How many HP on my MK3

Her kommer en ren, presis og forum‑klar engelsk oversettelse av teksten din, Vidar. Jeg har strammet den opp slik at den flyter godt for Access Norton‑publikumet, men uten å endre innholdet du formidler.

Engelsk oversettelse – klar til å lime inn på forumet​

I’ve carried out most of the upgrades I can find for my MK3. I started by boring the cylinder 0.5 mm over standard (77.5 mm, as far as I remember). Compression is set to 9.2.

From CNW I’m running the new STS Fullauto head, the CNW dual Keihin flat‑slide carburetors, the CNW intake manifolds, and Tri-Spark ignition.

From JS Motorsport I have the lightweight pistons with gapless rings and the longer rods. I’m also using Black Diamond valves, in standard dimensions. The camshaft is JS’s standard “stage 0” cam, together with his radius lifters.

The bike runs incredibly smooth, flexible, and very strong in my opinion, so I’m curious what kind of horsepower I can realistically expect from this setup. Of course, I should put it on a dyno to get an exact answer, but I’m thinking there might be some specialists out there who can give an educated estimate.


Hvis du ønsker en mer teknisk, mer formell, eller kortere versjon, kan jeg lage det også.

we will all be curious of the dyno results if you do that

Ops. I suddenly came up with more than I should have, at the top and bottom it says something in Norwegian that this Chat GPT helper added

Vidar

Low to mid 50s at the wheel.

Vidar, editing allowed! :=}

- Knut

vidar hjelm johansen said:

... From CNW I’m running the new STS Fullauto head, ...

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You still miss the effect of a big valve head, a solid crankshaft, and alcolhol injection

vidar hjelm johansen said:

I’m curious what kind of horsepower I can realistically expect from this setup. Of course, I should put it on a dyno to get an exact answer, ....

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There is no such thing as an exact answer, because the dyno test itself is inaccurate. To get an overview, please query ChatGPT about "error sources in a Dyno test".

- Knut

Norton used Heenan and Froud DPX water brake engine dynamometers. Very accurate, well maintained, calibrated and compensated for ambient temperature and pressure.

"query ChatGPT about "error sources in a Dyno test"."

Then query ChatGPT about "error sources in ChatGPT." Though ChatGPT probably won't badmouth itself.

hybridracer said:

Norton used Heenan and Froud DPX water brake engine dynamometers. Very accurate, well maintained, calibrated and compensated for ambient temperature and pressure.

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I didn't know they had one? Maybe they transplanted the dyno from AMC's development shop? Out of curiosity, are there pictures of the NV testing lab?

Readings taken off the crankshaft eliminate a number of error sources.

- Knut

What is the point of calculating potential HP? Bragging rights? If the point is to enhance performance for racing purposes, I get it.
But otherwise it seems an academic excercise in arm wrestling. Sorry if I have offended performance purists out there. Will crawl
back under my rock.

If it pulls your arms and push you back in your seat then that is all I care about and even better when the front wheel comes up when you open the throttle when you take off even better and keeping the front wheel up when going up the gears using the power of the motor, HP is just numbers, its how you ride and how you use the power of the motor, even a stock motor will do these things if you know how to ride you own bike, and gets me when some ask "how fast can it go", who cares, I have nothing to prove and only I will ever know, but I do like playing up in the ranges and tight twisties.

lazyeye6 said:

What is the point of calculating potential HP? Bragging rights? If the point is to enhance performance for racing purposes, I get it.
But otherwise it seems an academic excercise in arm wrestling. Sorry if I have offended performance purists out there. Will crawl
back under my rock.

Click to expand...

To evaluate the benefit of changes. That’s the only real reason. So the ‘actual’ number isn’t really important (and is open to variables as mentioned already), it’s the difference in numbers before and after that’s really important. Hence the importance of using the same Dyno.

Some will argue that their arse tells them all they need to know, actually most peoples arse dynos are really quite unreliable!

"Some will argue that their arse tells them all they need to know, actually most peoples arse dynos are really quite unreliable!"

ABSOLUTELY!!! In my (car) engine building days it was common to see an engine that someone had slapped a larger carburetor on and talked about how he (it was always a "he") could feel the surge in power at "x" RPM that the stock engine didn't deliver. Turned out the car was SLOWER in the 1/4 mile/less HP on the dyno. The "surge" occurred because the new setup had put a hole in the midrange so the surge occurred as the engine finally overcame the poor carburetoration and began accelerating "normally."

the butt dyno is, IMO, wrong far more than it is right. On motorcycles I have heard people claim they could feel a difference in power after lubricating a chain with "X" lubricant over "Y" lubricant.