Flowing a bowl?

[BrendellaJet]

Ive seen the work done on some peoples pumps that have spent lots of $$$$ to have the veins ground on to a sharp finish at that front and back side of the bowl. I haven't seen any work ever done to the inside of the bowl, seems like there are a lot of casting flaws that could be addressed? Has anyone ever spend the time/money to have their bowl extrude honed?

[comin' unscrewed]

I talked to Extrude Hone about doing a bowl and impellor in the mid 90's. They had the tooling and had done several. But I didn't go through with it so I can't speak to the results.

[Duane HTP]

Yes, over the years we've had several of them done. They sure look pretty. As for better performance, I suppose so. I've never seen enough difference over a hand flowed bowl that I thought was measurable. But, if you are trying to set the world record you do everything you can to get that tiny edge. It certanly doesn't hurt anything.

[Mopar426]

I had mine done durning the rebuild. I saw results, but I think the bowl grind and vane work produced the performance not so much as the extrude hone, but it sure looks good.

[comin' unscrewed]

Now that I think about it, Greg Shoemaker recommended shaping the bowl first by grinding, then having it extrude honed.

[GlastronGuy]

Had ours done by Walt. Had no gps numbers before so I am not sure what kind of difference it makes. The theory makes sense though.

[BrendellaJet]

Yeah, I just wonder how much though... How much was it to extrude hone?

[GlastronGuy]

Originally posted by BrendellaJet
Yeah, I just wonder how much though... How much was it to extrude hone?
We didn't go that route. He took a grinder, sandpaper and filler to the inside. Then coated it with a graphite like product.
I don't recall the cost, possibly around $150 range.

[BrendellaJet]

hmmmm-I wonder how he got all the way inside? Doesn't seem possible to do with control...

[GlastronGuy]

I sent him a link to this thread. Maybe he'll post.

[Jetman1]

Thanks for the heads-up Glastronman, so Brendella wants to know about bowl flowing. Well, you did a pretty good job of explaining what I do, except you added some things that are not used at all.
I have 2 Stages of bowl flowing I do currently. I used to do 3, but now include a little work on the exit if needed.(most don't)
Stage 1- Front of bowl vanes flowed, and large casting flash removed or smoothed. The secret is in the flowing, which is more like balancing and matching the ports on the bowl much like a head porter does. It's a feel thing that can't really be taught. You either know what it takes to maintain laminar flow or you get close, or mess the whole bowl up! I have seen so many back-yard flow jobs that made the boat run slower than any gains possible from a stock pump! I used to fax out a sheet to guys who wanted to try their hand at flowing, but it causes problems, so I discontinued it. But all gained something.
I coat the ground surfaces with graphite spray to protect the aluminum from water attack after the flowing is done. This Stage is in all of my Stage I pumps.
Stage II- All of the above and extensive work on the exit side of the bowl, as well as work on the entire inside of each vane port.
And yes, Brendella, it can be controlled, you just learn over time.
This Stage is only for big HP motors. If you don't have 1000+ HP or Torque, you won't be able to pull this bowl unless you go to 2 cuts under normal(or more!) to get the rpm up into the power band. I do most of these for big blown motors or big thumpers on juice, but mostly blowers.
There were some tests done a few years back that showed that if you want speed don't Extrude Hone. Water doesn't like smoothe surfaces, it causes drag, big time! You see, water doesn't like smoothe surfaces, it likes a rough surface, like sand cast for best results. This causes the water to roll on itself like ball bearings, which results in better laminar adhesion and more water flowed thru the bowl in a given period of time. It is like head porters say, air in, air out, as fast as possible. Same goes for water, a bowl and a pump. Water in, water out, as fast as possible, along with as much volume as possible for as much thrust as possible, which gives you as much speed as possible for your power.
The cost was mis-stated for my flowing, but only by 1/2 for the Stage I. I get $300 to $350 depending on bowl material, as some are much harder than others and take more time to do correctly.
This alone is worth a minimum of 5 mph, and much more depending on your pump accessories, like a diverter, and top loader.
The Stage II is $450 on G bowls and $500 for JC bowls. I do mostly JG bowls in this Stage. With the right power I have seen 10-15 mph with this flow, and over 22+ with a correctly setup boat. That high may soon be eclipsed by alot more than 22 very soon. It is as much flow as a Berkeley bowl can flow without weakening it into fatigue.
It is expensive if you just have the bowl done alone with no other changes to help flow. The bowl wants more water now, so a good top loader will help out more than just the top loader alone.
A pump is a setup. It all matters how all the parts are setup to work together. Good setup, good results. 1/2 way setup, gives you 1/2 performance.
Brands also effect the results. I get very good results from old Dominator G bowls. They are so bad on the inside, you wonder how they even worked! I get 7-10 mph gains on these, but again it is a setup. Wear ring style, top loader, impeller cut and material, and nozzle exit size all matter for top performance.
I hate to plug my website, but go there and read the pump facts.
www.walts***boat.com that pretty much explains most of it, because I am always learning ways to get more out of these pumps! Pump by pump, 800+ and counting, all brands, but not all the same results. Berkeley style bowls and pumps give the best results, and there are even some brand combo's that work even better together. I hope this helps you out a little.
Jetman

