sniper_eds
Super Veteran
and by the way traxx, are you using a stock cam or racing cam?? is it applicable if you use racing cam??
How to: SQUISHBAND your engine
- Thread starter traxxas-modifier
- Start date
bro i suggest to do it locally.sniper_eds said:
cebu city have lots of good machine shop.
the machine used is a common lathe machine
found in machine shop...
i use stock cam bro...sniper_eds said:
if you use racing cam, check the valve piston clearance
since racing cam might be a hi lift cam...
lc-motospeed
Super Veteran
i'll b opening up my bike real soon n checking all the clearance needed for the valve n do up proper calculations on wat will b the safe amount to b shaved off... i dun mind risking off a few block & piston set coz i have decided to quit playing cornering after my accident a few days ago... will b switching to full naked sprint test =) so all experiments will b worth while
sniper_eds
Super Veteran
bro trax what do you mean by 4th gear is ALIVE and KICKIN??? you mean it gain more power??? by the way whats your current top speed after the mods???traxxas-modifier said:
phl6684 said:
did you use caliper in checking?
pics please....
bro trax what do you mean by 4th gear is ALIVE and KICKIN??? you mean it gain more power??? by the way whats your current top speed after the mods???[/quote:2yu5jzlt]sniper_eds said:
the 4th gear gives more power.
my top speed is 130kph
i can reach it more quicker than before...
some bikes can reach 140kph
I'd not use a lathe to shave the cylinder. In my case I used a high speed milling maching with a 2 axis computerised bed. On a lathe machine, its very very difficult to get the right flatness. Infact there will always be a bit of convex chop when u measure. In microns though.
Looking at ur piston, I can see that the piston pocket is pretty deep and no wonder u could dare 1mm. However its on its limits.
Also u dont really need to modify the squish or rather have a larger squish for higher compression.
Too high compression and u'll end up ruining the engine. Unless its a single purpose full all out race engine where u dont need everyday reliability.
Since u have access to only a max of 96oct its not a very brave thing to exceed 12.5:1 compression ratio. Check whats the static compression. Dont keep it higher than 200-210psi if u looking at reliability.
We have access to fuels between 87oct to 97oct. Still I wont cross my limits. Only if its in full race mode, I would dare higher than 210psi on my air cooled Suzuki engine. It will also need 100 octane race gasoline then.
U please keep a watch on the engine noises going forward.
Looking at ur piston, I can see that the piston pocket is pretty deep and no wonder u could dare 1mm. However its on its limits.
Also u dont really need to modify the squish or rather have a larger squish for higher compression.
Too high compression and u'll end up ruining the engine. Unless its a single purpose full all out race engine where u dont need everyday reliability.
Since u have access to only a max of 96oct its not a very brave thing to exceed 12.5:1 compression ratio. Check whats the static compression. Dont keep it higher than 200-210psi if u looking at reliability.
We have access to fuels between 87oct to 97oct. Still I wont cross my limits. Only if its in full race mode, I would dare higher than 210psi on my air cooled Suzuki engine. It will also need 100 octane race gasoline then.
U please keep a watch on the engine noises going forward.
nice inputs joel
yah 1mm is brave heheh
thats why i decided to go for 1mm is because
i will change to vixion if something goes wrong...
and to really know how it will work on our bike.
so far after 5000km both city rides and we just completed
the 2000km long distance ride.
it works well on me
maybe our engine is special enough and really can accomodate that kind
of compression unlike other engines.
how to check the static compression ratio?
yah 1mm is brave
hehehthats why i decided to go for 1mm is because
i will change to vixion if something goes wrong...
and to really know how it will work on our bike.
so far after 5000km both city rides and we just completed
the 2000km long distance ride.
it works well on me
maybe our engine is special enough and really can accomodate that kind
of compression unlike other engines.
how to check the static compression ratio?
wow very high comp hehehejoel said:
thanks bro...
care to show the solution on computing it?
Sure, now ur cc is 134.3.
Volume of the combustion chamber is 13.6cc.
Since u have shaved 1mm off the cylinder, the new combustion chamber volume will be 11.32cc.
Based on formula for volume of cylinder, pi*r2*h = 2.28cc
CR = cc+Vc/Vc Where Vc is the new Combustion chamber volume.
Therefore 134.3+11.32/11.32 = 12.8
The new CR is 12.8:1
Volume of the combustion chamber is 13.6cc.
Since u have shaved 1mm off the cylinder, the new combustion chamber volume will be 11.32cc.
Based on formula for volume of cylinder, pi*r2*h = 2.28cc
CR = cc+Vc/Vc Where Vc is the new Combustion chamber volume.
Therefore 134.3+11.32/11.32 = 12.8
The new CR is 12.8:1
@joel
thanks joel!
that will be a good reference for computing engine compression ratio
BTW here is the picture of my piston after 3000km of using squishband. (both cityrides and long distance rides)
The space left (top of piston and top of cylinder block) after squishband
After 3000km of squish band usage, This is what t135 piston looks like when cleaned
This is what the cylinder head and valves look like after 3000km of squishband usage
thanks joel!
that will be a good reference for computing engine compression ratio
BTW here is the picture of my piston after 3000km of using squishband. (both cityrides and long distance rides)
The space left (top of piston and top of cylinder block) after squishband
After 3000km of squish band usage, This is what t135 piston looks like when cleaned
This is what the cylinder head and valves look like after 3000km of squishband usage