HRT 8

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by gto69judge:
<strong>Quoted by TXCAMSS:
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Personally , I prefer the 112 over the 114 primarily because I want my power band to stay at a comfortable RPM. the rule of thumb is that the 112 pulls the power in at a lower rpm and keeps you from having to wind the motor so high to reap the benefits of the cam and the 114 LC will require the motor to be wound a bit higher to achieve those gains.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You have that BACKWARDS. The powerband is WIDER with the 114LSA.
It is the larger (114) LSA that pulls better at lower rpms.

To state it differently, the narrow (112) LSA will develop more peak power in a narrower band, and it will be at a higher rpm when compared to a 114 LSA.

As far as idle quality and sound go, a 222/222 @112 LSA will sound and idle similar to a 224/224 @114 LSA camshaft.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That was my belief also.

Colonel

All things being equal a 114 will have a peak HP at a slightly higher RPM than a 112. I don't know why all of a sudden there is a misconception about this. For years it has seemed to be well known and well accepted.

JWRENCH

I was rooting around and found this chart. I know it's for bikes, but it's still four stroke so it should be pretty close. http://www.nightrider.com/biketech/camlsatable.htm

JWRENCH

Here is what the CraneCams site said. It pretty much backs up what the Colonel stated. Which was my understanding also.

What is camshaft lobe separation and how does it affect the engine?

Lobe separation is the distance (in camshaft degrees) that the intake and exhaust lobe centerlines (for a given cylinder) are spread apart. Lobe separation is a physical characteristic of the camshaft and cannot be changed without regrinding the lobes. This separation determines where peak torque will occur within the engine’s power range. Tight lobe separations (such as 106°) cause the peak torque to build early in basic RPM range of the cam. The torque will be concentrated, build quickly and peak out. Broader lobe separations (such as 112°) allows the torque to be spread over a broader portion of the basic RPM range and shows better power through the upper RPM.

ws6-speed

jwrench,

Your 2 last posts contradict each other. The bike page says that wider(numerically higher) lsa's give less top end power while your Crane post says "Broader lobe separations (numerically higher) .....shows better power through the upper RPM."

I'm so confused. <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />

Russ

kewlbrz

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 77-vette:
<strong>
I'm so confused. <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />

Russ</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">77-vette,
If the LSA is larger(wider), the power range is widened and shifted down.

If the LSA is smaller(narrower), the power range is narrowed and shifted up.

This is why in all out high RPM motors, you see very tight LSA, because they want to take advantage of RPM, and the power up high. Good for the street? Probably not.

for more info:

https://ls1tech.com/ubb/ultimatebb.p...c;f=1;t=007778

Black Magic

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Colonel:
<strong>All things being equal a 114 will have a peak HP at a slightly higher RPM than a 112. I don't know why all of a sudden there is a misconception about this. For years it has seemed to be well known and well accepted.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Agreed 100 percent. But I am also of the belief that a 112 is better for a stick, and the 114 for an automatic due to trans gearing.

Go for the 112.

<small>[ October 01, 2002, 01:44 AM: Message edited by: Black Magic ]</small>

gto69judge

iTrader: (32)

I think we ALL agree that the 114 LSA is better for an automatic transmission equipped car.

I also recommend the 114 LSA for a STREET driven M6 car for the same reason it works so well in an A4 car - a WIDE POWER BAND. It will provide more low end torque to lug down the RPMs. Having low end torque is especially important with overdrive transmissions.

Tight LSA's are fine for race applications where the RPMs are kept high and in a narrow range and maximum power is the goal.

On the street, the priorities should instead be a wider torque band for driveability and stable idle to prevent stalling and allow the use of A/C.

Black Magic

That's where gears come in. YOu can get away with running smaller gears, which will keep your RPM in the power band better, in a manual trans car. A wider power band just takes longer to get through.