Guys (and gals), Below is a link where a guy took an Indy Chrysler cylinder head and flowed them on two different bore sizes. The results are interesting. http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=2281647&an=0&page=2 With all of the testing that I have done on Buick cylinder heads, I have never had a cylinder where the flow continued to go up after .675-.700 lift. I dont know if its because I am too much of a wimp to install a sleeve at the center bolt hole or if its because the valve moves out of the cylinder head and gets too close to the cylinder wall which would causes turbulance. If you flow a cylinder head on a flow bench that has a larger bore then it might make a difference??? I dont know. So when flowing a head on a larger bore make sure the cylinder head is place on the bench so that the outside of the bore would line up with the bore just as it would if it were sitting on the block. I usually put the cylinder head on the block and scribe a line on the head showing exactly where the bore of the block would meet the block. Then the bore on the flow bench is lined up on that scribe mark......... Its been a long day.. I hope that makes sense LOL. The back angle of the valve could also make a difference. Are you guys using a valve with a different back angle??????? Later Later
This made me think of something I had read a long time ago. What they were doing was drilling the head bolt hole between the ports to a diameter large enough for the head of the bolt to fit in (Allen head, I guess) to a depth below the port floor. Then they made a filler piece that would fit in above the bolt that could be cut down much narrower than the bolt was. The red area would be the filler piece. The blue is supposed to be the bolt (don't laugh at my bolt!) ou: Really neat idea.
bore size makes a difference John, bore size does make a difference note the scribe line in the pic below.I not sure but maybe my post with the two different test shows where the air starts to crash at, test #1 at .650 and test #2 at .750 test #1 was done with a 2.200 valve with a back cut and test #2 was with a 2.260 valve with no back cut do to the machine shop error. I had a problem with that other post posting so I had to redo the info and forgot to post the 2 different valves. Like I was saying we couldn't put the back cut on the 2.260 valve do to the valve job being off.This head is the first buick head I seen flow past .650.All testing is done on a Lab Flow 520 bench with a head porter that has been porting many types of heads for 20+ years
More flow test results I just got back from doing some more flow testing on the stage 4's. I will list the 3 different test we've done so far. Test#1 was with a 2.200 int valve with a 30* back cut. Test #2 we did just for fun, we used a 2.200 valve from a big block chev head he was porting. Test#3 was with a 2.260 int valve with out a back cut do to missing the valve job slightly. Test#4 was with a 2.260 int valve with a 30* backcut. ----test-test-test-test lift---#1--#2--#3-#4 .100--74--81--70--76 cfm .200-154-158-140-149 cfm .300-225-225-204-213 cfm .400-281-291-269-281 cfm .500-335-339-325-332 cfm .600-369-362-360-363 cfm .650-382-380-380-370 cfm .700-378-370-385-379 cfm .750-***-***-390-380cfm.......*******means the heads crashed after the .800-***-***-***-379cfm.......last flow # posted****** I talked things over with my head porter and this is what we came up with, he has done about 20 set of various TA heads so far the last few sets were stage2's and 3's. We took 2 identical sets of stage 3 heads, one set we sleeved the head bolt like John was talking about, the other we didn't, every thing else was done the same in these heads. The ONLY differents the sleeve made was more work, and actually the heads with out the sleeve flowed slightly better in the higher lifts. Until now we never had a buick head that flowed much past .650 lift. My head porter has been telling me for awhile that he thinks that the problem is with the short turn, so on this head he went hard after the short turn o No: Did going after the short turn make these heads peak flow higher or is it because the runner is bigger o No: We think there is more in these heads but were done with this project, the only reason I did this test was because there seem to be some interest in the Stage 4's on here so I wanted to see for my self what they were all about. These heads are now FORSALE and we are now moving on to the stage 2 TE heads. Here's another observation: Look at test # 1 and 2 with the 2.200 int valve, the same thing happened with the stage3 heads, in testing it seems both the stage 3's and 4's responded quite well to the smaller valve 2.200 over the 2.260 valve that tells me there is a shrouding problem. The next test will be the stage 2 TE's, we are starting with a 2.200 int valve and then we will try the 2.260 valve. I can't wait to see what happens here being that the 2.200 int valve in these heads are .110 futher away from the cylinder wall then the 3's and 4's so my guess is the 2.260 valves will work better in these heads........Chris
So whats the ancient Chinese secret to the short turn? Did you lay it back more, less or just widen it. Inquiring minds want to know! I know, if you told me you would have to kill me. So tell me then kill me. I gotta know your killing me anyway! :laugh:
1550 For $1550 you to can find out :laugh: If I get some time before they sell, I'll make some templates and send you. John, my offer still stands, if you want to flow them on your bench let me know before they sell and I will be more then happy to send them if it helps, let me know :TU: ......Chris
:Brow: Send them to me Chris........Me and JZ can flow them and then track test them....... Those were 3/8 guides if I remember correctly weren't they?
