Those who know about flow benches and heads come in!
10-22-2004, 02:10 AM
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Those who know about flow benches and heads come in! Ok, so different flow benches will flow different numbers, I can understand that. How much variance between benches are there and does location, like east coast to west coast make a difference at all?
What i'm trying to figure out is if I got my moneys worth out of my heads. Instead of going to one of the sponsors to get my heads, I went to a local fbody shop who uses their own porter. I forked over two grand even, and this is what I got.
lift int exh
.200 132 109
.300 190 151
.400 237 182
.500 270 202
.600 288 215
stock int# - % exh / int
.200 120 80%
.300 174 79%
.400 217 76%
.500 255 74%
.600 239 74%
they're 5.3 heads (862) 2.00 intake valves 1.55 exhaust. This was all porting, no polish work.
I read that you should look at the numbers compared to what they were stock because of fluctuation in flowbenches, but when I look at the heads like the TEA's that put out more flow, for the same amount of money, I don't know if it's the bench, location, or if i just didnt get what I paid for. Pluss I really don't know what to look for because I really have nothing to compare to..
what do you think?
Thanks as always!
What i'm trying to figure out is if I got my moneys worth out of my heads. Instead of going to one of the sponsors to get my heads, I went to a local fbody shop who uses their own porter. I forked over two grand even, and this is what I got.
lift int exh
.200 132 109
.300 190 151
.400 237 182
.500 270 202
.600 288 215
stock int# - % exh / int
.200 120 80%
.300 174 79%
.400 217 76%
.500 255 74%
.600 239 74%
they're 5.3 heads (862) 2.00 intake valves 1.55 exhaust. This was all porting, no polish work.
I read that you should look at the numbers compared to what they were stock because of fluctuation in flowbenches, but when I look at the heads like the TEA's that put out more flow, for the same amount of money, I don't know if it's the bench, location, or if i just didnt get what I paid for. Pluss I really don't know what to look for because I really have nothing to compare to..
what do you think?
Thanks as always!
10-22-2004, 06:42 AM
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Numbers are not the whole story. Get to a track, compare your MPH before and after head swap, that is the numbers that count. Remember a dyno is a tool used for tuning also. Two grand is a bit much though. I hope you got what you paid for, but remain optomistic until you get some track time. Peace, Victor
10-22-2004, 08:12 AM
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Were the 2.00/1.55 valves production pieces? If they were those are pretty good #s without polishing, which is only good for a few cfm. The price is still steep though IMO. Getting 400 or more should not be a problem, look at your mph before and after. Good rule of thumb is 1 mph for every 10 hp gain.
10-26-2004, 07:52 PM
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Originally Posted by EDC
Flow benches are tools...
Dynos are tools...
People who live and die by flow numbers and dyno numbers are TOOLS...
Ed
Dynos are tools...
People who live and die by flow numbers and dyno numbers are TOOLS...
Ed
That's a good one, I'll use it in the future!To the original poster.... before and after numbers will let you know what you got, BUT... you can buy a hell of a set of heads for 2 grand.
10-26-2004, 08:11 PM
#7
what bore and what bench, and what port volumes.
FWIW i paid 1085 for my heads that flow on par with yours, 2.02/1.57 valves, cnc'd and hand finished, and fully polished chambers and PP golds. you are correct when you read that you should compare your numbers to stock but that is of your heads and done on the same bore/bench. that way you get a delta of improvement.
read this thread:
https://ls1tech.com/forums/showthrea...ead+discussion
FWIW i paid 1085 for my heads that flow on par with yours, 2.02/1.57 valves, cnc'd and hand finished, and fully polished chambers and PP golds. you are correct when you read that you should compare your numbers to stock but that is of your heads and done on the same bore/bench. that way you get a delta of improvement.
read this thread:
https://ls1tech.com/forums/showthrea...ead+discussion
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10-27-2004, 07:37 AM
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Originally Posted by NoseUpChromeDown
Great informative post Mr. Curtis... 
If flow numbers were so useless, you wouldn't require them to have one of your precious cams made...Sorry for the pissy response to your insulting post, but I hardly 1/2 agree with you. I agree with the 'flow benches are tools' statement 100%, but 100% dissagree with the concept you've passed on to the not-so-experienced croud that reads the thread.
Peak flow doesn't really say much. As long as mid-lift flow was up to par, I'd say they were going to make some power, but they certainly are not. 400rwhp, with a match cam, most likely, but definitely not worth $2000...
If flow numbers were so useless, you wouldn't require them to have one of your precious cams made...Sorry for the pissy response to your insulting post, but I hardly 1/2 agree with you. I agree with the 'flow benches are tools' statement 100%, but 100% dissagree with the concept you've passed on to the not-so-experienced croud that reads the thread.
Peak flow doesn't really say much. As long as mid-lift flow was up to par, I'd say they were going to make some power, but they certainly are not. 400rwhp, with a match cam, most likely, but definitely not worth $2000...
RE-READ the comment, think, and see why it is correct!
Ed
10-27-2004, 08:17 AM
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Don't concern yourself too much with flow numbers. Sure flow is important but velocity is where it is at. No one on this board talks much about port velocity. Port velocity is king.
You have some good mid range flow. That is really good. Don't concern yourself with mega flow at 0.600 lift, your cam doesn't go there, so why worry about it.
I say take them to the track, take them to the dyno and see how they perform. You might have paid a little more going to your local guy, but if they increase your track time what do you care.
BTW, you may question the PP $1300 heads reliability. Some guys have had some bad experiences with them.
Good luck.
You have some good mid range flow. That is really good. Don't concern yourself with mega flow at 0.600 lift, your cam doesn't go there, so why worry about it.
I say take them to the track, take them to the dyno and see how they perform. You might have paid a little more going to your local guy, but if they increase your track time what do you care.
BTW, you may question the PP $1300 heads reliability. Some guys have had some bad experiences with them.
Good luck.
