Re: Fast flowed my Chapmans today!
[Re: cheapstreetdustr]
#12438
07/27/04 09:54 AM
07/27/04 09:54 AM
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Joined: Jan 2003
Posts: 9,924 Weddington, N.C.
Streetwize
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Weddington, N.C.
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Cheap, That's why I was kinda holding off 'till Dwayne arrives; I do know he used the 4.375" bore fixture which is what I'll be running in the 517 low deck. Like I said, I just feel good that I have "official confirmation" of the Chapman Advertised numbers, If nothing else at least people can consider them as REAL. Steve D said he got the same flows on his bench so it looks like these pups might actually live up to their "Press Kit".
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Re: Fast flowed my Chapmans today!
[Re: Streetwize]
#12439
07/27/04 11:30 AM
07/27/04 11:30 AM
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Joined: Jan 2003
Posts: 19,537 Las Vegas
Al_Alguire
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I Live Here
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Posts: 19,537
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Like those numbers. Looks like you have a nice set of heads there for sure.
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Fast flowed my Chapmans today!
[Re: B1Ken]
#12444
07/27/04 06:19 PM
07/27/04 06:19 PM
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Joined: Jan 2003
Posts: 5,875 communist bloc of new jersey
jamesc
master
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Posts: 5,875
communist bloc of new jersey
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Quote:
O.K. I'm probably the only person who doesn't know this, but WTF is a Chapman head? How much do they cost?
well Ken after talking to you at the Grove i'd hafta say the only way a set would ever be found on your car is if someone gave em to ya.
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Re: Fast flowed my Chapmans today!
[Re: Streetwize]
#12445
07/27/04 07:14 PM
07/27/04 07:14 PM
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Joined: Jan 2003
Posts: 18,025 S.E. Michigan
ZIPPY
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That's impressive for a relatively small port
It outta run like a bat outta.......heck.
{edited for family consumption}
Rich H.
Esse Quam Videri
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Re: Fast flowed my Chapmans today!
[Re: cheapstreetdustr]
#12446
07/27/04 07:35 PM
07/27/04 07:35 PM
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Joined: Jan 2003
Posts: 14,531 So. Burlington, Vt.
fast68plymouth
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I Live Here
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Quote:
Quote:
What size bench does Chapman Flow on, and what is Dwayne using these days? I do recall Dwayne telling me ages ago, but I can't remember everything, lol. I do recall Dwayne's bench being conservative regardless.
AL...
actually the better question would be..
what size bore fixture was used?
what was the elevation, pressure?
airflow temps?
;these would be the biggest factors in seing different #s from one to another.
you have to understand conservative is relative.
now this is directed at no-one, just in general.
people have to understand.
proper bore fixture diameter, if not the same will show different results,too small for the heads application "can cause the stall" or lower peak #s
elevation in reguards to sea level is one of the biggest factors for the difference.
id say thats the biggest source of the confusion.
next would be the correction factors.to try to compensate..
just my 2 cents.
everyone is an expert
i think you need to do a little more homework on flow bench design before you start casting a shadow of doubt about whether or not flow data is directly comparable or not.
not all flow bench designs require corrections for weather variables.
from the Superflow website;
"the flowbench measures the ratio of the pressure difference across the orifice, to the pressure across the valve. Both the orifice and the head see air at the same temperature, density, and humidity. A flowbench of this design provides results, which are independent of the atmospheric conditions. In fact, if you put a cylinder head on the flowbench, and run it at a barometric pressure of 24" of mercury, and run it later at 29" mercury, with the same cylinder head, you will get exactly the same flow numbers. You don't have to correct for temperature or correct for pressure. "
my own personal opinion is that you cant directly compare results from any two flowbenches as being 100% equal.
i dont really have anything else to add at this point about these heads.
i was hoping to get some measurements off them today, but as it turned out, i was on the dyno all day.
the bowls "appear" to be pretty generous on both the intake and exhaust side, and there is much more height on the intake short turn than on the original VI's like what were used for the EM470 motor.
i'll paw through my notes and see what the best port on the EM470 heads was for comparison.
as for the port stalling at high lifts....thats more of a "welcome to my world" kinda thing.
the short turn doesnt "feel" like one that would make it to .800 lift on my bench without stalling...and it didnt.
on a bigger bench...who knows.
regardless....these things are pretty impressive in the mid-lifts.
they really put the hurt on the SR's, 440-1's, BD's, in those lower mid-lift ranges....and are impressive up top too.
the only concern i would have with these on a larger CI motor like what Wize is going to build is the port cross section of the exhaust port.
it appears to be a fair amount smaller than a good flowing SR or 440-1....and sometimes when there is a lot of volume to deal with(like on a large displacement motor)....they just need to be bigger.
from the looks of the flow numbers for all 3 versions of the Chapman VI's on the Chapman site, the exhaust ports are done the same for all of them. im sure its overkill for the small version, really good on the middle version....but i feel is a tad small for this version.
i'll have to test it with a 2" tube on it to see how it responds.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Fast flowed my Chapmans today!
