How to develop cam specs

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SchmidtMotorWorks
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How to develop cam specs

Post by SchmidtMotorWorks » Fri May 18, 2018 12:19 am

(actually most major dimensions)

1. Get a 1 D software and learn how to use it.

2. Design the best engine you can based on where the 1D software leads you

3. Build an engine based on #2

4. Plan a dyno session with the variety of parts that you can afford to test.
a. Cams
b. Cam index
c. Intake manifolds
d. Headers
Note, make the tests with both single-part changes and reasonable matching sets of parts.

5. Make 1D models for each combination planned in #4

6. Dyno test to the plan in #4:

7. Compare the dyno results to what the 1D models predicted

8. Understand the "simulationisms" (how the tests vary from the simulation)

Repeat steps 2-8 until you are satisfied.
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Re: How to develop cam specs

Post by Headguy » Fri May 18, 2018 12:27 am

Or open the catalog, look at the bottom of the page. Go up two cams from the bottom. 50% of the time it works every time.

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Re: How to develop cam specs

Post by SchmidtMotorWorks » Fri May 18, 2018 12:30 am

And just in case any of you think you are too old to use a computer for engine development or you know better.
The most experienced person alive working in engine development that I know of; Hans Herman, does 1D engine simulation as a consultant job for leading OEMs and race teams all over the world.

You can get some other information about projects he worked on at Stewart VanDynes shop.
http://www.vandyneengineering.com/c.htm
http://www.schmidtmotorworks.com Aerospace Machine Work: Prototypes, Tooling, Molds.

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Re: How to develop cam specs

Post by Headguy » Fri May 18, 2018 12:43 am

SchmidtMotorWorks wrote:
Fri May 18, 2018 12:30 am
And just in case any of you think you are too old to use a computer for engine development or you know better.
The most experienced person alive working in engine development that I know of; Hans Herman, does 1D engine simulation as a consultant job for leading OEMs and race teams all over the world.

You can get some other information about projects he worked on at Stewart VanDynes shop.
http://www.vandyneengineering.com/c.htm
Bottom line is a computer will get you close. ACTUAL TESTING will get you the best. DYNO AND TRACK.

And in my opinion a dumbed down formula is pissing in the wind. better off calling a cam company.

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Re: How to develop cam specs

Post by GARY C » Fri May 18, 2018 12:44 am

FYI thats a cam test!
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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: How to develop cam specs

Post by SchmidtMotorWorks » Fri May 18, 2018 12:50 am

GARY C wrote:
Fri May 18, 2018 12:44 am
FYI thats a cam test!
It is much more, the 1D software points to the next best test to consider with understanding of why, not just cams, all of the parts.

Please try to understand it more thoroughly, this is the standard procedure at better engine development organizations.
The beauty of it is that most people can afford to do it.
A 1D system is a few hundred$ and if they can't afford dyno-time they can measure car performance.
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Re: How to develop cam specs

Post by GARY C » Fri May 18, 2018 12:56 am

SchmidtMotorWorks wrote:
Fri May 18, 2018 12:50 am
GARY C wrote:
Fri May 18, 2018 12:44 am
FYI thats a cam test!
It is much more, the 1D software points to the next best test to consider with understanding of why, not just cams, all of the parts.

Please try to understand it more thoroughly, this is the standard procedure at better engine development organizations.
The beauty of it is that most people can afford to do it.
A 1D system is a few hundred$ and if they can't afford dyno-time they can measure car performance.
So if I lay out a specific engine will you give me the cam specs or cams needed to start the dyno testing?
Please Note!
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: How to develop cam specs

Post by SchmidtMotorWorks » Fri May 18, 2018 1:08 am

GARY C wrote:
Fri May 18, 2018 12:56 am
So if I lay out a specific engine will you give me the cam specs or cams needed to start the dyno testing?
Nope, I am all about motivating learning, try to follow the steps I listed and see what you learn.

Your question tells me you didn't understand my list.
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Re: How to develop cam specs

Post by GARY C » Fri May 18, 2018 1:17 am

SchmidtMotorWorks wrote:
Fri May 18, 2018 1:08 am
GARY C wrote:
Fri May 18, 2018 12:56 am
So if I lay out a specific engine will you give me the cam specs or cams needed to start the dyno testing?
Nope, I am all about motivating learning, try to follow the steps I listed and see what you learn.

Your question tells me you didn't understand my list.
I knew you wouldn't!
What you don't understand is I see simple methods will give you an idea of what range you will need for a cam in a few minutes if the conversation is just theorizing, beyond that I have 3 programs written by people who each have more engine build data than most will ever see and past that I am not above paying people a consultation fee if it is necessary, more times than not they all arrive at the same cam!
Please Note!
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: How to develop cam specs

Post by travis » Fri May 18, 2018 1:34 am

What 1 D software do you recommend for a semi-novice engine builder?

