just looking to see if anyone has head flow #'s for the 230/250/292 heads.
i would like to catalog them in 3 ways.
1. stock type intake port w/bolt boss and larger valves

2. boss removed and larger valves

3. lump port and larger valves.

please give valve sizes and which configuration with flow #'s. tom

I could possibly get some info for you, im fixing to start(2)heads. What size valves would you like to see used when you say larger valves. And by "lump" port, do you mean the real deal or the bolt-in kind.

it really does not matter as long as you give us the specs of the head being tested.

also if there is any chamber work. tom

Ok, I'll see if I can even throw in some pics as well.

pics would be great!

i am getting ready to test some head work and just wanted to compare the findings to other peoples work. tom

Tom, this is the info. I have,

All flow done on a superflow @ 28" - ports just cleaned up no extensive porting - normal 3 angle valve work - normal combustion chamber work around valves only. Will post exhaust only on the first one since all flowed the same with the same valve size.

stock head w/ post:
--------- .200 .300 .400 .500 .600 .650

1.94 IN 110.6 160.8 187.0 194.5 197.4 197.4
1.60 EX 102.0 133.5 157.0 171.0 177.4 179.0

stock w/o post:
1.94 IN 125.5 175.0 204.0 213.0 217.5 216.5

Sissel lump port:
2.02 IN 122.0 176.0 214.0 240.0 248.0 251.0

stock w/ post divided:
1.94 IN 113.0 150.0 169.0 176.4 178.0 181.0

Brazil 12 port:
1.80 IN 119.0 153.0 170.0 178.4 182.0 187.8

Port entry on the Brazil head is .500 higher( from the deck surface) a little taller and a little more narrow than a U.S. head, the area is about the same but not a good short side radius just a steeper angle to the valve, otherwise it is the same.

Harry

PS. Sorry it's not lined up correctly, this is why I use carbs !!

thanks for the #'s Harry!
you flowed all these yourself?
i am also going to run a few tests, just for my own curiousity.

looks like your new brasilian head will slightly out flow your old setup.

have you enlarged the valves on the new head yet?

Tom, The new head has smaller intake valves,1.800 wanted strength
more than anything. Hoping new head wet flows better than old head. Track opens soon,will find out.

Harry

I'll bite. I sent this flow information to a friend of mine. For all I know, he's full of crap. But here's what he said.

"...Brodix iron killer 200's barely flow 250 cfm@28" Is this guys math right? Or we all should be looking to build 235 stove bolts!!!! 250@28" = 150@10" X .4HP/cfm = 60 horse/cly x 6 = 360hp..."

I'm just trying to learn it. I am completely ignorant when it comes to this kind of thing... I don't even know what it is that my buddy sent back to me. That's why I'm hoping to learn.

Vectorsolid,
First of all these flow #'s are for 230-250-292 style heads not 235 older style inlines prior to 1963.

Your friend used a formula that uses air flow at 10" rather than the industry standard of 28" that is popular today, anyway some contend that you can figure the HP potential of an engine by the air flow but this is not always the best barometer of an engine potental many other factors figure into the equation.
It will give you a ballpark idea. The formula I had seen used air flow at 28". It is .257 X airflow at 28" X number of cylinders. IE .257 X 251 X 6 = 387 HP If the head was on a V8 it would be .257 x 251 X 8 = 516 HP the V8 has better potential of making this HP since the port has better air speed and wet flow and other characteristics.
Some have made way more flow than I have but they used way more lift up .900 to 1" my numbers are at .605 lift and not much port work.
The siamesed port is large and therefore looks to make enormous HP and a few have been able to do this.

The rule we use at our shop is each cfm@28" will support 2 HP if the rest of the engine is built do it. In other words a 250 cfm head with the correct parts (cam, exhaust, compression, intake, etc) has the potential of making 500 HP. From the engines I dyno this seems to be valid.

Ron

Ron, I've found that to be fairly accurate as well.

That is correct for a V8, but since the flow numbers come from a single port, you need to use a formula that takes into account the number of cylinders for anything other than a V8.

Port flow is the same, if a siamesed port or regular port.

Reversion is a product of valve timing.

Port velocity is a factor of port size and shape.

Port velocity is the same if FI or carbs, if the port is the same size and shape the velocity is the same.

