What I've learned about selecting cams...
My goal is to have a good performing cam that will:
Yield good power
Pass Emissions
Have a rough idle
Not have to replace springs every 15k miles or so
So far it seems that I need to go for a cam with a relatively low lift, such as a hotcam.
LS6 springs seem to last if the cam does not have a high lift. Hotcam also has a nice (lopey)sounding idle
So Hotcam this works out great,
except some say that Hotcam will NOT pass inspection, others say it will. (I will definitely be running cats), and I plan I getting LS1Edit.
Most other cams seems to be out of the question due to the spring issue. And an LS6 cam seems way too mild for me..
Could anyone give me an answer on whether or not a Hotcam will pass a NY state emissions test? In NY they put the car on a load test machine...
Thanks!
Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
My T1 cammed (221/221) 346ci barely passed.
The lope sound will depend alot on how loud your exhaust system is. All 220+ duration cams will lope if the idle rpm isn't abnormally high.
-Tony
I was kinda thinking the opposite:
At idle a hotcammed car would due worse (relative to a stock cam), due to misfires, lope, etc...
Under a load, the misfires go away, and it starts to work efficiently...
Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
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Most people want just about the same thing in a cam:
Yield great power
Pass Emissions
Not have to replace springs every 15k miles or so
Some want all this with no PCM programming
But then they make the statement that the [want] a "rough idle".
Whats the deal with a "rough idle"? What is the benifit of a rough idle?
I would think that max power with good street manners would be all anyone would want from a cam in there daily driver.
Let me tell ya; A cam that has a very rough, unstable idle will more than likely NOT pass emission testing.
Confused, <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
<strong> I am not flaming anyone here, but I just don't get it with the rough idle...
But then they make the statement that the [want] a "rough idle".
Whats the deal with a "rough idle"? What is the benifit of a rough idle?
<img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Its all about Nostalgia and what powerful used to sound like.
Can someone please comment on the Valvetrain wear and chance of passing emissions on these two:
MTI B1 (221/221 .558/.558 on 114 LSA)
TR 220 (220/220 .561/.561 on 114 LSA)
Which one will peak sooner?
I have read that the TR (XER) lobes are more aggressive and will cause more valvetrain wear (Replace Springs more often??)
<strong> Not to hijack your thread, but this seems like a good a time as any to ask.
Can someone please comment on the Valvetrain wear and chance of passing emissions on these two:
MTI B1 (221/221 .558/.558 on 114 LSA)
TR 220 (220/220 .561/.561 on 114 LSA)
Which one will peak sooner?
I have read that the TR (XER) lobes are more aggressive and will cause more valvetrain wear (Replace Springs more often??) </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The TR220 has .553" lift, not .561" FWIW. The TR220 will hit peak power sooner than the B1, but will be a little harder on springs due to the XE-R type lobes. My buddy has a B1 and his car idles significantly rougher than my TR220. Also, I would be that the TR220 would have a higher chance of passing emissions due to its 270* advertised duration compared to the B1s 280-283* advertised.
<strong> Nineball,
I was kinda thinking the opposite:
At idle a hotcammed car would due worse (relative to a stock cam), due to misfires, lope, etc...
Under a load, the misfires go away, and it starts to work efficiently...
Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Misfires are not the leading cause of bad emmissions. Rather, as the duration increases it basically pushes the efficiency of the motor higher up the rpm band so low and mid ranges suffer.
Nostalgia is exactly right. For some of us who were involved with drag racing in the late sixties and early seventies, our memories of the sound of those cars can be very evocative.



