Giving a talk on cam selection, and need your input

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Re: Giving a talk on cam selection, and need your input

Post by CamKing » Thu Aug 09, 2018 3:36 pm

JoePorting wrote:
Thu Aug 09, 2018 3:10 pm

How do you use the Effective CSA of a port when selecting a cam?
That's something I will cover. I just need to figure out how in-depth I need to go.
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Re: Giving a talk on cam selection, and need your input

Post by CamKing » Thu Aug 09, 2018 3:39 pm

Great suggestions. Keep um coming.

I'm also going to think of all the situations where I chose the wrong cam for an application, and figure out what was wrong with my thought process at that time, and how I corrected it.
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Re: Giving a talk on cam selection, and need your input

Post by PackardV8 » Thu Aug 09, 2018 3:40 pm

Since EMC has a Vintage category, we have random thoughts from the peanut gallery. The SBC guys already know it all:

1. Why a roller cam is almost always worth the money.
2. When can it use beehive springs and when the profile requires dual cylindrical springs.
3. Why some cam profiles/roller lifters/springs will live on the street and others won't. How to select one which will live. Which ones won't and why.
4. Compare the moldy-oldy profiles with today's best science. What have we learned.
5. What is required to have a custom cam made for a non-catalog engine and what are typical timelines and costs?
6. Do we trust the cam selection function of DynoSim, Pipemax,et al? Why or why not?
7. Then and now, if they don't have a master for a given engine family, some cam grinders will select the closest master on the shelf and say "Close enough." The limits of how this can and can't work.
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Re: Giving a talk on cam selection, and need your input

Post by mekilljoydammit » Thu Aug 09, 2018 3:44 pm

Maybe one of the little things in terms of complexity, but I think an illustration of why it matters tends to be a good thing - examples of moving to profiles that were mechanically kinder with similar performance, increasing performance without breaking parts, etc.

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Re: Giving a talk on cam selection, and need your input

Post by RevTheory » Thu Aug 09, 2018 3:48 pm

CamKing wrote:
Thu Aug 09, 2018 3:39 pm
Great suggestions. Keep um coming.

I'm also going to think of all the situations where I chose the wrong cam for an application, and figure out what was wrong with my thought process at that time, and how I corrected it.
Great idea. That's likely to stir up thought in everyone in attendance.

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Re: Giving a talk on cam selection, and need your input

Post by exhaustgases » Thu Aug 09, 2018 3:53 pm

This one is easy, I'd just say save yourself all the headaches of the technicalities of cam selection and let me do it for you for a fee of course. =D>

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Re: Giving a talk on cam selection, and need your input

Post by BigBro74 » Thu Aug 09, 2018 3:59 pm

RevTheory wrote:
Thu Aug 09, 2018 3:48 pm
CamKing wrote:
Thu Aug 09, 2018 3:39 pm
Great suggestions. Keep um coming.

I'm also going to think of all the situations where I chose the wrong cam for an application, and figure out what was wrong with my thought process at that time, and how I corrected it.
Great idea. That's likely to stir up thought in everyone in attendance.
I agree very good idea- people there will be interested.

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Re: Giving a talk on cam selection, and need your input

Post by ptuomov » Thu Aug 09, 2018 4:04 pm

I’d include stuff on engines that need to be operated on part throttle. For example, how ITBs can run much more valve overlap and still be drivable at part throttle, compared to plenum manifolds.

Another thing is turbo camshaft questions, and how “turbo camshaft” as a concept doesn’t make sense as everything depends on the intake vs. exhaust back pressure.

Finally, there may be people out there who by rules, space requirements, or by choice run exhaust manifolds instead of headers. What cams to run with exhaust manifolds?
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Re: Giving a talk on cam selection, and need your input

Post by GARY C » Thu Aug 09, 2018 4:45 pm

CamKing wrote:
Thu Aug 09, 2018 3:36 pm
JoePorting wrote:
Thu Aug 09, 2018 3:10 pm

How do you use the Effective CSA of a port when selecting a cam?
That's something I will cover. I just need to figure out how in-depth I need to go.
Ask your audience what they would like to know... a Q&A, that way your not spending time covering what they already know.

Lobe family and how you use CSA as mentioned would be 2 good ones.

How lobe profiles effect LSA and how the number on your cam card may not be the what the engine sees.
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBER AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!

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Re: Giving a talk on cam selection, and need your input

Post by steve cowan » Thu Aug 09, 2018 5:49 pm

Mike,
we all know you know your stuff,i agree with Gary C on the Q and A deal so you dont have to wear yourself out on prior prep.
the guys who are competing at the challenge will be super sharp people and conversation with yourself will be nothing short of amazing,good luck and have fun.
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Re: Giving a talk on cam selection, and need your input

Post by pastry_chef » Thu Aug 09, 2018 7:19 pm

Hope there will be a way for us to either see or hear the talk?

Topic suggestion -
Means to calculate / target "pump gas" compatibility?
How does valve overlap play into this for two cams with similar intake closing.
Mike R

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Re: Giving a talk on cam selection, and need your input

Post by Walter R. Malik » Thu Aug 09, 2018 7:41 pm

I would try to describe aggressiveness and the "layman's" difference of accelerations vs. velocity. Where and how these can be used as an advantage and become a disadvantage.
Everyone knows something about the different size duration of a camshaft and at least a little of what that normally does but, now learning how these parameters can make a big difference in the SAME size camshaft would certainly be informative about how to choose one.
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Re: Giving a talk on cam selection, and need your input

Post by 77cruiser » Thu Aug 09, 2018 7:49 pm

Would you use different specs for different styles of headers 4-1 straight collector, 4-1 merge collector, & 4-2-1 headers? Street exhaust vs. open?
Jim

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Re: Giving a talk on cam selection, and need your input

Post by MadBill » Thu Aug 09, 2018 11:45 pm

GARY C wrote:
Thu Aug 09, 2018 4:45 pm
...Ask your audience what they would like to know... a Q&A, that way your not spending time covering what they already know....
How much lead time do you have? Asking the attendees this in advance would be a plus.

PS: My question(s) would be 'On a new-to-you* pushrod application (*valve gear geometry, component weights, etc.), what factors govern/how do you come up with the correct seat and open spring loads for your lobes and does the tolerance of roller cams for higher loads mean that you typically dial in more 'insurance' with them?
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Re: Giving a talk on cam selection, and need your input

Post by blown265 » Thu Aug 09, 2018 11:46 pm

Hi Mike.
Along the same lines as the Q&A suggestion, consider all the questions customers have asked YOU over the years when buying their cam, and use those as a basis for part of the discussion. After all, these questions/answers are what we really need to know to maximise/justify our cam purchase.
Regards
Paul

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