SBM Edelbrock/Speedmaster Head Data

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Newbomb Turk said:
Ok, I got it now. I’d test with different pressures and then flow the port with the valve upside down.

I think that might give some direction.

But your flow curves definitely have a strange dip.

I’ll be glad to learn what it is when you figure it out.
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Here's some different test pressures and the valve turned upside down. I really thought the dip would go away at the lower test pressures. It did not. It's also interesting that the port flows more with the valve than without. Some people say they have never had it occur. I've seen it several times. Maybe it's just my screwed up methodology. Actually it's just the valve creating a floor to the flow zone and improving the pressure recovery in the chamber.

I also tried a 10-15 degree soft quench pad on the long side to try to deshroud the 0.600-0.700 lift area. Almost no change. I really thought it would help. Back to head scratching.

One last point. At 28 in, max flow before loss of the short turn (0.550 lift) is equal to the flow with the valve turned upside down. This means something. Not sure what, but it's a clue to something.

IMG_3258.jpg
 
Earlie A said:
Here's some different test pressures and the valve turned upside down. I really thought the dip would go away at the lower test pressures. It did not. It's also interesting that the port flows more with the valve than without. Some people say they have never had it occur. I've seen it several times. Maybe it's just my screwed up methodology. Actually it's just the valve creating a floor to the flow zone and improving the pressure recovery in the chamber.

I also tried a 10-15 degree soft quench pad on the long side to try to deshroud the 0.600-0.700 lift area. Almost no change. I really thought it would help. Back to head scratching.

One last point. At 28 in, max flow before loss of the short turn (0.550 lift) is equal to the flow with the valve turned upside down. This means something. Not sure what, but it's a clue to something.

View attachment 1716335363
Click to expand...


Does the port get noisy when it gets into that dip?

I’m not surprised the port flowed better with the valve in it. The valve has some influence on the flow curve even at very high lifts.

I’ll dig out the Don Terrell book out and take a picture of a top cut valve and what he says it does.

FWIW my testing did not match his testing on the top cut intake valve.

But that doesn’t mean that’s always the case.

I’ve had to eat the big poop sandwich more than once when I was 100% sure that something always worked (or never worked) and then I found a case where stuff like a top cut valve works.

Thats where great testing and note taking like you are doing will pay off big time at some point.

I still kick myself for selling my flow bench but what’s worse is I didn’t keep all my flow tests and notes when I sold it. I should have at least made and kept copies of them.

That was really, really STUPID on my part.
 
Newbomb Turk said:
Does the port get noisy when it gets into that dip?

I’m not surprised the port flowed better with the valve in it. The valve has some influence on the flow curve even at very high lifts.

I’ll dig out the Don Terrell book out and take a picture of a top cut valve and what he says it does.

FWIW my testing did not match his testing on the top cut intake valve.

But that doesn’t mean that’s always the case.

I’ve had to eat the big poop sandwich more than once when I was 100% sure that something always worked (or never worked) and then I found a case where stuff like a top cut valve works.

Thats where great testing and note taking like you are doing will pay off big time at some point.

I still kick myself for selling my flow bench but what’s worse is I didn’t keep all my flow tests and notes when I sold it. I should have at least made and kept copies of them.

That was really, really STUPID on my part.
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This port is pretty quiet all the way through. About 0.400 lift you can hear the faint 'train coming' rumble of separation starting. It never does get loud but there is some bouncing of the manometer at 0.600-0.650.

At this point I think I need to look at the shape of my short turn, especially in the corners. The center of the short turn is not that tricky. The corners are a different story. Lots of options there.
 
Earlie A said:
This port is pretty quiet all the way through. About 0.400 lift you can hear the faint 'train coming' rumble of separation starting. It never does get loud but there is some bouncing of the manometer at 0.600-0.650.

At this point I think I need to look at the shape of my short turn, especially in the corners. The center of the short turn is not that tricky. The corners are a different story. Lots of options there.
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How far away is water at the short turn up against the floor/wall point?
 
Isn't this just a practice head (never going on a engine) if so can't you drill a hole in the deck to be able to measure the ssr thickness ?
 
And something I noticed, me and @JDMopar were discussing a 273 build, with china magnum castings, and those have a rib cast in the port floor, something I saw Darin Morgan discuss. Has to do with keeping the flow from trying to go to the center of the short turn. Air loves to go straight, the whole trick is managing that
 
Here is a picture of a page out of the “Secrets of a 740 HP Winston Cup Engine” by Don Terrell.

He says the top cut on the valve reduces reversion but all of my testing said that valve job on the valve makes reverse flow better.

Smokey Yunik says he did it to shape the flow cone around the valve. I tried that to clean up the dip around .250 lift. It didn’t.

Just something else to look at and consider. I also saw he listed some seat cutters in the book and listed one 55 seat.

I’ve never used that cutter. But it’s very possible that if you used his cutter for a 55 degree seat and a top cut valve it may work.

I know on the 50 and 55 I use the top cut was a reverse flow helper.

