I reckon it will run smoother if you do it- and the main bearings should last longer too.
Big journal 1275 crank has lousy counterweighting, this is accentuated by stroking.
My 1412 stroker ran as smooth as on the engine dyno, after I wedged it.
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| wedged stroker crank https://www.ausmini.com/forums/viewtopic.php?f=5&t=41565 |
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| Author: | Goldbrocade_62 [ Tue Apr 29, 2008 10:00 pm ] |
| Post subject: | wedged stroker crank |
Have got a unassembled stroker motor does it need wedging for an occasional driver it will be balanced regardless |
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| Author: | TheMiniMan [ Tue Apr 29, 2008 10:01 pm ] |
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i wouldn`t bother if it`s just a roady/club race donk |
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| Author: | drmini in aust [ Tue Apr 29, 2008 10:35 pm ] |
| Post subject: | |
I reckon it will run smoother if you do it- and the main bearings should last longer too. Big journal 1275 crank has lousy counterweighting, this is accentuated by stroking. My 1412 stroker ran as smooth as on the engine dyno, after I wedged it.
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| Author: | mickmini [ Wed Apr 30, 2008 1:52 am ] |
| Post subject: | |
drmini in aust wrote: I reckon it will run smoother if you do it- and the main bearings should last longer too.
Big journal 1275 crank has lousy counterweighting, this is accentuated by stroking. My 1412 stroker ran as smooth as on the engine dyno, after I wedged it. mine too
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| Author: | willy [ Wed Apr 30, 2008 9:14 am ] |
| Post subject: | |
And mine  
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| Author: | belgord [ Wed Apr 30, 2008 4:02 pm ] |
| Post subject: | |
wedging is?? 
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| Author: | 1310/71 [ Wed Apr 30, 2008 4:48 pm ] |
| Post subject: | |
Trimming excess metal off the rounded counterweight parts of the crank. I don't know the orign of the term wedging (in relation to cranks ), but the ones I've seen end up being a bit triangular in shape, so maybe the "wedge" comes from that.
That'll do until Doc comes in and explains in proper engineer terms..... KB |
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| Author: | drmini in aust [ Wed Apr 30, 2008 4:50 pm ] |
| Post subject: | |
Wedging is removal of metal from the crankwebs on the side nearest each crankpin. This has the same balancing effect as making the counterweights bigger, but it also reduces the rotational mass (inertia) of the crank. Here's some pics of mine- I did it at home on the mill then got GR to balance it. 
<edit> that centre main strap in the last pic I made too, it's EN25, tuff stuff- made to fit the near-standard bearing cap without milling it flat (and thus weakening it). Bolts are Grade 8 hi tensile. |
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| Author: | 1310/71 [ Wed Apr 30, 2008 4:58 pm ] |
| Post subject: | |
So the term "wedging" comes from.........???? Cmon Doc, you're letting me down!
KB |
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| Author: | drmini in aust [ Wed Apr 30, 2008 5:01 pm ] |
| Post subject: | |
Look at the 2nd pic, it looks like a wedge....
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| Author: | mickmini [ Wed Apr 30, 2008 7:15 pm ] |
| Post subject: | |
make sure you also rebuild your harmonic balancer or get a new one. will help a lot to minimise harmonics that these cranks suffer from. |
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| Author: | drmini in aust [ Wed Apr 30, 2008 7:19 pm ] |
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mickmini wrote: make sure you also rebuild your harmonic balancer or get a new one. will help a lot to minimise harmonics that these cranks suffer from.
Also, lightening the flywheel assembly will reduce and move the harmonics further up the RPM scale. |
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| Author: | willy [ Wed Apr 30, 2008 8:11 pm ] |
| Post subject: | |
This be moine 
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| Author: | 69elf [ Thu May 01, 2008 8:17 am ] |
| Post subject: | |
Dr Mini, That Centre main strap looks great. I always wondered why, when the idea is to add strength to the centre cap, you have to mill some off to add a strap. Any chance of you running off a few to sell to us more technically challenged? |
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| Author: | Spaceboy [ Wed May 07, 2008 11:00 pm ] |
| Post subject: | |
stocko small journal 
smallblock stroker crank (1100) 
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