the results from the head porter, not good!:ball: numbers seem lower than stock. He said he will flow it again to make sure int exh 200 44 55 300 80 71 400 104 83 500 125 96 600 146 109 700 163 120 he does not do nailheads that often, my heads were the last he saw in a very long time. like I said he will reflow them , maybe I should give him a chart to go by. Should I take him the other head. From what you can see in the pics and work that I did its hard to believe they came out so bad. o No:
Snake, if you have a new or good valve job your .100 number should go up if you ported or not. I have been thinking about where he might of got it wrong. Could the .200 really be the .100? That would make it closer to where it should be. It dont make sense. You can open up heads and they will show cfm improvments on a flow bench, then go on your car and the car will run like a dog. What you did should not of knocked down the cfm that much. Take your other head to him a let him try a differnt runner on the other head. Ask him if he is useing clay at the entrance. Also what bore adaptor size. Wish you were closer to me we would figure this out. Hang in there.:bglasses:
Snake, he can have the bore adaptors changed and the head on the bench and flowed and switched from suck to blow in less than a hour. He has had them for about 6 weeks. You might want to talk to him about a week he might do this. He might of lost interest. I had a guy port a set of heads for me once and they came with flow numbers. Then I started playing with the heads my self and wanted to check them and when I told him on the phone what kinda heads he said he was out of buisnesso No: LOL. I couldnt belive it. After that I started looking into my own bench. I dont know how close you are to putting your engine together, you might have plenty of waiting time.
I have time, and at this crucial point I don't want to rush anything. I'm going to get valves and springs still. Clean up and paint the block then Start putting on all the bling bling. As Tom Petty put it " the waiting is the hardest part" !
We've done a limited number of fully-ported Nailhead heads over the years and your numbers are very "suspect". Can't say what the issue is, but there's a problem! I have a few numbers here for comparison just as a reference to a fairly decent port job! On a set of 425 heads with 1.880" intake valves and 1.500" exhaust valves we get the following: Lift= - Int/Exh .100" - 62/34 .200" - 128/83 .300" - 166/107 .400" - 195/128 .500" - 218/142 .600" - 226/145 .700" - 233/145 The above (nominal) numbers are indicative of a nicely ported (Nail) head! I don't have any numbers available today on non-ported iron heads. Thanks, Gary in N.Y. P.S. The above numbers were obtained using a 4.250" plate, this was the final bore size on the build!
Sorry to keep you all waitng so long, but had alot of other things on my plate. this was the final results of my heads flowed. On a set of 425 heads with new 1.880" intake valves and 1.500" exhaust valves @ 28'' with a intake range of 449 and exhaust range of 317 we get the following: Lift= - Int/Exh .100" - N/A .200" - 134/101 30/32 .300" - 190/127 42.5/40 .400" - 220/149 49/47 .500" - 237/162 53/51 .600" - 242/168 54/53 .700" - N/A The guy that flowed them said he picked the best port . Im not sure of the range # could be the plate? and the #s to the right of the CFM #s are what his flow machine read. so intake 449 x 30 = 13470, 134 and exhuast 317 x 32=10144 , 101. He said the inital .100 lift didnt even register it, but I am total stoked with these numbers . of course you would have to do all ports and average them to get a better idea. please give me your imput. :eek2:
Snake...my man. I knew your numbers were better than what he was first telling you. Very good for a first try and no flow bench to test them on. :TU: I haven't tried much stock valve porting but am finding my 1.90 intake valve flows as good as a 1.94. Wow them are some good .300,.400.500 numbers. To bad your cam isn't at least a .500 lift Bob
Bob, explain to me the Range or plate number , how does he get the numbers. The guy that flowed them can do some real great work in making heads flow great and cars to go fast. He basically told me I did as much as I could to these heads and could tell I have a lot of hours into them. He pointed out two small areas for me to work on and that was it. He said he would do no better, without making them full out race heads, that's not what I want. My cam intake lift is .469 and exhaust lift at 496 not .500 but close without having to notch pistons and that stuff.
Well the only thing I can think of would be bore adaptor plate. It is the plate they use and change for different heads and engine size. I use a 4.2" bore adaptor for my nailheads. The rest of your numbers he gave you are above my knowledge of flow benching . Mabey some of the other guys will chime in. I gotta tell you I seen a over sized exh. runner with some epoxy filler that was flowed and it flowed 168 to 170. Nice job on that exh. also Did he ever tell you what the big mix up was?
Okay, this makes more sense. The bench that was used was a superflow 600 there are ranges for that bench: Flow Ranges 1 36 38 2 72 78 3 151 156 4 300 318 5 449 481 6 598 644 So the exhaust test port flowed @ 28 inch 32% x range #4 318 = 101 cfm and Intake test port flowed @ 28 inch 30% x range #5 449 = 134 cfm
Snake, could you share with us what back cut you used? I have been playing with some and am hoping to get them middle lift numbers you got someday. I am going back to a stock valve and start working and testingou: Hope to start back this fall
The valves were new stock size stainless from Russ Martin I believe with a 30* backcut. I realy worked both shortside radiuses. If you look on the cutaway chamber intake to exhaust valves is very thin so dont take out alot there, plus I used a rough diamond bit to smooth out the intake bowls and runners and then touch them with a 80 grit, you can see the lines, I am trying to attempt CNC roughness. take the guides all the way down and tear drop them, experiment with a shop vac pulling from the port and light a oak branch and watch it flow inside the bowl to see with way to tear drop it, I know its the opposite but worked on two ports or just look at my pics and copy. for the runners get a metal or copper wire bend it 90* and use it like inside calipers to see what to knock down,as you go thru the intake. Exhaust gets tricky and too close to boss bolts if your not paying attention and takes alot of bends. Cleaned the chambers with a 80 grit lightly then a 120 to shine it and a buffing bit with metal polish at 25000 RPM on the chicago die grinder, leaves a nice polished finish same with the exhaust runners and bowls. Thats my secret!
