>Yep you guess it another cam question
Is there anyway to increase the (exhaust) duration of a cam ? Like if you added 1.6 roller rockers to the exhaust side while still using 1.5 roller rockers on the intake side . I know it will "increase" the lift , but will the duration increase also ? If you didn't guess it this is for a S/C application .
Later ...
stay safe

------------------
God Bless the United States Air Force ... !!!
1994 Z28 with some goodies
2000 Silverado LS Z71 ext cab

[This message has been edited by bowtiepwr (edited September 08, 2002).]

 

Yes it will affect the duration at .050 by maybe 4? degrees or so. It all depens on the lobes ramp as to how much it actually changes. The advertised duration or duration at .006 or .010 will remain the same. If you wanna how much duration at .050 it will increase with your cam you might call the cam manufacturer and tell them what you are trying to do and they surely could tell you. If they can not help and you really wanna know then break out the degree wheel and install one 1.6 rocker. Like I said it will raise the duration at .050 and make the valve open and shut like a "slightly" larger lift cam with a "slightly" more aggresive ramp with the same adv. duration would.

NightTrain66

 

>Thanks for the reply I will try and contact Crane Cams , but it is really hard to do that through their tech line .And it seems like they don't like to answer their email either . But I think I will use the 1.5 rr for the intake side and go with the 1.6rr for the exhaust for the Crane
HR-284-2S-12 IG cam .
Later ...
stay safe

------------------
God Bless the United States Air Force ... !!!
1994 Z28 with some goodies
2000 Silverado LS Z71 ext cab

 

If Crane is that hard to get a hold of just pick a "comparable" cam in comp and ask them, Or Call Comp and tell them you are interesterd in buying some 1.6 rockers from them and tell them what crane cam you have and see if they can help that way. As long as they think you are wanting to buy "something" from them they will surely help you. Comp is easy to get in touch with and they are allways helpful and pretty friendly.
If you are wondering Duration #s with the 1.6 it really doesn't matter what they tell you...If you are not gonna change cam and you are set on putting the 1.6 rockers on the car it will run better than it does now.
They could tell you 20 degrees or 2 degrees but you will get the same power increase no matter what duration #s they say. You may want to know just to know.

NightTrain66

 

>I was running the Crane Power Max 2050
http://www.cranecams.com/master/apps...#2.%20CompuCam (see second cam)
with the Crane 1.6 roller rockers for my N/A engine but it has a 116LSA and with the 1.6rr it brought the lift to .531 in/ex .
I have had Crane cams for all my V8 cars since high school ... stick with what works .
Later ...
stay safe

 

I wasn't suggesting to switch cams just call Comp and have them answer his tech question since Comp is easy to get in touch with. he was wandering what kind of diff. in Duration at .050 going from 1.5 to 1.6 rocker would make. I suggested if he can not get Crane on the phone then call comp and ask them. I have used a degree wheel on a hyd. roller cam motor before and checked the diff. and it was about 4 degrees. His cam may be more or less but it should be close to that. It will be greater than 1 and less than 10 degrees diff.

NightTrain66