[pastry_chef]

Originally Posted by llwta76

have a crank. pressure( done by the book) of only 164#. My DCR is 7.8 with this cam. That's w/9.7 SCR. I want to get it up to 175-180# and figure that I need to get my DCR to 8.0 or above to get me there.

IMO strange to target a value for cranking PSI. There is absolutely no guarantee the higher crank pressure will offer increased performance.

[72LuxuryLeMansLa.]

Originally Posted by llwta76

Thanks for the post! With my iron headed combo I currently have the UD 288/296 solid flat tappit cam w/a int. closing of 64*ABDC @ 4* advanced and have a crank. pressure( done by the book) of only 164#. My DCR is 7.8 with this cam. That's w/9.7 SCR. I want to get it up to 175-180# and figure that I need to get my DCR to 8.0 or above to get me there. What DCR calculator did you use. Also what's the int. closing point of your cam?

I use the one you download at the bottom of this page: http://cochise.uia.net/pkelley2/DynamicCR.html

Make sure you use the Advertised Duration numbers for this calculation.
My Intake Closing is at 71°ABDC

[llwta76]

Originally Posted by pastry_chef

IMO strange to target a value for cranking PSI. There is absolutely no guarantee the higher crank pressure will offer increased performance.

In my case raising cly. pressure to say 175-180#(raising DCR) w/the cam listed can only be done by increasing the SCR. Doing that will certainly increase power across the entire RPM range as long as I don't get into detonation.

[SD421]

Karl,

I have been going back & forth calculating different cams on the Wallace Racing Site.

This might be a stupid question but do you "advance" the intake centerline on the calculator?

Wolverine WG1096 (744 hi lift)cam 290/300 224/234 .465/.488 .512/.537

Lobe centerline 112 Intake Centerline 107

In other words if I take this Wolverine cam which has a 112 lobe centerline & a 107 degree Intake center line, to get the intake to "Close" sooner I just make the 107 ICL a 105 because I will be using a 2 degree advance key.

This is to get me a little higher DCR.

[72LuxuryLeMansLa.]

Originally Posted by SD421

Karl,

I have been going back & forth calculating different cams on the Wallace Racing Site.

This might be a stupid question but do you "advance" the intake centerline on the calculator?

Wolverine WG1096 (744 hi lift)cam 290/300 224/234 .465/.488 .512/.537

Lobe centerline 112 Intake Centerline 107

In other words if I take this Wolverine cam which has a 112 lobe centerline & a 107 degree Intake center line, to get the intake to "Close" sooner I just make the 107 ICL a 105 because I will be using a 2 degree advance key.

This is to get me a little higher DCR.

That is how it works. Be aware that advancing or retarding a cam without first getting a baseline in performance with the cam installed straight up is not recommended by most. In most cases I understand the best way to go about upping the DCR is by raising the static with a given cam instead of advancing it.
To give a theoretical example, using Engine Analyzer I advanced SD Performance's Stump Puller and saw a degradation of power up top with corresponding gains from idle to about 3500rpm. This basically shifted the power curve down on the rpm range. I raised the SCR and this of course raised the dynamic and the engine showed gains throughout the rpm range. Of course the performance you see will depend on the entire combination of vehicle weight, gears and wheels not just the engine.
Remember I am no expert on this and am learning just like you. Jim Hand wrote on this subject and you should read his and others writing on this.
http://www.pontiacstreetperformance....mpression.html

I used The Performance Trends Engine Analyzer Plus to show graphically what a 4° cam advance from straight up would do. The engine gained 5lb.ft. of torque from idle to around 3500rpm then lost up top with a 9hp decrease at peak.