streetknight
DCVING
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- May 26, 2001
- Messages
- 1,105
Anyone have this info? I've found a lot on the champions and others, but not the stockers.
Thanks.
Thanks.
Stock head flow #'s..
- Thread starter streetknight
- Start date
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This is what I found in another post. These cars are amazingly quick to have such terrible flowing heads.
Taken from the TBN-The Source Newsletter...stock heads.
Intake (lift, flow rate @ 28 in H2O)
.100, 51.7
.200, 108.2
.300, 149.0
.400, 152.2
.500, 155.1
.600, 158.4
Exhaust (lift, flow rate @ 28 in H2O)
.100, 45.1
.200, 83.9
.300, 101.2
.400, 108.2
.500, 111.1
.600, 114.85(this one is interpolated at this lift)
Taken from the TBN-The Source Newsletter...stock heads.
Intake (lift, flow rate @ 28 in H2O)
.100, 51.7
.200, 108.2
.300, 149.0
.400, 152.2
.500, 155.1
.600, 158.4
Exhaust (lift, flow rate @ 28 in H2O)
.100, 45.1
.200, 83.9
.300, 101.2
.400, 108.2
.500, 111.1
.600, 114.85(this one is interpolated at this lift)
That is a mostly incorrect statement of the thermodynamics of forced induction. There is a temperature increase when a gas is compressed, but it has very little to do with "shoving boost through a small hole". The temperature increase is in the turbocharger, NOT in the intake, or in the heads. And the intercooler takes care of most of the heat. The air flow is SMALL, because the engine is SMALL. 231 cubic inches, last time I checked. And the fuel choices are the same as if you had chevy or a ford-
I'll have to keep this thread alive... I believe the stock head (ported) can flow pretty *close* to what some of the aftermarket heads that are available now flow. I'm going to be running stock ported irons on what i hope will be a 9.?? s machine... maybe i'll bench them before I put em on and see how much an exhaustive porting job can be worth, then we can compare em to an aftermarket head's numbers.
So far, I have about a half of a year's worth of work on the porting... there isnt much more wall thickness in some spots by my gauge, so i think im at the limit in the critical areas. The intake ports are sized for a felpro 1200 to match the SM intake i have here... the exhaust ports are also about as large as i would like them... not too much wall left (maybe an 1/8" or so) for the header to seal against.
I, too, would like to know who out there is running how fast on these stockers.
Regaurds,
Phil
So far, I have about a half of a year's worth of work on the porting... there isnt much more wall thickness in some spots by my gauge, so i think im at the limit in the critical areas. The intake ports are sized for a felpro 1200 to match the SM intake i have here... the exhaust ports are also about as large as i would like them... not too much wall left (maybe an 1/8" or so) for the header to seal against.
I, too, would like to know who out there is running how fast on these stockers.
Regaurds,
Phil
Ormand said:
If that is true and boost is actually a measure of resistance to flow, then why wouldn't the temperature of the air entering the combustion chamber decrease with ported heads due to less less resistance even though the volume of air is still the same? I have difficult time believing that temperature of the air does not change with size of the path air is moving through if the volume of air is the same.
PhilM said:
There is a post of good discussion about ported heads and a person running 9.60s if I remember correctly @ 141 mph with Champion ported irons. My VPE heads flow more than Champion Irons and are only about 10 cfm from out of the box Aluminum heads so I agree with your statement.
I didn't say "boost is actually a measure of resistance to flow", and I would not say it, because it is NOT TRUE. "Boost" is the ratio of pressure, pressure on the compressor outlet divided by pressure at the compressor inlet. There is NOTHING in that definition about "resistance to flow".
If you had any experience with engineering fluid flow systems, you would have no problem at all believing that. The only effect that the passages would have on temperature would be from friction- and in the short runs that are involved there is insufficient friction to cause a significant temperature change. Probably not enough to cause a measurable change.
If you would like, I can suggest some reading for you to learn the basics of flow. In the meantime, streetknight asked a question, and I answered it, factually and correctly.
