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Yes you can make an exhaust port flow a lot more if there is enough material to get to the right port shape. The vast majority of mass produced CNC ported heads have a generic NA port programs. Most of the higher end porting shops offer some specific options for power adder heads. I have some 18* heads that flow almost 290cfm on the exhaust with a 1.600" valve and I have some AJPE 13* heads that flow 325cfm with a 1.625" valve. Both ports have a almost conical port profile to achieve these numbers. The 18* port exit is a rounded square shape, sorry I don't have a pic on my phone to post of that one. The pic below is the AJPE SB head, to put it in perspective the smallest header tube that can be run is 2.00" and it just barely large enough to not cover the port.

Holy smokes! That's a lot of exhaust flow, particularly out of a 1.600!! Same with the 1.625! I can almost see the picture although it is blurry. I am not sure what I need to do to see Photobucket pictures. But I can see enough to get the idea. I used some long reach probes to measure where the water is, (not calling them the right thing, where's the coffee!) and it appears that I have all kinds of room before hitting water. I have promised myself I would build a flow bench someday. Still hasn't happened. I'm using 1-5/8" primaries right now for headers, which probably doesn't help the entire picture. But at least I can open up to what I am using.
Thank you!
 

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Discussion Starter #23
The Profilers definitely are impressive and much more budget friendly than a symmetrical port head. Leaning towards just dry decking what i have and turning it up more.
 

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For me: Oh heck yes! But not in the budget for now.
I have heard that the lower valve angles tend to be less forgiving with the tuneup. Myth or reality?
They can be pretty easily managed with correct chamber profiles down to about 12* valve angle. There are heads with half that valve angle but they are specifically designed around boosted applications and piston crown design comes into play with this as well. The issue is not so much the valve angle but most of these cast heads start out being designed around NA combos and the chambers tend to have a very thin cross section due to the shallow valve angles. This make the chamber very efficient and has a very fast flame travel speed. The polar opposite of this would be a big, fat, slow hemi chamber that pretty much sucks NA but is king of boosted engine designs. Softened wedge head chambers try to get them a conical as possible to slow them down. The shallow valve billet heads designed for boost are designed around having the correct chamber profiles right off the machine. My AJPE SB heads are 13* splayed valve arrangement but have a 63cc chamber.
 

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Discussion Starter #27
Would love feedback from fast sbc guys as to what i might want to try next to keep the heads sealed up next season.
 

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Discussion Starter #29
Just Hylomar and no re torque. I did put a tq wrench on them and pull them back to tq before disassembling and the center ones took a small amount of turn before clicking but not much, the outside studs mostly all clicked without any amount if turn.
 

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Were they also new studs ?

I think I would just have the heads surface minimum , new studs , and back together .

Let the Hylomar set up for a few hours before installing .

Torque in three steps to ARPs recommended specs for the studs with their molly lube .

heat the heads and block with a couple heat guns . It takes quite a while , but you can get it pretty damn hot .

Wait til the next day a re-torque one at a time loosening the nut first , not just re-torque .

Im not sure I would go as far as checking the deck , but if you have the time and the $ , I would start from scratch .

I also scotch bright the gaskets and clean with alcohol even when they are new . Never annealed them , but some guys swear by it .
 

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Discussion Starter #31
They were brand new arp studs torqued in thier sequence with thier lube. I know i didn't let the hylomar set up that long and I'll definitely do the re torque this time.
 

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I run a inline chevy 6 1962 to 1980 style, it has a very shallow valve angle like 9* do you guys think it would help to soften the chambers like Allan Johnson sb heads. I run a hemi dish piston.

Also do you guys use Hylomar spray on the gaskets ?

I have been using Cometic head gaskets the gaskets don't blow but the head gets very hot between exhaust valves like in the one picture and gets the aluminum soft so that the steel gasket imprints the head surface, it's a filled block because the head studs would break out of the block, and I have special inserts that go into the block filler for more strength. It's a dry deck.

35 years of fixing the next weakest link. But It's fun to make a lot of HP.

Would clark copper with "o" rings be better than the Cometic that try to imprint? and may transfer more heat to the water in the head.
 

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Clark's gaskets don't need annealing as they are already put thru a special heat treat/annealing by Clark before being cut out. Use spray Hylomar, it is much easier to get a even coating on the gaskets. It is not as blue as the other types so try to not over do it because it's hard to see. The extra will flow out over the course of several hours. Re-torque after one(1) full heat cycle(no boost) is a good idea. I have used a propane bullet style space heater to heat cycle while the intake is off. I just hange it from the engine hoist and let it blow down I to the lifter valley. I also use a hot water setup I made that uses an electric tankless hot water heater and a remote electric water pump that works awesome.

Clark will cut the gaskets with small holes or no holes if you have any areas it would help sealing. Don't get the gaskets made any larger than the bore size. There are also ways to either feed coolant between/below center exhaust ports or return from there so either way cooling is increased and steam pockets are not formed there. Many heads/intakes can be drilled/tapped in the center to return water from this area also.
 

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If you can keep enough CR a parabolic dish piston can be used in place of chamber softening if having them machined is not an option.
 
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