Why Run More Lift on the Intake Than the Exhaust?
09-02-2006, 02:41 AM
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Why Run More Lift on the Intake Than the Exhaust? The latest cam designs seem to be running high lift LSK lobes on the intake with lower lift x-er lobes on the exhaust. Why not run LSK lobes on the exhaust? If the valve springs can handle the lift on intake shouldnt they be able to handle the same lift on the exhaust, since the exhaust valve is smaller and lighter?
09-02-2006, 02:50 AM
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I believe it's because the exhaust ports can only flow so much. If you noticed on CNC heads they show Intake Numbers.. 300cfm yada yada yada, but the exhaust numbers are always so much lower. There are a few reverse split cams that work really well but i couldn't tell ya why... Prob because of 
09-02-2006, 02:49 PM
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If you run less duration youll have less reversion. I think I am missing something cuz its pretty common for cams to run more lift on the intake than the exhaust.
09-02-2006, 04:50 PM
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I did it in order to slow down the exaust timing a bit. People will have diffrent views, but it all comes down to you exaust system, from the port to the tip. I have a highly effective exaust all the way back, so we slowed the exaust lobe down a touch. The lift is just a bi-product of the lobe we chose to get the correct VE's. In the end, it's all about the valve events and were you want them placed. IMO, lift is secondary.
