if Hobot can post Fat Freddy in the crankshaft thread, then hopefully I can get away with this. It uses Commando Superblend mains, only doubled up, so there is some Commando connection. It's a Terry Prince bob weight race crank for the 1360 Vincent engine. 102mm stroke.
Commando Crankshaft Porn
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Dances with Shrapnel said:
Just out of curiosity: Did you ever consider getting rid of the inner races and let the rollers run on the crankshaft directly? An NU306 would require a shaft dia of 40.5mm, the raceways call for an R_a < 0.2µm, R_z < 1µm and a hardness of roughly 60 HRC - sounds feasible to me. With a proper shoulder design you'd end up at a smiliar semi-floating arangement like the double NJ setup.
Tim
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Tintin said:
I gave it some thought but it was beyond the crankshaft manufacturers capabilities, thrust surfaces would have to be figured out and servicing worn surfaces would be a major undertaking. I also had concerns over heat treating control for durability of the overall crankshaft.
What I can say is that with the quality and durability of a nitrided billet crank, even a 30mm main journal is quite durable. As an example, I have yet to hear of any Steve Maney crankshaft failures with 1,007cc race engines (and 30mm main journals) and there are a few out there. And the 1,007cc engine spreads the rod to main journal centers out even further than an 89mm or 72.5mm stroke crankshaft.
May be worth another look at some point.
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Can you say a little bit more about the construction of the Vincent crankshaft? It looks like the main shafts are pressed into the flywheels and the rod journal is pressed into the flyheel; is that it or is there some welding involved.
Yes, that's correct , all pressed together. Standard cranks are 90 mm stroke, full round flywheels, crowded roller big ends and 1" mainshafts with double roller bearings. Because of the double roller bearing and narrow overall width, crank flex is minimal.
Terry builds standard cranks and stroked cranks to 94 MM much the same way as the originals, except he uses caged INA needle rollers on the big ends. These have proven to be nearly indestructable in racing.
After 94mm he goes to the bobweight style crank as shown in the photo. He found that after moving the rod journal out past 94MM there was insufficient flywheel material on the outside of the journal for a good press fit. The flywheel steel on the outside of the journal would yield outwardly upon pressing,so for strokes great than 94MM the flywheels are the bob weight type, larger overall diameter but still standard weight.
For 100 MM and 102mm stroke he increases the mainshafts to 30MM.
Over the years some Vincent racers have welded the cranks as a precaution, but most have opted for the pressed style crank with very few problems reported. I've never heard of a Vincent crank breaking, even though lots have been raced with methanol and as high as 14 to one compression. I have heard of one or two that have shifted, but even that seems very rare if the interference fit is good.
John Renwick runs a crank of this type in his big bore sprinter, it puts out 180hp at the rear wheel at 7,000 RPM . I think there was a link somewhere on this site to the youtube clip of his recent dyno run.
Glen
Terry builds standard cranks and stroked cranks to 94 MM much the same way as the originals, except he uses caged INA needle rollers on the big ends. These have proven to be nearly indestructable in racing.
After 94mm he goes to the bobweight style crank as shown in the photo. He found that after moving the rod journal out past 94MM there was insufficient flywheel material on the outside of the journal for a good press fit. The flywheel steel on the outside of the journal would yield outwardly upon pressing,so for strokes great than 94MM the flywheels are the bob weight type, larger overall diameter but still standard weight.
For 100 MM and 102mm stroke he increases the mainshafts to 30MM.
Over the years some Vincent racers have welded the cranks as a precaution, but most have opted for the pressed style crank with very few problems reported. I've never heard of a Vincent crank breaking, even though lots have been raced with methanol and as high as 14 to one compression. I have heard of one or two that have shifted, but even that seems very rare if the interference fit is good.
John Renwick runs a crank of this type in his big bore sprinter, it puts out 180hp at the rear wheel at 7,000 RPM . I think there was a link somewhere on this site to the youtube clip of his recent dyno run.
Glen
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This was $1,400 back in 2003.
From what I have seen, it seems like $1,400 is somewhat of a constant regardless of who you go to for billet or special Norton crankshafts.
From what I have seen, it seems like $1,400 is somewhat of a constant regardless of who you go to for billet or special Norton crankshafts.
