905 lives

Our homebrew 905 engine lives. Had it on the dyno to run it in for a couple minutes. Kept revs to 2000 for about 5 min, then adjusted the dyno to 2500. Couple minutes later I gave it 3000 and so on up to 4000 revs. At 4000 I took a reading of 65 nm at around 1/4 throttle. More was not needed to get it up to 4000. At the moment I run Commando headers which are way too small as the head is heavily reworked with bigger valves, tracks etc. The engine runs a balance factor of 60 % but doesnt vibrate at all. It seems it gets smooth above 1000 and stays calm all through the revs. I had several other Norton engines on this dyno (road and race) that vibrated much more. After checking the plugs (no Lambda sonde fitted yet) I found the 36 Dellorto pumpers to be too weak so I left it there. Tonight I take engine apart and check all the special parts - there is lots of them in there. To cut it short - here is what is STD Norton (albeit modified):
right crankcase, timing cover, cylinder and head, both crank cheeks - everything else in there is homemade...
If somebody wants to upload pics on this forum I will take some during the teardown and send them on - let me know.

Cheers

Hartmut

I would love to see some pictures. If you want to send them to me I will put them on the forum. Jim comnoz2@comcast.net

Good omen for all of us engine experimenters. Chevy V8's have about same bore and valve size and rpm range - they generally run 1 3/4" headers about same length as Commandos before entering collector of just left open. Biggest off the shelf headers I've seen are 1 1/2", so special order or DIY for next step up.

Photo's would be entertaining educational.
Race engines near that size imply 90-ish hp possible, don't know torque data.
How do you the start engine on a dyno?
What cam profile did you pick?
Any plans to try degreeing the cam for power band skewing?

Pics are on their way to Jim

Here are some explanations: the stroke is 90mm, bore 80mm. Conrods and pistons are homemade. Accidently bored the cylinder 0,02mm too large so coated the pistons to give a clearance of 0,08mm - I think we could run less as we have jets spraying lots of oil under the pistons. The oilpump was a nightmare to design: 3 times the output of the Norton pump, incorporates a PRV and anti wetsump valve as well. Cams: the one tested last weekend is the softest we made, 300/300 degr, lift 11,5mm - we have 4 hotter cams to test. The left crankcase incorporates an extra rollerbearing - I don´t like bending shafts so the bearing is in the middle of the 50mm belt. The crank got extra weight on the cheeks and no balance weight in the center - that steeldisc keeps it all in line the faster it spins. Never understood why the limeys put the weight as far away from the bearings as possible.
The head breathes through 36mm Dellortos and tapered down to 34mm inlet tracks, 41mm valves inlet, 36 exhaust. 7mm valvestems. Took the engine out of the dynocrate today and took it apart to see what (if any) is wrong. So far - so good. No problems inside. Everything turns smooth. Will reassemble the thing next week and do some serious testing. We will rev up to 7500, take a reading every 500 rpm and see where we are.

Cheers

Hartmut

Photo's would be entertaining educational.
Race engines near that size imply 90-ish hp possible, don't know torque data.
How do you the start engine on a dyno?
What cam profile did you pick?
Any plans to try degreeing the cam for power band skewing?[/quote]


Photos are on their way. To start the engine we simply push the button - there is a car flywheel and starter incorporated in the drive of the Schenk dyno. To connect the Norton engine to the dyno I built a crate with a 1/1 primary. The large disc at the back pulley is bolted to the dyno and off you go...
No plans yet to degreeing the cam - just dialed it in to have 0,4mm lead of inlet at overlapTDC.

Forgot a pic: the head is flushed with oil as well to get some heat out. In the pic you see the first test of the oilpump. I drove it with an electric drill to see if we got the jets right - seems so as there are strong streams coming out of the head front and back - when the engine ran on the dyno we had 80 degr directly above the exhaust track and only 50 on the valvecover whereas the lower engine was at 75 deg C. Seems to take away some heat of the head.

Some more pics to be found at: www.britishclassicbikes.de

Here are some pictures I received. Jim

Great stuff! Please keep it coming.

