Decomp effectiveness

FirePowerMinis

FirePowerMinis

Active Member
#1
#1
I'm planning to keep the revs low, and have high compression. Will the clone compression release bleed off enough to pull it fairly easy? Can it be modded to be even more effective?
 
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RobK

New Member
#2
#2
Depends on how high. I have a GX200 with a flat top piston and a 14cc head and it's no problem to pull. I think it should be about 11.8:1 compression.
 
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SAFETYpin

New Member
#4
#4
Its my understanding that the whole purpose of HiComp is to re-cooperate the compression lost do to a high duration/valve overlap cam.

So if your not planning on spinning, you won't need the cam or compression? Or my guess is not as high as your planning
 
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SAFETYpin

New Member
#6
#6
My mini is 11:1 with a black mamba cam and is very easy to pull start. Although you can't just snatch up the pull starter and yank, you have to roll it over to just past compression first and than let the rope back in. I also like to make sure the recoil "fingers" have engaged the flywheel before I pull, basically I baby the pull starter a bit.
 
MB165

MB165

Active Member
#7
#7
I posed the same question here a few years ago, before I did my gx200 buildup. I didnt get a good definitive answer, but I went ahead with my plan anyway. I was surprised to pull and realize the starting effort was no differant then a stock engine or maybe even easier! One thing I noticed was the nub for the release was a bit more taller than the stock cam, so that is a factor. I thought about taking a stone to it, but after figuring out a start proceedure i left it alone, it starts really easy. My specs NR .280 cam, +.010 rod, .035" off a 18cc head, flattop piston, .009" head gasket I figure its about 11.1 comp. ratio. The high compression will help you with that midrange.
 
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walker32

New Member
#8
#8
i am running a predator on that i built for the same thing low rev high comp on e-85

my specs are
14cc head milled .050 27in 25ex stainless valves locks and retainers
18lb springs,1.3 rockers, arc guide plate, ported by dlr racing
bored stock appearing carb .660 bore .044main .024idle
stock piston its .018deck height im using a .016copper ,head gasket stock predator cam
arc flywheel
i took .045 off my timing key
autolite 3910x plug
k&n filter with arc adaptor
i am leaving the 18lbs springs as a governor

i have my disk clutch engaging at 2800 full lock up and it pulls very strong until about 5600 floats the valves at 6,000rpm on my digitron tach
i have the vents on the blower housing taped up except for four to be able to get the engine temp above 300degrees the e-85 makes the engine run very cool
375 or so is required to get max power with it taped up it runs right at 380 after a hard wfo pass and quickly drops back to 330or so
the e-85 smells so good like moonshine and doesnt stink you up like exhaust after riding like gas does

sorry for rambling i just cant believe no one is running e-85
 
FirePowerMinis

FirePowerMinis

Active Member
#9
#9
Some great input! Thanks guys. I've lost a substantial amount of grip strength, but am encouraged. I forgot the reduced base circle leaves the nub higher.
 
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