Ormand said:
Actually, I believe he asked for the stock head flow numbers, but I could be wrong. This is a conversation that would probably be better continued through PMs or email. I'm interested in this because it's an area I'm more familiar with in practice than theory after putting a turbocharged 99 GT into the 10s on pump gas using incredible flowing P&P heads. It was impossible before that so something changed.
streetknight
DCVING
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Thanks for the info guys and this is a good discussion. I've just got my heads off was wondering if it was worth the bucks to go with champion irons or something while the car is down.
streetknight said:
Here is the route I took for $1,000 shipped to my door for the stage 3. I have several pictures of the heads and flow sheet numbers in a word document if you want further information.
http://vperacing.net/page14.html
Champion irons are more popular, but after seeing several of the results that people have received with VPE heads, i decided to go this route, plus it was less expensive.
http://www.turbobuick.com/forums/showthread.php?t=142097&highlight=vpe+HEADS
This post had a decent amount of information that might help you.
buickpower
polytetrafluoroethylene
- Joined
- Jun 27, 2003
- Messages
- 1,079
Ormand is dead on the money. I never liked the analogy of boost being a measure of resistance to flow. That might have some bearing if you were talking about a blower, but it seems people forget that the turbo is a compressor and that the air is already compressed as it comes out of the turbo outlet, not being compressed as it goes into the head like a blower. That "something" that changed on your mustang was naturally that you increased port area, but it didn't have much to do with the air being cooler because of a larger port size.
hmmm here is an interesting thing i found out just by swapping turbos the other day on stock heads, i went from a TA60 to a TE60 thats about 70cfm difference between the turbo's the ta60 had a .59 exaust wheel and the te60 had a .63 exaust wheel both being precision, making no changes whatsoever except the turbo when i went out for a test my boost went up from 21psi straight up too 27psi at WOT, i would assume this was due at trying to shove more hair from the turbo through the little heads this created back pressure on the lines hence the extra boost due to resistance from poor porting this heads suffer from.
You're right. I was not answering the original question, and we all got sidetracked.
In the Buick "Power Source", there are curves for flow through stock heads. But they only did the intakes, and they used 40" instead of the more standard 28". One is ported, and one is not. The interesting thing about their curves is that the unported heads flow more, up to about 0.40" lift. That means that you could port some heads, and if you are using a mild cam, you could end up with less flow, and less power, than before you did the heads. Like they say, it's all in the COMBO, you have to get everything to work together.
Don't know what the limit is, but I'm sure it's been discussed. But Tom Cramer (Jace's relative, I'm sure) has gone 10.85 on unported stock heads. That was in Las Vegas, so there's more there, I would think. (See the RJC web site for description) 'minor bowl work' is all he had done, still had the stock valves. And the A/C still works!
increased heat
anytime you increase velocity, AND pressure, you create heat.
how much, I dunno, but air movement past a fixed object, (or vice versa) will always create heat, look at the space shuttle, it glows red from the resistance to the atmosphere, ( I know were talking kinda fast, like apples and oranges) but the same hold true for air thru a port, or intake.
yes the intercooler cools it some, but the resistance in the intake port causes some increase in temp.
any improvement to resistance in air flow, will likewise create a decrease in temp.
I'm no rocket scientist, but thats what experience has shown me.
anytime you increase velocity, AND pressure, you create heat.
how much, I dunno, but air movement past a fixed object, (or vice versa) will always create heat, look at the space shuttle, it glows red from the resistance to the atmosphere, ( I know were talking kinda fast, like apples and oranges) but the same hold true for air thru a port, or intake.
yes the intercooler cools it some, but the resistance in the intake port causes some increase in temp.
any improvement to resistance in air flow, will likewise create a decrease in temp.
I'm no rocket scientist, but thats what experience has shown me.
Did your experience involve any super sensitive temp measuring instruments? Friction at space shuttle speeds and friction at intake flow speeds are not apples and oranges. More like apples and redwood trees. The space shuttle is traveling at something like Mach 16, 16 times the speed of sound. Don't know the speed of sound at that altitude, but that velocity is still somewhere on the high side of 10,000 feet per second. In an intake manifold, or the ports in head, the velocities are more like 200 t0 300 fee per second. Energy for heating is found from a (V) squared term, so the energy involved is more than 2500 times as much. In addition, when supersonic speeds are involved, you get "shock heating", when the air next to the surface is subjected to a shock wave. I didn't say there was NO heating- I said it was insignificant- maybe one or two degrees. One or two degrees is "some increase in temp", so I will agree with you that much.
Ormand said:
I think that makes sense from a standpoint of not using boost to force air in and the drop is due to less velocity. Could explain why cars like the S2000 rev to 9,000 rpms to make power. The velocity of air is so slow because the ports are so large. I would think under a boosted condition, this wouldn't be the case, but I could be wrong. There have been several guys that have put on P&P heads and run 11s with the stock turbo and 20 psi. I would be interested in seeing the fastest cars on pure pump gas with ported heads and not ported heads. I plan to only run pump gas so I wanted the best flowing irons I could get.
