Crowley

What type of power difference would you expect with a cam with identical specs say .. 230/230 on a 114, but one has XE lobes and one has XER lobes .. what differences would I see because of lobes?

thanks,
Crowley

MyLS1Hauls

iTrader: (2)

Probably only a few peak hp more, but more area under the curve. You'll also have a better idle and better throttle response.

Crowley

So the XER will have a few more peak HP but more area under the curve .. but the XE Will idel better and have better throttle response?

thanks,
Crowley

NA$TY-TA

iTrader: (21)

Are you saying better idel with XE lobes or XER lobes?? My cam is a XER and it idles fine......
Kyle

BigTex

iTrader: (16)

You'll probably get several answers as far as peak power gains, but I can't say for sure. One thing that the XER has going is the shorter .006 duration and longer .200 lift durations. That means there will be less overlap below .050 lift for the XER which should equate to a better idle and low end torque. Since the XER opens faster, at lifts above .050, it is a bigger cam than a similar XE-high lift cam. You may find that peak power would be equal between a 230XE and a 226XER (just guessing), but the 226 XER should have better idle and low end with the proper configuration.

Crowley

So for a daily driver (mostly street car), the XER lobe is the better of the 2 for drivablity as well as power under the curve?

thanks,
Gary

RyanJ

Yes, but spring wear is more of a concern over time with the more aggressive ramps (see Colonel's thread in this section).

BigTex

iTrader: (16)

The downside to the XER is increased valvetrain noise and valvespring strain due to the increased ramp rate. Think of the XE lobes as a smoother transition from open to close. But if you get good springs and can live with a little more valvetrain chatter, then the XER will be a good choice. The Thunder lobes are reported to be in between the XE and XER lobe rates, so they would be a good choice as well.

samz28

so good springs change every year or two?
20K miles?

MyLS1Hauls

iTrader: (2)

I'm going on 25k with my 918s and XE-R and so far so good. 918s and the XER lobes are still fairly new, so nobody's really sure how long the springs will actually last. I've yet to hear of anyone say "yup, my springs are trashed and the valves were floating" with 918s. Yes, XE-R cams will idle better with the same given .050" numbers over an XE, and thats due to a lower advertised duration.

SFVetteman

For a given duration and LSA, the XE-R should have more peak power as well, when compared to a XE cam because of the greater lift. For example a 230 XE-R lobe has .592 lift compared to .573 lift for the 230 XE lobe.