Carbs need a plenum to help cancel the reversion pulse unlike FI

Siamesed ports help cancel reversion because they are so big and the port acts like a plenum under the carb. But because of the firing order and most of all valve timing events, reversion is the biggest problem of six cyl. engines.

But talking about theoretical best HP from flow numbers, need only the formula:

.257 X air flow @28" X number of cylinders
ie .257 x 251 x 6 = 387 HP

.....if you say so.

Perhaps in future you might find it more productive, instead of simply discounting what I said without actually citing any source or authority, to say "I don't understand your statement".

Did I miss something?

panic,
i guess i am missing something. just what are you refering to? maybe you deleted a post. i do not see it in this thread. tom

Slowly, I'm learning that there's simply no reliable method of anticipating when a statement of (in my opinion) fact, or at worst, my own experience, will be completely discounted by merely making a contrary (and in this case, wrong) statement. In civil law (my profession before retirement) this is referred to as "unresponsive, devoid of factual content, and merely generic nay-saying" - and not permitted as a rebuttal.

This leaves me with a dilemma: should I expand on my own remark, offering data and citing authorities? Since the responder clearly had no idea what I was talking about (as evidenced by his rebuttal), this didn't seem to be a productive use of my time; I would be explaining to someone who neither listened nor understood.
Or, should I stop and permit the errors become the definitive answer? This is invariably seen as, and commented on as "you deleted your post because you knew you were wrong", "you got caught", "you think you know everything", and other rather petty and pointless remarks.

Granting greater weight to civility than to accuracy, let's just say that the prior comments are less than dispositive of the subject, shall we?

I'll be most careful to avoid in future offending the members here by posting information beyond the revered Mr. Science level.

wow! your really showing your brilliance with all that hoopla. i just asked a simple question. you did remove one of your posts. maybe you should expand on your flow vs hp thoughts to clear this up. tom

Panic,I have found that whether it is this forum or any other, that when you try to give anything other than an unbiased or neutral response on any topic, it usually reciprocates a challenging comment or atmosphere. Its difficult for some people to accept the advice from others when they have had moderate success with the methods they themself are using, even if what you are telling them is clearly a superior or a better way to do it....its just human nature or ego to do that. Too many times people get caught up in the emotion of a debate and forget the true purpose of a forum, and that is to pass along to others the knowledge and experiences learned. The old adage "You can lead a horse to water, but you can't make him drink it" pretty much sums it all up. They will either take your advice, or keep doing it the way they always have done it, right or wrong! But its usually in the presentation that makes people stop, look and listen to whats being said, or its overlooked completely and met with a challenge such as you are experiencing.... I have also found that people that actually have "hands on" experience in the subjects they are talking about, have a higher level of credibilty over those that are merely passing along info gathered from others that have done it, when they themselves have none. They try to make other peoples experiences their own, and try to speak in matter of fact tones to gain or add credibility for themselves. It rarely works out in their favor.

This topic seems to be turning into a LeeLites story.AND we all What happen to that.So If it keeps Up this topic will be closed.
What was and is Nailed right on the head for this topic is what Turbo6 has put up (TRUE FACTs)in regaurds to flow and HP. Some of what Others have said or brought up.Myself and Other PAID !!
Memebers alike have not made comments OR posts, Due to this being twisted around or for THIER OWN Gain or to ADD CREDIBILITY
to or For Themselves.

Most on here Knows what works for them Or has. OR they have taken the time to learn from thier misstakes.And are willing to share. And they don't come OFF as I Know It all!! For the most part (we'll) NEVRE KNOW it All. AND IF the few that do think that
you know it all THEN MY 2 CENTS is you stoped learning.

Again My 2 Cents I don't plain on stopping to learn.

Sorry if I offended anyone.

I have not seen any forum that states the source of information they are talking about. Forums just post thoughts, ideas, and information as " Food For Thought" everyone needs to reseach the info. and draw their own conclusions.

Again I'm sorry if something I posted is not correct, but I would like to know what is not factual for my own knowledge.

I have gleaned a lot of " Food For Thought" "LeeLites" and "Others" STUFF off of this site,filtered it,added in some of the 60 years of OLD SCHOOL and ended up with a little Peanut Whistle 6 in my car that puts a sticker under the saddle of those "CRATE MOTOR" SBC Dudes...I love it..You guys kiss and make up and keep us informed..Sure making ME look good out where the rubber meets the road..!!!

