NS Dev
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| posted on 3/10/06 at 08:04 AM |
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quote:
Originally posted by smart51
Yamaha R1 998cc 108 Nm
Citroen TU 954cc 74Nm
Toyota K1-3fe 998cc 93Nm
Honda fireblade 998cc 114Nm
Bike engines have less torque?
They have a higher compression ratio = higher torque. Bike engine tuning merely means that it happens high up in the rev range. You could fit a
different cam and have it lower down but you'd lose the power, but if you want your torque low down...
Ok ok nor could I:
My vauxhall XE 16v,
1998cc 231 Nm 204bhp
errr, so that's actually HIGHER specific torque than the best of the bike engines above, which I didn't expect!!!! 
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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02GF74
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| posted on 3/10/06 at 09:08 AM |
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If you want to have loads of bottom end go for a low overlap cam with plenty of lift (as much as you can get within the confines of your springing and
standard rocker ratio).
And also smaller valves/ports will give you better low speed torque - because you are increasing the gas velocity in the port for a given engine
speed.
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Gav
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| posted on 3/10/06 at 10:07 AM |
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quote:
My vauxhall XE 16v,
1998cc 231 Nm 204bhp
VAG 1.8T 311.48nm 
Although in something slightly lardier than a 7!
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NS Dev
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| posted on 3/10/06 at 10:47 AM |
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ahh but that has one of those horrid whooshy things attached to it! Can't argue with the numbers though!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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DaveFJ
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| posted on 3/10/06 at 10:51 AM |
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quote:
Originally posted by NS Dev
ahh but that has one of those horrid whooshy things attached to it!
Dave
"In Support of Help the Heroes" - Always
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smart51
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| posted on 3/10/06 at 11:28 AM |
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quote:
Originally posted by DaveFJ
quote:
Originally posted by smart51
Yamaha R1 998cc 108 Nm
Citroen TU 954cc 74Nm
Toyota K1-3fe 998cc 93Nm
Honda fireblade 998cc 114Nm
Bike engines have less torque?
They have a higher compression ratio = higher torque. Bike engine tuning merely means that it happens high up in the rev range. You could fit a
different cam and have it lower down but you'd lose the power, but if you want your torque low down...
My Fiat tin top..... 2470cc 230Nm
which is 93Nm for each 1000cc. sorry, not good enough
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NS Dev
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| posted on 3/10/06 at 11:39 AM |
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arggh you keep pulling me in on this one...........!! LOL XE = 115Nm/1000cc
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 11:40 AM |
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quote:
Originally posted by NS Dev
Higher compression ratio = higher torque.............
errrrr NO!
WRONG!
Err, I must disagree. Increasing the compression ratio of an engine DOES increase the torque that it generates. The energy released by burning fuel
is the same regardless of compression ratio but higher compression ratios couple the energy to the moving piston better. Higher compression engines
do give higher outputs.
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MikeRJ
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| posted on 3/10/06 at 11:42 AM |
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quote:
Originally posted by smart51
Yamaha R1 998cc 108 Nm
Citroen TU 954cc 74Nm
Toyota K1-3fe 998cc 93Nm
Honda fireblade 998cc 114Nm
Bike engines have less torque?
Not in terms of nm/cc, but who on earth puts a 1 liter car engine in their locost? Far, far more realistic to compare a bike and car engine with
simmilar power outputs....
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MikeRJ
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| posted on 3/10/06 at 11:47 AM |
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quote:
Originally posted by NS Dev
you can have all the compression in the world and make no torque at all, look at a diesel engine at tickover!!!
To be fair higher CR does help as it increases BMEP (up to detonation limit of course!). The old adage regarding displacement certainly holds true
though.
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DaveFJ
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| posted on 3/10/06 at 11:52 AM |
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quote:
Not in terms of nm/cc, but who on earth puts a 1 liter car engine in their locost? Far, far more realistic to compare a bike and car engine with
simmilar power outputs....
I considered using a Fiat 1.0l 'FIRE' engine... bloody good engine, indistructible, very light (1 man can pick up the engine/gearbox
unaided) and capable of well over 100Bhp... there is a company that makes race engines out of them..
Dave
"In Support of Help the Heroes" - Always
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Johnmor
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| posted on 3/10/06 at 11:58 AM |
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Torque v BHP
This is a real minefield.
Good example of how figures can be totaly blown out of proportion.
Circa 1893 Large static steam engine, I meter diam main cylinder, triple exspansion sysytem.
Almost 680lbs/ ft of torque, 90 bhp and all this at about 60 revs / min.
wouldn't look good in a locost though
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NS Dev
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| posted on 3/10/06 at 12:03 PM |
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too true!
There are a wole number of ways in which to generate motive power, steam engines CAN be a very effective way of doing it!
If current levels of piston internal combustion engine development were applied to steam engines who knows where we would be now??
