before/after 383 dyno results

[randy331]

I was just running your flows through Rick's Curtain area program, very pronounced increase in window DC at all lifts.

Is an increase in window DC always good ?
No limit to it ?
What else will you trade for an increase in window DC ?

Randy

And we're off!!!!!! I'd love to hear the answers to the questions you ask.

It will be mostly opinions. Very few (if any) have done enough testing to validate and KNOW the answers to those questions.
I have my opinions too and like to see good DC, but I can't say when the ideal trade offs are.

Randy

[Stan Weiss]

So what exactly is DC. It nothing more than a ratio of cfm per sq inch. So why do we need a ratio when we can just look at cfm per sq inch? Because the same head when flowed at different depressions will show a different cfm per sq inch, yet their dc will be the same.

So how does a change in valve seat angle change dc? It does this in 2 way. First at any given valve lift it will change the effective curtain area. Higher angles decrease the effective curtain area and smaller angles increase the effective curtain area. Second you will see a change in flow. Now based on what happens to each of these we can see either an increase or a decrease in DC. So while it is possible to see a DC of greater than 1 in different places (I will leave that for another post) a DC of 1 is theoretically max.

Stan

[randy331]

Why would they do this sort of valve job when they must know it not the normal,
Surly a 45 deg 3 angle VJ would outway a radius on the intake and produce a better product out of the box??

More low lift flowz. Uninformed consumers believe that's what they want, cause they heard it somewhere.
Heads are hard to sell if they don't flow a lot.
CFM sells.

CGT's heads on SN have very poor low lift flowz, it still seems to run,...well,... OK. LOL

Randy

[steve cowan]

Why would they do this sort of valve job when they must know it not the normal,
Surly a 45 deg 3 angle VJ would outway a radius on the intake and produce a better product out of the box??

More low lift flowz. Uninformed consumers believe that's what they want, cause they heard it somewhere.
Heads are hard to sell if they don't flow a lot.
CFM sells.

CGT's heads on SN have very poor low lift flowz, it still seems to run,...well,... OK. LOL

Randy

Randy,
i was reading some old threads last night from 2005,
Curtis Boggs,Darin Morgan,Larry meaux,Rick,Bill Jones,
EVERYONE SAID-
RADIUS SEATS DO NOT WORK AND DO NOT MAKE POWER (quote)
that was the general consensus then and seems nothing has changed in 2019,this is for a 2 valve performance type cylinder head not a turbo 4 valve 4 banger thing a ma jig.
As you have shown before with cylinder heads some valve jobs are reasonable from the manufacture,must be fun for the guys in the industry to say to the customer your new cylinder heads need a valve job,sorry about off topic

[makin chips]

Why would they do this sort of valve job when they must know it not the normal,
Surly a 45 deg 3 angle VJ would outway a radius on the intake and produce a better product out of the box??

More low lift flowz. Uninformed consumers believe that's what they want, cause they heard it somewhere.
Heads are hard to sell if they don't flow a lot.
CFM sells.

CGT's heads on SN have very poor low lift flowz, it still seems to run,...well,... OK. LOL

Randy

Randy, can you please not use that word?

Or maybe we can get them to put a filter on that word like the filter on cuss words or the filter on the most hated man at speedtalk's name {shrug}

That would stop it cold.

[Arthur]

Sticks and stones spitting chips
World is too soft
There she FLOWZ!!!

[CGT]

Randy, can you please not use that word?

Or maybe we can get them to put a filter on that word like the filter on cuss words or the filter on the most hated man at speedtalk's name {shrug}

That would stop it cold.

Do you really think that the disdain for said person and his self proclaimed mastery over the years is limited to speedtalk??? ….I'll give you a hint...its not.

So as a means of diplomacy I will try to help you with something that you seem to be so obviously struggling with.

FLOWZ: Slang for the plural of flows. FLOWZ: A speedalk derived word of currently unknow origin, used to describe the plurarility of a cylinder head valve lift curve as measured on a flow bench.

Example: Hey Tim, I heard you recently purchased some Vee funkeder heads. I've heard they will move air all the way to 2 inches of lift and contain a lot of "bowl" . Have you verified the dimensions and the FLOWZ that are claimed on your own bench?

[PRH]

Maybe the PC spelling is actually “flowzz”

Speaking of radiused intake seats and low lift flowzz....... what about when you retain the 45* seat, replace the radius with a couple angles....... and the low lift flowzz actual go up?

[77cruiser]

Maybe Randy thinkz that'z the way it'z spelled.

[ClassAct]

Maybe the PC spelling is actually “flowzz”

Speaking of radiused intake seats and low lift flowzz....... what about when you retain the 45* seat, replace the radius with a couple angles....... and the low lift flowzz actual go up?

Which direction did you measure the flow? I don't care if low lift flow goes up in the forward direction as long as it doesn't go up in the reverse direction. If low lift flow goes up both directions it's a power loser every single time.

[cgarb]

Maybe he worked at Sheetz in the past....like fryz or shmuffin...lol.

[Stan Weiss]

So have I got this right? The heads are better, the engine makes more HP and the car runs the more barbs and zingers someone posts.

Stan

[PRH]

Maybe the PC spelling is actually “flowzz”

Speaking of radiused intake seats and low lift flowzz....... what about when you retain the 45* seat, replace the radius with a couple angles....... and the low lift flowzz actual go up?

Which direction did you measure the flow? I don't care if low lift flow goes up in the forward direction as long as it doesn't go up in the reverse direction. If low lift flow goes up both directions it's a power loser every single time.

I didn’t reverse flow them, before or after.
In fact, the last set I reworked didn’t get a “before” flow test at all.
They were here for their 3rd valve job/freshening.

But, the lower lift flowz after the rework were a bit higher than what I’ve seen for any new ootb pair that had the radius intake seat.

I guess i’ll just have to see what happens on the dyno.

[CGT]

So have I got this right? The heads are better, the engine makes more HP and the car runs the more barbs and zingers someone posts.

Stan

No. That only works with bold colorful font using very mediocre grammar skills and no dyno sheets.... just theory

[RevTheory]

Grown-ass men, huh.