Maverick Spark - articles

[VirgLove]

Are those bad things?

[Rob Voska]

Remember maverick is a total loss of control of the spark. The engine will rev under light load conditions but will not pull thru the corners. That's why they always tried to control the RPM that maverick would start.

Virg it's not a problem if it's YOUR equipment but it would be if it was mine! LOL

[david a luciani]

exactly my thoughts Rob,

this stuff is neat to read about but that's it.
it's puzzling to me why people would want to use maverick spark anymore.
at the time back in the day it was the difference or EDGE that won races .
but with anything that makes you go faster you're also building in the hand grenade function.

with these old motors getting hard to find i think it's nuts to run maverick for a little extra punch.
the risk of picking up all the motor bits from the track after the motor blows is too high.
plus getting hit with hot chunks of metal shrapnel is no fun, though it is coool to watch from a safe distance.
if you want faster stick a bigger motor on the kart and save those old gems for slower exhibit stuff.

dave

[steveohara]

David,

Just a couple of comments to share on the subject. First, Maverick spark is not really optional... it will happen whether you want it or not and it can only be somewhat controlled by point spring tension, static timing and point gap. The speed at which the transition occures is not fixed and can be tuned with those adjustments but the change in timing will always occur over a range of speed.
Second, the change of the timing that comes when the points float varies depending on the choice of static timing and flywheel/coil relationship. Depending on the parts and assembly methods, maverick spark may or may not advance the timing. The 5 degree advance flywheel will produce a step up in the advance when the maverick condition occurs but it does not always produce a gain in power or rpm... that depends on many other factors such as the static timing, deck clearance and fuel type being used. The assumption that maverick spark leads to engine failures is also dependant on those same other factors since the extra advance can often be beneficial to the engine to help prevent certain component failures that result from lack of adequate combustion chamber pressure at high rpm. Most rod failures in the Mac engines are related to tension stresses applied when the piston reaches TDC and there is not enough combustion chamber pressure to offset the inertia of the piston. With more advance in the timing the rate or pressure increase and total pressure at TDC can be increased to help slow the piston and reduce tension stress on the rod, wrist pin, crank etc. To summarize.... in many cases with Mac engines the combination of maverick spark and a five degree flywheel can produce more power, higher rpm and greater reliability at the same time.
Regards,
Steve O'Hara

[david a luciani]

hi Steve,
thanx for the info definitely food for thought.
seems every time i decide on something that makes "sense " with a mcculloch i get it backwards.
dave