Irocss85

iTrader: (1)

this is for a somwhat budget build, I got 280flow at .600 lift, whick is alright, but that was before the valve job and ofcourse with stock valves. ET performance is doin the valvejob for me and are suggesting REV valves. what kind of flow increase should I expect for the $160 price of the aftermarket valves vs stockers? and, what that only be at low lifts or across the board better flow? like I said Im trying to keep costs down but if there's a def. performance advantage Id get the valves.

here's how the flow chart reads with stock valves and NO valve job yet.

I E
.100 91 83
.200 168 125
.300 223 157
.400 268 180
.500 272 196
.600 281 205
.650 285 210


let me know what you think I could gain with teh valve job and aftermarket valves and if it'd be worth getting the new valves.

the cam Im installing is 235/242 112+2 .650I .610E (the lift might be off a couple thou)
I know Im goin to have to flycut the pistons also. see my other post.

thanks predatorZ for helping me with the cam selection. cant wait to see what kind of power this thing wrings out.

chris

Full-Force

iTrader: (11)

I would like to see some pics of the portwork of your heads. You did a pretty good job especially on the intake going by the flow #'s.

I have ported a set of stockers too and my opinion is keep the job as cheap as possible which means dont do the better valves. The reason is because the more money you put into your ported heads the closer you will be to just buying a nice set of cnc LS6 heads with all brand new hardware.

Studytime

iTrader: (15)

Has the bench been recently calibrated? You got 223 cfm at .300"? That is nearly unheard of, especially for home-ported heads WITH stock valves and valve job.

How big are the intake runners? Please post pictures as well.

Ben T.

staringback05

iTrader: (8)

valves arent a bad idea

Irocss85

iTrader: (1)

I will post pics when i get back from vacation. the guys at ET performance said it flows really well considering I ported them myself. Im goin to guess ET calibrates there machines regularly? arent you supposed to do that every time you use it? I wasnt there when he flowed them so Im not sure. mainly I just wanted to know I wasnt putting somethinng worse then stock on the engine you know what I mean? but I think they did come out pretty nice if I do say so myself. I'll also repost when I get the results from the reflow same cyl. (I marked it) after the valve job.

Irocss85

iTrader: (1)

here are some bad pics. Im no photographer as you can see. plus these were taken as I was trying to leave for work so no time went into the setup. I'll have one head back post valve job tomorrow and still waiting for the re-flowtest of cyl. 5 intake/exh. ports. I'll post those as I get them. dyeing to see if the flow #s were some sort of fluke or will they be duplicated and then some due to the valvejob? we'll see I guess.


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[IMG]100_0399.JPG[/IMG]
[IMG]100_0401.JPG[/IMG]
[IMG]100_0398.JPG[/IMG]

Irocss85

iTrader: (1)

well, I just picked up the new flow sheet and Im not sure what to think. obvoiusly one of the tests were not done properly. or does humidity have alot to do with it? it was a very nice day when I got the first flow test done, and today its raining all day here. I thought they were "corected" to get around stuff like that? also, the first test does not show what bore was used, and the second test was done on a 3.90" bore? that same fella thought my heads were 4.8/5.3 heads. but there not. what bore does the LS1 use? the numbers seem to be consistently around 20cfm low on the second test. the only diff. is the valve job was done though. same cyl. was flowed as far as I know. I told them which one to test. however I wasnt there so maybe they did a diff. port? the orig. test port does have the turbulance ramp alittle lower then the others. which I could see adding cfm, but they recomended I not take the others down quite that far for the sake of a good mixture so the others are just a tad higher then the orig.s. I brought home one head so I could measure piston to valve clearance and see how far I can go on the mill job. I gained roughly .012" by cutting the valvs and seats so maybe I'll get lucky and wont have to notch the pistons. we'll see.

before/after valve job and about 6 weeks inbetween.
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Xtnct00WS6

iTrader: (8)

Make sure you're aware how much PTV clearance the new valves are going to eat up. Not only diameter, but margin size.

mattr228

iTrader: (10)

its not "unheard of" but you have got to be on your game to get those numbers at 28" , and by judging by the port pictures it doesnt add up... whoever flowed them the first time should have known the test was wrong ........trust the second set of numbers over the first

Studytime

iTrader: (15)

I'd still say unheard of for a home-port and stock valve job. After the valvejob low lift numbers should have improved. Anyway, FWIW 255 cfm for home-ported heads isn't bad at all.

Ben T.

mattr228

iTrader: (10)

for a beginning head porter yes ....

Irocss85

iTrader: (1)

yeah thanks. I just wonder what he did wrong? the first test doesnt show the bore used, maybe he used a 4.030 bore. Im a little dissapointed, but I know theyre better then stock atleast.
as for the ptv clearance, stock valves still after all. just decided it wasnt worth it. I'll make pop's step up to a pro-head when he has the cash and desire to make more power. I will be porting his stock heads when they come off though to see if I can improve on this alittle.
I wish there was a performance auto school close to where I lived like SAM. I def. would go there for this type of class. Im a 10 year dealership tech, so no need for the standard auto class', but something like that would be fun to me.
anyways thanks for looking guys.

mattr228

iTrader: (10)

possibly ... tested at a higher test pressure (36" for example), or the calibration be all out of whacK, thats why you test more than once, some things on the flow bench can look too good to be true!

Irocss85

iTrader: (1)

I wish I had the option to test a couple times. actualy thats why I went to ET Performance. figured THEY would know how to test for flow. after I get the engine all apart and test for ptv clearance, Im taking the head back anyways to have them milled. partially to get the best head seal possible and to gain as much static/dynamic compression as possible while Im at it. while back at ET, Im goin to talk to them and explain this problem and see if they will flow it again, while I wait, making sure its the correct cyl. thats being flowed and make sure its at 28" press. so the #'s will be comparable to whats out there. and that will tell for sure which chart is more accurate.

98turbls1

iTrader: (17)

What did you use to port your heads?? I'm trying to do mine and the dremel is doing wonderful but just wanting to get some opinions...

Irocss85

iTrader: (1)

[IMG]100_0369.JPG[/IMG]

these bits used in a dye grinder with an adj. speed regulator for the rough grinding, then switch to a mandrel and sand paper rolls to smooth it all out and give it its final shape. you need a large air compressor to use this setup though since it will go through lots of compressed air. the sand paper rolls/cartriges need around 11000rpm.

mattr228

iTrader: (10)

or you can go with the torque-y milwaukee grinder, they are heavy and tear you up after a good day of porting if youre not used to it, ive had that grinder thrown into my ribcage when a butterfly mandrel bent on me :o, best to put a rev control box on it, until you really need to hog some material out ..... go with several carbides and cartridge rolls ...... http://www.ruffstuff.com is a good start