IMG_1078.jpeg



Edit: sorry for the sideways picture. I can’t figure out how to rotate it. Maybe @toolmanmike can fix it for me. If he has the time.
 
NC Engine Builder said:
And something I noticed, me and @JDMopar were discussing a 273 build, with china magnum castings, and those have a rib cast in the port floor, something I saw Darin Morgan discuss. Has to do with keeping the flow from trying to go to the center of the short turn. Air loves to go straight, the whole trick is managing that
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I think you are right. It may work well here. The 1" wide flow of high speed air going through the pinch wants to stay 1" wide going over the short turn. It needs some persuation.
 
273 said:
Isn't this just a practice head (never going on a engine) if so can't you drill a hole in the deck to be able to measure the ssr thickness ?
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It is a practice head. Absolutely could drill, but I'm just going to see what happens. Nothing to lose.
 
Newbomb Turk said:
Here is a picture of a page out of the “Secrets of a 740 HP Winston Cup Engine” by Don Terrell.

He says the top cut on the valve reduces reversion but all of my testing said that valve job on the valve makes reverse flow better.

Smokey Yunik says he did it to shape the flow cone around the valve. I tried that to clean up the dip around .250 lift. It didn’t.

Just something else to look at and consider. I also saw he listed some seat cutters in the book and listed one 55 seat.

I’ve never used that cutter. But it’s very possible that if you used his cutter for a 55 degree seat and a top cut valve it may work.

I know on the 50 and 55 I use the top cut was a reverse flow helper.

View attachment 1716335473


Edit: sorry for the sideways picture. I can’t figure out how to rotate it. Maybe @toolmanmike can fix it for me. If he has the time.
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Never tried (or even seen) that one. Vizard did a groove on the face of the valve. Haven't tried that either.
 
Earlie A said:
Never tried (or even seen) that one. Vizard did a groove on the face of the valve. Haven't tried that either.
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I messed with it quite a bit. I don’t recall now if Smokey gave angles or not but Terrell didn’t.

So I screwed around with different top cut angles and widths and with the back cut angles and widths.

If I had my notes I could tell you what all that stuff was but it would just be a WAG at this point.

Like I said, it never worked for me with the seats and angles and widths valve jobs I use.

You may find that it works with the seats and angles and widths you use.

Edit: Terrell says 30-45 top cut angles so maybe Yunik gave them too. I just can’t remember or find his book.

I do recall I went through a lot of valves trying that stuff and I’m pretty sure I even tried the seat angle on the top cut. And different back cut angles.
 
Earlie A said:
This port is pretty quiet all the way through. About 0.400 lift you can hear the faint 'train coming' rumble of separation starting. It never does get loud but there is some bouncing of the manometer at 0.600-0.650.

At this point I think I need to look at the shape of my short turn, especially in the corners. The center of the short turn is not that tricky. The corners are a different story. Lots of options there.
Click to expand...
Are you taking air speed readings at all? Curious what the air speed at the pinch is, middle of port but at the pinch, before the dip, middle of dip, and after dip? If you can, also check air speed at the roof over the short turn in those lift ranges too.
 
Brian Hafliger said:
Are you taking air speed readings at all? Curious what the air speed at the pinch is, middle of port but at the pinch, before the dip, middle of dip, and after dip? If you can, also check air speed at the roof over the short turn in those lift ranges too.
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Here's the velocity numbers. The numbers on the floor are taken with the pitot right against the floor. At the apex, the numbers on the floor are actually taken slightly around the turn from the apex. I was searching for the highest number I could find at the time. If I take the pitot all the way to the right (cyl center) at the apex, the pitot reads 0 if pointed at the intake opening. Velocity in that area is all vertical, from the roof down. This is one area that needs work.

IMG_3259.jpg
 
Earlie A said:
Here's the velocity numbers. The numbers on the floor are taken with the pitot right against the floor. At the apex, the numbers on the floor are actually taken slightly around the turn from the apex. I was searching for the highest number I could find at the time. If I take the pitot all the way to the right (cyl center) at the apex, the pitot reads 0 if pointed at the intake opening. Velocity in that area is all vertical, from the roof down. This is one area that needs work.

View attachment 1716335535
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Can you take a reading, middle of port at the pinch? From .500 up to .700?
 
Here is some more velocity data. Sorry for the confusing format. This is just the best way I have figured out to use the software for my purposes. The circles mean nothing. They do not represent the perimeter of the port or the valve.

Here's the way to read this. Plane 1 is a pitot tube location - the center of the port at the pushrod pinch. At that location, the velocity was measured at 5 different lift points - 0.500", 0.550", 0.600", 0.650" and 0.700". Around the circle the valve lift positions are shown in red. The velocity at that lift is printed within the shaded portion of the circle.

For plane 2, the pitot tube was moved to the floor of the apex on the common wall side. Velocity readings were again taken at the 5 lift points. Planes 2-4 are on the apex floor. Plane 5 is the center of the port just above the apex. Planes 6-7 and plane 1 on the second row are all using a pitot tube that was bent (photo 3) to reach around the SSR to take velocity readings at or near the valve seat.