I ran a 91 mm crank with 80.5 mm bore for a while in a road racer, and it was a happy combination. Not nearly as trick as yours, though.

Ken

Forgot the lightweight followers - much lighter than stock and no stellite cap to fall off - they are case hardened.

Eye candy mental expander Weal.
I dragged Ken above and Jim Schmidt into piston oil jet cooling design last year. Jim figured out how/where to place jets, Ken figured out how to make and install them. I found how much oil flow is needed to lower piston temp 100' F in ordinary engines, over .5 liter a minute! Also found out how much oil to cool gasoline or diesel hot rods, up to 3 gallons a minute. I then figured Norton pump flow beyond engine needs, don't begin to even matter. Norton rod oil jets hit the piston pin twice a rotation in attempt to stop seizures that turned out to be bad piston batch, but rod holes never corrected. Racers block them off as two spits a turn just takes away bearing oil layer. I admit I'm taken aback at the size of pump you created! Will be quite the bulge to view down there : )
If Ms. Peel appears to need oil jets d/t detonation issues I'll have to use electric pumps to both feed jets and clear the sump separate from stock pump system.

Its standard practice in Brit cranks to put in light steel center and heavy slugs in cheeks but your crank is cat's meow and likely a stiff one to over 8000 or pistons top out from the stroke. Cryo tempering is worth while too. Knock your socks off skeletonized lifters!!! Should help drain the extra head oil too.

Trick way to get two DS crank bearings, a first in Norton I think. I've bent every shaft in a Norton, ugh, not all my fault so HIGHLY RECOMMEND a rev limiter.

I've give thought to exterior bearing supports in the primary cover. I don't think you need 50 mm belt to endure 900 cc power but wonder about the clutch and gear box holding it.

Impressed by the 'mildest' cam to try first. That is range of drag strip only.
Ms Peel's first cam experiment ain't too far from that and needed to lower low rpm effective compression from 10.5 to run on 91 octane.

Pray tell how will you be deploying this ripening fruit of your labors?

THAT is nice work, bravo

Jean

The engine will get a homemade gearbox, clutch and primary as well. I want a reliable 6-speeder without bending the mainshaft - no matter what power is working on it. So the gearbox has its outer bearing right in the middle of the clutch center (belt middle - just as the crank). Gearbox shells are cast already but the internals are only drawn up so far. I looked at the TT boxes but they follow the old Norton layout and I don´t want to worry about bending shafts and all that stuff.
When engine testing is finished (hopefully without exploding the plot) it will be fitted to my blue Norton for roadtesting. If it feels good I put it in my MX wasp outfit as this first engine is made from shabby parts - a welded up crankcase on the right and dozens of welded up fins on the head etc. I figured that if my calculations ain´t right and it explodes I will not lose perfect Norton parts. And an MX outfit doesn´t need a highly polished engine ... So I keep fingers crossed that all goes well and we will build a couple more engines. At least three of them are already spoken for - two going into the Dunstall frames that I built and sold last winter, the third goes into a 1957 Wideline 600. That might be a big angry wolf in sheeps clothing :mrgreen: But at least the 600 is painted bright red so people should be aware what is overtaking them on the freeway :twisted:


Cheers

Hartmut

Wow Hartmut what Norton's cute engine profile drives us men to indulge in!
A Wasp side car eh, oh my crazy corner antics those nuts seem to love.
Ms Peel's engine is 10:5 CR 920 with supercharger to avoid hi rpm let downs. I've twisted up trans shafts and even crankshafts to candy cane shape on hopped up Combat specs, so am saving up for bullet proof gear box as last major component to purchase. I figure $3500-4000 so maybe you are where I should spend it on?
I only seek 3 or 4 gears though but if 5 or six up to the torque then more the merrier.

I mention cryogenic tempering again, standard -300'F or better ~450'F. The Norton rotary fractured all metallurgy available in bearings and crank shafts to prevent production for years until they tried cryogenics and rest is history. I once read details on rotary development but have not found it since and current rotary crew just rolls their eyes up when I asked for references, but after Ms Peel disappeared her tach needle for some seconds bouncing off peg stop I rode her another 2000 miles w/o doing a thing but it did cut power and bend crank so had to start over again - so her new optic trigger ignition has rev limiter.

