SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: J2 on November 13, 2015, 10:23:33 AM
-
I'm having several winter thoughts after going to the gathering at Elsinore a couple of weeks ago, many more than I was having before the event :sly:
Having my 9 vane aggressor bowl extrude honed is a real thought. I searched the topic and read GT has had several done here in LA. Please share where you had this done and what it cost. I know it's a bit pricey.
Any other bowl tuning tips about entry & exit? I've read many posts here and away about this. I enjoy tinkering so I will do most of my work. Don't want to make a mistake that would ruin something.
B1 loader will happen.
I made the decision a while back to extend the point of thrust farther back like the straight snoot vs droop. I read many posts about this as well. I went with the 6" extension from American Turbine. Got a CAD drawing from them so I could remove 1/8" at the entry back 5/8" for a smooth transition. As a stock piece there was a 1/8" wall that the water hit exiting the bowl. Didn't know this when I bought it. Made wedge adjustments on the back end to find the sweet spot for the PD HPH steering nozzle thrust angle, I believe this is known as PD's mini droop. At this point the bottom pin on the nozzle was 1.5" above the ride plate. Everything I read about the droop was to get the bottom pin 3/4" above the ride plate. I wedged 4* down in front then 3* up in the back to get the bottom pin at the desired 3/4" keeping the steering nozzle at the same angle. Haven't run it, we'll see. This may not be the best way, but it's what I have.
Once I'm done with all of the angles and get the PD set for top end I'll make & install a positive stop. Jimpen showed me his and I'll copy it. Don't see myself moving from manual to hydraulic though.
Pics show before & after the wedge adjustments.
I want to be as efficient as I can, but not that interested in extracting every ounce of speed. After watching the top 2 boats run at Elsinore and understanding my boat would have to run about 130mph to run them down in the 800, um no thanks, way beyond my comfort zone. I'll enjoy watching you guys and running for the bottom area of the top 10 list next year 8)
-
Holy shit that pump sticks out there!
I'd just talk to Greg at GS and have it detailed. Cheaper more convenient and probably as good or better!
Sent from my iPhone using SoCal Jet Boats
-
I have not had one done in quite some time.
I think they are in Paramount Ca.
Way back when it cost $250 for the first one and $100 for each one after that on large orders.
I used to do four at a time. Been nearly 15 years since I've had one done. They come out smoother than you can imagine.
http://www.extrudehoneafm.com/
GT
Sent from my SCH-I545 using SoCal Jet Boats mobile app
-
Thanks GT
I thought that might be the place.
-
Just out of curiousity, how far does the pump stick out?
Garrett
-
Just out of curiousity, how far does the pump stick out?
Garrett
Thrust point 40" from transom. I really like the way this rides. When I first installed the extension the boat jumped up and ran much better than previously. Total feel of your pants difference.
-
Thrust point 40" from transom. I really like the way this rides. When I first installed the extension the boat jumped up and ran much better than previously. Total feel of your pants difference.
I would be curious to see what this would do with a full on old school droop.
What kind of speeds does this deal realize?
GT
Sent from my SCH-I545 using SoCal Jet Boats mobile app
-
I would be curious to see what this would do with a full on old school droop.
What kind of speeds does this deal realize?
GT
Sent from my SCH-I545 using SoCal Jet Boats mobile app
Not sure about speeds, phone app doesn't work well on my phone. GPS speedo is on the winter list. I ran side by side with Johny B, OGDP Branch at the Elsinore gathering. He has the single exhaust, I really like the way his boat sounds :thumbup:
My plan is to have a good GPS speedo so I can see the difference with each change I make from here on out.
-
If it was me, id start small then go from there.
Id take the extension off, try just a normal old full droop and see what happens.
but thats just my .02
-
I seriously don't think you would benefit from having your bowl or impeller extrude honed. However, I don't want to spoil your fun.
I wouldn't extrude hone the impeller at all. I would only detail the impeller by hand. Most people just polish the front and grind the edge off the outside of the impeller at the trailing edges of the vanes. Polishing the face does absolutely nothing, but it is easy to get at and looks cool in pictures. Grinding the outside of the vanes KILLS the impeller cut. It is accessible and reasonably easy to grind. It also changes the cut size to some unknown factor. Grinding by hand also makes the vanes uneven unless you are very good with a grinder. This causes each vane to push the water different and could flex the shaft enough to make the impeller rub the wear ring.
If I was going to have a bowl extrude honed, I would do some detailing of the vanes first, but not a complete detail. The extrude hone process forces abrasive paste back-and-forth, abrading and polishing the surface. It doesn't really recontour the the shape, but it will round sharp edges that need to be sharp.
I would blend the leading edges and surrounding area, removing the fillet radii along the outside wall and start thinning the vanes, but not sharpen them.
Honestly, you are better off spending that money on something that will make a substantial difference.
Good luck,
Joe
-
Most of you might not believe me. I run a stock Berkeley bowl not even cleaned up. Just ask Flusher.
Sent from my iPhone using SoCal Jet Boats
-
I seriously don't think you would benefit from having your bowl or impeller extrude honed. However, I don't want to spoil your fun.
I wouldn't extrude hone the impeller at all. I would only detail the impeller by hand. Most people just polish the front and grind the edge off the outside of the impeller at the trailing edges of the vanes. Polishing the face does absolutely nothing, but it is easy to get at and looks cool in pictures. Grinding the outside of the vanes KILLS the impeller cut. It is accessible and reasonably easy to grind. It also changes the cut size to some unknown factor. Grinding by hand also makes the vanes uneven unless you are very good with a grinder. This causes each vane to push the water different and could flex the shaft enough to make the impeller rub the wear ring.
If I was going to have a bowl extrude honed, I would do some detailing of the vanes first, but not a complete detail. The extrude hone process forces abrasive paste back-and-forth, abrading and polishing the surface. It doesn't really recontour the the shape, but it will round sharp edges that need to be sharp.
I would blend the leading edges and surrounding area, removing the fillet radii along the outside wall and start thinning the vanes, but not sharpen them.
Honestly, you are better off spending that money on something that will make a substantial difference.
Good luck,
Joe
Thanks for the input. Not going to extrude the bowl, makes no real sense to do it. Saw it early in my jet boat research and it seems it's no longer done.
I do want to tune my bowl myself and have been reading about it and saving pictures I find. I have several I found from B1 racing online posts. I have the Aggressor 9 vane I picked up from Tom several years ago. It's in good stock condition. I'm going to need you to dumb it down a bit for me please ??? I've read filing down on the pressure side which means the inside to me. Exit looks like narrowing the fins to me. Looks like filing down 1.5-2.0" on both intake & exit. If edges shouldn't be sharp how narrow, sand paper to round the edges after done with hand filing? I have the tools I used to port match my intake and heads a few years ago. This seems like it would be better to go slower with the process and use hand tools for the garage mechanic 8)
I won't touch my impeller myself. I bought the HTP Hi Helix B from Duane and paid him to race tune it. I have an inducer from Jim B, think it's the DMP, less than a year old. Will call B1 for a loader before next season, how much are they?
Thanks again!
-
Most of you might not believe me. I run a stock Berkeley bowl not even cleaned up. Just ask Flusher.
Sounds like you'll need to get that pump updated so you too can be in the 130 club. :o