Predator build up details
- Thread starter youngengines
- Start date
- Tags build details predator
thank you, in your opinion would a cam make a significant DIFFERENCE/percentage, comparatively, in the increase of hp across these carbs... or will it be a similar effect... as the rpm at which the max hp is attained increases, the difference in hp should be greater though right...
was going to wait until you were done with your testing, as opposed to buying the SA carb right now, because i already have the upgraded jetting and etube for the stock carb... but maybe i should just try and get the carb now... wish i could send you a cam (like the mamba jr) to run that test too with the stock head, vs ported head etc... im sure you are waiting for billet parts before any cam change?
was going to wait until you were done with your testing, as opposed to buying the SA carb right now, because i already have the upgraded jetting and etube for the stock carb... but maybe i should just try and get the carb now... wish i could send you a cam (like the mamba jr) to run that test too with the stock head, vs ported head etc... im sure you are waiting for billet parts before any cam change?
Actually, I already had the parts. Its back together now. It has a Arc Billet rod (.020 longer than stock), ported head with stock size stainless steel valves, aluminum lightweight retainers with split valve locks, 26lb valve springs. Arc Billet flywheel. I had to trim the top of the piston around .030 to get it back in the hole enough to run a thin head gasket. it now makes 11.27 at 4300, but it makes 17.75 at 6700 with the S/A carb (relay need more jet now).
now thats what im talking about! :thumbsup: stock cam? did you port the stock head or swap it? i have everything done as you stated, other than the S/A carb, ported head work and i have the regular size arc rod... getting the black mamba jr too...
thank you for taking the time to do the work and post the results... the numbers help me learn...
thank you for taking the time to do the work and post the results... the numbers help me learn...
ok, cool... with just milling the head, do you think the piston would need to be cut on a stock size rod, or was that because you put the thinner gasket on, along with the +.2 rod?
if i cant find anyone out here to do the head work, would you be opposed to doing it for my stock head as well and if so, can you pm me a price (sending complete head, or parts for complete head, minus rockers and returning ready to bolt on, minus rockers)?
if i cant find anyone out here to do the head work, would you be opposed to doing it for my stock head as well and if so, can you pm me a price (sending complete head, or parts for complete head, minus rockers and returning ready to bolt on, minus rockers)?
It depends on where the piston is already. This one was .007 in the hole, it would need cutting even with a std length rod to use the thin gasket. It is an older predator, one of the first series. Most seem to be deeper in the hole, and can use a .020 long rod and a thin gasket without cutting the piston. I get $80.00 to port a head the way the one is on this build (very time consuming). The head is where a lot of power is gained, or lost (along with the carb).
Ok, the build is complete. Here is what I got:
S/A carb that I ran on it when stock--17.75@6450
Larger S/A carb, (still on gas)-----18.83@6600
Dover S/A carb (on methanol)-----20.01@7100
348E Tillotson (on methanol)-----23.07@7050
Not bad, started at 7.24@3700 out of the box. Just a FYI, a AKRA legal, big pipe unrestricted Kart engine (clone) shows @ 12hp on my dyno.
S/A carb that I ran on it when stock--17.75@6450
Larger S/A carb, (still on gas)-----18.83@6600
Dover S/A carb (on methanol)-----20.01@7100
348E Tillotson (on methanol)-----23.07@7050
Not bad, started at 7.24@3700 out of the box. Just a FYI, a AKRA legal, big pipe unrestricted Kart engine (clone) shows @ 12hp on my dyno.