Dev
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| posted on 3/10/06 at 11:04 AM |
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Now there must be a bike engine that can compare with Chris's S2000 engine (current highest nat asp engine) or ned's XE (second
highest)???
I'm NOT doing this to wind anybody up, just to see how things compare!
What torque does a std hayabusa make? Needs to be around 125 lb ft to pull into the lead, which sounds reasonable to me but I just don't know
what they make!
What about the other "newer" bike engines, thay are smaller but I'm guessing more efficient, and engine size will make no difference
so lets see!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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andyd
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| posted on 3/10/06 at 11:29 AM |
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Standard quoted torque figure for a Busa is 98.4lb @ 7k rpm. Max power is 158bhp @ 9750 rpm.
So that makes about 11.42 ish?
[Edited on 3/10/2006 by andyd]
Andy
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