Ha! Perhaps you should shake hands with a 20 pounder! It will earn your respect and admiration. Pound for pound Thor pales in comparison. They don't idle, they don't flounder just pedal to the metal pure dynamite!Dances with Shrapnel said:RennieK said:
It would take someone from "The Island" to make an analogy about this crankshaft with FISH! I am truely hurt.
I would have thought Thor or something more noble or god like would have been more appropriate :lol:
Cheers
Im not sure whether Schrapnel's crankshaft is supposed to be a Salmon or a Trout.
Having caught Salmon larger than 20 lbs and the largest Rainbow Trout so far at a measly 12 pounds, I would say the trout reigns supreme. Recently I learned that Steelhead and Rainbow trout are the same fish, except Steelhead are Sea run.
The Salmon were great fun but the Trout was like hooking onto a rocketship!
Glen
Having caught Salmon larger than 20 lbs and the largest Rainbow Trout so far at a measly 12 pounds, I would say the trout reigns supreme. Recently I learned that Steelhead and Rainbow trout are the same fish, except Steelhead are Sea run.
The Salmon were great fun but the Trout was like hooking onto a rocketship!
Glen
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SteveA said:
Steve Maney Cranks = £1,225 plus shipping and insurance. Throw in a few years of price escalation at say a measeley 3% and we would expect to be paying much more than we do.
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lcrken said:
Ken,
This is a MOLDEX crankshaft. The fellow I went through was "Whity" who has since retired. I have been in contact with them since and it is not impossible for them to make up a new crank, just some historic knowledge is no longer on the shop floor right now. Their pricing has not changed much.
I was told that MOLDEX made Norton cranks for Ron Wood.
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Billet crankshafts are available from the following:
Dave Nourish of NRE Racing in England.
Steve Maney Racing in England
Scroll down a bit on the following page to find the ad from Ro-Dy crankshafts. Looks like the good (4340) material, nitiriding and for $1,700; about 20% more than the price I quoted for my cost on the MOLDEX crankshaft.
http://www.vft.org/vftforsale2Products.html
There's also MAP cycle; I think their crankshafts are from FALICON; somebody correct me on this if I am wrong.
http://www.mapcycle.com/
Download their catalog and see page 10; mostly Triumph cranks but at least one Norton crankshaft.
I am currently getting a 59.6 mm stroke 500cc billet put together by a specialist.
The point of all this is there's a fair selection of vendors of Norton billet crankshafts and some may be more flexible in accomodating special configurations.
Dave Nourish of NRE Racing in England.
Steve Maney Racing in England
Scroll down a bit on the following page to find the ad from Ro-Dy crankshafts. Looks like the good (4340) material, nitiriding and for $1,700; about 20% more than the price I quoted for my cost on the MOLDEX crankshaft.
http://www.vft.org/vftforsale2Products.html
There's also MAP cycle; I think their crankshafts are from FALICON; somebody correct me on this if I am wrong.
http://www.mapcycle.com/
Download their catalog and see page 10; mostly Triumph cranks but at least one Norton crankshaft.
I am currently getting a 59.6 mm stroke 500cc billet put together by a specialist.
The point of all this is there's a fair selection of vendors of Norton billet crankshafts and some may be more flexible in accomodating special configurations.
lcrken
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Good info, John.
As you said, Ron Wood had his cranks made by Moldex. Interesting story there. Ron told me that when he got the cranks from them, he was irritated that they were heavier than he had specified, but used them in his flat track bikes anyhow, and decided that he liked them better than the lighter ones.
I posted a picture earlier in this thread of a one-piece crank made by Falicon for Kenny Dreer, with larger main bearing journals, and it is a very nice looking piece.
Dave Nourish has been making them for many years, and I've used several of his cranks. I've had good luck with them, but I have seen quality control issues with some of them. They are also pretty heavy.
Steve Maney's cranks are very well made, and if you like light crankshafts, he's your man. He sticks with the original 3-piece design, which makes it much easiser to keep them light.
Marine Crankshaft here in SoCal also make custom billet cranks. I talked to them a while back about making Norton cranks, and they said they would be happy to do so, but I didn't pursue it. I've seen their work, and it is very high quality.