I have Engine Analyser 3.4. Comparing against known builds it is all over the place...sometimes it is close and sometimes it is miles off. It also seems to greatly prefer wide lsa cams for pretty much everything.

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Re: How to develop cam specs

Post by Vincenzo » Fri May 18, 2018 4:43 am

I believe that the majority of members of this forum are V8 engine enthusiasts, so what follows is specifically for their interest.
Any 1D software package has an inherent problem when simulating such an engine - it simulates a static valve lift design, whereas the engine running at the speed of the sim will be experiencing a dynamic valve lift design.
Because there is considerable difference between the two, most notably in a delayed exhaust valve opening, unless this can be effectively made allowance for, the result of the simulation may well be far different when compared to the measured output from a running engine.

This can be very effectively handled by combining the results from program 10 in Blair's software 4StHead, using a feature which enables the user to save a dynamic valve lift file, and then import it into Vannik's EngMod4T software, into the Dat4T section.

Of particular note might be the result from the program 10 in Blair's 4StHead, which are extremely accurate when compared to those from a Spintron for the same engine.

The delayed exhaust valve opening mentioned above, can be as great as 20 crankshaft degrees, and possibly even more. This delay is almost completely absent in a DOHC engine, so in this latter case the dynamic valve lift file is not as important

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Re: How to develop cam specs

Post by Geoff2 » Fri May 18, 2018 6:26 am

There IS a place for this thread, & on this forum; it is called Advanced Engine Tech.

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Re: How to develop cam specs

Post by Warp Speed » Fri May 18, 2018 7:22 am

B Original wrote:
Fri May 18, 2018 7:14 am
Warp Speed wrote:
Fri May 18, 2018 6:53 am
B Original wrote:
Fri May 18, 2018 6:04 am

Jon do you consider yourself a high-functioning sociopath? Or is this an engineers attempt to torment the lesser educated by posting when he gets drunken bored after midnight? An engineering version of a prank phone call lol.

What do you recommend the other 99.76% of us do that don't have your level of Education to understand simulation isms
So what's your deal?
You just like coming on here and insulting someone trying to help?
It seems many in here just want a button to push, instead of trying to understand what really happens in an engine and why.
It ok to disagree, but the above post is a joke, and is exactly what is wrong with this board!
Learn to open your ears more and keep your trap shut, and you might evolve from the "lesser educated" you speak of! :wink:
what Geoff said "
There IS a place for this thread, & on this forum; it is called Advanced Engine Tech." Jon's post is way above the Tech level of this thread.

And please accept my apologies if I have offended you but Your rant could be directed back at yourself when you post you're next condescending comment
You've been here one month and are right in the middle of this underlying deal. I suspect your joining this board had an agenda.....and it obviously wasn't learning. [-X
And you damn sure didnt "offend me", but really dude?!?
And now the defense is this is above engine tech, and should be in the advanced section. This all gets better by the minute. Lol
It's a shame really.

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Re: How to develop cam specs

Post by n2xlr8n » Fri May 18, 2018 7:30 am

Warp Speed wrote:
Fri May 18, 2018 7:22 am
It's a shame really.
It is.

Thanks for your post, Jon.

I'd suggest those fussing at Jon (and DV, for that matter) email Larry Meaux sometime. If you haven't used Pipemax and understand its input/output, you'll be lost.

Asking for help / suggestions comes with the caveat that one doesn't get to raise hell about the provider's response....more than once.
He who is in me is greater than he who is in the world.

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Re: How to develop cam specs

Post by Orr89rocz » Fri May 18, 2018 8:25 am

I basically followed this recipe but no where near ready to test. And to be honest i may just stop after the initial cam selection and dyno/track testing.

I got the free week long trial version of engine analyzer pro. I had pipe max and also got controlled inductions cam software.

I am building a 555 bbc twin turbo street strip deal. I had my previous sbc 401” twin turbo deal as a guide to test the software. I had a cam guy do the cam for that sbc so i plugged in all the known parameters from the build and my exhaust lengths etc. cam software came out fairly close on the cam specs but seemed slightly lower on power output but thats ok.
The engine analyzer seemed to be pretty close to my engines actual performance numbers. I made some corrections to the inputs and outputs to get the numbers to closely match. Rpm and power seemed right. So i felt the software could help with the bbc development

So i plugged in everything i knew on the new motor and ran tons of simulations. Used the cam software to get some good idea of lobe profiles and durations. Pipemax as well to see choke lift and such. All in all, i got some decent looking results and selected a cam. Ordered it up and now just busy building the engine and turbo system. Will dyno na first. Working on headers now

Its not that hard to simulate but you do have to understand a decent amount on engines and such and have alot of measurements. Then look closely at the outputs and really ponder about things. Make one change at a time to see effects

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