Mr.BigE

I got a complete stroker motor built by one of the most reputable company's on here and i specifically asked for the stage 3 ls6 heads and i asked specifically that i wanted them to be over 340 at the intake side at 600 lift and was told they will do it. i made sure i said this about 6 or 7 different times we talked but anyway look at these closely and tell me what you think!
Intake exhaust
71.1 at 0.1 52.9 at 0.1
136.6 at 0.2 110.2 at 0.2
203.9 at 0.3 152.6 at 0.3
261.9 at 0.4 188.6 at 0.4
309.2 at 0.5 213.2 at 0.5
341.1 at 0.6 233.4 at 0.6
323.9 at 0.7 239.5 at 0.7

I am told by quite a few of my friends that it looks like someone put the 341.1 in there to apease me, i hope this is wrong! i have some friends that want to take them off and flow them, but i just want it to be what i paid for with no problems!
Anyway i really liked the company that worked on this motor, I was actually sending them another car for a complete conversion, i just want what i asked and paid for!Not trying to start problems.
Other than this i am quite satisfied with the motor, of course its not in my car yet!
Thanks!!!

Mr.BigE

Bye the way these are 2.08 intake valves and 1.6 exhaust on the ls6!!!!!

hellbents10

iTrader: (10)

Well it does look like a big difference between 500 and 600 lift. It is possible that they massaged the heads till they reached that number @600 lift. Allthough as a whole the yshould flow relitivly well under the area under max lift. It looks like a cam right in the 600 area should work well as they appear to fall off hard after 600 lift. Little wierd? Yes. I would think about having them flowed by another reputable shop maybe. Have pics of the work, especialy the bowls and also what size are the runners (cc). How about the valve size too?

hellbents10

iTrader: (10)

well you answered right as I posted that. Thats a fairly large intake valve so I could see it flowing well above 600 lift. So that makes me think it is a little wierd. Maybe a very experienced head guy will jump in here.

jrp

iTrader: (16)

well who's heads are they? what are the port volumes. i peronally dont trust any flow bench numbers unless they can be verified within reason on another bench. your midlift numbers are nothing super and exhaust are run of the mill. was the exhaust w/ or w/o a pipe?

TVWilkes

I would get them flowed by someone local to you.340 cfm is a very hard number number to get,and be real.What size bore did they flow them on?

Beast96Z

iTrader: (21)

It looks as if someone hacked up the shortside in liue of a big .600 number at the sacrifice of low to mid-lift. The lower to mid numbers aren't great and won't perform as well as a head that flowed better low-mid numbers with less .600 flow. Unless specifically needed, the .600 number isn't near as important as the .200-.500 numbers. Your engine spends twice as much time in the lower to mid numbers as it does at peak. I'd speak to whomever ported them and tell them you are not satisfied with them. Personally I would flow them locally to see if the numbers even come close, then go from there.

TVWilkes

261 @ .400 is not bad.I think 321 @ .600 is more realistic number.

Beast96Z

iTrader: (21)

That would make the numbers seem more legit.

JZ'sTA

iTrader: (23)

I you feel the numbers are incorrect the have them flow tested on another bench.
I however would be more worried about the dyno numbers and the track number then what the heads flowed.
You asked for a 340 cfm head and sometimes you will loose a little in the midrange to get the high end results. You probally went around this the wrong way. 309 @ 500 isn't too shabby, and again the flow number really dont mean a damn thing if the car is as fast as it should be.
Give us a complete list of your mods, and what you made on the dyno, then we can tell if there might be a set of non flowing heads on that motor.

777

iTrader: (21)

only ONE way to know for sure...get them flowed by someone else...what you said to them was prolly not the best thing to do...that is like someone going to a car dealer and saying i want to pay 400 a month on a 425 a month car...and they do that but then add 24 months more to the time you pay for it..then they think they got a great deal but in the end they got screwed...

