Dyno Day

Status
Not open for further replies.
Carbonfibre said:
Interesting to sort out fact from fiction regarding power outputs, and that Amal carbs are the ones to fit if you are looking for best possible performance!
Click to expand...

Who would ever say Amals give best performance? They are a step up from a single carb.

The winning bike on Saturday had Kehein 35mm FCRs. Just under 10-1 compression and a small port head I did several years back.

Second place bike was also an 880 with 10.5 compression , a cleaned up RH4 and Amals. [and it was idling on one cylinder] Jim
 
The correction factor is figured from a coastdown test by the dyno so it is not always the same but the 64.7 crankshaft figure gave 55.8 at the rear wheel. Jim
Click to expand...

I'm not in yoose guys league but have stayed in cheap motels and followed for a decade power reports and drive train losses to sense that your conversion factors may not be worth reporting as Nortons should only have 9-10% power loss to rear patch so 65 hp crank should rear wheel dyno closer to 59 hp. IIRC Maney had both crank and rear wheel tested for 100.4 shaft hp and 90 at rear patch. Super duper moderns lose about 15% which would match your conversion factor, so get up to speed on this to raise the mood after dyno reports. Thin lube like ATF might be worth an extra hp or more at rear tire, poor moderns stuck with shared engine oil.

On my pure factory Trixie I can lightly pinch the clutch center with index and thumb and spin rear tire w/o much effort and it keeps spining a bit after I quit, I can't do that on my '99 SV650 or pinches my fingers.

Boyer analog at full advance should not hinder top end power but will delay power before it reaches its sluggish rise to full adv. Jim Schimdt out lines a resister-shorting of trigger leads for more spunk out of turns.
 
Actually the 55 horse figure is drum power so it also has the tire to drum loss to figure in with the trans loss.
You know them British guys got big gallons and little horses. :D Jim
 
Actually the 55 horse figure is drum power so it also has the tire to drum loss to figure in with the trans loss. You know them British guys got big gallons and little horses.
Click to expand...

Then should be report as rolling drum hp, not road wheel to road surface hp I'd think. Just keep 10% road going drive train loss in mind as you grow in your knowledge of Norton reality.

For my further education, can ya give a few reports of displacement vs power readings at 5252 rpm?
Ever test engines with more exotic-expensive fuels:?
 
hobot said:
Actually the 55 horse figure is drum power so it also has the tire to drum loss to figure in with the trans loss. You know them British guys got big gallons and little horses.
Click to expand...

Then should be report as rolling drum hp, not road wheel to road surface hp I'd think. Just keep 10% road going drive train loss in mind as you grow in your knowledge of Norton reality.

For my further education, can ya give a few reports of displacement vs power readings at 5252 rpm?
Ever test engines with more exotic-expensive fuels:?
Click to expand...

I have played with different race fuels. There is definitely some power to be found there.
You know my thoughts on published horsepower readings- mine or anyone elses- they generally are not worth the paper they are written on. Dyno readings can vary greatly and I would only use them as a tool to compare before and after modifications or to compare two bikes on the same dyno on the same day. Jim
 
Jim,
Sorry for the ignorance, but what's dyno day?
Are you dialing in bikes or is it just a peak HP bragging rights type of thing thing?
Do you do it very often?
how many bikes showed up?
 
Mark said:
Jim,
Sorry for the ignorance, but what's dyno day?
Are you dialing in bikes or is it just a peak HP bragging rights type of thing thing?
Do you do it very often?
how many bikes showed up?
Click to expand...

Dyno day was an event organized by the Co. Norton Owners Club, this was the first year, just a BS session, lunch and run you bike for bragging rights, we had a small turnout as the weather was not so good. Probably will do it once a year if there is interest. Jim
 
You know my thoughts on published horsepower readings- mine or anyone elses- they generally are not worth the paper they are written on. Dyno readings can vary greatly and I would only use them as a tool to compare before and after modifications or to compare two bikes on the same dyno on the same day. Jim
Click to expand...

Oh y mean like Combat numbers in the work manual?
A nod to your seasoned skill to keep variables as honestly constant as practical to base the grins on or next wallet mass reduction. TC's Hog Slayer 150 hp nitromethane engines lingers in my mind on fuels for short max out attempts.

Here's a blip on how to judge the dyno out puts and whats actually being tested,
http://www.revsearch.com/dynamometer/to ... power.html

Horsepower = torque X rpm / 5252

Here's an interesting bit of trivia; below 5252 rpm any engine's torque number will always be higher than its horsepower number, and above 5252 rpm any engine's horsepower number will always be higher than its torque number. At 5252 rpm the horsepower and torque numbers will be exactly the same.
Click to expand...

