Which type/size headers do I need?

[Vipersix]

I always hate sidetracking on other people's threads, but here goes anyway!

1. The 'Custom Cam Guy' I am talking about isn't sitting in a factory somewhere. He is THE guy who designed the cam to work with THAT set of parts.
He is THE guy who set that combo together.

This is the same guy I am referring to. He sits in a factory and dreams up cam grinds based on popular and/or average parts on the market. In addition, he is able to grind a cam based on the parts on your particular motor. I don't think we are disagreeing with this point.

2. Nothing personal, I am sure you are a smart guy...
But, a true 'Custom Cam Guy' would pick a better cam for your motor than you would.

If you'll notice, not once did I claim that I can pick a better cam than the cam guy. In fact, I'm pretty stupid when it comes to cams and wouldn't even know where to begin! I've got the basic theory of cam operation down but I would bet that if I designed a cam for my engine, it wouldn't run at best and push the valves into the pistons at worst.

What I am contending, is that I have the ability to take the entire combo AFTER I receive my new custom grind cam and design an exhaust system around it. Better so than the cam guy. Of course, the only reason I am able to do so is because the cam guy was nice enough to provide me the numbers necessary to plug into the various formulas in order to determine said exhaust numbers.

But as we also agreed earlier, most people 1) don't care 2) don't have the time 3) don't have the need to put very much effort into a tuned exhaust system.

Cheers!

 

[vristang]

I always hate sidetracking on other people's threads, but here goes anyway!

No worries... he hasn't been back anyway...

This is the same guy I am referring to. He sits in a factory and dreams up cam grinds based on popular and/or average parts on the market. In addition, he is able to grind a cam based on the parts on your particular motor. I don't think we are disagreeing with this point.

I am actually disagreeing with who you consider the 'custom cam guy'... that is all.
There are MANY guys answering phones, who can spec out a "custom" cam for you.
I'm talking about calling Jay Allen (or the like), filling out a buildsheet (which can be found on his site if you're interested), and recieving a cam purpose cut for your collection of parts.

If you'll notice, not once did I claim that I can pick a better cam than the cam guy.

That isn't the point I was trying to make...

What I am contending, is that I have the ability to take the entire combo AFTER I receive my new custom grind cam and design an exhaust system around it. Better so than the cam guy. Of course, the only reason I am able to do so is because the cam guy was nice enough to provide me the numbers necessary to plug into the various formulas in order to determine said exhaust numbers.

How is the cam guy going to decide what the exhaust valve events should be, without having any idea of what the exhaust will be?
The answer is he wouldn't... so the cam guy would at least ROUGH OUT what headers would work best.
When you got off the phone with your cam guy, you would KNOW what primary diameter to start with, and have a solid starting point for primary length

I agree, if you dork around with primary lengths over the OOTB headers, you could most likely find some power.
What you don't seem to even acknowledge is that the cam guy has already done the vast majority of that work... You are all ready to run off and cut your custom length primaries, when most likely you just need to pick up the phone and ask the cam guy for a little pointer in the right direction.

Again...
Who on this site has tuned the length of their primaries?????
(so why even bring it up )



And BTW...
If ANY of the Custom Cam guys (Jay, Ed, etc.) heard you say that you could do a better job than them by using your little exhaust equations




The point is,
The OP has a custom cam and he is here asking random yahoos (no offense intended) how to get the best performance out of it.
Unless the cam was designed by a phone jockie, then the ONLY person who can answer the OP's question with any certainty is the man who designed the cam. Period.
If the cam WAS designed by a phone jockie, then all bets are off until all of the valve events get revealed.

jason

 

[Vipersix]

Sorry, I have to do it...


I think I understand where we are disagreeing and I believe it has more to do with internal combustion theory than anything else. You mention that the cam guy (never heard of this Jay character, but there are certainly numerous borderline-genius guys out there) needs to have a rough idea of the exhaust system in order to work out EVO timing. I most certainly agree. However, the actual exhaust will be the last item to be added to the vehicle and there is no possible way for the cam guy to know the needed lengths based on theoretical effects of his cam on that particular engine.

For example, you and I could build two identical motors using the same parts from ground up and I will guarantee you that they will not produce identical power outputs. This is what makes racing such a competitive sport. There are so many additional ways to massage a few horses out of a motor that a technician simply has no way to tune an exhaust to an engine unless he has that motor in front of him. He most certainly is able to suggest options and approximations as I have done, but tuning is done on the vehicle as you have already mentioned.

You give me too much credit. My "little exhaust equations" are elaborate beyond my understanding and not technically mine. And I will stick with my original assertion: I will do a better job of tuning the exhaust on my motor than anyone else for one simple reason if nothing else, I am in possession of it.

Oh, and I have tuned the length of my entire exhaust (the primaries are just one small portion of the system) system to my motor. Nice to meet you.

And in closing... the quality of the yahoos on here is pretty abysmal (no offense). So the likelihood of this particular guy having a "custom" cam is low. For most people, the cam is the second or third part they change. I think you'll agree with me that this singular event proves the level of competence in the atmosphere. (Not to say I'm any particular genius. But I like to think I know how to do my homework and get professional assistance.)

Then again, maybe I'm just addicted to debate...

 

[vristang]

(never heard of this Jay character, but there are certainly numerous borderline-genius guys out there)

Camshaft Innovations - Home
just in case you would like to acquaint yourself...

But that's enough of that, as surely a couple of guys here are calling me leg-humper right now


Good for you,
You 'tuned' your exhaust... more power to you...


My only point has been that the OP needs to contact his cam grinder. It is foolish not too...

I'm done,
jason