airflow Information

Walline · Post by **Walline** » Fri Apr 30, 2004 12:30 am

I am a 28 year old Ford senior master tech, but I love to study and build race engines! I am going crazy trying to find good info! I can not stop thinking about Engines and HP. I have Don's winston cup book, and many of Vizards books but I am looking for good cylinder head info. Like how to figure cross section and how to calculate airspeed. I am going to buy a flow bench soon, and want to start studying! THANKS EVERYONE!!

speedtalk · Post by **speedtalk** » Fri Apr 30, 2004 8:02 am

Thanks for joining the forum.

1) Hang out on this forum - there are a few head porters
2) Buy a Flowbench as soon as possible - nothing will beat experience

Check out this thread:
viewtopic.php?t=155

Are you going to specialize in certain heads?

SW · Post by SW » Fri Apr 30, 2004 12:29 pm

Hi,
i know your probably a ford guy, but you should read "how to build and modify chevy small block cylinder heads" by david vizard. It is a huge wealth of info. that applies to all heads.
Shawn

Denzil · Post by **Denzil** » Fri Apr 30, 2004 12:54 pm

I don't agree with Vizard on everything, but I have really enjoyed his books.

I have a half finished flowbench sitting in my garage waiting for us to get back to work on it. I suppose I should brush off the dust and get at it again.

speedtalk · Post by **speedtalk** » Fri Apr 30, 2004 1:09 pm

Hey Denzil, Let's see some pics.

Walline · Post by **Walline** » Fri Apr 30, 2004 4:43 pm

I have, or should say had david cylinder head book, but loaned it out, never to be seen again. I work on Fords, but race Chevys. Has anyone messed around with protopline heads? I ran a set of 235s last year and want to mess with them as soon as I get a bench!

SW · Post by SW » Fri Apr 30, 2004 6:00 pm

I'm in the process of building my own bench, too. The SF600 just isn't cutting it anymore for some of the things I want to try. Those pro topline heads a pretty good. What kind of motor is it? What are you using it for?They are a pretty big head out of the box, so you really have to watch the cross-sectional or you'll get it to big, making the motor really lazy.
Shawn

Walline · Post by **Walline** » Sat May 01, 2004 9:10 am

My motor is a 406 14.23:1 compression, solid roller cam, (266 272 .675 .633 on 112) cheap proffesional products intake, similar to super victor. I run the motor in a heads up, with true radial tires in a 3300lb car, TH400 and 2300 stall speed and 4.56gear. The car has went 11.03 @132MPH not catching the tire until 880. I was very worried about the heads being too large also, but here is something I would like someone to coment on. I had a holley 950Hp and the car would pull off the boosters by just tipping the throttle off idle in netrual and load up! At full throttle it would be ok. It seemed to have a very strong booster. I swiched to a 1050 dominator, and the car picked up e.t and MPH, about 6MPH and would pull up to 7600RPM. With the 950Hp I would shift about 6800RPM. Just wondering what people thoughts are. I wonder what it would run like with the smaller 220cc heads? THe motor does not act like the heads are to large. Throttle response is very good even below 2500RPM.

speedtalk · Post by **speedtalk** » Sat May 01, 2004 3:48 pm

Walline wrote:I run the motor in a heads up, with true radial tires

Now that would be a challange.
I think your dominator test shows what you need to do - kill the bottom.

SW · Post by SW » Mon May 03, 2004 4:46 pm

That sounds like a really good combo. I think that is the correct head on their now. A lot of people (obviously not you) think that they need to put that head on their 9.0-1 hydraulic cammed daily driver, and wonder why it feels so lazy.With that head the smallest area is at the pushrod. I would try to keep that are about 2.6 to 2.7 sq.in. This will keep velocity up. You have to watch that you don't poke a hole in it. With this dimension that area gets pretty thin.As always, the short turn can use a little work, but I wouldn't touch it unless you have a bench to check your results while your doing it.
One thing you might try on your car is a timing computer. We do a bunch of that street car stuff and to get the cars to run harder on the bottom end we pull timing out to soften them up, then roll it back in further down track when you can hook it up.
Shawn

speedtalk · Post by **speedtalk** » Mon May 03, 2004 7:21 pm

SW wrote:we pull timing out to soften them up, then roll it back in further down track when you can hook it up.

Is this legal? I thought they were treating it like traction control.

SW · Post by SW » Mon May 03, 2004 7:51 pm

It's not anything that elaborate.It doesn't have wheel speed sensors or anything.As far as I know, almost all drag classes will let you have timing controls, but not anything that is tied to any wheel speed sensors or motor acceleration.This is pre-programmed to start the timing at a predetermined place and then change it at a certain time interval. For example, one car we run we pull about 12 degrees out at launch and put it back in at about 2.0 seconds into the run.

Shawn

speedtalk · Post by **speedtalk** » Mon May 03, 2004 9:34 pm

Hey Shawn, can you post a link to the computer you use?

SW · Post by SW » Mon May 03, 2004 10:13 pm

sure, here it is-

http://www.msdignition.com/

go to products,timing controls,then multi-function ignition controler.
this is the box that will adapt to almost any msd box, or the digital 7 i think contains most everything this box does
Shawn

Walline · Post by **Walline** » Mon May 03, 2004 10:35 pm

I thought about running the MSD with slew rate, but decided to wait. My car is still cometetive, and I would rather the class be a drivers race. As far as pulling timming out at launch, I do about ten degrees. This is my first high compression motor and do not want to cook it. Am I wrong in my thinking? Exhaust temp to high? Thoughts?

Don Terrill’s Speed-Talk

airflow Information

airflow Information

Head Porting - Flowbench

Slew rate MSD