redtail2426

iTrader: (10)

Before i post up results i will tell you this is on an 853 head and i ported one intake runner,one exhaust runner and removed the rough casting finish in the chamber.On the intake runner i only removed 8cc-stock-202-ported-210..On the exaust it was the same 8cc from 72-80cc.I then had the two runners i did flowed and two completely stock runners.This was done on a superflow 1020.They used a 4.125 bore fixture,and said its no big deal as this is an a-b comparison.I will get some pics up later of the ported set.I will probably do more work on the intake runner and have it done again,as most people remove about 20-25cc worth of material.My buret to cc the runners came in the day i went to drop off the head.Now that i have it i can gauge my grinding.here are the numbers.Great mid and low lift on the intake,and i reduced flow on the exhaust in the low lift somehow.The intake started slowing down after .450.



Intake stock/ported
.05 29 33 +4
.100 61 65 +4
.150 95 102 +7
.200 131 142 +11
.250 165 176 +11
.300 190 204 +14
.350 204 224 +20
.400 211 241 +30
.450 216 242 +26
.500 223 245 +22
.550 228 251 +23
.600 231 256 +25
.650 234 259 +25
.700 236 264 +28


Exhaust stock/ported no pipe
.05 24 26 +2
.100 58 56 -2
.150 84 83 -1
.200 105 104 -1
.250 124 118 -6
.300 140 134 -6
.350 157 149 -8 ouch
.400 167 170 +3
.450 174 183 +9
.500 179 193 +14
.550 183 200 +17
.600 185 206 +21
.650 187 209 +22
.700 188 211 +23

allngn_c5

iTrader: (3)

Not bad for an at home DIY project, but way off on the aftermarket bro. I'd be careful about hogging out the intake ports too much. You may increase the flow some, but if you kill a/f port velocity the heads are going to make the car perform like a dog down low. Not to say that it wouldn't benefit a track car, I am saying a street/DD car.

Looking fwd to seeing the pics.

allngn_c5

iTrader: (3)

I cut and pasted this from one of Tony Mamo's threads. Very good info, thought you might be interested.



All numbers recorded utilizing 4.125 bore unless otherwise noted.

“T” indicates turbulent and could not record any data

“Stg 3” heads were heads that I knew were advertised as such. Others might have been “Stg. 3” but I only labeled heads I was sure of.

INTAKE FLOW

Head…………Int. Valvelift…………………..........Runner
…..….200….300….400….500….550….600…….Volume……… …Comm ents……….

“A”….136….199….257….294….305….313………232 cc’s
“B”….134….195….239….267….280….289………229 cc’s
“C”….131….189….240….275….287….282………221 cc’s…(LS1 castings)
“D”….141….206….259….291….303….313………231 cc’s
“E”….145….203….253….295….309….321………246 cc’s….Stg 3
“F”….141….206….263….300….315….332………245 cc’c….Stg 3
“G”….135….201….260….304….316….”T”………239 cc’s……Stg 3
“H”….140….211….260….285….286….287………243 cc’s……Weak for size
“I”…..137….207….252….290….306….318………242 cc’s……Stg 3
“J”.….126….186….231….263….277….290………228 cc’s
“K”….121….190….246….278….293….306………230 cc’s
“L”….146….208….264….301….314….323………237 cc’s.Stg.3 (good overall)
“M”…137….207….252….290….306….318………242 cc’s……Stg 3
“N”….136….190….249….288….301….312………241 cc’s……Stg. 3
"O"...147....213...264...300....308...304..... .249 cc's.....Stg. 3
"P"....144...205...259....299....316...330.... ..24 9 cc's....Stg. 3
"Q"....129...200...258...295....305...308..... .232 cc's
"R"....135...200...251....293....311...317.... ..25 4 cc's....Stg3 (BIG!)
"S"....148...200...247....289....301...304.... ..23 1 cc's...LS6 head w/ 2.02
"T"....132...195...240....283....296... "T"......227 cc's...LS1 head w/ 2.02
"U"....136...194...248....267....275...281.... ..23 4 cc's....5.3 head/weak #'s
"V"....128...186...238....274....287...293.... ..23 1 cc's
"W"...141...206...256....299....315...324..... .236 cc's ...LS6 Casting/Good#'s
"X"....143...207...265....298....313...."T'... ...2 40 cc's....Ported 6.0 Casting
"Y"....136...197...242....281....294....293... ..23 0 cc's...Stg 3 (soft #'s)
"Z"....137...211...270....310....324....336.....24 0 cc's ..New "Best" peak #'s
"a"....138...205...259....295....304....309... ..25 4 cc's ..CNC Ported Dart/BIG
"b"....160...240...305....342....N/A....368.....275 cc's ..."b" for BAD AZZZZ!
"c"....141...214...267....303....306....311... ..21 5 cc's....Very good #'s (11')
"d"....138...215...264....304....317...."T"... ...2 29 cc's....Rolled Valve (13.5')
"e"....158...228...279....315....324....331.....23 0 cc's....Huge area under curve
"f"....161...225...272....312....321....323.....24 0 cc's....Very solid #'s!
"g"...159...228...281....314....324....330.... .230 cc's....Ported AFR 225's
"h"....142...202...260....303....316....323... ..24 9 cc's....Hand ported 205 casting

