[eschaider]

This kind of dialog is particularly unhelpful for the OP and most readers. That said, if this is what you want, let's explore a bit …

You said:

Originally Posted by Buddy Rawls

optimizing A/F has nothing to do flow parameter imbalances. optimizing A/F cylinder to cylinder is a compensation for those flow imbalances. You cannot improve flow of a motor by A/F compensation. it doesnt work that way. You are simply tuning the motor cylinder to cylinder, compensating for those for those differences cylinder to cylinder.

I don’t believe I said what you are taking issue with. That said, for the most part, what you are saying is correct.

In your post #36, in response to my post #35 you stated,

Originally Posted by Buddy Rawls

that has zero to do with the airflow thru the motor. runner differences and flow parameters are a flow issue, not a fuel and air matching to compensation. you are talking about tailoring cylinder to cylinder A/F needs as a swap for flow differences. thats not a swap, thats a compensation to the flow differences.

I was attempting to address a corrective solution for the OP, who was concerned about air charge differences between cylinders with differing intake ports and whether a creative cam design might help. The direct solution remains the correction of the (mass) air flow problem, which is the varying Intake runner size and length. The solution is achieved by using an intake that has identical inlet runners — like the one in the picture. Multi-pattern, multi-lift, and/or LSA cams do not correct for a bad intake runner design.

Once you make all the intake runners the same, you now need to equalize the fuel delivery to the cylinders. The easiest way to do that is with an EFI, which supports individual cylinder fueling control, and an EGT thermocouple at each exhaust port to measure exhaust temperatures under load. The EGT sensors are necessary because of variations in injector flow behavior (which can sometimes be significant) The EGT sensors allow for a significantly more precise calibration.

Originally Posted by Buddy Rawls

Ok, I see your issue. You wrote "If you accept the premise that individual (mass) air flows for cylinders of the same volume, vary in relation to intake runner size and volume, then obviously, making all intake runners the same shape and length eliminates the variable and the differentiation."

I have consistently found that reading words will significantly improve messaging, especially if the reader can understand the words.

Originally Posted by Buddy Rawls

yes, that fixes the situation of needing different lobes by cylinder. But that is not the question. The question was, if differing lobes for the cylinders for a single plane intake manifold design a snake oil concept? The differing lobes on one cylinder to the next is used to compensate for flow parameter differences. When the question is about the reasoning for a multi pattern cam within its design parameter, ie the typical single plane manifold, your answer is, if it had an IR manifold it wouldn’t need such a cam. You’re basically agreeing that different flow cylinder to cylinder can benefit from a cam that address cylinder to cylinder differences.

Snake oil can be relative, which is why process understanding is important here. The question was soliciting a yes or no opinion on a snake oil labeling for cams that use multiple profile cylinder by cylinder architectures/designs.

The significant issue here is that the lobe gymnastics do not fix the problem of differing power delivery from different cylinders. The OP accurately identified the phenomenon as resulting from varying cylinder-to-cylinder inlet manifold passage flow dynamics. If the problem is optimizing and normalizing cylinder power, the solution is absolutely not multi-profile cams.

So is the multi-profile cam snake oil? The answer is indeterminate without additional conditions and specifics. In particular, as you identified, if the manifold is not changeable (for class rules reasons). In that case, the multi-profile cam, might, be helpful. Most tests have shown the improvement to be at the noise level and very often inside the widow of repeatability (margin of error) for an inertia or water brake dyno. Sort of begs the question, why are we wasting money and time?

Let’s say the manifold is not mandated and is, in fact, changeable — sort of like on our cars and the OP’s car. Now, if we want to positively correct for the differing cylinder power levels that are being impacted by the differing (mass) air flows, we simply acquire the pictured manifold or a similar manifold. That intake manifold, along with a single or dual pattern cam suited to the engine and the car, will address the problem the OP was originally thinking about corrective measures for.

Back to the universal truths, two cylinders with the same charges of fuel and air, same c/r, same ignition will always produce the same power output, assuming the same fuel. Similarly, two cylinders with the same charges of fuel but differing weights of air, even with the same c/r, same ignition, etc., will always produce a different power output using the same fuel. It is inescapable!

Originally Posted by Buddy Rawls

If this was a class motor that had specific rules for intake manifolds, the answer is not use a different manifold. So is it snake oil? No it’s not. But if you go with an OTS camshaft that may not respond to the actual motors’ flow differences it’s junk.

Yes, it is snake oil! The improvement is down below the margin of error on virtually any inertia or water brake dyno. If the problem is important enough to the car owner to go chasing after it (I think it is foolishness), then the solution is identical inlet runners, EFI, individual cylinder fuel control, and EGT sensors. You will absolutely solve the cylinder-to-cylinder power level differences and spend a lot of money. You will also discover that the bang for the buck spent would have been much better had you gone to a driving school and diligently learned what the school instructor was attempting to teach about driving a road race car.