Cam card help

-
mbaird

mbaird

mbaird
Joined
Dec 10, 2005
Messages
9,388
Reaction score
6,597
Location
Boise, Id
I am degreeing the solid roller cam on my stroker tonight and the cam card is different than the other I have had. Help me figure out if I have this thing degreed correctly.

IMG_20171113_195432.jpg


The actual #s I am getting straight up is
int open= 19.7ish
int close= 47.7ish
ex open = 56
ex close= 14.5

Lift seems to be correct @ .405

What is the TDC # refer to ?

thx
IMG_20171113_195432.jpg
1534993795531559762592.jpg
 
Move the dial indicated to the number 1 INTAKE lobe. Looks to me from the picture you are on an exhaust lobe.
 
I checked intake 1st.... I was checking exhaust in the pic.

explain the TDC number.....
 
yellow rose said:
Move the dial indicated to the number 1 INTAKE lobe. Looks to me from the picture you are on an exhaust lobe.
Click to expand...

Ryan @ Shady Dell had the cam ground to match his portwork but no mention of recomended install. Do you think I should leave it where its at ? This rollmaster timing gear is really tight on the crank and I dont want to have to pull it on and off any more than neccesary ( that means 1x)
 
it's usually how far the lift is at Top Dead Center
problem is that Piston to valve is not usually closest at TDC
but it's a start
nice they give you both cam and at valve (rocker ratio dependent)
advancing/ retard changes
 
ok... that makes sense.

Do you think Im good to go where it is at now ?

Wyrmrider said:
it's usually how far the lift is at Top Dead Center
problem is that Piston to valve is not usually closest at TDC
but it's a start
nice they give you both cam and at valve (rocker ratio dependent)
advancing/ retard changes
Click to expand...
 
The cam card is showing the cam 4° advanced. The cam is ground on 108° centers.
IF the cam is properly phased (ahead 4 °) the intake lobe lift will be .115 @ TDC.
SO, if it's less than that, you need to advance, if it's more, it's too far ahead.
 
'63GT said:
The cam card is showing the cam 4° advanced. The cam is ground on 108° centers.
IF the cam is properly phased (ahead 4 °) the intake lobe lift will be .115 @ TDC.
SO, if it's less than that, you need to advance, if it's more, it's too far ahead.
Click to expand...

I am not sure how you figured that out but it is interesting.
I never thought about degreeing a cam that way.

How did you figure out it is 4* advanced ?
 
mbaird said:
I am not sure how you figured that out but it is interesting.
I never thought about degreeing a cam that way.

How did you figure out it is 4* advanced ?
Click to expand...

well cause the cam card showed 2 different lobe centers for Int/Exh. If the numbers were the same, it would be straight up. The LCA is 108° cause 104+112 /2 = 108 Since the Int number was 104, thats 4° ahead.
The .115 lobe lift approach is actually faster/easier than ALL the math required the other way..
As long as the cam grinder does his job right, anyhow..
 
It's in real close. Unless you are ultra anal retentive, I'd run it!
 
I'm with CB. Run that beeeeeeeeeotch. .7 of a degree can be lifter bank angles, shaky hands, cross eye dominance or any other number of things.

As for the TDC numbers, that's how far the lobe has moved at TDC and how far the valve has moved at TDC. I suspect with zero lash, but you can do that if you want to. Too damn early for me to do the math.

Isky calls that Valve Opening @ TDC. I wish every cam grinder provided that info. You can figure it out when degreeing the cam, but it's nice to verify.
 
Thanks for all the help.
Its good to learn...
I will check the TDC lift for ***** and giggles then move on.
 
mbaird said:
Thanks for all the help.
Its good to learn...
I will check the TDC lift for ***** and giggles then move on.
Click to expand...

It's important to note.. cam card specs are LOBE numbers. (cause that's where you measure from)

I like the lobe lift @ TDC for its simplicity. But I always find myself measuring he cam anyway, in case the duration @ .050 is not as specified. Which, in turn, would effect its installed center..
Not to muddy the waters, I plead. just to make a distinction.
 
