toolong
I was reading a cam card last night , a roller cam from Crane to be exact, and I got confused, here is the confusing bit:
Cam timing: Intake opens 5.0 btdc closes 39.0 abdc
Exhaust opens 53.0 bbdc closes ( 1.0 ) BTDC
What the ... about the exhaust ??
Any ideas ??
AMX69PHATTY
Those are the angles at .050 lift right ?
The angles at .005 lift should result in some overlap
where the .050 lift values indicate no overlap, -1 deg I guess.
Is this what you're talking / asking about ?
toolong
Sorry, I'll start again,
Lift: intake @ cam : 339 @ valve : 542
Exhaust @ cam : 352 @ valve : 563
Cam timing @ .004 int opens 32.0 btdc closes 74.0 abdc
exh opens 80.0 bbdc closes 34.0 atdc
Duration int: 286.0 exh: 294.0
Cam timing @ .050 . int opens 5.0 btdc closes 39.0 abdc
exh opens 53.0 bbdc closes 1.0 btdc
Duration int : 224.0 exh : 232.0
Max lift int : 107.0 atdc exh : 117.0 btdc
Again this is a roller cam, I hope this make more sens, and thanks again for your help.
toolong
A bit more clues,
I'm rebuilding my 1981 360, for off road going, in my scrambler.
Intake : mpfi Edelbrock
Heads: Blended and flowed
valves : int 2.025 esh 1.680
rockers : roller
Exhaust : ported stock manifold
pistons : Ross forged balanced
Rods : forged balanced
Crank : Stock balanced
Cam : Crane roller
So, here are my hopes of assembling a good motor, having more experience with european 4 and 6 than american 8 :-|
jeep_man_401
What are you wanting to know?
Those are just timing events so you can dial in the cam timing with a degree wheel.
Looks like they are thinking of the circle in 180 degrees intead of 360 degrees.
Clues...btdc= Before top dead center
abdc= After bottom dead center
bbdc= Before bottom dead center
atdc= After top dead center
Intake duration= 286 degrees at .004 lift
Exhaust Duration= 294 degrees at .004 lift
Exhaust opens 53 degrees BEFORE BOTTOM dead center and closes 1 degree BEFORE TOP dead center.
53+180-1=232 degrees duration @ .050 lift (at the cam)
Don't know if this helps or if you already know this?
ironman_gq
I its for off road use you probably want a can that is on the conservative side. It will let you keep your low end torque which is where your going to spend most of your time. I would pick a hydralic flat tappet cam built to make power from idle to about 4-5000rpm's. Crane should be able to recommend one that will best fit your needs.
