RPM Limit for SBE LS7 with OEM Dry Sump?
01-16-2015, 04:30 PM
#1
Launching!
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RPM Limit for SBE LS7 with OEM Dry Sump? What rpm has anyone pushed a stock bottom end LS7 to with the OEM dry sump?
We are contemplating whether or not to compete in a CAM ONLY race. The valvetrain can be altered as necessary so valvetrain stability is no longer a concern. The limiting factors may be rod bolts, wrist pins, and pistons due to piston speed. Many have also criticized the OEM dry sump. Since the car has a manual trans, higher revving during shifts does occur during a pass. This will need to be factored into cam choice. I have followed JMB's build on CF and researched here. (I have found very informative posts but no answer as of yet.) I would greatly appreciate any additional insight and experience.
TIA
We are contemplating whether or not to compete in a CAM ONLY race. The valvetrain can be altered as necessary so valvetrain stability is no longer a concern. The limiting factors may be rod bolts, wrist pins, and pistons due to piston speed. Many have also criticized the OEM dry sump. Since the car has a manual trans, higher revving during shifts does occur during a pass. This will need to be factored into cam choice. I have followed JMB's build on CF and researched here. (I have found very informative posts but no answer as of yet.) I would greatly appreciate any additional insight and experience.
TIA
01-17-2015, 06:46 AM
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Launching!
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01-17-2015, 11:38 AM
#4
While not a factory LS7, my buddy runs a TSP 416 in a 2012 GS Vette. He runs at Road America in half hour track sessions with 7000 upshifts and 7200 down shifts. Because his car is a stick it did come factory with a dry sump oil system. Now he did send his pan out to someone who put a custom square pickup tray/baffle system in the bottom. They left quite a lot of shavings and metal chips, so I unbolted it, cleaned it and ported/radiused all the pan port holes for smoother flow. He also sparred no expense by running the blue anodized Katech oil pump. This engine has been in the car for more than two years now with over 15000 miles of street abuse....and believe me he is relentless. Since he can easily afford a replacement engine at any time...he truly drives it in a manner which dares it to break. I'd say he's also run at least 50 track sessions so far.....enough to brutally destroy some aftermarket rotors/pads/calipers.
FWIW his pistons are forged but his rods are considerably heavier than yours. Point is with a bit of enhancing to the pan/pump set-up you can make them live surprisingly well.
FWIW his pistons are forged but his rods are considerably heavier than yours. Point is with a bit of enhancing to the pan/pump set-up you can make them live surprisingly well.
01-17-2015, 08:59 PM
#5
The Katech billet LS9 oil pump is key to making it live.... Supposedly the stock oil pump cover deflects and bleeds off pressure at higher RPMs. But after you spend that $ you may as well just put on a real multistage dry sump setup on the motor. The LS7/GS dry sump is not a quality dry sump setup.
I spun my LS7 to 7300 rpm plenty of times with comp cams trunion bearing kit on stock rockers.
Above 5000rpm the oil pressure simply leveled off and didn't increase. That concerned me. After much research I decided the factory system needed many fixes and they were just band aids in the end vs. running a real dry sump setup. I sold the motor and am building a real race setup (Dailey billet dry sump).
I spun my LS7 to 7300 rpm plenty of times with comp cams trunion bearing kit on stock rockers.
Above 5000rpm the oil pressure simply leveled off and didn't increase. That concerned me. After much research I decided the factory system needed many fixes and they were just band aids in the end vs. running a real dry sump setup. I sold the motor and am building a real race setup (Dailey billet dry sump).