how much total timing are you running on your na motors?
#41
Registered
Re: how much total timing are you running on your na motors?
Combustion chamber design, spark plug placement, piston design, and machine work has a ton to do with timing. OE motors are mass produced so basing two exact motors to each other (same crate motor) is typically fine.
Basing one builder built aftmkt engine to another is not valid.
Timing is not just about detonation. It's about drivability, effeciency, and overall power.
Say, your 11:1 BBC engine produces best overall power / effeciency at 38 degrees total timing, however you run into detonation. Is it better to take a bunch of timing out or run required fuel octane ? If you can't get the required octane fuel, then the engine was not built correctly for your needs.
Basing one builder built aftmkt engine to another is not valid.
Timing is not just about detonation. It's about drivability, effeciency, and overall power.
Say, your 11:1 BBC engine produces best overall power / effeciency at 38 degrees total timing, however you run into detonation. Is it better to take a bunch of timing out or run required fuel octane ? If you can't get the required octane fuel, then the engine was not built correctly for your needs.
#42
Re: how much total timing are you running on your na motors?
8.75:1 and yes you should be fine at 34 with any aluminum heads....your 651 cam is doing a good job of controlling cylinder pressures as well......set it there, go run it and see if you can pull more rpm (virtually certain) then check some plugs to see what they look like.....if they look good, turn it up to 36 and REPEAT....I would run at least 89 if not 91-93 octane. I probably wouln't run above 36 even if it does pull more....once it stops pulling more you have your timing...I/E if you turn to 36 and the tach/speed doesn't move then turn it back down to 34......
Frankly you are probably being harder on your motor running 28 degreees than 34....
Sb brings up many good points about componets, etc but your motor is not a "radical" deviation from the normal performance build.
Frankly you are probably being harder on your motor running 28 degreees than 34....
Sb brings up many good points about componets, etc but your motor is not a "radical" deviation from the normal performance build.
Last edited by jdnca1; 06-23-2006 at 03:00 PM.
#43
Registered
Re: how much total timing are you running on your na motors?
Originally Posted by jdnca1
8.75:1 and yes you should be fine at 34 with any aluminum heads....your 651 cam is doing a good job of controlling cylinder pressures as well......set it there, go run it and see if you can pull more rpm (virtually certain) then check some plugs to see what they look like.....if they look good, turn it up to 36 and REPEAT....I would run at least 89 if not 91-93 octane. I probably wouln't run above 36 even if it does pull more....once it stops pulling more you have your timing...I/E if you turn to 36 and the tach/speed doesn't move then turn it back down to 34......
Frankly you are probably being harder on your motor running 28 degreees than 34....
Sb brings up many good points about componets, etc but your motor is not a "radical" deviation from the normal performance build.
Frankly you are probably being harder on your motor running 28 degreees than 34....
Sb brings up many good points about componets, etc but your motor is not a "radical" deviation from the normal performance build.