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| To wedge or not to wedge... https://www.ausmini.com/forums/viewtopic.php?f=2&t=5057 |
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| Author: | FatMaserati [ Thu Feb 24, 2005 6:34 pm ] |
| Post subject: | To wedge or not to wedge... |
I'm currently in the midst of an involuntary $3000 engine rebuild in which my visibly cracked crank has to be replaced (along with the shredded flywheel, primary gear, clutch, what have you...). Cono (the head mechanic) at Minicraft here in WA told me about wedging the crank to increase performance, but adds $275 to the total ($1250 in total for crank, with crack testing, stroking, heat treating, and wedging). I'm thinking, bugger it, may as well go all out whilst the engine is gutted. Anyone out there got a wedged crank? Noticeable difference? |
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| Author: | 68matic [ Thu Feb 24, 2005 6:48 pm ] |
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wots a 'wedged' cranksaft mate |
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| Author: | simon k [ Thu Feb 24, 2005 6:54 pm ] |
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someone grabs it's jocks from behind while the engine is running, makes it go faster |
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| Author: | drmini in aust [ Thu Feb 24, 2005 7:08 pm ] |
| Post subject: | |
`Wedging' as applied to cranks involves milling the crankwebs so as to remove weight from area around each crankpin. Same effect as making counterweights heavier. This changes the balance factor and reduces crank whip at high rpm. Also wedging makes crank lighter so reduces rotating mass. 1275 cranks are a bit `light on' in the counterweighting dep't. For the road? I don't bother.... 
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| Author: | nuclear_mini [ Thu Feb 24, 2005 9:11 pm ] |
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i thought reducing the rotating mass can also decrease torque..... tell me if I am wrong doc.... |
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| Author: | 68matic [ Thu Feb 24, 2005 10:05 pm ] |
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nuclear_mini wrote: i thought reducing the rotating mass can also decrease torque..... tell me if I am wrong doc....
Nuke that would sound logical but the mass reduced is very close to the rotating axle, so very little moment would be noticed i'd apply that trend to the fly wheel i reckon |
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| Author: | drmini in aust [ Thu Feb 24, 2005 10:23 pm ] |
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68matic wrote: nuclear_mini wrote: i thought reducing the rotating mass can also decrease torque..... tell me if I am wrong doc.... Nuke that would sound logical but the mass reduced is very close to the rotating axle, so very little moment would be noticed i'd apply that trend to the fly wheel i reckon Neither the weight of the flywheel, or of the crank will affect torque or power produced as such. Flywheel weight will store a little energy but will not produce it. OTOH an engine with a lightened crank and flywheel etc will accelerate faster in the lower gears. Particularly noticeable in 1st gear- mine broke traction sooner with a lightened backplate- I could feel the difference. On hills? pfffft- 1275s accelerate up hills..:wink: |
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| Author: | nuclear_mini [ Thu Feb 24, 2005 10:26 pm ] |
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so your saying doc that a lightened flywheel wont decrease the amount of torque i have, but make it accelerate faster? nice |
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| Author: | drmini in aust [ Thu Feb 24, 2005 10:28 pm ] |
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True. That's why race cars have super-light flywheels. Read Vizard's HYMYM- it explains it pretty well. It's like chucking weight overboard.. 
Even Mini Mad's 1152 has a lightened flywheel now..
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| Author: | 68matic [ Thu Feb 24, 2005 10:28 pm ] |
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yeh thats more logical |
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| Author: | nuclear_mini [ Thu Feb 24, 2005 10:32 pm ] |
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that good aye.... so how much would it cot t have this done??? very interested... |
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| Author: | drmini in aust [ Thu Feb 24, 2005 10:36 pm ] |
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Talk to Graham Russell- he has a lathe set up for it. But it WILL need balancing, so be prepared to give him your complete clutch assembly. He can spin it up on his balanced crank. My spare one is being balanced there next week for the 1360..
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| Author: | danidad [ Sun Feb 27, 2005 1:29 am ] |
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this ones cheap enough (20 pounds) shame its in the uk and not for post http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7956974456 |
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