This is the first time I've heard of Ro-Dy cranks, but they look interesting.
There have been others like Jim Comstock who have made one-piece crankshafts from auto cranks (VW diesel for Jim and Alfa for a 500 twin in Canada), but those were one-offs for their own use. I still have a partially machined lump of 4340 VAR that I started to turn into a crankshaft but never finished. Lost my motivation when Steve started making them at a reasonable price. It makes a good doorstop.
Ken
As you said, Ron Wood had his cranks made by Moldex. Interesting story there. Ron told me that when he got the cranks from them, he was irritated that they were heavier than he had specified, but used them in his flat track bikes anyhow, and decided that he liked them better than the lighter ones.
I posted a picture earlier in this thread of a one-piece crank made by Falicon for Kenny Dreer, with larger main bearing journals, and it is a very nice looking piece.
Dave Nourish has been making them for many years, and I've used several of his cranks. I've had good luck with them, but I have seen quality control issues with some of them. They are also pretty heavy.
Steve Maney's cranks are very well made, and if you like light crankshafts, he's your man. He sticks with the original 3-piece design, which makes it much easiser to keep them light.
Marine Crankshaft here in SoCal also make custom billet cranks. I talked to them a while back about making Norton cranks, and they said they would be happy to do so, but I didn't pursue it. I've seen their work, and it is very high quality.
This is the first time I've heard of Ro-Dy cranks, but they look interesting.
There have been others like Jim Comstock who have made one-piece crankshafts from auto cranks (VW diesel for Jim and Alfa for a 500 twin in Canada), but those were one-offs for their own use. I still have a partially machined lump of 4340 VAR that I started to turn into a crankshaft but never finished. Lost my motivation when Steve started making them at a reasonable price. It makes a good doorstop.
Ken
is anyone here can help me with this information
bolt pattern and hole size i heard that mk2 and mk3 have a different hole size?
I already order a norton cranks to measure it... planning on making flywheel and counterbalance using 4340 i want to design it 1st with CAD if i can get this info while i'm waiting on the shipment to arrive..
bolt pattern and hole size i heard that mk2 and mk3 have a different hole size?
I already order a norton cranks to measure it... planning on making flywheel and counterbalance using 4340 i want to design it 1st with CAD if i can get this info while i'm waiting on the shipment to arrive..
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Hey Ken, did ya get a rush with the NOS this time?
Peel's Rod Fratellnelli [sp] flywheel was made 4.5 lb lighter but also 1/2" smaller OD, does this help rpm and crank flex tolerance or just less mass to spin up as quick to danger zone? I wonder if Peel's lighter tighter crank had less gryoscopic effect to change lean angles easier/quicker? Definitely felt more stable on THE Gravel if I stayed in lower gear than a higher one that still allowed rear spin on throttle ups, so not a power-traction effect. For sure it did not interfere with hook up traction climbing loose steeps or laid over on hi throttle on solid surfaces, or slow idle compared to my SV650 on super soft non DOT balloon tires. I sense something to do with the isolastics and maybe the power pulse spacing of 360' crank. SV650 also got more tip and skip stable if rpm kept up 5000-ish in 30-50 mph zone on loose stuff, but remained scary to press much as I liked to on Peel.
What would be desirable steel alloy to maKe a flywheel of?
Peel's Rod Fratellnelli [sp] flywheel was made 4.5 lb lighter but also 1/2" smaller OD, does this help rpm and crank flex tolerance or just less mass to spin up as quick to danger zone? I wonder if Peel's lighter tighter crank had less gryoscopic effect to change lean angles easier/quicker? Definitely felt more stable on THE Gravel if I stayed in lower gear than a higher one that still allowed rear spin on throttle ups, so not a power-traction effect. For sure it did not interfere with hook up traction climbing loose steeps or laid over on hi throttle on solid surfaces, or slow idle compared to my SV650 on super soft non DOT balloon tires. I sense something to do with the isolastics and maybe the power pulse spacing of 360' crank. SV650 also got more tip and skip stable if rpm kept up 5000-ish in 30-50 mph zone on loose stuff, but remained scary to press much as I liked to on Peel.
What would be desirable steel alloy to maKe a flywheel of?
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