MJ23FE

This is a dyno with the same profile of cams with different material. The motor is a 2-liter k20a with full featured IPS signature series Cunningham rods and JE pistons (12:1cr). 3 year old header.

RBC intake manifold
PR velocity stack
custom CAI

Exact same profiles, all that is different are material's.



-Jalal

Professor15

might wanna elaborate on which is which and what the differences may be?

MJ23FE

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Professor15 &raquo;</TD></TR><TR><TD CLASS="quote">might wanna elaborate on which is which and what the differences may be?</TD></TR></TABLE>
8620 = Turquoise (higher)
Ductile-Iron = Green (lower)

The only difference are the material's used to make the cam.
Both are IPS-K2's. One is made from 8620 billet, the other is made from Ductile Iron.

-Jalal

MJ23FE

http://www.k20a.org/forum/showthread.php?t=8651
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by edo &raquo;</TD></TR><TR><TD CLASS="quote">
8620 is the preferred material for roller rocker valvetrain because of its strength, consistency and deflection resistance capacity. It has the potential to outperform the ductile iron cores. It isn't anything new, aftermarket V8 roller cam makers use nothing else.

-Ron</TD></TR></TABLE>

Some more info about this material.

-Jalal

flyrod

I doubt the differences are due to the cam material. Especially since the K uses roller rockers (can't claim less friction). All steels have the same modulus, so deflection is a function of the geometry of the part and the load applied. If the metal in the cams is yielding, then the "deflection" will be short lived (i.e. part failure).

MJ23FE

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">I doubt the differences are due to the cam material. Especially since the K uses roller rockers.</TD></TR></TABLE>
http://www.k20a.org/forum/showthread.php?t=8651
http://www.intrinsicperformance.com/

Did you happen to go to the thread i linked? Also, check out the IPS website, it IS the differences in material that make for the increase in power.

Ron Acevedo says it himself, as i quoted him above.

-Jalal

flyrod

What exactly is:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MJ23FE &raquo;</TD></TR><TR><TD CLASS="quote">deflection resistance capacity</TD></TR></TABLE>

As I tried to explain, deflection is determined by the shape of the part, the type of material, and the load applied to it. ALL steels have basically the same modulus. Are the cams the same shape?

flyrod

I read the thread, and I didn't see claims of more power just due to the material. It sounded to me that the reason for the material is fewer rejects in manufacturing (vs. the cast cores), and no limitation in cam profiles for race applications. I think the 4% difference shown on the dyno graph is due to other differences. Slight update to the cam profile, slightly different conditions, etc. etc.

b19coupe

I had heard about the use of different materials for camshafts having produced different power results, but I find it very hard to believe that you can gain 8 ft-lbs. of torque and 13 HP just by changing the material in the camshaft blanks. There is something else going on.

D-Rob

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">I had heard about the use of different materials for camshafts having produced different power results, but I find it very hard to believe that you can gain 8 ft-lbs. of torque and 13 HP just by changing the material in the camshaft blanks. There is something else going on.</TD></TR></TABLE>

Agreed.

I notice that run conditions are not listed on the dyno sheet...?

MJ23FE

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">I read the thread, and I didn't see claims of more power just due to the material. </TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by edo &raquo;</TD></TR><TR><TD CLASS="quote">8620 is the preferred material for roller rocker valvetrain because of its strength, consistency and deflection resistance capacity. It has the potential to outperform the ductile iron cores. It isn't anything new, aftermarket V8 roller cam makers use nothing else.
-Ron</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">What exactly is:
deflection resistance capacity
</TD></TR></TABLE>
From what I gather, the more resistance to deflection there is, the less the cam loses shape as it rotates and hits the valves. The profile stays more true, and you lose less power due to deflection. I am by no means an expert at all, just posting what I think deflection resistence is and what I think the reason is for the power increase. Correct me if I am wrong.

I do not know if edo will be on here to further explain this, I don't expect him to be.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">It sounded to me that the reason for the material is fewer rejects in manufacturing (vs. the cast cores), and no limitation in cam profiles for race applications.</TD></TR></TABLE>
The rest of your reasons were correct, except he has not changed the profile of the cams, and his tests have always been performed in a way to minimize discrepancy as much as possible.

-Jalal


Modified by MJ23FE at 10:43 AM 1/16/2007

mar778c

iTrader: (1)

The newer material has less contact resistance which lowers both mechanical and thermodynamic power losses.

9~10 additional whp may be a little high but it is hard to agrue with results

mgags7

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D-Rob &raquo;</TD></TR><TR><TD CLASS="quote">

Agreed.

I notice that run conditions are not listed on the dyno sheet...?</TD></TR></TABLE>

Agreed. Run conditions.