1 cylinder You guy's will have to build a 1 cylinder. There 11/32. I'm sure there will be a bit of differents between benches, but we aren't racing flow benches. What kills me about these heads is they keep pulling up to .800 lift o No: and keep in mind there's more in these heads we don't have much time in them.
Alan, A couple days ago I was at the machine shop get my guides honed on my stage 3 heads and I said how I need to sleeve the bolt hole between the intake ports. So he starts telling me just put a thin wall brass sleeve in there and you should be fine. Then half way through that he starts telling me how he could put the bolt under the port just like you described in you funny picture :laugh:. He also said you will know right away if you need a chromoly sleeve, just try torqueing the head and if it wont torque we will have to do something. As soon as he started to say it I thought of your picture and said I know exactly what your talking about. :TU:
Hey Chris, This is a nice information that you giving out to everyone. I am sure this info is costing you $$$$$ and taking a bunch of your time so its appreciated when you share. Thanks! Its interesting to see the how the valve diameter kills the low numbers. And its kind of what I have seen also. The higher numbers are a bit surprising and very nice indeed. The smallest part of the ports is right at the top of the short turn. I thought by removing the head bolt bulge would help open up the cross sectional area at the point. But again.. I am wayyy to much of a wimp to try it and ruin a good cylinder head for 10-15 cfm. Did your head porter say if the ports got noisy with any of these valves???? If the head bolt bulge was removed the port become more quiet??? If you dont mind me flowing the head I would love to do it but I honestly dont know that I want to be responsible for losing a cylinder head that your trying to sell. Again.. great information and thanks for sharing!!!!!
heads John I've been at all the flow test over the years, the head porter is a good friend so the stage 4 deal was free, I was only trying to give some input here to help give some input (right or wrong) :grin: .There was no abvious crashing of air this time like we had on the stage 3's the air seemed clean but we didn't have alot of time this last time out. I don't know if you recall the 2 sets of stage 3's we tested one that was sleeved and one that was not, the on that didn't have the sleeve started to turbulent at .580 lift and the one with got turbulent at .540 lift . Both sets of heads were the same other than the sleeve and the head without the sleeve got alittle more work in the short turn, it also flowed slightly better through most of the lifts.I would like to see if someone else has done a test like this or are they just assuming it made a difference. I just like you though it would make a difference thats why I did the sleeve deal. I also know there is more air in these heads but I set out to do what I wanted to do here. And yes the higher #'s are more then surprising to me. Now as for you testing this head, there is not alot of people I'm comfortable with testing or using my speed parts but you and or Gary are a couple of them. It may or may not help your cause, I don't care about the sale of these heads, helping out a well respected fellow buick guy is more important. Rick H will be here within the week I will see if he can drop them off to you......Chris
Make an offer?? If anyone is interested in my stage4 heads there going cheap so make a offer, the worst that could happen is me saying no. I want to move on to other projects now that my 540 is gone.Thanks..........Chris
