Silverado_L31

Robin, in that flowbench pic, do you have the putty on that intake port to help reduce turbulence? how much are the flow numbers affected without it?

Robin L

It helps the air entering the port. And we have never flowed without the putty so I don't know. Those numbers would be useless as far as I am concerned.

Really most flow numbers are just marketing and test hype. Most Pro Stock teams don't use flow benches anymore. It's more about getting the correct cross section and what the heads make power on the dyno and at the track.

Like other measuring tools it helps those of us without the knowlege of a Pro Stock team get in the ballpark.

Robin

njc.corp

Thanks robin very helpful-

so gmpp will provide its own intake for this-like a cast intake-

hard to see a plastic intake keep up with this?

Haans249

iTrader: (24)

Very enlightening! I remember your posting those pics before Robin L, very interesting to see more come to light!

On a side note, anyone notice that my thread was deleted?! I contacted a moderator, have not heard anything back yet.... I posted up all of those HI-res images of all those new LSX parts from GM. Whether they were leaked photos or not, who knows?

Regardless, they're still all available to preview online...

Robin L

Where did you get those images?

LS6427

iTrader: (2)

I've got all the pics saved too. I want those heads the second their available.

Haans249

iTrader: (24)

I got them from this post! Check the links, and then instead of 508 at the end, just make it 510 for instance, and walla, pics.

so...

for instance, take the first link in this thread:

http://gm.wieck.com/forms/gm/previewpage?049517

and change it to

http://gm.wieck.com/forms/gm/previewpage?049510

and there you go, more pictures, it goes from like 507-520 something, can't rmemeber exactly.

Hans Grüber

iTrader: (2)

They have been publicly available on the GM Media website for a long time before I even made this thread.

Here is a direct link to all of them:

http://gm.wieck.com/forms/gm/*query?...rce=all&page=1

Haans249

iTrader: (24)

Thanks!

Moderators, can I have my thread back that I spent several hours at the wee morning hours posting?

Thanks...but i suppose its worthless now with that link above, good deal.

Beaflag VonRathburg

iTrader: (176)

I saved the pictures to my computer, but I noticed that the thread was gone.

ZO6 LandRocket

Any word from the SEMA show on these heads?

Bill00Formula

iTrader: (4)

Are these heads overkill for most strokers, meaning 427CI or less?

GrannySShifting

iTrader: (10)

overkill, likely unless your building a 9k rpm 14:1 450 inch+ engine

LS6427

iTrader: (2)

Why would they be overkill for a 427ci.

Seems like 427-454ci's just keep making more and more RWHP/RWTQ over the years as heads and intakes have been getting better and better.

Don't BBC 427's make alot more power because the heads flow near 500cfm?
427 cubes is 427 cubes, right? If the heads keep flowing better, there's more power to be had, right?

Of course there is a limit that 427 cubes can suck into an engine, but I doubt 430cfm small block LSX-DR heads are more than 427 cubes can absorb.

Stang's Bane

iTrader: (22)

Listen to Granny, he is right. For street applications they are overkill.

For a street driven 427, stock ls7 heads are at the upper end.

You are right about a 427 making more power now than ever before, and teh improved cylinder heads are no small part of it. Look at the air that a stock ls7 head will move and compare it to a stock BBC ls6 head. I think you would be surprised.

LS6427

iTrader: (2)

Whats a BBC LS6 head?

Overkill is good if you simply want more power though, right?

GrannySShifting

iTrader: (10)

Overkill is overkill, if the engine doesnt need the cross section of that head, its gonna be a dog no matter what the flowbench says.

And unless its turning 9500 rpm with those cubes, or is 540 inches I doubt that head is what it would want really. And if you have enough camshaft to turn that rpm, Im sure its going to need more than 11:1

Look at all the big cfm L92/LS7 250-270cc headed engines you see on here that are complete dogs. A 6 speed car with 340+ cfm and only 520 rwhp is off. Were using a 230cc cyl head and making 530 to the wheels on a Mustang dyno, with a loose 6000 stall and steep gears. Normal 12:1 compression, cam is not crazy in the 250s range (Vengeance has 260/270 stuff in cars that are "streetable") Get the right cylinder head. Not the biggest.

CalSpeedPerformance

iTrader: (64)

I spoke to the head GM engineer/designer of the LSx program for about 45 minutes at the SEMA show...we went over alot of things that he asked me to not repeat on the internet regarding the details of their LSx parts in development...but i do have some details on the DR heads I can repeat

They have seen over 450 cfm on some of the port jobs they have done on these heads. These heads have *possibly* made over 1000 horsepower NA on tall deck LSx block testing.

They have been testing them between 305cc-320cc intake runner size.

njc.corp

if what u are saying is true-i dont think anyone would dare run them on the street-

but as always their will be one nutter--

Beaflag VonRathburg

iTrader: (176)

If you had the added cubes of the tall deck block you could run them. I'll be interested when more details come out about these. So far they sound really nice.