matching the combo



matching the combo

Postby grumpyvette » February 8th, 2015, 6:36 pm

RSB wrote:Greetings. I have received good advice here before about my C1 vette and help identifying my 350 camshaft - level 3 with operating range 2,400-6,800.

http://www.crower.com/chevy-262-400-pro ... -5860.html

Now I'm looking at the powertrain as a whole and trying to figure out if the builder knew what he was doing in terms of gearing. The transmission is a close ratio Super-T10, rear is 3.08 posi, and it's running 235/60-R15 tires.

To me, it feels like there is a fine line between stalling and roasting off the line. At 60-65 mph, it's just above 2000 rpm on the tach which is fun when you nail it at that speed but kind of sucks for slower cruising. Maybe I'm just not driving it right - favoring the lower gears to keep rpm up.

Do I need different gearing given my setup? If so, where do I go from here? I'm not certain I will keep the current motor indefinitely. I may switch to a milder cam'd 350 or perhaps a numbers matching 283 if I run across one someday just to regain some originality but for now, I just want to enjoy what I have and I appreciate your advice.

Thanks in advance.




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that cam certainly is a MIS match to the rear gear ratio (3.08) that you listed, especially if your compression is below about 9.8:1. the charts above should be helpful
a cam like thats designed to operate in an engine with near 10:1 compression
the cam you link too would perform noticeably better if your cruising rpm was closer to 2700rpm, especially if the engines compression is up close to 10:1 or slightly higher.
its intended operational rpm band is from about 2500rpm-6000rpm so thats what youll generally want to gear the car to cruise in that rpm band, if max performance is the goal, and yes obviously you can cruise in a lower gear to keep the rpms up, but as stated the engine would also operated best matched to about a 10:1 compression so check that also



Chevrolet - 262, 267, 283, 302, 305, 307, 327, 350 & 400
Performance level 3 - Pro-Street - High torque with more mid-range. Crisp rpm. Really nice camshaft.
INT/EXH - Dur @ .050” Lift: 242°/248° RR: 1.5/1.5 Gross Lift: .482”/.504” LSA: 114° RPM: 2400 to 6400 Redline: 6800


http://www.wallaceracing.com/gear-speed.php

viewtopic.php?f=71&t=741

viewtopic.php?f=71&t=555

viewtopic.php?f=52&t=82

viewtopic.php?f=52&t=10705&p=46582&hilit=better+expected#p46582

http://www.crankshaftcoalition.com/wiki ... ationships
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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