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2 different cam profiles to discuss

Twisted Steel Performance

Twisted Steel Performance

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I have 2 different cam profiles that I'm not going to identify other than they are both 6.x cams, maker isn't important in this thread.

These readings were made on a "cam doctor" so they are accurate.

This is the exact info one should receive with any cam being installed and being able to insure clearances and proper set up... simply a cam card...

This is for discussion as to the differences in spec's and possible differences in performance.

------------------------------------------------------------------------------------------------------

Cam # 1

Intake & Exhaust
lobe center sep = 110.5 cam deg
valve overlap = -30.3 crank deg

Intake
valve opening = -20.7 'BTDC
lobe center = 110.5 'ATDC
valve closure = 19.1 'ABDC
Duration = 178.4 crank deg
max cam lift = .27969" inch
net valve lift = .41953" inch
lobe "area" = 18.05 inch * deg

Exhaust

Valve opening = 31.2 'BBDC
lobe center = 110.5 'BTDC
valve closure = -9.6 'ATDC
Duration = 201.6 crank deg
max cam lift = .28016" inch
net valve lift = .42024" inch
lobe "area" = 20.49 inch * deg

-----------------------------------------------------------------------------------------------------

Cam # 2

Intake & Exhaust
lobe center sep = 110.4 cam deg
valve overlap = -29 crank deg

Intake

valve opening = -23.3 'BTDC
lobe center = 110.4 'ATDC
valve closure = 22.7 'ABDC
Duration = 179.4 crank deg
max cam lift = .28" inch
max valve lift = .42" inch
lobe "area" = 18.17 inch * deg


Exhaust

valve opening = 28.3 'BBDC
lobe center = 110.4 'BTDC
valve closure = -5.7 'ATDC
Duration = 202.6 crank deg
max cam lift = .27996" inch
max valve lift = .41994" inch
lobe "area" = 20.59 inch * deg

------------------------------------------------------------------------------------------------------


Alright lets see what you all think about the differences in the 2 grinds ....

Does anyone know enough to be able to SPECULATE on what if any difference either cams would make performance wise... what about 1.6 or 1.7 ratio rockers....

Open to discuss possible pro's & con's of each and possible improvements that could be made.
 
I don't know there doesn't seem to be a lot of difference IMO. Ones got more lift but the others got more duration
 
First I would change the - BTDC to just ATDC , the negative sign just throws you off unless you think about it .
Both of them seem to be fairly close , in terms of lift and duration , however if the term " lobe area " is area under the curve then the second cam is " larger " .
 
EWC said:
First I would change the - BTDC to just ATDC , the negative sign just throws you off unless you think about it .
Both of them seem to be fairly close , in terms of lift and duration , however if the term " lobe area " is area under the curve then the second cam is " larger " .
Click to expand...

This is how the cam reader printed it out so that's what I posted is all..
And it does mean under the curve..

They do look close in most areas, like Will stated, the "tork/power" band has more than likely been moved some in the rpm band but how much & where is yet to be seen, I suspect cam# 2 both bands were moved up some in the rpm's maybe..
 
I think it would be good to post the specs from a stock cam just to see if the regrinds are way off . Anyway John can do a stock cam ?
 
These lift figures @ 1.5 ratio ... is that your question??

edit.. I see I used the word "max valve lift" in #2 but I meant to type "net valve lift"....
 
No , I guess I should have asked what tappet lift did you start measuring .
 
These figures were gained using a cam doctor machine & software, I haven't measured it in the motor yet to check setup yet, haven't gotten that far yet..

I didn't watch the cam being run so I can't explane it all, I do know the machine tho, most larger builders use them to run different scenario's with the valve train..

It wasn't free but I needed to know exactly what I was working with for this one..
 
Probably used .050 tappet lift as those numbers are close to my Crane . So now that you have some numbers to go by , what are your thoughts on the stock cam ?
 
Don't have a opinion at this time, we already know their isn't much room for change other than small areas. I'm not going to go through having cams made, I suspected something was different with the P motor other than the obvious just wasn't sure... now I know..

I'll be going with 1.7 rockers and cam#2, a good flowing set of heads etc, just attempting to maximize flow through the motor...
 
It would be interesting to get some flow numbers from the P400 heads . That , and the newer cam , would see what direction to go with mods .
 
Might look at Kennedys custom pistons , the tops are quite different and may give you some more clearance . I wouldn't be afraid to flycut the pistons . Cut one in half once , top had to be maybe 1/2 " thick .
How's it going with your heads ?
 
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