First trip to the flow bench with my Stage 2 heads. 2" pipe 4"long on the Exhaust. Taper inlet on Intake side 4.5" stand Bore. @28". IN EX 100- 64 56 200- 130 119 300- 180 161 400- 226 204 500- 262 233 600- 278 249 700- 278 255 I am fairly happy with the Exhaust but think more work is needed on the Intake. My combination is: .038 over 455 (with girdle poured lifter valley) Ross pistons (flat top with notches) Eagle H-beam rods 6.635" long pistons are .027 above deck (using .060 copper gas, o-ringed) Stage 2 heads TA 308S cam TA Dominator Intake 1050 Dominator carb Can someone with the fancy computer programs give me a rough idea where I am at for HP now. Thanks In Advance
Jeeez Todd.....all bets are now officially OFF for the first 69 GS Ragtop in the 11's Im gonna go hide somewhere now....you dont play fair:gt: Seriously.....good luk with the project !! Are you planning to put a bar/cage in it ?? do your local tracks let you run as is ??
Todd, Yes, more intake work! I would love to have that set here, for a flow test, to see if something is goofy with those intake numbers. We just finished up a set of SE Heads, they went 321 and 259 at .600 with bowl and chamber work. Good low numbers too.. (226 and 181 at .300) I expect this 11-1 464, with a few extra tweeks and a 250ish duration solid, to make 600-625 HP. It's got the rest of the goodies. I will email you the flow sheet, for your info. It's not a huge $$ deal to make these heads really turn on. They need good bowl and chamber work, and valve work, the ports themselves are already plenty big enough, at the entrances/exits. JW
Todd, The next time you have those heads on a flow bench.... throw that exhaust pipe in the rubbish. Just kidding!!!! It does give you an idea of what the port is going to do with the headers on the car but it does inflate your numbers. I talked with Ron from Ron's Porting Service and a few other well known cylinder head porters about using the exhaust pipe. They all told me that they look at the numbers with the exhaust pipe but that is not what they use to determine which camshaft to use. I would strongly recommend that you call a few of the countries best head porters and ask them about the use of an exhaust tube. With the numbers you posted your exhaust ports are flowing more than 90% of the intake. That is a bit on the high side. Ideally you will want anywhere from 75% to 85% then adjust your camshaft lobes to compliment the flow. Example: 75% E to I use a cam with a 4 to 8 degree larger exhaust lobe. 80% E to I use a cam with a 0 to 4 degree large exhaust lobe. 80% plus keep the intake and exhaust lobe the same durations. Where your heads are at right now you would need a cam designed with an intake lobe larger than the exhaust. So take Jim's advise on the combustion chamber and the bowls. The short turn radius is the most critical area on a cylinder head!!! If you would like for me to send you some pictures of a nice combustion chamber let me know. Has anyone out there heard of people grinding cams with larger intake lobes? Good Luck
Don't worry Alan this is for my 69 GS hardtop, I did switch back to the TA intake on the Convertible that has always been worth .2 so I am confident in that 11 sec slip. Jim after looking at the pictures of the aluminum Stage 1 heads more work in the chamber area between the valves is needed. I was wondering if you enlarged the inner diameter of the seats in those heads.
You definately need more intake work on those heads. As stated previously, you should have those intakes up in the 320 to 330 range. Your current flow could net you around 520 horsepower, , 320 cfm could net you 0ver 610 horsepower. It's really not hard to get the flow up on the heads, and it is correct, the flow aint gonna be found in the ports, they are fine. Jim Burek P.A.E. ENTERPRISES
Hi Todd-I too am doing up a set of Stage 2 TA heads for a mild street motor.They have been ported but with no chamber work.I will have that done to try and pick up the low lift numbers.The flow results on mine at this point(no exhaust pipe) are as follows: IN. EX Lift 75 66 .100 141 117 .200 202 170 .300 252 211 .400 288 240 .500 313 261 .600 The numbers aren't too bad but I would also like to see the intake higher percentage-wise relative to the exhaust.The motor will use my existing Hemi-Killer cam which may work okay with the lack of exhaust -biased duration.I will let you know the numbers post chamber work as soon as I can.This is all not much help to you except to commiserate respecting the lack of spread between intake and exhaust flow at this juncture.Good luck.Rod
Todd, No, not specifically... but they do in fact get enlarged somewhat as they are blended into the casting smoothly.
Yeah, you caught that too Kerry. If the flowing was done on a 4.5 inch bore opening, the numbers will be higher than if done on the correct Buick sized bore. Jim Burek
4.5" inch bore Well that is what Chevy Boy machine shop has written on the flow sheet. It was pretty funny when I was concerned about the numbers and he said they flow better than his ASA sprintcar heads and I said "SO WHAT" I have been looking over the pictures Jim has posted of the Stage 1 heads and noticed where my problems are, and have one cylinder ready to go back. I will keep you posted. :TU:
