my first case reed project
- Thread starter mrfubs
- Start date
jet richer to slow the burn (this is what most turbo car guys do, but you lose power because you're not achieving the optimal ratio). Or buy a jaguar or lightning CDI, as the retarding spark will reduce cranking pressure by letting the piston go beyond TDC before complete combustion takes place. Normally as the spark advances, full combustion takes place just after the piston goes beyond TDC, and it continues to advance so full combustion keeps happening at that point. But the problem is the piston has to fight the rising pressure as it ascends, causing massive pressure buildups, and possible cranking losses if it's too advanced (in addition to detonation). The retarding spark means the piston is already descending by the time the spark fires, so it doesn't have to overcome the rising pressures, saving your bearings, as you could imagine, 400 PSI at 9500 RPM is 158 times per second. Retarding the spark can reduce that to 100-200 psi. You may lose some power at your top end, but you're going to save your bearings, and money. If you want, my HT performance parts list, lists a silver Gilardoni racing wrist pin that will work in our motors.
Thanks mew that was a very good explanation! Freds going to enlarge the chamber on my head and fix the indents. That will help lower compression and heat. Another thing im going to do is use my other magnet with retarded timing and see what happends, i may buy an adjustable magnet for the heck of it too. If none of this helps i will fork out 80 buck for a new cdi.
It will be a little while before i get it running again because i have to re do all of the crank work do a new crank...
It will be a little while before i get it running again because i have to re do all of the crank work do a new crank...
A custom sheer key is a very cheep way to advance or retard timing. Get a bigger key then custom grind it offset over a notch. I would be carfull about advancing tho as these buggers get pretty hot.
http://www.pistonbikes.com/product-p/mmatm.htm
here is an adjustable magnet. basically you dont use a key way and is held in place by friction. just as sketchy as the rest of the engine so it should work fine. it may or may not be worth it. the way i look at it is if the timing is retarded enough there may be no detonation with the stock cdi along with a noticeable power loss to gain reliability will be just fine with me.
here is an adjustable magnet. basically you dont use a key way and is held in place by friction. just as sketchy as the rest of the engine so it should work fine. it may or may not be worth it. the way i look at it is if the timing is retarded enough there may be no detonation with the stock cdi along with a noticeable power loss to gain reliability will be just fine with me.
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It hasn't been in stock for years - don't hold your breath, you might pass out waiting
Chris
AKA: BigBlue