Too much lift for stock carb?

joler1302

New member
Hi.

Running a GX270, nrracing .280 lift 220* torque cam, stock carb, 55lbs springs and raceseng 1.3 rockers. and the head is shaved 1,2mm. Now with these rockers i should have a calculated lift of .364, and i a few days ago found out the the guys who are winning races are running stock rockers. We all run stock carbs.

I was wondering if .364 lift is too much, and simply a waste of effect? Probably gonna try putting the stock rockers back on this baby to see what it has to say.


Thoughts?
 

496 BB

New member
Ive found the only way to tell if ratios work or hurt is try em out on track and switch back. Check lap times or equivalent while testing. I run a 1.3 on intake side only and it likes it. But Im on a clone so not sure about yours.
 

joler1302

New member
Any specific reason for only doing it on the intake? I've got a pair of raceseng rollers so i can't really go stock arm on one side.. But i've been thinking about getting SA ratio rockers, but not sure if they will hold up to our endurance races. Just recently we had a 24hour race. That **** was rough. 3/24hours was repairs on our end, everything went wrong!
 

496 BB

New member
The reason I put on intake only is from what I saw there was no gains by going on exhaust side. It made it sound like it had a larger cam (which it should) and I didnt want to share that with everyone we race with...lol.

What cam are the other guys running? Are you getting beat in straights or off the corners? Is track more straights or more turns?

Reason is from my research it seems a low duration cam with high lift creates alot of lowend tq but not necessarily alot or top end.

Easy way to tell is just put stockers back on and try it.
 

clone king

New member
I built a bsp 196 back in 08 or 09 it had stock crank, arc billet tod, Honda stock bore flat top, stock 14cc head stock vlcs 32 lb springs head milled .040 piston at zerro eck height , arc 6619 billet fw. Dynocam 308 with steel stamp ratio rockers 1.3:1 intake 1.2:1 exhaust. Ruixing stock carb factory bore @ .612 low jet .24 main jet .038.. .880 rapp pipe. 32degrees timing. Cam degreed to 109 c/l. 93 Pump fuel
This build didn't have much to offer in power becsuse of the build. It yielded 10.53 hp @ 6600 rpm
Basically the cam was to big to work good. carb & vlvs too small.

i can double that power now with thr same build with bigger stroke vlvs intake with tillotson, bigger bore with wiseco piston, 1.25 custom exhaust, m5 methanol fuel
turn 20+ @ 6900 rpm. Just 2 examples of whst change can fo
so many other combos available to try. lol
It comes down to part combinations for applications .
 
i built a bsp 196 back in 08 or 09 it had stock crank, arc billet tod, honda stock bore flat top, stock 14cc head stock vlcs 32 lb springs head milled .040 piston at zerro eck height , arc 6619 billet fw. Dynocam 308 with steel stamp ratio rockers 1.3:1 intake 1.2:1 exhaust. Ruixing stock carb factory bore @ .612 low jet .24 main jet .038.. .880 rapp pipe. 32degrees timing. Cam degreed to 109 c/l. 93 pump fuel
this build didn't have much to offer in power becsuse of the build. It yielded 10.53 hp @ 6600 rpm
basically the cam was to big to work good. Carb & vlvs too small.

I can double that power now with thr same build with bigger stroke vlvs intake with tillotson, bigger bore with wiseco piston, 1.25 custom exhaust, m5 methanol fuel
turn 20+ @ 6900 rpm. Just 2 examples of whst change can fo
so many other combos available to try. Lol
it comes down to part combinations for applications .
m5 !!!! :)
 

joler1302

New member
Really interesting, will probably soon try to take off the rockers and put on the stock rockers, they will be able to hold up right? They're original honda so i think they will. Also, does anyone make SA ratio rockers for 270's?
 
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