Radius under the seat is different than a radius seat.B Original wrote: ↑Fri Apr 27, 2018 6:00 pmGenuinely Interested in what you have to say STATSYS please teach. Want to understand how the radius affects differently from the flat cut 45 or where the radius comes up short. I always lap the seat on final prep this may soften the radius but not by much I am sure.statsystems wrote: ↑Fri Apr 27, 2018 5:07 pm Never use a radius on an intake seat, even if it flows more.
If you only test at 28 inches you won't learn much.
A flow bench is a tool. You can make it lie. Just because a port flows more on the bench doesn't mean it will make more power. See the first sentence.
cast dart 165cc test head for novice
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Re: cast dart 165cc test head for novice
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Re: cast dart 165cc test head for novice
B Original wrote: ↑Fri Apr 27, 2018 6:00 pmGenuinely Interested in what you have to say STATSYS please teach. Want to understand how the radius affects differently from the flat cut 45 or where the radius comes up short. I always lap the seat on final prep this may soften the radius but not by much I am sure.statsystems wrote: ↑Fri Apr 27, 2018 5:07 pm Never use a radius on an intake seat, even if it flows more.
If you only test at 28 inches you won't learn much.
A flow bench is a tool. You can make it lie. Just because a port flows more on the bench doesn't mean it will make more power. See the first sentence.
That 4556 cutter will flow almost as good backwards as it does forward.
I think the OP would help himself a bunch if he just stuck to learning how to flow test a head, do it consistently and learn to develop a port before he gets into measuring air speed and using all the other bells and whistles. You will get information overload right quick.
Also, the OP needs to KNOW that flowing in one direction and at one test pressure is almost a waste of time. Before I ever measure air speed I flow at different pressures and work from that.
Re: cast dart 165cc test head for novice
True! knowing how to use the data is more important then having the data and will take years of testing flow vs dyno vs track... Rinse and Repeat.statsystems wrote: ↑Fri Apr 27, 2018 6:53 pmB Original wrote: ↑Fri Apr 27, 2018 6:00 pmGenuinely Interested in what you have to say STATSYS please teach. Want to understand how the radius affects differently from the flat cut 45 or where the radius comes up short. I always lap the seat on final prep this may soften the radius but not by much I am sure.statsystems wrote: ↑Fri Apr 27, 2018 5:07 pm Never use a radius on an intake seat, even if it flows more.
If you only test at 28 inches you won't learn much.
A flow bench is a tool. You can make it lie. Just because a port flows more on the bench doesn't mean it will make more power. See the first sentence.
That 4556 cutter will flow almost as good backwards as it does forward.
I think the OP would help himself a bunch if he just stuck to learning how to flow test a head, do it consistently and learn to develop a port before he gets into measuring air speed and using all the other bells and whistles. You will get information overload right quick.
Also, the OP needs to KNOW that flowing in one direction and at one test pressure is almost a waste of time. Before I ever measure air speed I flow at different pressures and work from that.
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
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Re: cast dart 165cc test head for novice
Exactly! But how the hell can the op be expected to do all that and get his racecar back together within the next 2 years?
C'mon guys.. there's the perfect ideal.. and then there's the reality of what a newcomer can achieve in shorter order. Maybe just help fast track the guy towards improving what he can over what he had. From his other thread the car was already decent as it was, so why not help him make the basic and elementary improvements he was originally looking for to begin with?
That will get him near 90% of the way towards an idealized port design anyways. The last 10% will take far longer due to the ever increasing learning curve that will be involved to get there.
Last edited by groberts101 on Fri Apr 27, 2018 7:11 pm, edited 1 time in total.
Re: cast dart 165cc test head for novice
Yes. As in if the top cut of the valve job is 38, the back cut of the valve is 38.B Original wrote: ↑Fri Apr 27, 2018 6:33 pmHuhh Back cut implies its the second cut on the back side of the intake?Headguy wrote: ↑Fri Apr 27, 2018 6:20 pmwhy not back cut the valve to the same angle as the top cut for starts?B Original wrote: ↑Fri Apr 27, 2018 5:00 pm I see in the second and third picture is where I would start. Do a 30 degree back cut on the intake valves.
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Re: cast dart 165cc test head for novice
Seriously?.. on an intake port?B Original wrote: ↑Fri Apr 27, 2018 6:43 pm In a moderately well designed port wouldn't you expect the flow to approach and sometimes pass supersonic as it goes past the seat section minimizing the shear or grab effect?
Please teach me how to do that!.. I have money!
Re: cast dart 165cc test head for novice
Can i have your money? I'm a little low on it myself. lol.... j/kgroberts101 wrote: ↑Fri Apr 27, 2018 7:15 pmSeriously?.. on an intake port?B Original wrote: ↑Fri Apr 27, 2018 6:43 pm In a moderately well designed port wouldn't you expect the flow to approach and sometimes pass supersonic as it goes past the seat section minimizing the shear or grab effect?