[Jetman1]

Thanks for the heads-up Glastronman, so Brendella wants to know about bowl flowing. Well, you did a pretty good job of explaining what I do, except you added some things that are not used at all.
I have 2 Stages of bowl flowing I do currently. I used to do 3, but now include a little work on the exit if needed.(most don't)
Stage 1- Front of bowl vanes flowed, and large casting flash removed or smoothed. The secret is in the flowing, which is more like balancing and matching the ports on the bowl much like a head porter does. It's a feel thing that can't really be taught. You either know what it takes to maintain laminar flow or you get close, or mess the whole bowl up! I have seen so many back-yard flow jobs that made the boat run slower than any gains possible from a stock pump! I used to fax out a sheet to guys who wanted to try their hand at flowing, but it causes problems, so I discontinued it. But all gained something.
I coat the ground surfaces with graphite spray to protect the aluminum from water attack after the flowing is done. This Stage is in all of my Stage I pumps.
Stage II- All of the above and extensive work on the exit side of the bowl, as well as work on the entire inside of each vane port.
And yes, Brendella, it can be controlled, you just learn over time.
This Stage is only for big HP motors. If you don't have 1000+ HP or Torque, you won't be able to pull this bowl unless you go to 2 cuts under normal(or more!) to get the rpm up into the power band. I do most of these for big blown motors or big thumpers on juice, but mostly blowers.
There were some tests done a few years back that showed that if you want speed don't Extrude Hone. Water doesn't like smoothe surfaces, it causes drag, big time! You see, water doesn't like smoothe surfaces, it likes a rough surface, like sand cast for best results. This causes the water to roll on itself like ball bearings, which results in better laminar adhesion and more water flowed thru the bowl in a given period of time. It is like head porters say, air in, air out, as fast as possible. Same goes for water, a bowl and a pump. Water in, water out, as fast as possible, along with as much volume as possible for as much thrust as possible, which gives you as much speed as possible for your power.
The cost was mis-stated for my flowing, but only by 1/2 for the Stage I. I get $300 to $350 depending on bowl material, as some are much harder than others and take more time to do correctly.
This alone is worth a minimum of 5 mph, and much more depending on your pump accessories, like a diverter, and top loader.
The Stage II is $450 on G bowls and $500 for JC bowls. I do mostly JG bowls in this Stage. With the right power I have seen 10-15 mph with this flow, and over 22+ with a correctly setup boat. That high may soon be eclipsed by alot more than 22 very soon. It is as much flow as a Berkeley bowl can flow without weakening it into fatigue.
It is expensive if you just have the bowl done alone with no other changes to help flow. The bowl wants more water now, so a good top loader will help out more than just the top loader alone.
A pump is a setup. It all matters how all the parts are setup to work together. Good setup, good results. 1/2 way setup, gives you 1/2 performance.
Brands also effect the results. I get very good results from old Dominator G bowls. They are so bad on the inside, you wonder how they even worked! I get 7-10 mph gains on these, but again it is a setup. Wear ring style, top loader, impeller cut and material, and nozzle exit size all matter for top performance.
I hate to plug my website, but go there and read the pump facts.
www.walts***boat.com that pretty much explains most of it, because I am always learning ways to get more out of these pumps! Pump by pump, 800+ and counting, all brands, but not all the same results. Berkeley style bowls and pumps give the best results, and there are even some brand combo's that work even better together. I hope this helps you out a little.
Jetman

[HammerDown]

Question...so just how is this "flow work" precisely measured? Seeing is believing when a Cylinder Head is put on a flow bench.