If cases made so crankshaft off center to bore, to the rear IIRC that relieves somw of the piston jerk down acceleration.

At your level of skill/involvement there is a planetary gear geometry that turns pure reciprocating motion into pure rotary motion and center supports crank w/o bearings and no need of piston motion on a fixed to it connecting rod. Then could shorten stroke so pistons could take more rpm and gearing advantage.

Hartmut -

are you going to but some wheels under this engine and bring it to Bonneville next year? Or you only run Bonneville with twin engine setups?

keith Kelly

Black/White photo era vintage Norton racers told me they would run to 8500 to out run more modern Hondas and such in the opens. Drag racers missing a shift also mentioned seeing 8500 and no blow up.

Both Commando powered. More to see here.
http://www.sidecarcross.com/photo/vintage/

pkeithkelly said:

Hartmut -

are you going to but some wheels under this engine and bring it to Bonneville next year? Or you only run Bonneville with twin engine setups?

keith Kelly

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Hey Keith

Have we met already in Bonneville saltflats? Sorry - can´t remember you. Anyway - I´d love to bring my own bike to the flats to wring its neck. I thought about this from the first year (2004) that I was there racing the Lambky liner. I have built years ago a Triumph sprinter with a Shorocks blower - would be nice to see what it will do flat out with a high gearing. The new Norton engine is still under full development but should be ready by spring next year. But it will have so much power that an ordinary Norton gearbox will not handle it. So I need to make the new gearbox and primary as well. If I could find a sponsor I would surely come back to the flats with a tricky Norton and find out what it could do - the goal would be to beat the new Norton - can´t remember the speed of Cathcart this year but it didn´t impress me. My Dunstall bike is way smaller and lighter (ca 140kg with oil / no fuel) so should have some advantage here.
As it stands I will be back next year and do the riding of Max´s Vincent streamliner once more - we need to go 300 +++ as its long overdue.... Maybe Terry Prince/ Australia will be there again - this year he offered me to ride his Vincent sidecar outfit in case the streamliner breaks down. I would have loved to give his bike a WFO on the flats.

Cheers

Hartmut

hobot said:

Black/White photo era vintage Norton racers told me they would run to 8500 to out run more modern Hondas and such in the opens. Drag racers missing a shift also mentioned seeing 8500 and no blow up.

Both Commando powered. More to see here.
http://www.sidecarcross.com/photo/vintage/

Click to expand...

I never needed to rev 8000 on my Norton Wasp - was always able to beat the Yamis etc with good handling and high torque. The new engine will be an eye opener for all those that thought the Norton twin is dead in sidecarcross. I can compare as I run a 975 Yamaha twin as well - this one also with a homebrew cam (actually the same is is now fitted in the 905) and dry clutch as the mass of power was too much for the wet clutch.
I do know that a Norton will rev up to 9000 by an expensive mishape that a friend of mine had. He was out on his 750 roadgoing featherbed (tricked out with tuned engine, full fairing etc - that thing was timed at the Salzburgring with 225 kmh! during a Ducati owners race) He accelerated hard uphill and at around shifting time (7000) the Schafleitner gearbox jumped out of gear - revs shot instantly way up before he could release the throttle. He put it back in gear and accelerated again and found it started to vibrate a bit at 7000 - gear went out again - revs up and the crank exploded, Flywheel smashed the crankcases and flew into the gearbox and broke that case as well. He was lucky to stay upright and came to a halt. When looking at the Chronometric rev counter it showed 9000 - as they need movement to let the needle come down this was clearly the revs that the engine did at the moment it died.

Cheers

Hey Hartmut,

How did you increase the stroke by 1 mm using standard crank cheeks?

Bert

johntickle said:

Hey Hartmut,

How did you increase the stroke by 1 mm using standard crank cheeks?

Bert

Click to expand...

Grind the bigends offset and use smaller shells. Easy!

Cheers

Hartmut