Please help me understand cam specs

[joey b]

I found the cam specs, but I'm unsure how to read them.

Lobe Lift (Intake)

0.370 @ 108° Crank ATDC
Lobe Lift (Exhaust)

0.370 @ 115° Crank BTDC
Timing Reference Set Position with Camshaft Timing Flats in Clamped Position-Right Bank


TDC-1Piston Exhaust Stroke +/- 2° of Crankshaft
Timing Reference Set Position with Camshaft Timing Flats in Clamped Position-Left Bank

TDC-4 Piston Exhaust Stroke +/- 2° of Crankshaft

I can easily see the max lift and what that means. However, what I am unable to understand is at what point the Valves are opening and at what point they are seated again.

[bszopi]

RE: Please help me understand cam specs

The durtations aren't listed in what you are showing, so there is no way to describe it to you. But the max lift is listed as .0370" @ 108º Crank After Top Dead Center, where TDC is the point when the #1 cylinder is at the top of its rotation. BTDC is just Before TDC.

[joey b]

RE: Please help me understand cam specs

so how many degrees are the duration? At what point do the valves begin to open and at what point are they seated?

What do the second series of specs tell us?

[Synestral]

Re: RE: Please help me understand cam specs

so how many degrees are the duration? At what point do the valves begin to open and at what point are they seated?

That information isn't in the cam specs you posted.

What do the second series of specs tell us?

That is just how to find tdc in reference to which cam you're setting.

[joey b]

RE: Re: RE: Please help me understand cam specs

Does anybody know the specs for the duration and at what point the valves are starting to open and when they are seated?

[your_I.D.]

That would be IVO (int valve open),IVC (close),EVO(exhaust valve open) and EVC (close). No one seems to know it. Or know lobe centerline to figure it out. Info at this link will explain cam technology and degreing. You'll have to read it a few times. Theres alot of info to absorb.http://www.iskycams.com/pdfcatalog/2004-05/page205.pdf