Box Stock

Cam selection advice please

D

dirttrax

New member
Current build.
208cc predator
Weisco piston
Arc long rod
14cc head with alot of Port work
28/32 valves
Tilly 304 alky
Currently has nr274-0207 with 1.3 rockers

Now I'm running a small banked bull ring, 11/68 gear with 4500rpm clutch engagement.

I want the motor to run in the 8500-8700 range
And it currently does but it doesn't pull like I feel it should off the turns. I'm getting beat by several friends who run dyno 356 cams. And there's seem to pull harder everywhere.

So my question is what cam rocker combo do you think I should try or just leave it?
Thinking of trying 356 or isky 350 lift with stock ratio rockers.
Thanks
 
And it has 36 dual springs and if weight matters I'm 320 race ready.
It's a local sat night open small block class
 
There are several things that I would be looking at first. Not that I'm an expert, far from it, but there are things that can affect that coming off the corner speed.

Do your rpm's drop enough in the turn to where the clutch is slipping? At what rpm is your clutch slipping coming off a dead stop? Sorry, you said 4500. Is that engagement RPM at peak torque?

14 cc head, but what's the combustion chamber CC's? What's the actual compression pressure? With a 14 cc head, what's your compression ratio? What fuel are you running? What octane?

What's the radius of the turn and how much stagger do you run?

I get a lot of arguments, but in my experience, "compression is the Holy Grail".
 
Al, a 14cc head is 14cc combustion chamber....that is why its called a 14cc head lol.

dirttrax, id try the 356, it is a great cam for open racing and works really well....or maybe consider the P-open cam from dyno
 
W5R said:
Al, a 14cc head is 14cc combustion chamber....that is why its called a 14cc head lol.
Click to expand...
You don't know what a combustion chamber is I guess! I've always calculated it using the thickness of the head gasket and the distance the piston is in the hole at Top Dead Center. LOL. That's with a flat top pistons. If it's a dished piston, you would also have to include that.
 
A 14cc head does not equate to a 14cc combustion chamber. and no that is not why it is called a 14cc head. If the Honda 196cc engine on my tiller had a 14cc combustion chamber it would have come from the factory at 15:1 static compression ratio, a hot rod tiller.
 
Every Honda 14cc head I have checked with fluid in the chamber was 14cc's, if you are talking about total cc's including piston depth and head gasket thickness then that is a different story. I read Als post as him asking how many cc's the Honda head had, if I misread that then its my mistake
 
W5R said:
Every Honda 14cc head I have checked with fluid in the chamber was 14cc's, if you are talking about total cc's including piston depth and head gasket thickness then that is a different story. I read Als post as him asking how many cc's the Honda head had, if I misread that then its my mistake
Click to expand...
Just a little confusion with the terminology. When I say CC's in the head, I'm talking about just the head, when I say combustion chamber, I'm talking about the volume with the head bolted on the engine which would include the head gasket and what ever the CC's are from the top of the block to the top of the piston.

Now are we talking head CC's, or combustion chamber CC's?
 
The head is 14cc al. I don't know the combustion cc. I'm not looking to change anything with the motor except cam. I'm satisfied with the motor combo but figured guys here could help with cam choice so I don't have to buy several to try. Thanks
 
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