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Author Topic: What can a dynamometer tell me?  (Read 690 times)

jedaks

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What can a dynamometer tell me?
« on: December 17, 2013, 07:14:59 PM »
If I was to take my '04 iron barrell to one of these places, what tests would/could they do and how could I use that information?

thanks

motomataya

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Re: What can a dynamometer tell me?
« Reply #1 on: December 17, 2013, 07:51:48 PM »
An iron barrel on a Dyno. You could blow it up real good for the rebuild. It will tell you max power. If it is hooked up to a sniffer it will give you some jetting info. Be very afraid of your bike on a  dyno.

ace.cafe

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Re: What can a dynamometer tell me?
« Reply #2 on: December 17, 2013, 08:01:46 PM »
It could show you your power curve and torque curve, and also if it has a sniffer, it can tell you your air fuel ratio over the throttle range

Don't be shocked if the power output shows low on the dyno. It is common. You can establish it as a baseline, and any future mods can be tested on the same dyno, and then you can see if you improved or worsened things with the mods. It's at its best as a comparative tool to use on your own bike and compare the next dyno run to the last, and see how things have changed.

It's not really very useful for reading your absoulte horsepower, because dyno readings vary quite a bit from one to the next, and also there are a million different little things which can influence the readings.

If you are tuned up well, chances are you'll be around 20-22 hp at the rear wheel with your mods. With the typical Enfield drive-train losses, that equates to probably around 27-29 hp at the engine.
« Last Edit: December 17, 2013, 08:15:26 PM by ace.cafe »
Home of the ACE Fireball 535 Bullet,  Ace GP Hi-Lift Roller Rocker Head . Pistons, cams, etc. Highest performance Bullet engine mods available .  AVL mods. Redditch 700/750 Twin mods. UCE kit soon.

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Blltrdr

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Re: What can a dynamometer tell me?
« Reply #3 on: December 17, 2013, 08:06:21 PM »
I agree with Motomataya. Buttintheseatometer
2003 Classic 500 5 spd
1992 Kawasaki ZG 1200 Voyager XII
1977 Yamaha XS 360-2D (Cafe Project)

High On Octane

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Re: What can a dynamometer tell me?
« Reply #4 on: December 18, 2013, 02:12:20 AM »
First of all +1 to Ace as always.    ;)

An iron barrel on a Dyno. You could blow it up real good for the rebuild. It will tell you max power. If it is hooked up to a sniffer it will give you some jetting info. Be very afraid of your bike on a  dyno.

Your chances of blowing up on the dyno are no greater than it blowing up on the street.  And if you're trying to drag race on a dyno you're an idiot.  The reason why I say there's no increased risk is because you're not really working the motor that hard.  You gradually get up to speed easily working thru the gear box.  Once you get to about 2000 RPMs in top gear you roll the throttle WOT until the motor peaks, and you close the throttle.  That's it.  You run more of risk doing damage going for The Ton than you do on a dyno.  JMHO.

Scottie
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The Blackhawk
1958 Enfield/Indian 711cc Twin

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Arizoni

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Re: What can a dynamometer tell me?
« Reply #5 on: December 18, 2013, 04:04:24 AM »
IMO, stock Iron Barrels don't like to run for any period of time at Wide Open Throttle.

They can easily overheat.  Their notoriously weak piston can crack  and their lower end is far from being robust.

Iron Barrels were designed for moderate riding during an era where 55 mph was considered fast on the roads so unless someone is willing to spend large amounts of money beefing up the engine I can't see where running the bike on a dyno serves any useful purpose.
Jim
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72westie

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Re: What can a dynamometer tell me?
« Reply #6 on: December 18, 2013, 04:42:06 AM »
Hell, my racebike was broken in on the dyno. I don't think it even had any street miles on it before it was revved to the moon. Dyno's don't work the bike harder then riding it on the street, with a dyno there is no wind resistance. I think we had 100+ runs on a stock crank, then over another 500 or so throughout the years.

Stock Iron barrels are around 17rwhp. I really wish I still had all our early dyno work, but a computer mishap lost all our early data. 200+ runs lost.  :P
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High On Octane

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Re: What can a dynamometer tell me?
« Reply #7 on: December 18, 2013, 12:58:04 PM »
IMO, stock Iron Barrels don't like to run for any period of time at Wide Open Throttle.

They can easily overheat.  Their notoriously weak piston can crack  and their lower end is far from being robust.

Iron Barrels were designed for moderate riding during an era where 55 mph was considered fast on the roads so unless someone is willing to spend large amounts of money beefing up the engine I can't see where running the bike on a dyno serves any useful purpose.

I'm ITCHING to get The Blackhawk on the Dyno to do some real fine tuning!  As far as iron barrels not liking WOT.....  Maybe for you Bullet riders, but my Twin loves being raped by the throttle!  Like for real.  Once I'm at operating temp, I take off from damn near every stop light at half throttle or more.  My bike has so much torque it just begs me to twist the grip a little bit harder than everyone else!    ;)

