Effect of lift on cam performance?
Effect of lift on cam performance? Hey guys, I was reading jrp's cam guide and had a question regarding what effect the lift has on the cam performance? Does a higher lift produce more/less HP or Tq? Does it effect the idle? The section from jrp's sticky is below...
B. Lift:
- Lift is defined as the difference in height between the radius of the circle and the height of the eccentric. This is called lobe lift.
- When viewing cam specs the lift portion is the gross lift, meaning its calculated with the 1.7 stock rockers.
- To get the lobe lift you take the advertised (gross) lift and divide it by 1.7. If you follow the T1/X2 cam card you’ll see that they list both lobe lift and gross lift.
- If you want to add higher ratio rockers and want to know your new lift you do the following using the T1 as an example:
.559 / 1.7 = ~.329, you then take that lobe lift and multiply it by whatever rocker ratio you want. With SLP 1.85 rockers your new lift specs become .329 X 1.85 = ~ .609
B. Lift:
- Lift is defined as the difference in height between the radius of the circle and the height of the eccentric. This is called lobe lift.
- When viewing cam specs the lift portion is the gross lift, meaning its calculated with the 1.7 stock rockers.
- To get the lobe lift you take the advertised (gross) lift and divide it by 1.7. If you follow the T1/X2 cam card you’ll see that they list both lobe lift and gross lift.
- If you want to add higher ratio rockers and want to know your new lift you do the following using the T1 as an example:
.559 / 1.7 = ~.329, you then take that lobe lift and multiply it by whatever rocker ratio you want. With SLP 1.85 rockers your new lift specs become .329 X 1.85 = ~ .609
Increasing cam lift and performance is a function of how well your heads flow. More lift can mean more power if properly matched to the heads/intake. Remember its the sum of the parts, not just one aspect in particular.
Teching In
Joined: Dec 2004
Posts: 37
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From: Australia
More lift will move the power curve up all things being equal, higher lift will accelerate valve train wear as the rate of valve acceleration will increase. Should not change the idle quality unless the overlap is changed.
Originally Posted by SPIV
More lift will move the power curve up all things being equal, higher lift will accelerate valve train wear as the rate of valve acceleration will increase. Should not change the idle quality unless the overlap is changed.
