Commando Crankshaft Porn

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Commando Crankshaft Porn

Postby lcrken » Sun Jan 02, 2011 2:00 pm

(Edited with additional details 1/3/11)

There have been a lot of interesting pictures of crankshafts on various posts here, so I thought I'd try to get as many of them as possiible in one post. I'm posting all the ones I have collected over the years, and hope others will add to them.

First, a factory Commando crank modified the way we used to do them back in the '70s. Custom steel flywheel, heavy metal, radiused output shaft, shot peened, and high strength 3/8" fasteners. This one is still running in a friend's 920 AHRMA twins class race bike. I ran it in my 750 Commando Production Racer with a 62% BF. The 920 is in a featherbed frame, and I added more heavy metal to he flywheel (not shown in this picture) for an 80% BF. That seems to work really well for this particular bike.

Image

Next, a Dave Nourish 89 mm crankshaft with Crower titanium rods from Martin Adam's Commonwealth Norton racer, now owned by Fred Eiker and running at Bonneville as a landspeed bike. Martin's bike had a Caffrey Seeley replica frame and 872 cc engine. The crankshaft BF was a little over 80%.

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Another Nourish crank, this one an 80.4 mm 750 short stroke with Carrillo steel rods, part of an engine build I'm doing now. I had this one made with the wider width to fit Mk3 850 cases. I raced it one in my PR for a while with the stock steel rods (till one broke) and a 62% BF. I replaced the rods with Carrillos with no other changes, which raised the BF to 71.6%. It still worked fine with the isolastics.

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A Falicon 89 mm stroke crank built for Kenny Dreer, with larger diameter main bearings. It's on the shelf, along with the crankcase from Kenny with larger bearing bores, waitng for me to decide what to build with it.

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An offset crankshaft by Chris Large. I don't know the status of this one.

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An offset crank by Geoff Collins. Geoff makes these, along with other confiturations, to order.

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And last, but not least, our own hobot's Geoff Collins crankshaft with custom steel flywheel by Ron Fraturelli. I'm in the process of modifying this crank, but at the moment, it weighs 21 lbs.

Image

That's it for now.

Ken
Last edited by lcrken on Mon Jan 03, 2011 10:31 pm, edited 1 time in total.
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Re: Commando Crankshaft Porn

Postby lcrken » Sun Jan 02, 2011 2:21 pm

(Edited 1/3/11 to add more details)

And one more, a 91 mm Nourish crank, without the large lightening holels in the short stroke Nourish crank I previously posted. It makes for a very heavy crank, but it worked well with 80.5 mm pistons on my race bike. That's grease, not rust on the crank, in case anyone was worried about it. This one is also waiting on the shelf for me to decide what to use it for. I used this in my Commando PR for AMA Pro-Twins racing until the cases broke at Daytona. The BF was 62%, which is what I preferred for engines I raced in isolastic frames.

Image

Image

Ken
Last edited by lcrken on Mon Jan 03, 2011 10:39 pm, edited 1 time in total.
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Re: Commando Crankshaft Porn

Postby lcrken » Sun Jan 02, 2011 2:30 pm

And yet another, this one a Steve Maney crankshaft, with flywheel and halves machined by him on his CNC equipment. Available in a variety of strokes. I have several of them, but haven't taken any pictures yet, so this is the one from his websiste.

Image

Ken
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Re: Commando Crankshaft Porn

Postby hobot » Sun Jan 02, 2011 2:57 pm

Boy too bad Norton don't have a sight glass in their cases! Could they?
Peels looks so old fashioned crude. Could you give a ballpark listing of what each crank might cost for some ID of bang for the bux? Guesstimates of which is stiffest most rpm tolerate? Total weight each across this scope would be lasting educational - if extra time to spend on others.

Minus the shipping and straightening and plating and drill lightening, most the exce$ Geoff returned to me, so Peel's ball parks at $1500. How many towels needed for tears and other juices spent on Commando life style?
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Re: Commando Crankshaft Porn

Postby Chris » Sun Jan 02, 2011 3:50 pm

Hi Ickren
Thanks a superb collection of cranks.
Some of the made up offset cranks are amazing. Not something I would even dream of trying!!! Stunning stuff.
Keep it coming
Chris
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Re: Commando Crankshaft Porn

Postby marinatlas » Sun Jan 02, 2011 4:18 pm

Image

this one is from Jean Noel Gindrat, a french tuner who made most of his stuff himself..........
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Re: Commando Crankshaft Porn

Postby comnoz » Sun Jan 02, 2011 6:28 pm

Great, I love porn. As long as it's dirty motorcycle parts.