Turbo6,

I think we may have got off track

250cfm seemed awfully high for a factory cylinder head.

That head was a Sissel Kirby lump port. Not a stocker.

AFR's airflow to horsepower formula is .2454 x # cylinders x cfm. I generally also multiply it times a VE figure: .75 for street motors, .85 for street/strip, 1 for racing only. A good combination with the proper compression with a racing intake/exhaust setup on it will pull 102 to 105% VE. This will get you pretty close to what you are going to get on the dyno.

.

so far 2 people have given info to help this cause. thanks turbo6 and cnc.

someone else has to have real #'s to share. please nothing from a allready printed souce.

please none of the flow vs hp debate. tom

I think Larry, Twisted6 has all that info,,,yes,,,no?

MBHD

Yes And soon what your looking for will be More & Up-dated in the New Power manual.And Besides that all this info is in the Power to start with.And has been.

When is the newer version available Larry?

MBHD

It is still in the Workings.With much more to all (early and Late ) I'll let you know when It's closer to Print.

Ignorance is treatable...stupidity is forever. I'm ignorant on this stuff and have no idea how to read and interpret these numbers. Can someone please explain?

--------- .200 .300 .400 .500 .600 .650
This is how much the valve is open.200" .300" etc.

1.94",,,1.60" that is the size of the intake & exhaust valves.

1.94 IN 110.6 160.8 187.0 194.5 197.4 197.4

the 110.6,is checked @ .200" lift (valve off the seat)
And has a SCFM ( a measure of how much it flows)

So @ .200" valve lift,the intake valve flows 110.6 SCFM

Same goes for the exhaust valve.

1.60 EX 102.0 133.5 157.0 171.0 177.4 179.0


MBHD,
I am not good @ explaning stuff.

Kerry,

Sometimes the flow numbers are easier to understand when they are plotted, rather than just in tables. Here is a link to a plot of Harry's flow data .

A few years ago, HRM published an article about Mike Kirby's work with the 250-292 engines. Here is a plot of the intake flow data from Kirby's tests. from the June 2005 issue. There does not seem to be a direct comparison between Harry's heads and Kirby's heads, but results are consistent - and interesting.

Hoyt, Yes the tables show the info. much better.

My stock version has an 1.94 intake valve and is ported, Mikes is completely stock witha 1.72 intake valve. I would think is the reason for the difference in flow.

My 12 port from Brazil is more like a stock GM port layout. And Mikes intake comes in at a very high angle, thus makes way better short side radius, and great flow numbers. This head is by far the best aftermarket replacement head ever made.

I only wish this is what I had, but at the time I believe they were out of production. Does anyone know if the version with water passages are back in production?

Harry

Hey Turbo, what size valves are in your Brazil 12 port head! I've got some guys wanting me to evaluate them for some better alternatives than are currently used on them in Brasil, just curious!

CNC,
Intake 1.800 exhaust 1.600 had trouble with cracks between valves using 1.940 valve,like sbc chevys but the six will leak water if it cracks there.

Ok, thanks!

For those that have asked Here is a flow sheet on the T6Racing Lump kit with VERY mild port work

Larry, would you have a flow sheet for a stock head so we can see the difference?

I am doing some more updating & testing. Which there will be more info for the stock head. In regaurds to the Stock Valve & head. With no port work once so ever. and so on.And all I am going to say in the rest of this matter for now, Is has to do with redesigning and Increased flow.

I now have flow #'s back on my first flow benched head.

This is a head with 1.84 intake valves and 1.60 exhaust valves. It has had valve unshrouding done to it and the guides have been coned shaped.

