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View Full Version : Chevy SB/BB valve springs.



MassSupra89
January 19th, 2008, 03:20 PM
How many people are using these BBC inner valve spring?
Or have more info on using them in the 7M?
Haven't decided which springs to use with my BC cams yet.

Link- http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_114346_-1

need new tires
January 19th, 2008, 07:23 PM
i am using cca-975-12 (bbc inner spring) here. several other local guys have been using them for a few years.

Dan_Gyoba
January 19th, 2008, 09:34 PM
Well, while I know that the lift on SBC/BBC cams is (typically) greater, from what I recall, 5000 RPM was a big INCREASE in redline on those, so I'm not sure about the suitability of the springs for carst aht are intended to run at 6500+ RPM. I remember a lot of guys with the V8s having valve float issues at 5500 RPM with upgraded valves and rockers.

That's not to say that it couldn't be done. I knew a couple of guys who had 7500 RPM monsters, too.

Doward
January 19th, 2008, 10:06 PM
Valve float is due to valvetrain weight vs spring used.

The BBC inners are stronger than our springs stock, so they are great!

bfr1992t
January 20th, 2008, 08:45 AM
Don't forget about boost pressure assisting with float on the intake valves. ;-)

I've run the 975 springs for 5+ yrs now. 1.5mm over valves, 25+psi, 7200 rpm. I had my stock 92T springs tested at 65kmi and they were weak.