Cylinder head/airflow... the math

[travis]

I’ve been digging through old posts looking for info, but it is widely scattered and you have to dig through a lot of irrelevant info to find it. I’m looking to compile a bunch of info in one spot.

What I am looking for in general is cylinder head math...the formulas and equations the you guys use to figure/calculate things like port sizes, HP/rpm peaks, etc...pretty much anything. In particular, I’ve seen a lot of old posts where someone will give a ports pushrod pinch area and someone will respond with something like “it will potentially make X horsepower at Y rpms before it chokes”. How do you figure that? Anything relevant you can throw into the pot would be appreciated.

I’m not looking to become a professional level head porter, but I do want to up my game a bit. I’m looking at getting some sort of flow bench in the near future.

[B Original]

Here is a start http://www.wallaceracing.com/Calculators.htm

[pastry_chef]

Others:

http://users.erols.com/srweiss/calcplv.htm

http://users.erols.com/srweiss/calcfps.htm

http://users.erols.com/srweiss/calcacsa.htm

[steve cowan]

harold bettes 001.JPG

Travis,
Harolds book is one of the best books i have ever read you should purchase a copy.
i suggest you have a look at Chad Speier's website
go to main web page
click on to MORE on the right side of the screen
will show -SHR hand porting info
manifold lengths
formula sites
head size info
these are only starting points,you will read alot of freaky engines that make amazing power and torque with small CSA and smallish cams etc,at our level (novice) we have to be very careful not to get ahead of ourselves,if you are serious about purchasing a flow bench make sure you have plenty of spare time and there is a bit of money to spend to get set up.
it is very exciting to do the testing but be sceptical with your testing and re-test to confirm your findings,i applaude people who do cylinder head work for a living or even a hobby as it is tough work to grind on heads and manifolds etc,
i will admit it is time consuming to go through old posts but i still think there is amazing information to be found,i hope i have helped a bit,
thanks

[midnightbluS10]

Another to possibly get would be Performance Automotive Engine Math by John Baechtel. I haven't personally read it but I'm sure there are plenty in there since that's all it's about.

[steve cowan]

midnight,
i have that book as well
it is excellent,great book thanks for posting that one

[V Remian]

An oldie but goodie- https://www.speed-talk.com/forum/viewtopic.php?t=840

[V Remian]

Another-https://www.speed-talk.com/forum/viewtopic.php?f=1&t=771er-

[V Remian]

One more for tonight, and it comes with a spreadsheet at the bottom of page 9.
viewtopic.php?f=15&t=37049

[digger]

Pipemax

[travis]

Thanks guys...looks like I have a lot of reading to do! And I hadn’t been on the Wallace Racing site in years...looks like it has expanded a lot!

[groberts101]

An oldie but goodie- https://www.speed-talk.com/forum/viewtopic.php?t=840

Not sure how I missed that one! Thank you, and Larry of course, for sharing that. Wish I knew even 1/10 of the things that guy has forgotten through the years. Very gracious contributor as well... highly commendable.

[maxracesoftware]

An oldie but goodie- https://www.speed-talk.com/forum/viewtopic.php?t=840

Not sure how I missed that one! Thank you, and Larry of course, for sharing that. Wish I knew even 1/10 of the things that guy has forgotten through the years. Very gracious contributor as well... highly commendable.

groberts101 , thanks, hopefully i can continue to Post a lot more detailed information from Flowbench + Dyno tests + Dragstrip tests

[Warp Speed]

An oldie but goodie- https://www.speed-talk.com/forum/viewtopic.php?t=840

Not sure how I missed that one! Thank you, and Larry of course, for sharing that. Wish I knew even 1/10 of the things that guy has forgotten through the years. Very gracious contributor as well... highly commendable.

groberts101 , thanks, hopefully i can continue to Post a lot more detailed information from Flowbench + Dyno tests + Dragstrip tests

I certainly hope you do!
Thanks!

[swampbuggy]

Man i will 2nd that Warpspeed, it is unbelievable how much time Larry gives to this forum!!!