Please teach me how to do that!.. I have money!
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Re: cast dart 165cc test head for novice
Would you think at Mach a way to disrupt would be shear?
Goes back to a rectangle port intake on an oval head?
Goes back to a rectangle port intake on an oval head?
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Re: cast dart 165cc test head for novice
You'll have to generate some crazy ass fake flow sheets and get me drunk enough to fall for them first!MTENGINES wrote: ↑Fri Apr 27, 2018 7:18 pmCan i have your money? I'm a little low on it myself. lol.... j/kgroberts101 wrote: ↑Fri Apr 27, 2018 7:15 pmSeriously?.. on an intake port?B Original wrote: ↑Fri Apr 27, 2018 6:43 pm In a moderately well designed port wouldn't you expect the flow to approach and sometimes pass supersonic as it goes past the seat section minimizing the shear or grab effect?
Please teach me how to do that!.. I have money!
Re: cast dart 165cc test head for novice
I wasnt going to show you anything. i was just interested in the money. lolgroberts101 wrote: ↑Fri Apr 27, 2018 7:22 pmYou'll have to generate some crazy ass fake flow sheets and get me drunk enough to fall for them first!MTENGINES wrote: ↑Fri Apr 27, 2018 7:18 pmCan i have your money? I'm a little low on it myself. lol.... j/kgroberts101 wrote: ↑Fri Apr 27, 2018 7:15 pm
Seriously?.. on an intake port?
Please teach me how to do that!.. I have money!
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Re: cast dart 165cc test head for novice
LOL.. now you sound like my wife! That's what happens when you stay married to the same one for too long.MTENGINES wrote: ↑Fri Apr 27, 2018 7:26 pmI wasnt going to show you anything. i was just interested in the money. lolgroberts101 wrote: ↑Fri Apr 27, 2018 7:22 pmYou'll have to generate some crazy ass fake flow sheets and get me drunk enough to fall for them first!
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Re: cast dart 165cc test head for novice
Hypothetical calculation If you have an average port speed in a 2.2 square area of 300 fps at .200 how fast do you think the air speed is flowing past the curtain area at .200 lift = about .64 square area ? 2.2/.64=3.44 so 3.44x300 fps is 1032 fps.
1X mach speed is 1125 fps. "near or past mach speed at the seat"? Not disputing you about the radius below the seat tho.
Not here to prove someone else wrong just presenting what I understand wanting to learn if I am mistaken so don't beat me up too bad
1X mach speed is 1125 fps. "near or past mach speed at the seat"? Not disputing you about the radius below the seat tho.
Not here to prove someone else wrong just presenting what I understand wanting to learn if I am mistaken so don't beat me up too bad
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Re: cast dart 165cc test head for novice
Gary,GARY C wrote: ↑Fri Apr 27, 2018 5:12 pmDid you put a valve in from the top to account for the stem or no valve at all?steve cowan wrote: ↑Fri Apr 27, 2018 4:25 pm forgot to mention i have not checked a as cast port yet,have not checked the exhaust just wanted to share what i have at the moment.
i checked intake with no valve went 214
with the valve at 0.600'' went 217 cfm is this because the air went turbulent out of the seat area??? thanks
I turned the valve upside down, it didn't encroach past the bottom of guide, greased stem to stop leakage,
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Re: cast dart 165cc test head for novice
The way he is doing it, start with a baseline car, getting help on the porting and then retest and keep learning. Thats how I started, I couldn't afford dyno testing on top of everything else so i did what I could at the track and then just tried different things and learned from others around me.groberts101 wrote: ↑Fri Apr 27, 2018 7:10 pmExactly! But how the hell can the op be expected to do all that and get his racecar back together within the next 2 years?
C'mon guys.. there's the perfect ideal.. and then there's the reality of what a newcomer can achieve in shorter order. Maybe just help fast track the guy towards improving what he can over what he had. From his other thread the car was already decent as it was, so why not help him make the basic and elementary improvements he was originally looking for to begin with?
That will get him near 90% of the way towards an idealized port design anyways. The last 10% will take far longer due to the ever increasing learning curve that will be involved to get there.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
Re: cast dart 165cc test head for novice
normally you want the stem to go through as if the valve is in but it eliminates the valve head influence.steve cowan wrote: ↑Fri Apr 27, 2018 7:49 pmGary,GARY C wrote: ↑Fri Apr 27, 2018 5:12 pmDid you put a valve in from the top to account for the stem or no valve at all?steve cowan wrote: ↑Fri Apr 27, 2018 4:25 pm forgot to mention i have not checked a as cast port yet,have not checked the exhaust just wanted to share what i have at the moment.
i checked intake with no valve went 214
with the valve at 0.600'' went 217 cfm is this because the air went turbulent out of the seat area??? thanks
I turned the valve upside down, it didn't encroach past the bottom of guide, greased stem to stop leakage,
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!