Why don't 1.6 arms work on SBC exhaust.Attn.Big Joe

[CamKing]

Current technology Pro-Stocks are 55-60%.so are many other high HP per cu.in.racing engines.find the right balance of air flow,port size,crosssection,air speed and cam timing its a balancing act ,many hours of R&D

And the exhaust duration is 23-30 degrees longer then the intake.
Pro Stock is as advanced as it is because of the influx of NASCAR cam and port design technology.
The Exhaust flow is very important in cam design, and any top cam designer will tell you this.
When you start working on top class racing like Pro Stock, Indy Car, and NASCAR, where you have a lot more restrictive rules, and the engines need to be extremely efficient, you really see where tuning the exhaust comes into effect. It's something that escapes the "throw a bigger cam in it" mentality of most drag race engine builders.

[3V Performance]

Current technology Pro-Stocks are 55-60%.so are many other high HP per cu.in.racing engines.find the right balance of air flow,port size,crosssection,air speed and cam timing its a balancing act ,many hours of R&D

And the exhaust duration is 23-30 degrees longer then the intake.
Pro Stock is as advanced as it is because of the influx of NASCAR cam and port design technology.
The Exhaust flow is very important in cam design, and any top cam designer will tell you this.
When you start working on top class racing like Pro Stock, Indy Car, and NASCAR, where you have a lot more restrictive rules, and the engines need to be extremely efficient, you really see where tuning the exhaust comes into effect. It's something that escapes the "throw a bigger cam in it" mentality of most drag race engine builders.

I think the key word here is efficient. Peak number are good for bragging and efficient numbers are for racing.

[SStrokerAce]

Current technology Pro-Stocks are 55-60%.so are many other high HP per cu.in.racing engines.

Is that intentional, or just the result of putting more importance on the intake?

Randy

That's due to the limit of the bore centers, which limits the bore size, which in turn limits the amount of valve you can put in the motor and at a low 90% throat to valve diameter relationship limits the amount of air you can get into the motor!

The exhaust valve is secondary to importance on getting a larger intake valve throat in the heads so you can turn the motor harder.

Bret

[bigjoe1]

And that is the way it is in real world too


JOE SHERMAN RACING

[SStrokerAce]

And that is the way it is in real world too

Only if you have more RPM and cubes than your throat size can handle and in drag racing most times that's the key more cubes and RPM.

Now in motors that are lower RPM or cube limited I go by some other rules.

Bret

[randy331]

Now in motors that are lower RPM or cube limited I go by some other rules.

Those rules would be?


Randy

[SStrokerAce]

Now in motors that are lower RPM or cube limited I go by some other rules.

Those rules would be?


Randy

Well that's the secret

[randy331]

Now in motors that are lower RPM or cube limited I go by some other rules.

Those rules would be?


Randy

Well that's the secret

I guess you didn't read what you agreeded to when joining speed talk.
You see in the fine print it says ALL questions asked by Randy331, must be answered with complete honesty, with all details, or your membership will be terminated!!

Randy

[3V Performance]

Those rules would be?


Randy

Well that's the secret

I guess you didn't read what you agreeded to when joining speed talk.
You see in the fine print it says ALL questions asked by Randy331, must be answered with complete honesty, with all details, or your membership will be terminated!!

Randy