timming advance

[woodt8369]

how do u know when u have the right advance? Ie how far do i advance it and does it help out in the takeoff lower rpm range.

 

[freakboy]

you just gotta play around with the advance and see which ones the best...

 

[1992suburban]

advance timing helps tq...

a car on the race track if you pull timing out on the big end it will gain some more MPH

 

[1992suburban]

what engine are you working on??

 

[motor_head]

advanced timing helps top end won't help bottom end

 

[mike75925]

setting your timing or dwell is like tuning the slow speed on your carb. when you advance too much, it will run like crap if it will even run. same with retarding the engine

 

[1992suburban]

i know for a FACT that advance ignition timing HELPS bottom end..

i know for a FACT pulling OUT timing will hurt bottom end..

this is true with a Gasoline engine

advance timing (tuned properly) aid in building TQ

 

[motor_head]

yes but if advanced too far it will ignite too soon at low rpms and cause premature wear, the main reason for advanced timing is so at higher rpms the spark can travel through the wire and still spark at the right time and not later since the piston travels faster as rpm go up and the electricity from the coil travels the the same speed regardless of rpm

 

[mike75925]

length of plug wire, plugs resistence, coil productivity (hot or cold coil), also play a part. when she starts loping, you know you are really close. just make sure she's getting enough fuel/air. and hope your engine case is strong enough not to break from the mounting tabs.

 

[NJOHC]

To the OP, dont go too far with it if you want to use 87octane fuel. To much and it will start to detonate or ''ping" and it could ruin your engine. If we knew what kind of engine you had we could tell you what was safe.

 

[1992suburban]

"throws in the towel"...

 

[modelengineer]

the main reason for advanced timing is so at higher rpms the spark can travel through the wire and still spark at the right time and not later since the piston travels faster as rpm go up and the electricity from the coil travels the the same speed regardless of rpm

Sorry, this isn't right. The speed of electricity is around 95%+ the speed of light. The speed of the piston does not even come close to a fraction of this.

The reason you want more advance at higher RPM is because the mixture takes time to ignite fully. If you ignited it at the same angle BTDC as at idle then the mixture would not have fully burnt by the time the exhaust valve opened, leading to less power and more heat on the exhaust valves and exhaust system.

 

[motor_head]

ok maybe i tried to fill in some info that i couldn't think of at the time, but at higher rpms you do want it to ignite sooner and thats what i was trying to think of the, burn time. once i thought of it later that night i felt really dumb

 

[Doc Sprocket]

Modelengineer nailed it... And beat me to the punch!

 

[woodt8369]

Advance

I have a 6.5hp clone. Took the gov out and put in the 18lbs springs. Put in a78 main jet and the better tube that goes in before the jet. Also put on a cold air intake and put spak plug gap toward exhaust. Had .065 taken of the head for higher compression. Made my own exhaust and took off everyother blade from clutch fan. Any other tips would b great

 

[1992suburban]

maybe drill low speed jet out (did mine .020")
8 degree advance timing key
1.2 ratio rockers

motor should run pretty darn good..

whats it on?
whats it geared??
top speed??

 

[woodt8369]

its just on a little go kart and ten tooth clutch with 54 tooth sprocket 15'' rear tires runs about 50 on a straight stretch. i just want to do every thing possiable to make it that much better. http://

 

[woodt8369]

what is the low speet jet and where is it at?
i put in the gx140 emulsion tube.

 

[1992suburban]

the low speed jet is under the idle adjustment screw. its pops in.. use a screwdriver to pry pry it out..

your kart runs pretty good.. by the math your turning 6krpm.. I wouldnt mess with it much more. without going inside the motor.

 

[NJOHC]

Shane from AGK told me a 6 degree advance is safe to do if you want to stick with 87 octane, but if you guys go 8 without any probs go for it! Nice engine set up too.Im sure it runs pretty good!