Hello Buick Guru's, What do you think about trying this modification to a Stg 4 cylinder head. I was thinking of lowering the port entrance to increase he cross sectional area at the pushrod hole??? My intake is an Indy intake that has epoxy in the floor because the runner was larger than the Buick therefore it could be lowered to match the intake port and cylinder head. This would also increase the overall volume that a larger cubic inch engine requires.
Another question..... Do we really need that air flow directional device at the top of the runner. If swirl is so important wouldn't that stop air swirl???
A man after my own heart. Now John what could be on your mind:Brow: I love that special touch of the head on the kitchen/dining room table with that dash of Christmas decorations. Best of luck on your quest. Happy Holidays! Rick Martinez
John, I think this is something you should pose to someone like Greg Gessler directly. This way you know you would be getting input from a "professional" source. I wouldn't chance something like this with a set of those heads. But then I can't prop up my heads on my wallet. Mine is to thin.:ball:
John, I'm no Guru, I have too many unanswered questions in my head for that, but here's my take. Before anything, Make a latex port mold and measure the cross section area's thruout the port, to see if the 'pushrod area' is truly a restriction. Also keep in mind that the 'pushrod area' is straight and air flow has a easy time traveling thru there, Its the bend into the bowl area that makes or breaks a head.... Along with a half of dozen other issues.... Be careful of sudden port size changes within the port runner.
Not a guru; just being nosey. I thought the Stage-4 cylinder heads off-set the pushrod hole locations so they on longer protrude into the intake port? Have you already widened the ports beyond stock? Nice photo, but your wallet already looks a bit thin.
Rick, Considering this was my birthday present to myself therefore any Xmas gifts are for the wife!!!! Bill, I can use my wallet to hold up the whole engine since there is sooooo much hard plastic inside it. Greg, I have heard of people using a latex in the port to measure cross sectional area. Do you know of a place where I can purchase this material? Also Greg, what do you think if that air directional device on the roof of the head? While at the PRI show I noticed that NONE of the cylinder head manufacturers used it. Tommy, The port has not been touched from the entrance into the port about 1 1/2 inches. When looking at this area it seems like it would be the smallest point of the port. I know it SHOULD BE... but maybe it could be a bit larger. o No: Thanks for the input guys!
John, I have actually done exactly what you are talking about on a set of stg-3 heads. I got some really excellent flow results, and I don't just mean at high lift. I have even done to a lesser degree something similar on the iron stg-1 stuff in the past. If you want give me a shout, we can talk. Jim burek P.A.E. ENTERPRISES
stage 4 heads Hi John, if I remember right on my stage 4 heads the smallest cross sectional area is a inch or so in not at the opening. With just mild port work 2.19 valve(too small of valve next test with a 2.25) they went 386 cfm @ 680 lift (PEAK) and low #s were good to boot. We tried titanium bbc valves and it did not like the angle on the back side of the valve the TA's flowed way better, to my head porters surprise (chev guy). We tested with the bump for the head bolt still in and with out bump and it did not changeo No: As for the floor Ta moved that up for a reason. You don't want to ramp the air up and try and make the short turn it won't work. The short turn is the problem area. Are next test will be 2.25 valve,then sonic test the short turn to see how hard we can work it. Head porter says we need to change the short turn and at the same time not screw up the area before the valve grind. For example on my stage1 iron heads we raised the floor 1/4 inch at the opening to level the floor and it picked up big time peaked @ 306 cfm @.600 lift as well increased the .300,.400,.500 lifts. I believe with the cross sectional area you have with your stage 4s, horse power will peak @ about 6600 to 6800 rpm, Do you want to spin a buick higher then that and make it last the season? I won't be testing till the new year but I will let you know how it went. Do you still want are crank grinders phone#? I hope you have a merry xmas and happy new year:beer ...Chris
Let me just start off by saying I am not a head porting expert, but I did work in a Turbine refurbishing plant for a year where all I did was port on turbine vanes for jet engines and run them on air flow machine. Porting the bottom of a runner is a no no !!! While this may increase your runner size, it also makes a sharper turn on the bottom of the runner to the intake valve, sometimes called the "short turn radius" The "short turn radius" needs to be as smooth and gradual as possible. The steeper the angle of approach you have on the short turn radius, the better flow you will get. (Hence, the advantage of a raised runner head) Runner size is not as important as flow, so do not go by what size of runner you need for a certain size of engine, it is the head flow the engine needs, not the runner size. If you do have somebody do port work to you cylinder heads, make sure they know what they are doing. Also have your heads flowed so you can see if progress has been done. There are a lot of guys out there that claim they can port really good, but do not have a clue about the physics and geometry involved in head flow and velocity. If they do not know any of this, do not let them touch your heads, especially since they are stage 4. Blair Phillis
I want to know too. Do you have to use a realease agent before you pour to get it out of the port?o No:
Hi Guys, John....I know that you can purchase the latex materials and the release agent from Bill Mitchell Hardcore Products. His website is www.theengineshop.com. Hope this helps...
Thanks Kerry, you have an answer to every wierd a$$ question I ask!:TU: I found the hardcore stuff but was sticker shocked (I'm a tite one) SOOO I started some research and found this site: Click here It said you can find the stuff at a hobby shop. I don't know if it is any cheeper. I 'll have to make a run to hobby lobby.
stage 4 those should be hi port heads they raised the runners to direct air flow at the valve in the most efficiant way.i would call ta about porting or jim at tri shield perf as they would have the best info for ya. andyo No:
Results thus far: Lift.... .300 ..... .600 Int .... 218 .... 353 Exh.... 185 .... 256 Int vavle 2.20 Exh valve 1.80 Take a look at the pictures. The restriction seems to be at the short turn and the valve guide area. The numbers (circumference) from the plenum to the valve are as follows. 7.47 .... 7.47 .... 7.47 .... 7.12 .... 6.95 .... 6.95 .... 6.60 .... 6.25 .... 6.25 .... 5.90 .... 6.08 .... 5.90
Another pic of the layout. At this time the short turn radius is around 1.00 inches. If your running a 2.20 valve is should be 1.10" radius.