Here is a 89mm crank from my old racebike.
It was the second crank built . The first one weighed 15 lbs and I could not get good track times from it. The one in the picture weighed 18 lbs. and was much better. If I put it back together again it will be 22 lbs or so. Balance factor was 65%
Image

And a short stroke crank from the same bike.
It weighed 15 lbs and was balanced at 65%
Image

And here is one for people who like large handgrips. Rev the engine and the handgrips would get about 2 inches in diameter. A few miles and your hands would crack and fall off.
It weighed 14 lbs and was balanced to rotating weight only.
Image

And here is the 91 mm crank ready for the new engine I am building for my bike.
It weighs 24.5 lbs. 2 lbs more than a stock crank. It is balanced to 60%.
Image

Image

And last is a custom 4 piece crank
It weighs 19.5 lbs. and was well overbalanced which was likely part of the reason it broke.
Image
Last edited by comnoz on Wed Jan 05, 2011 8:52 pm, edited 1 time in total.
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Re: Commando Crankshaft Porn

Postby hobot » Sun Jan 02, 2011 6:54 pm

Wow to all the hi end variety displayed, even Jim's applying newest fracture technology like they do rod big ends now. Costs extra I'm sure, custom always does.
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Re: Commando Crankshaft Porn

Postby xbacksideslider » Sun Jan 02, 2011 11:52 pm

Looking at those pics, I got excited. Had to slap my lap.
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Re: Commando Crankshaft Porn

Postby Cheesy » Mon Jan 03, 2011 1:00 am

[quote="comnoz"]Great, I love porn.

Here is a 89mm crank from my old racebike.

Image

And a short stroke crank from the same bike.

Image

And here is one for people who like large handgrips. Rev the engine and the handgrips would get about 2 inches in diameter. A few miles and your hands would crack and fall off.


And here is the 91 mm crank ready for the new engine I am building for my bike.


And last is a custom 4 piece crank

Were you running a 3rd centre bearing in these engines?
Also did the have roller mains or plain bearings? Pretty impressive work
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Re: Commando Crankshaft Porn

Postby speirmoor » Mon Jan 03, 2011 6:57 am

The last one pictured has VW and Audi markings?
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Re: Commando Crankshaft Porn

Postby RoadScholar » Mon Jan 03, 2011 7:11 am

After all the following these seem almost plebian:

Image

As seen in another post. Falicon, Carillo, JE

I ziped it into the cases and measured .014 end play with no shims and no Yamabond; to think that 39 year old cases could mate with a crank that is less than 3 months old and work so well!!??

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Re: Commando Crankshaft Porn

Postby comnoz » Mon Jan 03, 2011 7:47 am

quote:
Were you running a 3rd centre bearing in these engines?
Also did the have roller mains or plain bearings? Pretty impressive work

I had a set of original cases that I modified with a center main and plain bearings. The cranks were made from VW water cooled diesel cranks.
I have a third crank that was cylinders 2 and 3 from a Mercedes 6 cylinder but it is in a motor. Jim
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Re: Commando Crankshaft Porn

Postby speirmoor » Mon Jan 03, 2011 8:20 am

Awesome stuff, amazing!
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Re: Commando Crankshaft Porn

Postby Jeandr » Mon Jan 03, 2011 9:58 am

comnoz wrote:And here is one for people who like large handgrips. Rev the engine and the handgrips would get about 2 inches in diameter. A few miles and your hands would crack and fall off.
Image

And last is a custom 4 piece crank
Image


I would have thought a 180 crank would have been smoother :!: :!: Didn't the Yamaha XS650 have a 180 crank at some point (I think they went for a 360 crank only for the sound), the Honda 450 was a 180 twin too and what about the Laverda 750, that was a 180 twin wasn't it :?:

Is that Kenny's crank :?:

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