Flows are approx as follows:

0.500 lift - 302 cfm
0.550 lift - 309 cfm
0.600 lift - 305-313 cfm
0.650 lift - 300 cfm
0.700 lift - 304 cfm

As can be seen in the pictures, a jig was used to try to keep the pitot in a consistent location as the lift points were changed.

I am interested to hear everyone's feedback. I have some thoughts, but I'll hold them for a while so I don't influence your opinions.

IMG_3267.jpg


IMG_3261.jpg


IMG_3262.jpg
 
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I’m surprised at how little activity there is, and how it keeps dropping as the lift goes up, in the plane 7 test.
Yet, the 2,3,4, planes are fairly steady with lift increases.

It would be interesting to see how all of that would compare on a port that didn’t have the dip in the curve.
 
PRH said:
I’m surprised at how little activity there is, and how it keeps dropping as the lift goes up, in the plane 7 test.
Yet, the 2,3,4, planes are fairly steady with lift increases.

It would be interesting to see how all of that would compare on a port that didn’t have the dip in the curve.
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I actually expected plane 6 and plane 1 (on the second row) to react the same as plane 7. I thought the velocity would go to 0 at the seat in all 3 locations. I think it actually does, but I could not get the pitot all the way to the seat. As a matter of fact, at the seat, the flow actually changes directions and is moving up the port at about 170 fps. I measured this with a different pitot in a different test a few weeks ago. I might try that again in the morning.

I may also try taking velocity readings at these same lift points around the guide boss. In this port I have noticed that the guide boss has impacted turbulence/separation more than any other port I have worked on.
 
Earlie A said:
I actually expected plane 6 and plane 1 (on the second row) to react the same as plane 7. I thought the velocity would go to 0 at the seat in all 3 locations. I think it actually does, but I could not get the pitot all the way to the seat. As a matter of fact, at the seat, the flow actually changes directions and is moving up the port at about 170 fps. I measured this with a different pitot in a different test a few weeks ago. I might try that again in the morning.

I may also try taking velocity readings at these same lift points around the guide boss. In this port I have noticed that the guide boss has impacted turbulence/separation more than any other port I have worked on.
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An interesting side note to your last paragraph is the W5 head has the bolt boss right across from the guide.

That little bump, like the pushrod pinch forces what air there is along that wall over to the guide.

And when it does (man I miss my notes) it pushes the air across the guide and into the common wall.

I don’t remember what made me even start looking at it but I ended up using some strings down the port and you can watch the air move off that bolt boss right across the guide.

I do know I had the brilliant idea to use a cigarette to get some smoke in the port to see what was happening.

Bad idea. Unless the cigarette is 14 inches long and an inch in diameter it burns so fast your fingers get toasted.

They go quick. Not being a quitter (I’m not a smoker either) I decided to go get some cigars and use those.


Bad idea. You get about 4 seconds more with a Swisher Sweet than you do with an unfiltered camel. That’s it.

Hence the string.

I took the bolt boss out entirely and it cleaned that up.
 
Earlie A said:
I actually expected plane 6 and plane 1 (on the second row) to react the same as plane 7. I thought the velocity would go to 0 at the seat in all 3 locations. I think it actually does, but I could not get the pitot all the way to the seat. As a matter of fact, at the seat, the flow actually changes directions and is moving up the port at about 170 fps. I measured this with a different pitot in a different test a few weeks ago. I might try that again in the morning.

I may also try taking velocity readings at these same lift points around the guide boss. In this port I have noticed that the guide boss has impacted turbulence/separation more than any other port I have worked on.
Click to expand...

So look at the fps #'s in the middle of the pinch from .550 to .600 and .650...it's slowing down. Actually, backing up! Those speeds (flowing at 28") are WAY too fast. I would really try to get the speed down at the pinch. I know everyone is talking about pinch not a problem, but once you have the port moving or trying to move good air, speeds both local and avg. will make or break the port.
And look at the flow on the floor of the apex, it's slowing down with more lift...very bad! And way way too fast! The port is very out of balance like a crank that's never been balanced...put it on a machine and watch how bad it can be!
One thing I do with eddy heads and SM heads when I'm using a 2.055 valve, looking for 290'ish cfm, is leave the guide boss alone on the front side. It looks ugly, but it stabilizes the air above .550 lift. At least with my porting + valve job + chamber it does. Your dip is coming from way to fast air speed. The valve job + chamber your using may be causing some of this. This is the epoxied chamber/bowl and 50°?
 
Newbomb Turk said:
An interesting side note to your last paragraph is the W5 head has the bolt boss right across from the guide.

That little bump, like the pushrod pinch forces what air there is along that wall over to the guide.

And when it does (man I miss my notes) it pushes the air across the guide and into the common wall.
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That is something I need to try. I've seen pictures of a tubed bolt boss protruding well into the chamber. I think Brian even posted one here a while back.
 
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