Re: Cylinder head flow - What is crucial in a stocker?
 

Congrads Barry, since you are going to be commitment free, we look forward to seeing you at a lot of events this year putting a spanking on racers from near and far with that bad *** camaro!

Eric

Re: Cylinder head flow - What is crucial in a stocker?
 

Sorry for any confusion. I originally put .07 but like someone said earlier in a post it's 7 tenths you pick up with heads and an intake. I do still stand by my statement if you pick up anywhere near 7 tenths from a good set of heads and intake you better stop going to the lawn mower shop for your machine work. BP Thanks Bill for catching it. Trying to do to many things at the same time.

Re: Cylinder head flow - What is crucial in a stocker?
 

Thanks Eric never thought I would sell it during Covid. Sold it for a little less than it was worth but glad to have it gone.
Most of my years racing I always had to leave late and take phone calls all day while away. Most of the time a friend or two would meet me at my house 6 at night to finish getting my car ready than to load everything and get on the road for midnight. Drive half of the night and hope someone saved me a spot. Get in in the morning and unload the car to rush to make the first time shot. It will be nice to be able to enjoy the races this year. BP

Re: Cylinder head flow - What is crucial in a stocker?
 

Been a while, Bill.

Re: Cylinder head flow - What is crucial in a stocker?
 

I will answer your question: My stocker combination also had .398 lift @ the valve. I dyno tested my engine as it came out of the car 474 HP @ 5400 RPM. I re rung the short block and turned my attention to the heads and intake. I focused on the .200 .300 .400 lift flow and made a nice gain. The engine went back on the dyno, I now had had 513 HP @ 5700-6000. In the real world that HP increase picked my car up exactly 3.2 MPH.
A BBC oval port head with either .398 or .460 lift @ the valve will require either welding the intake seat or Intake valve seats to do what your trying to do, as cast the bowl is too big for a 2.070 valve, which destroys low lift flow.



Example

Re: Cylinder head flow - What is crucial in a stocker?
 

There ya' go..Talk about sharing..Wow!

Re: Cylinder head flow - What is crucial in a stocker?
 

Hey Yac, what do you think it's gonna take to make THAT^^^ look "stock"?

Re: Cylinder head flow - What is crucial in a stocker?
 

Looks like a good start for Super Stock.

Re: Cylinder head flow - What is crucial in a stocker?
 

Well then you can say the welding is for Super Stock and the seats are for Stock.........theres more than one way to get there.

Re: Cylinder head flow - What is crucial in a stocker?
 

Special medicine..........

Re: Cylinder head flow - What is crucial in a stocker?
 

Correct Velocity, Velocity, Velocity
Flow is always talked about & highly sought after, but
the correct Velocity is what accelerates the engine/vehicle and is seldom mentioned.
Just my .02 for free.

Re: Cylinder head flow - What is crucial in a stocker?
 

THIS^^^^ Bigger does not mean better.

Re: Cylinder head flow - What is crucial in a stocker?
 

harold bettes, stated , port shape and velocity is everything, don't get hung up on port flow ( cfm).

Re: Cylinder head flow - What is crucial in a stocker?
 

I think when your talking about Stock and Super Stock heads you only have a smaller than optimum cross section on most heads anyway, and moving the power up is always your goal as an engine builder. Heres another thing Harold Bettes very often would also say: "It always comes down to flow" And I agree when your talking about a stocker.

Re: Cylinder head flow - What is crucial in a stocker?
 

X 2 Velocity

Re: Cylinder head flow - What is crucial in a stocker?
 

When the lift is only 2,3 4 or .500 flow is everything...its the _"venturi" effect that speeds up the velocity...when the lift gets to be 7,8 .900 and above the focus is on the velocity and cross section, not flow because the valve lift outpaces the port...in other words it's all relative and stockers are not supposed to alter the ports so the valve job is everything it's the only way to get an increase of anything...legally...my Cleveland heads that I no longer own, they moved 328 at .500 and 349 at .550 and they were legal heads , I taught the owner that owns them now how to do it and he achieved the same results...they fell off like a rock above 600 by design

Re: Cylinder head flow - What is crucial in a stocker?
 

Bill,
So you could do nothing to the ports, but made nice CFM improvements at low valve lift with your valve job. Explain to me how those CFM improvements did not increase the velocity in your untouched ports?

Stan

Re: Cylinder head flow - What is crucial in a stocker?
 

Stan, I think sometimes people confuse CFM with CC'S. IMO, CC is not near as important as CFM. Take that for what's its worth. I have somewhat of an understanding of the goal, but it's the process of getting there that eludes me lol. AND...if valve job was the only thing done to Stocker heads, everyones crap would run with mine:D

Re: Cylinder head flow - What is crucial in a stocker?
 

Maybe someone who is doing stock heads will speak up. How far below the actual valve seat into the head can the bottom cuts / angles go? I have seen heads where those bottom cuts went well into the throat area. I don't know if those heads were NHRA legal or not.

Stan

Re: Cylinder head flow - What is crucial in a stocker?
 

I don't know, you tell me.....according to the "experts" and there are many, the flow bench is worthless, I beg to differ, but what do I know?

Re: Cylinder head flow - What is crucial in a stocker?
 

Any machine cuts are legal and if that cut is 85 degrees or so it's going to go deep.

Re: Cylinder head flow - What is crucial in a stocker?
 

Re: Cylinder head flow - What is crucial in a stocker?
 

Mark, that's what most all my heads have looked like till these 416 heads. They seem to have a deeper turn that didn't get touched

Re: Cylinder head flow - What is crucial in a stocker?
 

Mark,
Thanks for the picture. It has been a while since I saw this head. But from what I can remember there was an area where the bottom cut went at least twice that amount below the seat.


Stan

Re: Cylinder head flow - What is crucial in a stocker?
 

I recently had the head off of the 6 cylinder on the flow bench. Boy were we surprised how good the head flowed even at the .388 lift I am allowed. Flowed better on the intake than a stock small block head, and the exhaust flowed 80% of what the intake did. The reason it flowed as good as it did was the fact that the intake ports(there are only 3 btw) are WAY too big. While I do believe flow is very important, when the rest of the engine (in this case the 200 cfm carb and small cam) can't support the flow you can get out of the head, you're going to run into an issue with air not moving fast enough. There's a reason the most common aftermarket chevy 6 cylinder head mod is to weld in a "lump" to the bottom of the intake port to take up some volume. As odd as a chevy 6 cylinder may be, I can only imagine the same principal applies to a wide range of combos.

Re: Cylinder head flow - What is crucial in a stocker?
 

Good morning Doug and to all,
Back when all we had was stock castings from which ever car Mfg. that we chose to play with, was when the "advent" of commercial Flow Bench's came to be. The use of these machines has lead us to where we are today with all the aftermarket support, and the advertised Flow Numbers helped sell products. Now in todays world of Big Horsepower and Big Engines the cylinder heads that have been developed all started off life on someone's Flow Bench. Okay that being said - we as Stocker Racers should still be able to gather useful information from these Flow Bench's, especially given the Lifts that we have to deal with.
They may not be the Final answer, but I consider there use an asset in the further development of engine performance. It's a tool just like a dyno
so how you use the tools that are available to us will determine the amount of improvement you'll find in your engine development programs. The facts are right in front of you, follow them as you see fit.
Just my Two cents from a very small spot in a very large world.

Respectfully,
Henry Kunz 1534 H/SA