Scottie
Bulldog Kustoms - Denver, CO
Specializing In Kustom Paint

The Blackhawk
1958 Enfield/Indian 711cc Twin

Building the 1st EVER Supercharged RE Twin
FULL RACE motor with ACE Performance

Bullet Whisperer

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Re: What can a dynamometer tell me?
« Reply #8 on: December 18, 2013, 01:57:18 PM »
A dyno will not damage a Bullet or anything else for that matter. An idiot operating the dyno can, though, as I once witnessed.
 Many 'iron barrel' Bullets suffer as a result of being wrapped in cotton wool by their owners, many wrongly believing that by keeping the revs low and the gear high, that they are saving on wear and tear. Wrong. I have seen many exhaust valves and seats in 350 and 500 Bullets [other machines too] which were badly burned because the machines had larger gearbox sprockets fitted and were routinely made to lug up hills in top gear at around 45 mph with W.O.T. and 'cruise' at about 60 mph on full throttle, this being almost the top speed of an untuned, overgeared 500. One such machine has just been through my workshops - 19t gearbox sprocket, loud but restrictive exhaust and MK I Amal with too large a main jet for the otherwise standard engine. This is a better way to kill a Bullet than putting one on a dyno with a competent operator. This machine also had trapped second and oil rings, coked into their grooves by the combustion gasses blowing past them - this would be a good way to overheat the barrel and piston and cause a seiziure. Big ends and mains suffer from being overloaded in this way, too.
 A session on the dyno will enable you to get the best from any machine, in any state of tune, without causing it any harm, but tell the operator a maximum RPM figure for the machine and get it warmed up first, by doing a few runs to about 75% of  full speed RPM's, before testing for max power.
 B.W.

Blltrdr

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Re: What can a dynamometer tell me?
« Reply #9 on: December 18, 2013, 02:09:50 PM »
I understand using a dyno for checking progress in high performance Bullet builds to establish a reference point and to use that info to track your progress but can not see the value or necessity to spend time on a dyno for a stock Bullet. I guess if you have got a hole in your pocket you could hook your lawnmower up to one too.
2003 Classic 500 5 spd
1992 Kawasaki ZG 1200 Voyager XII
1977 Yamaha XS 360-2D (Cafe Project)

ace.cafe

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Re: What can a dynamometer tell me?
« Reply #10 on: December 18, 2013, 02:12:22 PM »
A dyno will not damage a Bullet or anything else for that matter. An idiot operating the dyno can, though, as I once witnessed.
 Many 'iron barrel' Bullets suffer as a result of being wrapped in cotton wool by their owners, many wrongly believing that by keeping the revs low and the gear high, that they are saving on wear and tear. Wrong. I have seen many exhaust valves and seats in 350 and 500 Bullets [other machines too] which were badly burned because the machines had larger gearbox sprockets fitted and were routinely made to lug up hills in top gear at around 45 mph with W.O.T. and 'cruise' at about 60 mph on full throttle, this being almost the top speed of an untuned, overgeared 500. One such machine has just been through my workshops - 19t gearbox sprocket, loud but restrictive exhaust and MK I Amal with too large a main jet for the otherwise standard engine. This is a better way to kill a Bullet than putting one on a dyno with a competent operator. This machine also had trapped second and oil rings, coked into their grooves by the combustion gasses blowing past them - this would be a good way to overheat the barrel and piston and cause a seiziure. Big ends and mains suffer from being overloaded in this way, too.
 A session on the dyno will enable you to get the best from any machine, in any state of tune, without causing it any harm, but tell the operator a maximum RPM figure for the machine and get it warmed up first, by doing a few runs to about 75% of  full speed RPM's, before testing for max power.
 B.W.

Hear, hear!
BW hits the nail on the head!

However, I do agree with the other points about not "needing" to put a stock bike on a dyno for no reason beside curiosity. Not that it would really hurt it, but it costs probably $75 or more to have it done, and if you're not getting anything out of it, it's not worth doing.
If you want to see results of mods, or need help jetting/tuning for AFR, and can't do it any other way, then the dyno can help with that.
Home of the ACE Fireball 535 Bullet,  Ace GP Hi-Lift Roller Rocker Head . Pistons, cams, etc. Highest performance Bullet engine mods available .  AVL mods. Redditch 700/750 Twin mods. UCE kit soon.

Please visit my new website:
http://autos.groups.yahoo.com/group/AcePerformanceBullets/

High On Octane

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Re: What can a dynamometer tell me?
« Reply #11 on: December 18, 2013, 02:39:45 PM »
I heard a commercial the other day on the radio advertising for a performance shop in Denver that let's you run your baseline for free.  I need to look into that.   :)

Scottie
Bulldog Kustoms - Denver, CO
Specializing In Kustom Paint

The Blackhawk
1958 Enfield/Indian 711cc Twin

Building the 1st EVER Supercharged RE Twin
FULL RACE motor with ACE Performance

jedaks

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Re: What can a dynamometer tell me?
« Reply #12 on: December 19, 2013, 06:30:50 AM »
Thanks for the input.
I should have mentioned that my '04 iron barrel has been modified into a 535 with an alloy barrel, 19t sprocket, roller bearing big end, steel conrod, Accralite piston, Ace Canister, goldstar style exhaust, HD clutch springs and a few other things I can't remember at the moment. The head is still stock but was reconditioned. I'm still using the mikcarb vm28 and contact breaker points. I think about getting rid of the mikcarb now and then but it suits my purposes just fine (daily commuting and highway riding at 100kph easily)

So, a dynamometer would tell me if there was room to advance/retard my timing and a fuel sniffer would tell me if I was lean/rich at various throttle openings?

Bullet Whisperer

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Re: What can a dynamometer tell me?
« Reply #13 on: December 19, 2013, 07:43:06 AM »
One thing is for certain, without using a dyno, jedaks - you are very definitely NOT getting the best from your machine with that carb on it, when you have all those other mods, even with a standard cylinder head. Read my previous post regarding that 19t gearbox sprocket. There is much more 'in the bag' for your machine, if you want it  ;)
 B.W.

jedaks

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Re: What can a dynamometer tell me?
« Reply #14 on: December 19, 2013, 10:15:22 AM »
Thanks Bullet Whisperer...I believe I will exchange the carby one day. Since I'm not a "power-user" I haven't given it much serious though. When I cruise at 60mph I'm on 1/2 throttle. However, going to WOT doesn't give much more performance than 1/2 throttle with the mikcarb.

I want to keep the points though.