On modern day dynamometers horsepower is a calculated value. It's important to remember the dyno measures torque and rpm and then from these calculates horsepower. On the dyno it takes more water flow to the water brake to increase the load on the engine being tested. As the test engine's torque rises more water flow is needed. As the test engine's torque drops less water flow is needed. The dyno's water brake does not respond to Horsepower. Major adjustments to water flow are needed as an engine crosses its torque peak but none are needed as it crosses its horsepower peak. In other words the water flow to the brake during a dyno test follows the engines torque curve and not its horsepower curve. Torque is what twists the tire, prop, or pump. Horsepower helps us understand an amount or quantity of torque. (Torque + time and distance)
Click to expand...
 
How to cheat towards low power reading on chassis-tire dyno. Reverse for the opposite fudging. A teaser quote below but covers a number of things, especially tires that apply to Nortons or any cycle.

We guess he may be trying to guess how to race in a series where the rules says 300HP max with a 380HP engine. We guess that in that series they control if the rulebook is being obeyed with a dyno run :mrgreen:
Click to expand...
http://www.f1technical.net/forum/viewto ... f=5&t=7053
 
Trying to grock this dyno deal myself so looking into cheat factor revelations. I've had V8 set up my way for propane and took 5 runs tweaking to win bet with engine shop it'd out perform the evaporate rating. Took some auguring and $200 more to move cam 0.5 degree to do it though. Below is almost a book on it.


Overview:
Many dynos, but probably not all of them have one or more ways to cheat the results. The most common way to cheat is to set a "Correction Factor" -- which is a number that is used to multiply the results before they are displayed on the screen. But other ways of cheating exist as well. It's possible to cheat by manipulating the pressure sensors to read higher or lower when the need arises. Hopefully this thread will expose some of these techniques and give people ways to catch the cheaters.
Click to expand...
http://www.pencilgeek.org/2009/09/expos ... w-the.html
 
Well I could give you a half a dozen different horsepower readings from one dyno run, and none of them would be cheating, just different ways of figuring it. :shock:
 
Well I could give you a half a dozen different horsepower readings from one dyno run, and none of them would be cheating, just different ways of figuring it.
Click to expand...

Yes I'm aware of this but not the actual details to control or fudge so my mention of your experience to give some relative meaning to the figures. I'm going to have to depend mostly on the G-meter road going 'dyno' and 'consistent' test conditions and operation and electric stethoscope. Still a graph from you is bragging rights I'd love to have before I go. I'd like to hit 160 hp/120 lb ft once, though don't expect that to be realistic but when mounted on a dyno with me spritzing its head and mine with garden sprayer.
Nitromethane gives about 3x's road gasoline power, but then so does 3x's mixture packed in with enough water octane timing can stay at max pressure peaks. I did not think this possible until Bruce reported loading his 850 Drouin to 15 PSI level, OMG! Highest I dared plug boot factor in various engine calculators was 12 PSI @ 8000 and freaked me out. These calculators are easiest to fudge for fun but only a few accommodate inner cooling and anti-detonation fluids.
 
Well as a rule of thumb on my dyno I have always looked for .6 to .7 horse per 10cc on a street motor and .8 on a race motor. Jim
 
Informative ballparks to expect in Nortons. Hot rod V8 run to same rpm levels as Nortons can stand generally make at least 1 hp per cid. A 750 is ~45 cid and 920 is ~55 cid, so a bit confused by your summary. My 406 chevy V8 made 449.8 hp @ 5600 rpm and 423 lb ft at lowest rpm dyno could measure ~2500 rpm on 93 octane. I figure it'll take about 3 hp per cid to do what I want but may never reach. At least fun to try before I'm done.
 
I didn't mention cubic inch. Just cubic centimeter. So a 920 would be 92 x .7 or 64.4 horse in good street trim. Jim
 
comnoz said:
I didn't mention cubic inch. Just cubic centimeter. So a 920 would be 92 x .7 or 64.4 horse in good street trim. Jim
Click to expand...

The old rule of thumb was 1 published horse power per 10cc now they are way beyond that either published or real. I guess the old Brits are still stuck in the past with real or imaginary numbers :wink:

Jean
 
oHhhh, cc's not cid's, smack, now that fits what little I know on Norton spunk, over a hp per cid. Implies only double natural inhaling power may do what I seek.
3 days of record rains slowed up so off to recover mower to clear path to get to Trixie Combat to let out to risk life and bike on. Lost a bunch of work during this and may take some days for folks creeks down and bridges up to reach me.
Cuts into cycle parts budget but gives more time to fuss with em.


65 hp / 55 cid = 1.18181818hp/cid.
 
Status
Not open for further replies.

Similar threads

E
  • Locked
850 Dyno Run
Replies
13
Views
3,183
Fullauto
F
yves norton seeley
  • Locked
Back on the dyno to day: Satisfaction!!
Replies
5
Views
1,975
Jagbruno
Jagbruno
Fast Eddie
  • Locked
Exhaust dyno testing
2 3
Replies
52
Views
5,749
Fast Eddie
Fast Eddie
comnoz
  • Locked
Dyno test
2 3
Replies
44
Views
8,023
NoiseyNorton
NoiseyNorton
o0norton0o
  • Locked
rough day...
2
Replies
30
Views
2,149
speedrattle
speedrattle
Back
Top