WITH the intake and exhaust centerlines BVVC degreeing the cam by measuring down say .050 on each side of the lobe and splitting the difference
Asymetrical grinds will be off the cam grinder may have to be consulted to find out how they find the lobe "center"
They may use a different number for down each side and may be giving you a "timing " lobe center for such down each side use not the actual "lobe center"
YMMV pointy lobes are easier, "dwell lobes" well how far down do you have to go
Isky also give lift at before and after tdc for the intake and exhaust lobe differences
See "Valve Timing for Maximum Output" by the Camfather Himself
 
Last edited:
Wyrmrider said:
without the intake and exhaust centerlines BVVC degreeing the cam by measuring down say .050 on each side of the lobe and splitting the difference
Asymetrical grinds will be off the cam grinder may have to be consulted to find out how they find the lobe "center"
Click to expand...

Very true. I don't know why this information isn't listed.
But, Asymmetrical's are usually found in large Super Stock Hemi profiles, or other equivalent categories.
A 'shelf' grind, like MBaird's at 246° @ .050, is purely symmetrical, at .050 at least, most changes in profile is usually found further up the lobe. Asymmetricals are more easily identified by measuring duration at .200 lobe lift.
 
'63GT said:
Very true. I don't know why this information isn't listed.
But, Asymmetrical's are usually found in large Super Stock Hemi profiles, or other equivalent categories.
A 'shelf' grind, like MBaird's at 246° @ .050, is purely symmetrical, at .050 at least, most changes in profile is usually found further up the lobe. Asymmetricals are more easily identified by measuring duration at .200 lobe lift.
Click to expand...



That's why it's hard to get at .200 numbers. Many cams sold as asymmetrical are actually not asymmetrical at all.

I know my Racer Brown is asymmetrical.
 
I am curious as to how this cam will behave. Idle , low end , torque curve , rpm range....

9.7 to 1
TTI 1 7/8s
Victor W2 port matched
20lb Mclead Sfi flywheel

IMG_20171113_193908.jpg
 
yellow rose said:
That's why it's hard to get at .200 numbers. Many cams sold as asymmetrical are actually not asymmetrical at all.

I know my Racer Brown is asymmetrical.
Click to expand...

Exactly. In my earlier days, I had full access to a Cam Doctor. kinda wish I had one for myself.
Confusion gone in 5 minutes :lol:
 
i have no idea how it will run….but i know it will be fast :)

246/[email protected]" on 108 LSA with the pro-prepped W2 Heads, it will be a really powerful engine. I think it will pull to 7000. I´m jealous!

Michael
 
mbaird said:
I wasnt saying it was meant for a good idle and low end torque... I am wondering how those characteristics will behave.
Click to expand...

If you're spoiled with the drivability of a Camry, you'll be pissed.
But if you're used to muscle cars, you'll love it.
Just make sure the carb is right, and you have plenty of gear out back. Or just put an automatic in
 
'63GT said:
If you're spoiled with the drivability of a Camry, you'll be pissed.
But if you're used to muscle cars, you'll love it.
Just make sure the carb is right, and you have plenty of gear out back. Or just put an automatic in
Click to expand...

My very 1st car was a 70 Charger SE 383 mag and I owned it up until 2 yrs ago. It had a 440/6 with a solid roller when I sold it....
I had a 73 340 4sp Dart with a W2 motor and Comp .638 solid roller with around 308 adv duration ( still have the cam card somewhere).
a 65 Coronet with a Bigblock
and numerous other mopars.
And 1 Chevy Monte with a 454 hyd roller dawg...
But this cam has a mild duration but big lift... that combined with the stroker I really cant visualize how the
engine will behave.
 
mbaird said:
My very 1st car was a 70 Charger SE 383 mag and I owned it up until 2 yrs ago. It had a 440/6 with a solid roller when I sold it....
I had a 73 340 4sp Dart with a W2 motor and Comp .638 solid roller with around 308 adv duration ( still have the cam card somewhere).
a 65 Coronet with a Bigblock
and numerous other mopars.
And 1 Chevy Monte with a 454 hyd roller dawg...
But this cam has a mild duration but big lift... that combined with the stroker I really cant visualize how the
engine will behave.
Click to expand...

you'll like it better than the shivy. :lol:
 
You must log in or register to reply here.
-

Back
Top