Dyno readout of Mike Hamiltons 850 with JS parts

WZ507, sorry didn't answer your query earlier JS#2 camshaft.
Noted on the HP readouts and yes there is room for the operator to adjust for rear wheel or carnk readouts, as I have just been out to the same dyno shop with my Roadster and could only manage 45RHP on the same dyno and with the same operator and settings on the dyno PC, I am confident the 64 shown on the readout for the original post by JS is correct.
Regards Mike

72Combat said:

Wow, I dream of the BMW having 64 BHP..... currently only about 50-55,

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It's quite possible.....my 1070 based airhead shows around 72 bhp on a dyno jet, with perfect road manners and reliability, it's not cheap!

Brooking 850 said:

WZ507, sorry didn't answer your query earlier JS#2 camshaft.
Noted on the HP readouts and yes there is room for the operator to adjust for rear wheel or carnk readouts, as I have just been out to the same dyno shop with my Roadster and could only manage 45RHP on the same dyno and with the same operator and settings on the dyno PC, I am confident the 64 shown on the readout for the original post by JS is correct.
Regards Mike

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Well given that bit of info, not to sound too Hobot, but YEEHAW !! It will be a lot of fun to ride.

Glen

I don't understand. Is this being done with a road bike ? I always hot up a racer, how can you use it on public roads ? Around here you have to ride at least 60Km to find a road which is in any way interesting - the rest is droning down long straight roads to get there, and the cops are vigilant on those.

acotrel said:

I don't understand. Is this being done with a road bike ? I always hot up a racer, how can you use it on public roads ? Around here you have to ride at least 60Km to find a road which is in any way interesting - the rest is droning down long straight roads to get there, and the cops are vigilant on those.

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What not to understand?!
Some people like to tune road bikes!
And we're not exactly talking about fitting Nitros injection to an R1 here, even at 64RWHP, its not exactly going to be unmanageable / unusable is it?
But it will be a whole lot of fun to ride.
So there's your answer: It is fun!

I got all heated up, some time ago, about throwing some real money at my Combat (since sold). JS pistons, rods, camshaft, flatslides and a Fullauto head prepped by Comstock or Goff. I realized no matter how much I spent I'd still get blown away by any run-of-the mill 600cc Jap bike, not to mention the probable loss in reliability. Nortons are fun to ride, attract loads of attention and are special to own, but by no means are they fast by today's standards. Upgrading for reliability and smooth performance makes sense to me, but going for outright speed with a Norton is a fool's errand, IMO.

I would add: Many's the time I've been on a fool's errand.

Here's a dyno readout of Mike Hamilton's 850 Commando with JS lightweight pistons and JS stage 2 radiused cam kit.

64 HP is very impressive on an otherwise stock Nort.

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64 hp out of a mostly stock 850?

I just had my new fuel injected 865 DOHC Triumph Bonneville on the dyno putting out 61hp at 7000rpm rear wheel

I have seen a number of dyno print outs showing around 44 rear wheel horsepower from all stock Commandos

But 64hp with a little better than stock cam can add maybe 2-3hp from my readings and as light weight as the JS pistons are, how exactly do they produce more hp at the same rpm as say stock pistons? compression higher?

I guess I need some help, can you guys tell me where this amazing increase in hp came from exactly?

Hey Mike, you'll need that 65 HP as I managed consistent sub 1.29's in the weekend with 50-55 HP :mrgreen:

hi guys, there seems to be some conjecture here, and perhaps a little lack of attention.
The 64 rhp is produced by a race bike I built out of a stock 1973 850 and although it may have JS rods, pistons and JS #2 cam with light weight lifters and shortened push rods, the rest of the motor is genuine 850 including the balanced crank, barrels over bored 0.040", a RH10 head with Black Diamond valves of standard size and beehive springs. All rockers and spindles are std, not lightened, headsteady that I made myself.
The valve angle is as per RH10 head from the factory, the inlet manifolds are stock standard items (not lengthed yet) cleaned up to match the inlet tract and brand new 2 x Amal 32 mm Premiers. The torque comes from the head which has been cleaned up by a master in New Zealand 9 he lives 10 minutes from my house)as per the likes of Jim Comstock, all the advice I took from members here on the forum, so no special secrets applied.
I did list all of this in another thread during the build. I run it on Avgas
The 45 rhp motor is in my stock standard 1973 Roadster that I did one track k day on a couple of years ago, ride to all the rallies and races I can (when I am not racing) put it up a runway for some drags recently and ride it all year round in New Zealand.
Hope this clears up any confusion out there.
Regards Mike

Ten minutes from your house in Tauranga ? Interesting.

