Woops... maybe? mk sp squishing?

[sharkyboy]

Well i got a mk sp 70 bore kit on my motorhispania (am6) which i fitted myself. My mate that works in a garage said im a complete idiot cause i didnt squish it?

huh? i read a few topics about people wid sp's squishing them aswell?

Also sum1 told me that slightly drilling out the rubber hole in the reed block helps performance if you got a bigger carb?

My setup is:
Ginaelli exhaust
21mm dellorto
70 sp bore
carbon reeds (not that they do ne fin!)
polini air filter

[samRS]

If you fitted it yourself properly following the instructions it should be fine

drilling a hole isnt neccesary at all unless you need to for an oil input i think

[sharkyboy]

If you fitted it yourself properly following the instructions it should be fine

drilling a hole isnt neccesary at all unless you need to for an oil input i think

DRILLING A HOLE!!??? I didnt get any instructions! i just put it on like i would with a normal cylinder!

EEEK! HELP

[samRS]

oh wait i missread, i thought it said manifold

in the reed cage you can remove the rubber V piece with a larger carb and bbk

[sharkyboy]

oh right ur talkin about my reedcage lol, i fort u wer on bout my cylinder!

Well i just drilled it out so its 21mm diameter, i dont really see the point in me doin it cause i still got a std intake which is like 12mm lol.

Know ne fin bout the cylinder? cause thats wht im afraid of!

[RiejuR51]

why are you still messing around with 50's when your 17 lol

[Pierce]

Does the bike run? If it does then your squish is fine. Don't worry about anything if the bike runs fine.

[AndyS_RS]

squish is just the minimum clearance between the top of the piston and bottom of head at TDC. Too little squish and your piston may impact the head when it all heats up and expands, too much and you lose out on compression ratio. Different thickness base gaskets are used to set the squish clearance.

[sharkyboy]

Why am i still messing with 50's when im 17? cause no matter wht anyone says, you have more fun on 50cc wid ur mates then you will ever have on a 400/600/1000 when your older. I dont care if i crash my 50 cause its worthless, i dont care wheelying wonderin if im goin to come off. If i had like a r6 i would be soooo pissed off if i come off, plus i wudnt have ne1 to ride with as im the oldest in my year. Im doin my test after chrismas and hopefully get a nice 4stroke supermoto but until then, im havin fun on my bang bang pop

Ne way, i put the thinest gasket on for most compression. Shall i guess i should of put 1/2 bigger?

[RiejuR51]

too right, stil rather have me 125 over that rieju lol

Did think about a shitty ped to jst abuse bt then i thought i cba cos its more insurance n w.e

[sharkyboy]

WELL! now i know the the squish band is,

ANY ONE ERE GOT A SP70 AND WHT GASKET DID YOU USE? WHT PERFORMANCE DID YOU GET?

CHEERS.

[Craig]

Doesnt matter what gasket anyone else used as it can differ from bike to bike. You need to measure it properly and set it for your bike.

[fast_tzr]

squish is just the minimum clearance between the top of the piston and bottom of head at TDC. Too little squish and your piston may impact the head when it all heats up and expands, too much and you lose out on compression ratio. Different thickness base gaskets are used to set the squish clearance.

Isn't that combustion chamber volume? Thought the squish band was just a ring around the cylinder head that pushes the fuel mixture into the middle of the combustion chamber so it ignites better or something, I'm not too sure.

Am I right or wrong?

[AndyS_RS]

head volume + pi x bore radius squared x distance between top of bore and top of piston at tdc = combustion chamber volume. thats what I thought anyway.

Im fairly sure squish is as i described. your pics show a difference in head volume and profile, therefore a difference in combustion chamber vol.

[priller]

Squish Band - Outer area of head that forces the unburned fuel air mix into the center chamber for combustion. The squish band angle is usually 1-2 degrees greater than the angle of the piston dome. Verticle clearance and squishband width affect MSV.

Squish Clearance - Verticle distance between top of piston and head. Measured at the edge of piston. See "Squish Test" for measuring with soft lead solder over wrist pin.