[Re: Streetwize]
#12450
07/27/04 09:24 PM
07/27/04 09:24 PM
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Joined: Jan 2003
Posts: 1,361 Wild West
M_D
pro stock
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pro stock
Joined: Jan 2003
Posts: 1,361
Wild West
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Guys and their toys, what can you say? (o) (.) Does one valve guide look off center or is it just me?
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Re: Fast flowed my Chapmans today!
[Re: fast68plymouth]
#12451
07/27/04 10:42 PM
07/27/04 10:42 PM
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Joined: Feb 2004
Posts: 6,257 acworth / N. georgia - south e...
cheapstreetdustr
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acworth / N. georgia - south e...
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Dwyane, iam not in disagreement with what you said.
you may have mis understood me.
"not all flow bench designs require corrections for weather variables. "
the key is not all. some do , i wasnt refering to your bench as incorrect/
just that to compare his flow numbers to someone elses #s done elsewhere shouldnt be taken so literally.
and that some bench's do require correction factors/math
they should focus/measure the change. and that one bench cant/should not be compared to another.
are there differences in benchs ?,yes in most cases..
IMO the cream will rise to the top so to speek. people who do there homework will know the diffence..and find out who's doin it right..
but IMO flow #s that get posted should be accompanied by the other data.
like what i mentioned in 1st post..you do agree that it makes a difference yes?
bore fixture size's are important due to valve shrouding.
and temp,baro make a diff. and should be considerd
since none of this ever gets posted along with the #s then the differences would be relative
thats all..
people get bent about the data but dont have all the info..
thats what iam tring to say..
and i like what you said in your world..not having to go super big lifts. i agree with that.
is that Int valve 2.14? or 2.18?
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: Fast flowed my Chapmans today!
[Re: Skeptic]
#12454
07/28/04 08:55 AM
07/28/04 08:55 AM
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Joined: Jan 2003
Posts: 9,924 Weddington, N.C.
Streetwize
OP
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The combo I envision is a 517" low deck 12.5:1 These heads ~270/276@.050 mild solid roller 1250 Dommy or.....DFI 2 1/8 headers Not looking to turn it more than 6800-7000 through the lights. Anything over 800 is a bonus, rather keep the revs down ~2950lb A body of some sort 4 speed 4.10 or 4.30 gears 29.5" x 12-ish" DOTs Just want an E-Z wheels-up nothing radical 9 second street car.
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Re: Fast flowed my Chapmans today!
[Re: cheapstreetdustr]
#12455
07/28/04 10:39 AM
07/28/04 10:39 AM
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Joined: Jan 2003
Posts: 14,531 So. Burlington, Vt.
fast68plymouth
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Quote:
the key is not all. some do , i wasnt refering to your bench as incorrect/ just that to compare his flow numbers to someone elses #s done elsewhere shouldnt be taken so literally. and that some bench's do require correction factors/math they should focus/measure the change
well, if someone is using a bench that requires correction calculations for changes in atmospheric conditions, then they should be posting corrected flow numbers. the corrected numbers "should" be able to be compared to the numbers taken from a bench that uses no correction factors. looking at uncorrected flow numbers from that type of flow bench is like looking at uncorrected HP numbers from an engine dyno, and not knowing the atmospheric conditions for the tests were. those numbers would more or less be meaningless.
Quote:
but IMO flow #s that get posted should be accompanied by the other data. like what i mentioned in 1st post..you do agree that it makes a difference yes? bore fixture size's are important due to valve shrouding. and temp,baro make a diff. and should be considerd since none of this ever gets posted along with the #s then the differences would be relative
i agree that the bore fixture diameter has an impact on the flow numbers....but i dont think you've let it sink in yet that temp, baro, altitude, air density, etc, do not make any difference to the flow numbers from the type of flowbench that SuperFlow manufactures, and therefore dont need to be listed, or considered. they have no impact on the flow numbers. this is the most common type of flowbench design(and some other brands of benches use this same principle). IMO, if the flow numbers listed are from a bench that requires atmospheric corrections, and the corrected numbers are NOT what are shown....only then would the atmospheric data be relevant.
its just like corrected dyno numbers. you shouldnt need to know what the weather was if youre looking at corrected numbers.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Fast flowed my Chapmans today!
[Re: Streetwize]
#12457
07/28/04 03:35 PM
07/28/04 03:35 PM
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Joined: Jan 2003
Posts: 1,361 Wild West
M_D
pro stock
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pro stock
Joined: Jan 2003
Posts: 1,361
Wild West
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What is the valve length again, or how how much are the spring seats raised? Did they raise the rocker stands also?
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