ESE's works engine tuner

[katinas]

VHM TC 85 is 27 hp incl. exh/head/piston/that air thing

27 hp less vhm parts is 25 hp 25 hp to the wheel is 25 hp - 3.125 hp (12.5 % ) 21.875 hp


Did you test both stock bike's !!!!!

The higher you make exh. degree the beter stock pipe

Your upgrade is oke only not your numbers

Thank you again for correction. So, 25 hp is what we needed to set for std engine, than modified could be 33-34 hp from crank.
Yes we tested both std, but one new earlier this year with 27 hp, other little used, just month ago 27.7 hp.

We didn't change blowdown, but rise cylinder until mid range started to drop. This gave 1.2 mm base.

[Muhr]

Did not see it yesterday when I looked in the cell phone.

[Muhr]

Thank you again for correction. So, 25 hp is what we needed to set for std engine, than modified could be 33-34 hp from crank.
Yes we tested both std, but one new earlier this year with 27 hp, other little used, just month ago 27.7 hp.

We didn't change blowdown, but rise cylinder until mid range started to drop. This gave 1.2 mm base.

Found this picture from the 85 tests we did. has unfortunately happened more than once.
Was a bit too aggressive with ignition and 16.75mm reduction along with a cdi that is not adapted to the RPM we want to run

[katinas]

Muhr, yes with 17mm insert we retarded ignition with woodruff key, as there is no possibilities to adjust stator on TC85. But mainly, because of milled spark that protruded deeper to combustion chamber. Maybe this proteced piston.

[porttiming124]

Hello !
here is a snowmobile cylinder!
look at the big radius in a corner of: B: port!
just on the side of: C: port.
Do you think it's in order to open progressive or is it to give more support to the ring gap?

[wobbly]

If the ring gap is between the B & C then it doesnt need that radius at all.
Saying " opening progressivly " is another way of saying , making less power by reducing the transfer area.
Unless there is no hook on the B rear wall , and this is some wierd attempt at reducing the B inertaction with the C flow.

[porttiming124]

it is a 2 ring piston with ring gap between the b and c port!
and yes there is a hook in the b port.

[wobbly]

Be the first thing I would grind out - if it needs more transfer STA , but how the hell can that be modelled in EngMod.
And wow , look at the step in the A transfer roof , never seen that before - a good way ( just maybe ) to help stop short circuiting up to the Aux.

[porttiming124]

I also removed the radius!
this is how i did in engmod.

[porttiming124]

Regarding the A port with two steps(2.8mm) in engmod I averaged the 2 heights to have the right area in my opinion!
on the other hand by doing this I am aware that I do not have the right blowdown!
what would you do with that?
thank you

[wobbly]

I cant see the numbers , too small and they are blurry if I enlarge them.
See if you can post better images first.

[porttiming124]

larger image but I just realized what is not common sense sorry wobbly

[porttiming124]

another try

[andreas]

Maybe treat the A port as two separete ones.

[wobbly]

So get rid of the big radiuses , and split the A port into two = 7 port.
Whats the STA page look like then.