Using Blair to spec a Cam

[statsystems]

Am I the only one with blurred writing on Hoffmans post? I can barely read it. Might be time for a trip to the eye doctor if you all can read it clearly.

[hoffman900]

Am I the only one with blurred writing on Hoffmans post? I can barely read it. Might be time for a trip to the eye doctor if you all can read it clearly.

Can you take a screenshot? It looks fine on my end.

[RevTheory]

Am I the only one with blurred writing on Hoffmans post? I can barely read it. Might be time for a trip to the eye doctor if you all can read it clearly.

Not just you. I thought it was just my vino

So how do you spec a cam for a 10.5:1, 6,500 rpm, 383 SBC with AFR 195 heads and an Air Gap style intake using Blair's formulae? Leave the car out of it just to simplify things.

No sarcasm intended; I'm genuinely interested.

[Stan Weiss]

Bob,
My software is not an Engine Simulation program it is more like a Swiss Arm Knife.

I can read in a cam file and produce these stats.

Intake BTDC (IVO to TDC) =
Intake Pumping (TDC to BDC) =
Intake Ramming (BDC to IVC) =
Intake Overlap (IVO to EVC) =

Exhaust Blow-Down (EVO to BDC) =
Exhaust Pumping (BDC to TDC) =
Exhaust ATDC (TDC to EVC) =
Exhaust Overlap (IVO to EVC) =

I can adjust RPM, rocker arm ratio, advance / retard, open / close LSA.

What I was looking to do with this thread was take the output from Blair's calculation and work backwards to cam events.

Stan

PS Yes Your second post is out of focus.

[statsystems]

Am I the only one with blurred writing on Hoffmans post? I can barely read it. Might be time for a trip to the eye doctor if you all can read it clearly.

Not just you. I thought it was just my vino

So how do you spec a cam for a 10.5:1, 6,500 rpm, 383 SBC with AFR 195 heads and an Air Gap style intake using Blair's formulae? Leave the car out of it just to simplify things.

No sarcasm intended; I'm genuinely interested.

I wondered if I can't see it. I know it's foggy without my glasses. Still foggy with it. I'll be calling the optometrist Monday dammit.

[hoffman900]

The image I posted is a little out of focus, but I can read it just fine still. Hmm...

[Warp Speed]

The image I posted is a little out of focus, but I can read it just fine still. Hmm...

Yep, little blurry, but still, VERY useful!
I don't understand allot of Blaires stuff, and it takes multiple reads to get through my noggin, but this is where the next step begins!

[statsystems]

The image I posted is a little out of focus, but I can read it just fine still. Hmm...

It's me. My wife can read it. Damn.

[SchmidtMotorWorks]

One big decision that should be made early on is whether to graph the valve motion or not, like the graphs shown above.

For a beginner, that is a bit steep of a task to code, even if you use an existing code like Zed-graph. It definitely makes it cooler.

In any software project, the thing that most often determines the difference between success and failure is a good list of requirements for what the software will do. Then work exactly to that plan and resist adding things to the plan as you go along (that is called scope creep), I have seen that wreck more projects than anything else, even with programmers with 30 years experience at top-notch companies.

Have to be careful because adding too many challenges might stall some people, it all depends on how hard they are willing to try.

When considering that question, I will say, that learning to code, takes a lot of mystery out of how software works and gives you a huge toolbox of ways to solve problems and earn money.

[SchmidtMotorWorks]

I will suggest Visual Studio C#
You can get Visual Studio community for free here:

https://www.visualstudio.com/free-developer-offers/

[pastry_chef]

What I was looking to do with this thread was take the output from Blair's calculation and work backwards to cam events.

That would be awesome!
I'm not a programmer and I'm not sure how well I understand these values.

Brute force might be one way.. have a database of 10 to 20 cam files.
Set an algorithm to strategically hunt and sort through all the calculated values.
Then output in a table highlighting the most accurate hits for each segment target.

[Stan Weiss]

Jon,
I am not sure what your last two posts are for.

Just a little background.

I have been programming since the late '60's

I wrote my own graphing routine 25 or so years ago (MS-DOS). It has come a long ways of the years.

The mission statement was "What I was looking to do with this thread was take the output from Blair's calculation and work backwards to cam events." Let add hopefully in away the readers of this thread can duplicate.

Stan

[SchmidtMotorWorks]

Jon,
I am not sure what your last two posts are for.

Just a little background.

I have been programming since the late '60's

I wrote my own graphing routine 25 or so years ago (MS-DOS). It has come a long ways of the years.

The mission statement was "What I was looking to do with this thread was take the output from Blair's calculation and work backwards to cam events." Let add hopefully in away the readers of this thread can duplicate.

Stan

My point is that if they are going to duplicate it, you and they will need to choose a language.
You mentioned pre .net VB, I'm thinking that if people are going to get started as beginners they should use a modern language and environment.
That way they are learning skills that can be carried forward.

Also wanted to urge people not to push for scope creep.

[digger]

Paging Vannik to the courtesy phone...

Neels does caution that the STA values are rough guidelines, which help "creating a new engine or when analyzing an existing engine".

Jon's Camflowrpm did some of this, but was a bit less sophisticated. With Neel's you adjust the BMEP and RPM and import a measured (ideal) or simulated (ideally to every 1*) valve lift profile.

what program is that? 4sthead?

[SchmidtMotorWorks]

Paging Vannik to the courtesy phone...

Neels does caution that the STA values are rough guidelines, which help "creating a new engine or when analyzing an existing engine".

Jon's Camflowrpm did some of this, but was a bit less sophisticated. With Neel's you adjust the BMEP and RPM and import a measured (ideal) or simulated (ideally to every 1*) valve lift profile.

what program is that? 4sthead?

EngMod4T,

This is the 1D software that is both affordable and very capable.

Vannik posts in Advanced

http://vannik.co.za/