How to degree my cam?

[Zwap]

I'm familiar how to do it but what does the - (minus) sign means on when intake opens at 0.050?
The cam card says -1.5, should I degree it 1.5 degree BTDC or is it 1.5 ATDC as there's a minus sign?
The most cam I've been in touch with use to be degree 7-8 degree (without a minus sign) BTDC, never seen this -1.5 degree before

 

[70bigblockdodge]

1.5 degrees before top dead center a positive would be after top dead center.

 

[max1196]

The 108 is the number you'll be working with to degree the cam (intake centerline) . If you want to know about the -1.5, do the math. Total degrees of duration is added up as 180 + the event opening degrees BTDC + the event closing ABDC = total degrees at .050 So you have 34.5 plus 180 plus a (negative) 1.5 = 213 degrees at .050. The negative in this example is because the card states BTDC, BUT in this case it's not occurring at BTDC it's actually occurring ATDC, so to keep the math in check , a double negative is required.

 

[Zwap]

Got it, thanks alot for clearing that out!!