AVG..137….200….252…..289….302….308....…237 cc’s

AirFlow Research #’s
205….145….210….257….290….301….308………205 cc’s...(205 w/ 4.125 #’s)
225….151….221….270….306….315….322………229 cc’s


EXHAUST FLOW w/ 1.875 pipe (curved to simulate header)

Head………….Exhaust Valvelift…………………..Runner
……...200….300….400….500….600............Volum e

“A”….113….150….180….208….230…………….84 cc’s
“B”….107….147….196….218….228…………….85 cc’s
“C”….107….153….184….205….217…………….82 cc’s
“D”….112….165….195….215….228…………….86 cc’s
“E”….111….156….202….235….246………...…88 cc’s
“F”….126….170….204….226….236…………….85 cc’s
“G”…117….164….201….229….242………………87 cc’s
“H”…113….156….189….221….231………………85 cc’s
“I”….114….145….179….211….237………………87 cc’s
“J”…..97….133….166….193….213………………89 cc’s……Very weak for size
“K”….117…157….194….218….228………………83 cc’s
“L”….114….155….214….238….252……………..90 cc’s……Big, but good #’s
“M”…120….177….219….240….251……………..87 cc’s….....good #’s
“N”….105….144….177….208….222……………..89 cc’s……Very weak for size
"O"....115...166...202...228...241............ .88 cc's
"P"....116...163....211...236...241........... .84 cc's
"Q"....109...156....208...224...227........... .89 cc's.....Weak for it's size
"R"....113....156...195...227...241........... .91 cc's......(BIG!)
"S"....108....146...188...226...235........... .84 cc's....Soft low/midlift #'s
"T"....120....171...200...217...224........... .84 cc's...1.570 vlv, good low#'s
"U"....111....147...189...209...224........... .84 cc's
"V"....111....144...168...186...194........... .86 cc's....VERY weak Exh #'s
"W"...126....177...215...230...241............ 82 cc's.....Good #'s
"X"....115....150...177...194...208........... .89 cc's....Very weak for size
"Y"....119....160...182...195...200........... .83. 5 cc's..Small port/Very soft #s
"Z"....117....170...215...241...253........... .95 cc's.....BIG port / strong #'s
"a"....114....153...193...220...233........... .90 cc's.....BIG port / avg. #'s
"b"....120....176...205...221...230........... .86 cc's.....Needs MORE!
"c"....118....164...207...232...245........... .96 cc's.....Good numbers / BIG
"d"....110....174...213...231...240........... .84 cc's.....Good #'s
"e"....128....184...228...245...253........... .85 cc's.....Big numbers everywhere
"f".....124....164...203...226...235.......... ..84 cc's
"g"....131....179..230...249...255............ 85 cc's.....Ported AFR 225's
"h".....119....160...189...213...227.......... .?? cc's.....Weak considering intake flow/size

AVG...113….157….194….219….230…………….86 cc’s

AirFlow Research #’s
205….118….171….206….226….240……………..84 cc’s
225….120….180….220….241….250……………..85 cc’s


What's interesting to note is how well the AFR 205's faired among a group of cylinder heads that have a huge advantage in port volume. It becomes a little clearer why the 205 has consistently put up good numbers on the dyno and great results on the street.

Hope you guys enjoyed the data....It represents quite a bit of time invested.