I'm sure there is some validity to what edo is saying, but keep in mind flyrod isn't babbling some kinda BS, he knows his ME. When he said ALL steels virtually have the same modulus he is saying that there is no reason that one steel would deflect more than another if the shape were kept constant.

Flyrod, I somewhat question that though....since the young's modulus for different elements is, of course, different, how could the material used not affect the yield strength of the part?

Aquafina

iTrader: (3)

Interesting.

WHITFIELD-TUNED

does this perhaps have something to do with rotating mass?? are the materials density similar?

GSRCRXsi

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bb4ever &raquo;</TD></TR><TR><TD CLASS="quote">
Flyrod, I somewhat question that though....since the young's modulus for different elements is, of course, different, how could the material used not affect the yield strength of the part?</TD></TR></TABLE>

im not quite sure what you are asking, but ill attempt to answer. maybe some re-wording is in order to make the question more clear. but it seems the answer is quite simple, the material used WILL affect yeild strength, as different materials will yeild differently. however the yeild strength doesnt correlate with the modulus of elasticity. ie, you can have 2 different materials with the same modulus that have different yeild strengths.

0VtecKiDD

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">I had heard about the use of different materials for camshafts having produced different power results, but I find it very hard to believe that you can gain 8 ft-lbs. of torque and 13 HP just by changing the material in the camshaft blanks. There is something else going on.</TD></TR></TABLE>

even more interesting is the timing of the posting of this graph, just DAYS before my Skunk2 Stage 2 vs IPS K2 showoff............

MJ23FE

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VtecKiDD &raquo;</TD></TR><TR><TD CLASS="quote">

even more interesting is the timing of the posting of this graph, just DAYS before my Skunk2 Stage 2 vs IPS K2 showoff............</TD></TR></TABLE>
We could say the same about Skunk2 considering ductile iron is no longer the standard material used for IPS cams.

That whole situation is just taking away from the discussion at hand, so lets please keep this on topic.

Thanks dude!

-Jalal

0VtecKiDD

thanks for the dyno, i question the timing of it as im sure you get what im hinting at.

nice numbers regardless

b19coupe

I talked to a couple of people in the know, and the theory behind the power gains/losses is based on camshaft twist. Apparently the ductile iron cams (this includes stock cams) have a tendency to twist, thus the cam timing on #4 cylinder is not what it should be. #3 is affected to a lesser degree, #2 even less, and #1 is basically where it should be. That is the theory. I am still not convinced, but it is interesting.

DonF

Was that the high or low carbon content 8620? Cast Iron is actually 'stiffer" than 8620 billet material, If it were twisting ( changing cam timing) it would break sooner, steel (8620) has a higher elasticity.

mgags7

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSRCRXsi &raquo;</TD></TR><TR><TD CLASS="quote">

im not quite sure what you are asking, but ill attempt to answer. maybe some re-wording is in order to make the question more clear. but it seems the answer is quite simple, the material used WILL affect yeild strength, as different materials will yeild differently. however the yeild strength doesnt correlate with the modulus of elasticity. ie, you can have 2 different materials with the same modulus that have different yeild strengths.</TD></TR></TABLE>

Understood. What I said was a mix of a quick wikipedia read and what flyrod said. Thanks for explaining it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">I talked to a couple of people in the know, and the theory behind the power gains/losses is based on camshaft twist. Apparently the ductile iron cams (this includes stock cams) have a tendency to twist, thus the cam timing on #4 cylinder is not what it should be. #3 is affected to a lesser degree, #2 even less, and #1 is basically where it should be. That is the theory. I am still not convinced, but it is interesting.</TD></TR></TABLE>

Good point

Rocket

Does this also apply to 8620 steel cylinders v. ductile iron cylinders?

Rocket

The answer is supposed to be that 8620 steel can be heat-treated to a thru hardness above that of ductile iron. This gives the 8620 billet a higher resistance to the roller digging a tract into the lobe. So theoretically a 8620 billet that does not have a tract dug into it from the roller will perform better than a ductile iron cam whose lobes have roller tracts dug into it.

But what do I know about cams?

Where's my happy meal?

Scott_Tucker

Ron says, "It has the potential to outperform the ductile iron cores."

but what does that mean? Performance of a part can mean a number of things. It could mean it makes more power. or it could mean it lasts longer, among other things. I would lean towards the latter because, as someone said, the modulus of elasticity is nearly the same for all steels (at least in shear as this would be). It's not going to have less friction because it's a roller cam. There is no sliding action to make more friction. If it were not a roller cam I could see a possible benefit. On a non-roller cam you have to be careful with the material you make the cam out of because if it is not compatible with the material the rockers are made out of you could have a flat cam pretty quick.