I was always musing over the possibility of using waste heat on an internal combustion engine that operated at high temperature to operate a secondary
condensing steam turbine co-coupled to the internal conbustion engine output.............................but that's a whole different story!
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 12:05 PM |
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Its a B@*st*rd replacing the dilithium crystals though
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MikeRJ
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| posted on 3/10/06 at 12:06 PM |
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quote:
Originally posted by Johnmor
Almost 680lbs/ ft of torque, 90 bhp and all this at about 60 revs / min.
Ahem.
60*680/5252 = 7.7bhp
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NS Dev
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| posted on 3/10/06 at 12:10 PM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by Johnmor
Almost 680lbs/ ft of torque, 90 bhp and all this at about 60 revs / min.
Ahem.
60*680/5252 = 7.7bhp
eek, good point, never actually checked!
Old engines were very inefficient! (having said that the very last of the steam express locos were comparable to IC engines)
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Volvorsport
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| posted on 3/10/06 at 12:14 PM |
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what about the anglia MAE engine ?
wasnt that over 100 bhp from 997cc, with the obvious downdraft ports etc .
www.dbsmotorsport.co.uk
getting dirty under a bus
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DaveFJ
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| posted on 3/10/06 at 12:22 PM |
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Steam? hows about this ?
Linky
I think 145 mph and 300Bhp is qute acceptable from a steam car.... whats interesting is the land speed record for a steam car in 1906.... 128mph!!!
Dave
"In Support of Help the Heroes" - Always
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Johnmor
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| posted on 3/10/06 at 12:34 PM |
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Steam Engines
I may be wrong ( i often am )
But i think fromula applies to Internal combustion engines.
Henry Robinson's formula (*) —
Area of ram x stroke x pressure
33,000
This was used in steam engines in the late 19th centuary.
James Watt defined the horsepower as 33,000 ft lbs per minute.
This alllows steam engines to be calculated without using the revs per minut as they of produce their maximum torque just before the stop moving.
IE Max torque at 0 rev/min.
as i say I may be wrong
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tks
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| posted on 3/10/06 at 12:55 PM |
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maybe
they have then the best filling grade...
Tks
The above comments are always meant to be from the above persons perspective.
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mcerd1
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| posted on 3/10/06 at 02:31 PM |
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quote:
Originally posted by stevec
More torque Big flywheel perhaps.
Steve.
-that won't affect torque just momentum
quote:
Originally posted by smart51
Citroen TU 954cc 74Nm
My 1992 pug 106 has the same engine (TU9 954cc) but it has a carb instead of EFI and as a result its power is 45ps instead of 50ps and the torque
suffers a little too (but I can't remember how much of the top of my head)
It would be slower than the new ones if it wasn't lighter (and no rev limiter helps)
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mcerd1
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| posted on 3/10/06 at 02:52 PM |
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quote:
Originally posted by DaveFJ
I think 145 mph and 300Bhp is qute acceptable from a steam car.... whats interesting is the land speed record for a steam car in 1906.... 128mph!!!
FYI there is a new steam record attempt car being built in this country (I'll have to find the article)
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DaveFJ
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| posted on 3/10/06 at 03:00 PM |
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the link in my post is to the new record attempt site.....
Dave
"In Support of Help the Heroes" - Always
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MikeRJ
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| posted on 3/10/06 at 04:47 PM |
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quote:
Originally posted by Johnmor
I may be wrong ( i often am )
But i think fromula applies to Internal combustion engines.
Henry Robinson's formula (*) —
Area of ram x stroke x pressure
33,000
This was used in steam engines in the late 19th centuary.
James Watt defined the horsepower as 33,000 ft lbs per minute.
This alllows steam engines to be calculated without using the revs per minut as they of produce their maximum torque just before the stop moving.
IE Max torque at 0 rev/min.
as i say I may be wrong
The imperial horsepower is defined by RPM*TORQUE(lbft)/5252, which in different units happens to be about 746 Watts or 33,000 foot pounds/second.
It's entirely possible for an engine to produce both 90bhp and 680lbft at 60 RPM , but it couldn't do both at the same time.
Note that:
Power = Work/Time
Work = Force*Distance
If there is no motion (or distance) e.g. zero RPM, then there is no useful work being done, and therefore zero power. This means you could have
infinite torque and yet zero power. This is the reason you can't get an engine a power rating by looking at stall torque.
You are correct that different methods of power calculation have been used of internal combustion engines. One of the most famous of which was the RAC
horsepower, which bore virtualy no resemblance to actual power output of an engine, but was used for taxation purposes for quite a long time.
http://www.designchambers.com/wolfhound/wolfhoundRACHP.htm
By the way, the characteristic of maximum torque at zero RPM is also shared by (most) electric motors.
[Edited on 3/10/06 by MikeRJ]
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Simon
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| posted on 3/10/06 at 07:18 PM |
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My ZT - 410nm at 4000rpm
ATB
Simon
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