Regards,
Tony Mamo

redtail2426

iTrader: (10)

yeah i think if i just remove the swirl ramp,maybe bring the port up to like 217-220 and it should flow much better past .450.The exhaust lost some because the valve seat on the short side radius sticks into the exhaust port a lot.Real bad core shift from the seat on that side.And i blended the seat in on the short side.I will get pics up tonight to show what i am talking about.For a 210cc port its not too bad.

redtail2426

iTrader: (10)

okay i discovered what happened with the exhaust when i was able to get a look at it.The guy that flowed it said it was probably something i did with the valve job or the short turn radius.Since all i did to the short turn was sand it i knew that wasnt the problem.I made the mistake of opening up the valve seat just ahead of the valve job.I did this to try and blend it in with the bowl.Since these 853 heads have such a huge difference between the seat and bowl,it becomes a bit of a problem.The only way to fix this is to intall a new seat,which i dont plan on doing.This particular head will be used as a learning tool.I will get up some pics of the exhaust port later when my better half gets home with the camera.But i have a couple pics i took before of the intake port.If i could add material in the exhaust port in one particular area then these could flow really nicely at those low and mid lift numbers.

redtail2426

iTrader: (10)

here are the exhaust pics.The stock one you can see the nasty transition from the bowl to the seat,thats what F*&$#ed me up.

02 BLK WS6

iTrader: (11)

I'm in the process of porting a set of 241's right now. I plan on keeping the intake a little rough and will smooth the exhaust. It looks like you're doing a good job that should net some decent gains.

Nitroused383

iTrader: (10)

Here is a pretty good article that might help you out. I'm not sure what you are running from a valve job, but with a good valve job you can pick up 20-30 cfm. The valve job and the bowl are the most important areas. Also the throat should be opened up to %86-89% of the valve size for max velocity. Looks like your spent some time on those, how long did that take you? I ported a set of sbc dart iron eagle heads, I will never port cast iron heads again, it takes forever!

http://www.enginebuildermag.com/Arti..._the_flow.aspx

lt1mf

iTrader: (3)

so what kind of power gains could you expect with what youve already gained??

Havok2

iTrader: (118)

good job for home port.

5_02ls1

iTrader: (20)

ive done 3 sets of ls heads in the last year each set took 20hrs+...the bowl areeas seem to take the longest espeacially on the exhaust side....

Jessica

That is pretty SAD considering the bore size.... to bad they aren't all tested on the bore size guys run them on. Any of those "Bad ***" heads that also have some king kong .200" lift flow number will be turds.... not to mention without dyno testing them it doesn't say anything.

Haans249

iTrader: (24)

Turds in what sense? Heads with high low/mid lift flow will make MAD torque. They won't be turds, they'll pull them right out your ***. Now if you're talking about the 275cc head, yes, they won't work well on a 3.9" bore and will be slow to build port velocity and torque, but anything 4.125" and larger they will shine.

Mikey 97Z M6

iTrader: (37)

Did you unshroud the valves in the combustion chambers at all? You can pick some impressive flow just by doing that. Just make sure you don't go larger than your bore size.

Mike

Rapin'Ya

iTrader: (1)

Pull the short side back in the intake and make sure your hook wall is straight. You should pick up the flow after 450 lift. Also check your valve and seat angles cause that will also have a lot to do with it as well.

Rapin'Ya

iTrader: (1)

How do you figure the .200 numbered heads that are strong will run like poop? Are you sure you know what you are talking about? .200 is the largest lift area on the cams. A strong .200 number will fill a cylinder very well with a cam to complement the port. Please refrain from talking out ya *** and assume the position...

Only thing I agree with is the heads are very week considering the bore size they are flowed on.

Jessica

Boys, boys, boys....

I can tell you haven't passed physics class... or math class for what I can see here.

1. ".200" is the largest lift area?" Are you joking?
2. "Heads with high low/mid lift flow will make MAD torque." Have you ever dyno tested your "theory"?
3. "A strong .200 number will fill a cylinder very well with a cam to complement the port." I guess you have never heard of a guy called Bernoulii? Maybe you should get out the text books or and figure that one out.

At least you realize the bore size pretty much makes that whole test irrelevant for any "Gen III" LS user.

Jes

Talking cars with young boys is almost is bad as dealing with their pickup lines!

BigKap94z

iTrader: (47)

HA, i gotta subscribe to this thread. it should get good soon.

67STRIPES

iTrader: (2)

kmracer

iTrader: (1)

lol, i know exactly what happened. he skimmed over partick g's article on making 500whp on a stock short, and pat talks ALOT about low/mid lift characteristics and how they affect cyl filling and such. i dont think that he quite took the point right. pats point was merley not to forget about these numbers, especially seeing as most guys run a FAST intake and 280+cfm numbers are cant quite be taken advantage of with the FAST intakes...


some people though...