First port is a intake that has had the bolt boss removed and has a cap screw sitting in the bottom, like it would be in use.
1.84 intake @28" on a superflow
lift flow
.100 62.1cfm
.200 115.3cfm
.300 168.7cfm
.400 184.3cfm
.500 195.6cfm
.600 202.0 cfm

1.84 intake with a HI-FLOW bolt in intake lump
lift flow
.100 57.8cfm
.200 112.9cfm
.300 166.9cfm
.400 202.0cfm
.500 215.6cfm
.600 226cfm

What is interesting is the 10% increase in flow with the bolt in lump at higher lifts.

how do we increase flow at lower lifts also? i do have a easy way for me, turn up the boost.

also does anyone know how to present this info to show total flow difference, such as thru a valve open to close flow?

tom

Tom I find it very interesting That you say your Lumps out flow mine. at least 10 cfm off pretty much right from the start?? Well some where then I think/feel you need to go back and Relook at your head work Or Lump. Those numbers seem to be off?
This is from a head that Had No valve guide work and Next to nothing for port work.You can go back and look at the Flow sheet
topic i posted.(For those that have asked Here is a flow sheet on the T6Racing Lump kit with VERY mild port work.) Well sorry that it just jumped to the Top of page 5 here. But anyway you will find the sheet.

larry,
when have i said my lumps outflow yours? they may, it is just a matter of more playing with the head. the only thing i did say is they fit better. i have used both yours and mine and PES lumps. PES fitting the worst, they are almost like bolting a rock in the port. i have a spare set if anyone wants them.

i think all in all, my head flows very nice.

the next thing i am working on is a ramp to bolt into the intake manifold and meet a squared lump in the head. according to leelites and PES this is the ticket for flow. it is worth a try. tom

There is a guy you want to get advise from,,,, Leelites.

If you want the ticket for flow I would get advise from CNC dude.

Or Larry, but I don't think Larry will help you,,,now I could be totally off about that,, LOL.

There is a lot more to cylinder head flow than you think there is,but you might get it & then you might not.


MBHD

Well Tom
I wasn't saying yours OR PES's didn't flow.But also I can see Just From YOUR sawZall Video that they don't Fit any Better either,and i am flattered you copied mine so well Thank you.And Honestly I can't see anyone Telling someone to USE a sawzall on there head. But Yes I hear alot from many in AND out of the Grape vine as one would say. I have flowed many heads with different valves, angles, port shapes,and LUMPs.And I am still doing so.Right along with intake design.So now anyway their will be a new and improved design comming out in the near future.

Hank
I would also like to add I have been working on what you sent me
sometime ago.Designing it to work better with a lower lump. That
is all I can really say about this at this time.

Partly more of my2cents

OK Larry, just as long as my name gets mentioned.
:-)


MBHD

As many seem to ask what the stock head flows with the stock 1.72 valve It's in the Book. and Like i have said many times before It only flows about 170 cfm. and in the book it states 169
on the intake. The exhaust with the stock 1.50 flows 122 cfm.

You guys are comparing flow numbers from two or three different machines in different parts of the country in different weather conditions, so the numbers don't really count for much other then for bragging rights. If you get all the heads to one shop on the same day, then you can compare side by side results.

Dad and I have a flow bench and have seen different results from the same head on the same machine with just weather changes.

So it numbers don't mean much, its the average increase each of you see on your own machines that counts.

Joe

Joe you are so right. This same issue came up a few yrs back and I had said the same thing many times over. Humdity,rain an so can change it all. Even in the same day.
The head will also flow differently with a port plate? if i remember right. But that is something I will recheck myself.So i can my brain a little more up to speed lol.

Well, its not like a stock head you flowed 170 SCFM then the next time it flows 200. Correct?

MBHD

it is much less than that. but with my heads, i have seen a honest 10% increase over the open( no bolt boss) port.

so far i also see about 163 on the exhaust @ .600 lift. tom

No is doesn't change quite like that.The differents are not that far Off. Not that i ever seen a few CFM at most. Nothing like 10,15,20 point difference. But then again I have never taken a head from the south to the North or the East,west.Nore have i seen weather make that type of change either.

No its not a drastic change, but the point was, don't use numbers to compare yours to mine. Flow benches are like engine and chassis dyno's, it all come down to how the operator sets up the machine.

Whats really needed is a flow as you go test.
Start with truly stock head with good valves and guides,
change out the valve size for the next step,
cut out the bolt boss,
add a lump,
with flow testing between each step.

This would show just what happens at each step, adding port work would change the out come since each guy porting is different.

Joe

By efi_diy at 2008-10-05




ok I couldn't resist....










Ported 2006 4200 head...


As Tom said once "I feel like I showed up at a gun fight with a knife.."