PostPosted: Sat Jul 26, 2008 3:11 pm Post subject: BB Chevy
How much power does your engine make?? how big is it(cubic inches) When I used to run pistons that looked like that, putting a big radius on all the shart edges was an immediate turn on( 40 HP )Based on your pictures, I say that you have an oil controll problem.How much timing does it want ??
PostPosted: Sat Jul 26, 2008 3:31 pm Post subject: oil
I would look at your valve guides first. We run much lighter and no problems. Was the cyl leakage good?
PostPosted: Sat Jul 26, 2008 3:38 pm Post subject:
What is that beside the spark plug, A knurled piston ? I hope thats not what your running.
PostPosted: Sat Jul 26, 2008 3:42 pm Post subject:
Are you running a "out of the box" 3 circuit dominator???
PostPosted: Sat Jul 26, 2008 5:25 pm Post subject: BB Chevy
Do you tune for best performance or do you just run it as is ?? ( bracket racer )When I used to run BB Chevys, I ran the timing way up there ( 42-44 )If you want it to go faster, you could learn alot on an engine dyno. What spark plugs fo you run ??
PostPosted: Sat Jul 26, 2008 6:16 pm Post subject: oil
The other thing to check is your piston to wall clearence. Do you know what your final bore size was? Also what did your piston measure?
Joined: 01 May 2008
PostPosted: Sat Jul 26, 2008 4:34 pm Post subject: Reply with quote
i was kinda in the same boat as you, i ran low tension oil rings;fish scaled @12-15 lbs of tension,i had a engine smoking problem,even had oil all the way up in the intake ports Shocked i changed to a set of total seal rings with a med tension,[never did fishscale them and they wen't in with a lot more drag than before] well what do ya know the smoking stopped,oil not in the intake ports and the car actually ran faster...if ya believe that.in my opinoin you probably don't need a really low tension ring pack to get good performance,maybe unless its a all out max effort deal.
PostPosted: Sat Jul 26, 2008 10:12 pm Post subject:
Please tell me that someone did not knurl the sides of those pistons.
PostPosted: Sat Jul 26, 2008 9:22 pm Post subject:
I'd round them pretty good. The flame front being able to hug the piston as it travels across the piston is very important. Sharp edges will promote turbulance in the flame front, which will trim hp from your engine. You wouldn't want turbulance in your intake runner, would you? This is as important or even more. Lay back the valve reliefs a lot, also. You shouldn't be trimming much compression, but if you do then deck the head some to get it back. IMO...wherever the flame isn't hugging the piston it isn't getting full force pushing the piston down the hole during combustion.
This is all just my opinion, but hey...I'm just a want-a-be ...lol