[Jake W]

Just thought I would through a price difrence out to you guys.Last winter MPD charged me 150 for flowing front and the back of my Aggressor bowl.That was nothing through the middle or any kind of coating.
Jack had sugested a impeller detail over a flowed bowl for a lake boat app with out a ton of HP.
But like Walt said it would be better to do it all ,as in setting all clearences flow the bowl and detail imp cut out the droop deviter(if your so inclined) and be able to change nozzels(FTN Place or race nozzel) top loader, inducer, stuffer.And of corse Check or reset your intake to the corect angle machine the intake for shoe and rideplate.With all of this stuff I would hope you would pick up some MPH over stock.
I am not a pump builder.
Jake:rolleyes:

[GlastronGuy]

Originally posted by Jetman1
...The cost was mis-stated for my flowing...
It was too long ago and I've slept since then.
:)

[Jetman1]

I will post one message and answer all the last few questions, it's easier that way.
Hammerdown, Like all good pump guys, I came up thru the machinist route to the marine business. Guys like Jack were in aerospace before starting to substitute their income to boat race by working on these pumps. I had 28 years of tool and die experience, I designed my own windsurfing fins, very fine symetrical foils and all designs, both glass and aluminum. I power sailed to 42 mph on a surfboard with a sail on it! All controlled by less than 70 sq. in. of surface area per side in the water. Don't seem fast, but on a 9 foot board, it feels like a popsicle stick in 50 mph winds, while holding onto a barn door!
Like I said it is a "Feel thing", and some experience working metal.
I can sight gage to around .010" and I wear glasses. I used to be able to guess within .003 or less without the spec's.
I am sure all good pump guys have a very good knowledge of metal working, it is a must for this type of work.
Thanks
Jake, You said it all right there. It is a setup. All the pump parts have to work together or it won't give you max performance for whatever your power level. It may be a little easier for more power than less, and alot easier than real big power, but get a 300 HP 396 to 70 mph on 87 pump gas in a 19 foot Phantom hull and you have a very well set up boat. That is where fun starts. Get the most out of what you have to work with!
Thanks
GlasstronGuy, No biggie, I was glad you emailed me about this post. I don't like to see guys spend alot of money on stuff that doesn't give the boat any boost in performance. Some things are worth it, and others are only needed if you are out to set the world record like Duane said earlier. Most boaters have between 400-550 HP and do the best they can with it for most lake boats.
Make it turnkey, run all day on a tank of gas, and hold it's own with the boys in the evening, and you have a happy customer.
I am sure all the good builders will agree, and they were mentioned earlier.
Thanks again,
Walt

[ChetCapoli]

Originally posted by Jetman1
The Stage II is $450 on G bowls and $500 for JC bowls. I do mostly JG bowls in this Stage. With the right power I have seen 10-15 mph with this flow, and over 22+ with a correctly setup boat. That high may soon be eclipsed by alot more than 22 very soon. It is as much flow as a Berkeley bowl can flow without weakening it into fatigue.
Where's are boy HB??? I figured he's be all over this.....
22+mph....:eek!:
So mr. jetman....how does this G/C bowl "flowwork" compare to say.....a 9 vane aggressor bowl that has all this done factory and is pretty close on price to boot????
CHET

[LVjetboy]

9 VANE aggressor bowl. Geez Chet, at least spell vane right for once.
Vein = blood to the brain...something you seem lacking?
Vain = Chet
Vane = fixed airfoil
Blade = rotating airfoil
jer

[Jetman1]

Chet,
Call me and I would be glad to discuss the differences between the 2 brands. I'll be waiting with so much info it would choke this computer. Or drop me an email direct walt@walts***boat.com but it will take about 5 emails before you get it all consumed. I don't get much time to just type on these boards. I have pumps to build.
Jetman
PS Just so you don't think I am side stepping your post, the cost you wrote was very low compared to what I am quoted by Aggressor(less than dealer!), and from working with both since Aggressor was around, You can buy a new bowl flow, or buy a new bowl for the same amount.(not exactly, better call Dave) But a stock Aggressor had almost 5 mph in it after flowing and that was on top of 106.5 GPS,radar, speedo/Gaffrig, and blowing the tail at speed! And that is scary! I got it to 110.5 and no more tail blowing. Call Dave and ask him about DTJ's boat! Ask him about the one Walt flowed, he may remember, it was only 3 years ago.