Power band

[skyllark]

Daily Driver

69 skylark 350, 670-4brl, headers, TH350w/trans kit.

the car is fast but i want to get every last bit of power, where is it hiding?

i'm going to port and match the heads and throw in a street/race cam.

i want to learn about power bands and when to shift, max RPM, what can i expect if it does float a valve?

when i do rebuild the bottom what comp. ratio

i don't know how much hp i've got now maybe 300, 350 would be very nice.
but i do want to keep it a daily driver.

Thanks!

[bob k. mando]

i'm going to port and match the heads and throw in a street/race cam.

then you aren't going to know ANYTHING about your specific powerband without throwing the motor on a dyno. a street/strip cam will move your hp peak significantly higher and you're talking about changing practically everything else that affects your rpm range and powerband.

if you're going to be throwing a bunch of money at this you'll want strong springs on that high lift cam and you'll run the engine out to whatever you decide to set for a redline; 6,000-6,500rpm. a factory cam will probably be done by 5,000.

the first rec for any Buick engine is recurving the distributor. you may want to consider swapping in a 74 or newer HEI unit as well although some guys like the points systems.

also make sure your quadrajet is in really good shape. you may want to have John Osborne in Elizabethtown, KY recondition it.

one thing to note; the highest factory rating on a 350 was the 1970 Gran Sport 'SP' code motor. 315 gross hp from the factory. if you're going to do all this work, 350 hp at the flywheel should be childs play.

[skyllark]

thanks Bob!
thanks for the carb tip.

what do you mean when you say the stock cam is done @5000, (is that what I hear up around 5k? some spooky rattle!)

whats the scoup with curving the distributor, i've got a Petronics unit in now, new weights and playing with the springs and my timing light.

what is sending it out going to do? as i change my engine should it be recurved?

i guess i'll be booking some time on the local dyno.

Thanks!!!!!!

[skyllark]

just read a great artical about distributor curves on the MSD site.
http://www.corvettefever.com/techart...curving_power/
seems like a lot of trial, testing and charting results.

sounds like my kind of fun!

[rcull]

Here's a bit:
http://www.teambuick.com/forums/view...=engine_timing

[bob k. mando]

what do you mean when you say the stock cam is done @5000, (is that what I hear up around 5k? some spooky rattle!)

when i say it's 'done', i mean the engine will stop pulling. the stock cams normally don't have the valve events open long enough to support the high rpm breathing that a hp motor needs. this results in the engine 'running out of breath', kinda like an artificial rev limiter.

if you've got an upper rpm rattle i'd pay special attention to clearances, bearings and valve spring degradation when you rebuild. normally worn out springs, especially the softer stock ones, will result in valve float when you try to rev the motor up. worst case, this could actually result in valve to piston contact.