I got a really good result from Denby in Thames.

I think this dyno reading is very feasible. Most street Commandos dyno in the 43 to 48 range. But is not so hard to get into the 60s with a mildly tuned race bike. A moderate cam, head work, exhaust and most importantly a well set up engine will get you there.

Ok cool corralling scope of reports on rwhp, standard factory mid 40''s and if factory parts mixed and matched - head to came to carbs and timing, like DyhoDave might see 49+ish on honest to god factory engine. Stage one adds another 15ish hp and state two another 10ish. That implies State 3 like comnoz and Dances and Woods and Axtel and old world buiders seeing upper 70's with 750-ish engines. Then there's Stage 4 with special fuels like TC 150 definitely essentially pure stock 850's and finally stage 5 with power adders. May a stage six in which the factory engine is merely used to pump buckets of raw fuel and oxidizer in with plasma ignitions making the peashootesr earn their names with rocket thrust so no rwhp at'all.

Btw on powerful engines there should be various color exhaust jets out the ends of headers on straight thru muffers. Peel's were mostly deep purple painted with orange-yellowish tinges on throttle ups not back fire over runs.

[video]http://www.youtube.com/watch?v=KTx5v8jeFdw[/video]

comnoz said:

Dynos are a great tool for tuning and seeing the results of changes made.
As far as advertising and absolute numbers they are meaningless. Jim

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I have been contemplating on having a dyno run and posting the results with the single Mikuni TM40-6 (HS40). But what's the point unless I had a baseline done before everything else.

I am not sure what posting erroneous results will prove other than inviting critical responces. There is one thing for sure, if it wasn't right(righteous) in any aspect, I would be using something else.

I do not know what the cost is for a Dyno run, but I bet I could get a fresh tire or two for the cost of this service. A fresh set of skins is worth more than trying to prove something to this bunch of (fill in the blank).

Pete, once again you have hurt the collective feelings of this bunch of a$$ wholes

worntorn said:

Pete, once again you have hurt the collective feelings of this bunch of a$$ wholes

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I was thinking more along the line of " a bunch of fine fellows" or "a bunch of knowledgeable gent" or "a bunch of devoted comrades".

I'm sure that was your intent, :roll: but you have to understand I have been waiting for quite awhile to use that photo :mrgreen:

The term Nortoneers covers it for me. If it ain't in common usage a long time or in expected configurations then its gotta be a bodged oddball too silly to believe. Just don't let the wind dry your tongue out like me.

Pete v, yes you are right about the cost of dyno runs anywhere in the world, with the bike only finished by two weeks before my first race meeting and only a few illegal rioad miles of test runs on the engine and bike set up, i completed the engine run in on the dyno(about 30 minutes) then the rest of the time setting mixture and changing mufflers to get the mid range back.
What it proved was that i was close with everything, gave me the confidence to run it pretty hard first race meeting, and know full well I wasnt going to damage the engine first time out, small price to pay in my mind and also not a hell of a lot more than the price of a set of mufflers which I didn't need to buy.
There wasnt any boasting intending by posting the dyno results, In fact I sent them to a few members privately to see what they thought, Jim S asked me if he could post them publicly as his internals were used.
Also that result is my baseline before I make any more changes, if any.
Regards Mike

Mike, if I managed to build up a Norton motor that made 64 rwhp, I would brag a little or perhaps more than a little.
It is a very good result, sorry I questioned the number. It seemed too high for the relatively small number of changes made, so I wondered about the dyno settings, clearly they can move numbers around.
However, your test of a standard bike on same dyno is close to a baseline , so obviously those changes made have had a big effect on power output.

Glen

Mike,

It would be nice if you would be so generous as to post the dyno graph for the stock engine. This would allow the less informed (me) to compare the differences in power development between your 2 engines. Thank you.

I'd be more impressed if you guys posted your lap times on various race circuits after you've posted your dyno readings. Like some other things 'it is not what you've got, but what you do with it'. 'Don't measure the length, feel the breadth'.