Tony Mamo @ AFR

iTrader: (13)

I will flow them for you at no charge...and pour them to check runner volume as well. I don't know how close to the LA area you are but you would only have to ship one cylinder head so no matter where you were located the freight cost wouldn't be to bad. AFR will cover the freight back to you as well and I would turn the head around for you very quickly so as not to hold up your project. I would be very impressed if 340+ CFM materialized at .600 lift and as someone already mentioned, your exhaust figures seem only average and are certainly attainable. Contact me by phone or PM if you have an interest.

Tony M.

Cary@Perf-Induction

iTrader: (1)

Too many worries, IMHO I would just run it and forget about the flow sheet. Too many times people will get so caught up in the numbers game, yes they do matter, But I can sit two heads next to each other, both flowing identical numbers, same valve size, etc. The two heads can be 30 horsepower apart. We build our best cylinder heads for people who could care less about their flow sheet legitimacy. All of us cylinder head porters are judged by their numbers rather than how they perform. It has been set as a standard. Flow numbers are just the first itty bitty piece of information that even matters. Same goes with camshafts, I see people an the forum all the time using an XE lobe and then throwing 1.8 rockers to it and then be suprised when they have a broken valve spring. No matter wht any of us know, There is still a black art in cylinder heads. Sorry to carry on, Just run em'

383ss

iTrader: (14)

who cares what they flow at .600??? how much lift is your cam?

Mr.BigE

Over 600! and if nobody should care how it flows why do we need head porters and why dont we stay with the stock ports

SPANKY LS1

iTrader: (24)

Who is this reputable company? I would bet that its a misprint and they really flow 321@.600 (which are great numbers). Is the intake "cathedral" still intact?

Shawn

Mr.BigE

I am not going to say the company at this point.
i talked to them today and they were professional about the matter and said they would stand behind the matter.
This motor is a 408 stroker , 12 to1 compression, with a cam with over 610 lift, lsx intake and 90 mm tb,kooks headers and all the other goodies and have close to 13 grand in it! the heads alone were over $ 3,500.
I was offered by the company to have them flow tested by anybody and they would pay shipping and for the flow testing!
They said they will stand behind it and i believe them!
What would you guys do?????
1. get the heads flow tested and if not what they were suppose to be send them to have them reported!
2. keep them and wait till i get the motor in the car to see what it does!



The point is i said i wanted a stroker motor that will be at 525 or over at wheels with a 6 speed and 4.10,s!
Thanks

Bo White

iTrader: (59)

Put it together and see what it puts down. I believe the numbers people should be concerned with are not on the flowbench but at the dyno and the track . But Tony, being the fella he is, is supplyin' a service that is super rarely given away to someone that is not a customer.

2000RATA

I believe he mentioned it because of a post of his in the Dyno section. His 408 is making stupid good power from a small cam and small heads.

Sounds like you have everything you need to get yours together. Quit thinking about it, don't worry, put it together and it will make the power you are wanting. 525 RWHP will be a piece of cake.

Chris

JZ'sTA

iTrader: (23)

That isn't what he is saying.
Flow numbers are flow numbers.
You could take a head and make it flow 400 CFM's with a 330 cc runner. Have fun trying to make power on a LS1 with that combo though. What is being said is that if a company has a good rep for their heads and has a proven track record then the flow numbers aren't that important.
The dyno numbers and track numbers are where you need to be looking. I would rather have shop A port my heads and make 320 peak cfm's and a avarage of 275 CFMs from 300-600 and make 500 HP then buys shop B's heads peaking at 370 and avaraging 310 but only making 430 HP. There is a need for ported heads, that is why many of us have them. Stock heads dont FLOW well enough.

Maybe a better example would be the comparision between AFR heads flowing 300 CFM's and a 205 intake runner volume vs say Patroit performance heads that might flow 20 cfm's more on the same bench but have a ~228 intake runner volume. While the Patroits out flow the AFR's the AFR's will probally make a little more power.