What does longer cam duration mean?
A 280-degree-duration cam holds the valves open longer than a 260-degree-duration cam. Holding the valves open longer allows more air and fuel into the engine and also allows more to get out through the exhaust. Longer duration (higher number) improves top-end power but almost always sacrifices low-end torque.
What is short and long duration camshaft?
Virtually every cam maker uses duration to rate camshafts. When someone talks about a “big” cam, they are referring to cams with longer duration. This keeps the valves open longer, increasing midrange and top-end power at the expense of low-end torque. A shorter duration cam does just the opposite.
Does cam duration affect idle?
Again, keeping all else constant, more duration will make the engine less efficient at low rpm, with more overlap dilution of the induction charge, and the later intake valve closing reducing the trapping efficiency. Therefore, a long-duration cam will cause rough running at idle (lope) and a loss of low-rpm torque.
Is more cam lift better?
Designing a cam profile with more lift results in increased duration in the high-lift regions where cylinder heads flow the most air. Short duration cams with relatively high valve lift can provide excellent responsiveness, great torque, and good power. But high lift cams are less dependable.
What makes a cam have a lopey idle?
what makes the cam have that lumpy sound? The overlap of the exhaust valve closing and intake valve opening causes the engine to be inefficient at low speed which results in the lumpy idle. The closer the Lobe Seperation Angle the more the overlap, the more duration the more (typically) the overlap.
Does cam lift affect idle?
Therefore, a long-duration cam will cause rough running at idle (lope) and a loss of low-rpm torque. The latter of these factors can be compensated for to an extent by using a higher static compression ratio.
What is a low lift performance truck Cam?
These low lift performance truck cams are specifically designed and engineered to take your Silverado, Sierra, Tahoe, Yukon, Avalanche, Suburban, hot rod, or street rod to the next level.
What is camshaft lift and duration?
The easiest way to explain camshaft lift is to think of it as how far the valve opens to its furthest point off of the valve seat. Camshaft duration can be simply explained as how long the valve stays open off of the valve seat.
What’s the difference between high lift and high duration cam lobe?
A high lift, high duration cam lobe is gentler on the valve train than a high lift, low. duration cam because the ramp speed isn’t as quick. High ramp speeds coupled with weak valve springs can result in a) “ski jumping” just after maximum lift is achieved and B) valve float.
Should you put a lift cam in a 500-lift engine?
The opposite applies if you only put a .500 lift cam in an engine with heads that flow more air — you’re leaving a lot on the table because you’re not getting the full potential of the engine,” Yoder says. Getting the right duration needs to be approached slightly different, according to Yoder.