i cant open the top-secret-section.. can u pls help me sir traxxas..Hi guys
If you just bought uma superhead here are the tips and tricks that you can do to your uma superhead and uma 62mm bore
First the unboxing
Now you have already the superhead, Is it plug and play?
Yes its plug and play together with the 62mm uma borekit for superhead.
However if you want more performance, its advisable to finely tune it.
which means you need to
-port matching & resurface the intake port
-polish the exhaust port
i dont want to call it port and polish due to it might be misunderstood.
What i mean by port matching is you have to make sure that the intake manifold outlet side perfectly
match to the lip of the intake port. it should not block the air coming from the manifold.
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you need to remove that excess material in the head so that the air flow will not be obstructed.
resurface the the wall of the intake port. Do not enlarge!
you just need to resurface it so that the roughness is equal.
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KNIFE EDGE the DIVIDER in the intake port
yes that wall in the center that divides the air going to the left intake valve and right intake valve.
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by default the front side is not knife edge which destroys the smooth flow of air. you have to make that
front surface as sharp as knife that will cut the air into two.
Mirror Polish the exhaust port if you can
make the exhaust port as shiny as possible like a mirror
that way the carbon deposits wont build up in the exhaust port
Do not enlarge! you just need to mirror finish it .
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in here, the exhaust port is not yet mirror finished, it takes time and effort to do it.
some users say the valvespring that is included in the uma superhead is too stiff!
when i compared both the included valvespring stiffness of the uma superhead and the cms valvespring
the uma vspring is much stiffer, so i decided to use the CMS valvespring since im satisfied with it
on high lift cams.
besides my target RPM is on 12,000 - 13,000rpm so i dont need a too stiff valvespring.
if you want higher rpm you can use the included uma valvespring.
I am using 26mm Yoshimura TM MJN carburetor.
before i install superhead, i use the ff jettings
bigvalves 18/22 jettings on MJN 26
-pilot jet #37.5
now after installing superhead, i found out that this jet are perfect
on yoshimura 26mm
FOR TIPS ON YOUR UMA 62mm PISTON
visit this Top Secret Section
Enjoy your superhead!
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