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#Post#: 49001--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: EHP Date: November 8, 2014, 9:23 am
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Adam, my first pistons I made were out of 4032 , I found i had
no problems of any kind until I tried to really high rpm the big
bores , the 60 mm piston worked perfect and I still have that
piston here . I put it in a real used 3120 and put it to work
cutting big firewood and ran it for a solid week then took it
out to see how it looked , I figured if the thing blew up I was
not out alot of money . If you phone Wiseco and need just 1 or 2
pistons of a bore they donot do they use 4032 or a different
number alum. but I cannot remember it now maybe 4031 something
like that. I seen the alum. sitting on the floor last time I
went threw the piston plant . There are other guys making
pistons and I have tried them but they may work great in a
snowmobile engine but broke all to hell in a nitro motor , When
you got chainoil all over your boots and the piston pin goes out
the pipe its not a good day ;D
#Post#: 49007--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: aclarke Date: November 8, 2014, 3:56 pm
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Thanks for the info. That opposed twin looks like sweet motor.
Looks like the crank is forged with an added machined center
section. Great idea.
Adam
#Post#: 49010--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: aclarke Date: November 8, 2014, 4:12 pm
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Ed, I think I remember seeing a picture of one of your pistons
many years ago. I may try another with the 4032 for fun. Spent a
ton of time machining them and got frustrated after seizing a
few motors. I'll see if I have any pictures
#Post#: 49011--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: 660magnum Date: November 8, 2014, 4:12 pm
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That is correct about the crank. There were two cranks turned
end for end with new longer crank pins pressed into a circular
connector plate. There was a big decision about the plate to
make it a "Dog Bone" or circular shape. Finally for crankcase
volume considerations it was made circular. The back crankshaft
was cut off and the bearing sets in a blind pocket. The original
single cylinder engine (doner Parts)was a cantilever design with
a read valve and carb at the rear.
#Post#: 49012--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: Eccentric Date: November 8, 2014, 4:21 pm
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Great info guys. What's the minimum # of units (of a custom
piston) that Wiseco will do? About what do they charge per
unit?
#Post#: 49014--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: aclarke Date: November 8, 2014, 4:46 pm
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Thats a neat idea of putting the bearing in a blind hole in the
crank as the shaft isnt needed with your application.
#Post#: 49015--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: aclarke Date: November 8, 2014, 4:49 pm
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These are 62mm that i never used after seizing the 60mm
version...
[img width=337
height=600]
HTML http://i1184.photobucket.com/albums/z329/Aclarke123/20141108_142913_zpsf3fe4c58.jpg[/img]
#Post#: 49016--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: aclarke Date: November 8, 2014, 4:51 pm
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heavy compared to Eds 62mm wiseco pistons
[img width=337
height=600]
HTML http://i1184.photobucket.com/albums/z329/Aclarke123/20141108_142936_zpsba374939.jpg[/img]
#Post#: 49022--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: EHP Date: November 8, 2014, 6:43 pm
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your pretty thick on the piston skirts , that causes seizing
cause the thicker grows more in size than a thinner skirt . I
keep mine as thin as the stock piston from the factory and have
never seized a piston but I never put a piston in without
coating the hell out of it either and pay very close attection
on piston clearance , A couple 1/10's of a thou makes a huge
difference , If its a race motor run it abit loose and if on gas
run it looser again. As far as Wiseco goes you need to design
your piston and it is not to be the same as anyone elses but
Wiseco is pretty much just like a Hooker on the street corner ,
if you got the money they will build you anything
#Post#: 49047--------------------------------------------------
Re: Sachs Dolmar 166 big bore
By: aclarke Date: November 8, 2014, 10:15 pm
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Ed thanks for the input, probably why I had issues.
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