onesubdrvr
01-15-2006, 07:54 PM
I'll try not to make this a boring thread, but ever since I built the engine for the Ragazza, I feel I have this huge gap in knowledge.
So, lets start with the Crank - doesn't really increase performance (unless stroker), but reliability with better cranks for HP machines.
Rods - S.A.A.
Pistons - OK, here we start, the piston can effect the compression ration - domes / dished / etc. so with CR, the higher the CR, the more HP, BUT, also higher heat, and the requirement for higher octane fuels (?)
Heads - intake / exhaust ports sizes can also effect the CR. as well as how far you open the valves (or the valves can open)
Intake - OK, here we talk flow, gotta get enough air to the cylinders through the heads (?)
Exhaust - Gotta get rid of the gasses, so flow
Cam - single most important part(?) Also seems to be primary effect on RPM / torque curve. Now, most of us have to run peak HP 5500 or lower, so doesn't that really affect the cam pick (?) Obviously lift, and duration effect flow as well.
I guess long and short, how do you decide what pieces are the best fit for the other pieces(?) Obviously if you pick a high lift / duration cam, and are running a fairly high CR, then you need more flow, so you even if everything else here is good, if your carb is too small, you screw yourself.
How do you know what kind of HP you are going to make before you build the engine? If someone said - OK, I want to build a 450hp SBC for my 18, how would YOU do it?
Wayne
So, lets start with the Crank - doesn't really increase performance (unless stroker), but reliability with better cranks for HP machines.
Rods - S.A.A.
Pistons - OK, here we start, the piston can effect the compression ration - domes / dished / etc. so with CR, the higher the CR, the more HP, BUT, also higher heat, and the requirement for higher octane fuels (?)
Heads - intake / exhaust ports sizes can also effect the CR. as well as how far you open the valves (or the valves can open)
Intake - OK, here we talk flow, gotta get enough air to the cylinders through the heads (?)
Exhaust - Gotta get rid of the gasses, so flow
Cam - single most important part(?) Also seems to be primary effect on RPM / torque curve. Now, most of us have to run peak HP 5500 or lower, so doesn't that really affect the cam pick (?) Obviously lift, and duration effect flow as well.
I guess long and short, how do you decide what pieces are the best fit for the other pieces(?) Obviously if you pick a high lift / duration cam, and are running a fairly high CR, then you need more flow, so you even if everything else here is good, if your carb is too small, you screw yourself.
How do you know what kind of HP you are going to make before you build the engine? If someone said - OK, I want to build a 450hp SBC for my 18, how would YOU do it?
Wayne