I've been talking to a local mechanic about building my motor - cams, cam gears, fpr, blah blah blah. The works. I told him I wanted stage 3 cams, he told me that with stage 3 cams that the idle would be kinda funny. I asked him to elaborate, he said it would fluctuate between the rpms. Like it would go below 1k and above 1.2k.

My question to you guys is:
Do you guys know if Stage 3 cams of any type (JUN, Skunk2, Toda, etc) really do cause the idle to be kinda weird ?

 

The term "stage 3" is loosely used. For instance my Jun 3's have just about the same specs as a skunk stage 2. Other stage 3's like skunks pro series and Toda's C2 will definitely be more aggressive. When you have big primary lobes is when the idle gets to be finicky when tuning. If I could do it again, since I have so much dynamic compression, a cam with bigger primary lobes would suit me better. But then again, my idle is so much like stock that I really luv it.

 

Yeah, idle depends on the primary lobe specs of the individual cam.

A more common downside is accelerated wear of the valve seats, rocker arms and timing belt.

 

Camlob, you have the Jun III's and they don't idle funky ? And what do you mean by same specs as the Skunk2 Stage 2 cams ? I'm very.. lacking of motor knowledge

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ViSioNxBoY &raquo;</TD></TR><TR><TD CLASS="quote">Camlob, you have the Jun III's and they don't idle funky ? And what do you mean by same specs as the Skunk2 Stage 2 cams ? I'm very.. lacking of motor knowledge </TD></TR></TABLE>

when i wake up, i'll post in here. someone remind me

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ViSioNxBoY &raquo;</TD></TR><TR><TD CLASS="quote">Camlob, you have the Jun III's and they don't idle funky ? And what do you mean by same specs as the Skunk2 Stage 2 cams ? I'm very.. lacking of motor knowledge </TD></TR></TABLE>

The duration and the lift of the big lobe is more or less similar to the skunks. The other stage 3 cams have much longer durations and higher lifts so a lot of static compression will get lost. Try to figure out what cam you intend to get and see if your static cr will suffice.

 

I think you all might be throwing out terms that this guy doesn't understand...

visionx, search around in the archives for cam information. I don't know of any good tutorials off the top of my head, but the Allmotor forum is probably a good place to start. Find out what duration, lift, and lobe size are and how they interact with other aspects of the engine (like compression, for example).

Just to get you started "specs" refers to measurements. You know how a cam is a shaft with sort of bumps on it? Those bumps are the lobes, and their size and shape determines how they open and close the valves, thus changing engine behavior and power. Now go find more!