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Discussion Starter #1 (Edited)
I dunno I'm about to grab the dewalt and tap my pump to see how it's loading. And wondered if anyone had any sugestions ....all the way from intake pressure, to tap location, to what drill bit size to use for the 1/8" npt tap. Thanks , well at leasts I didn't ask for much.lol:)grn Oh btw it's a split bowl berk.
 

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Kreg,

While you have the tape measure out, measure your truck too. If you need more Pix of the pump pressure tapping, I can uncover mine and get a few tomorrow.
 

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Discussion Starter #6
Thanks Cy. I'll shoot ya a pm on a couple deals. As far as pressure. Down in the Shoemaker section Sleeper was saying 20-30 lbs is good and 30-40 is better? Is that a pretty good rule of thumb? Anyone?
 

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Resident Ford Nut
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Thanks Cy. I'll shoot ya a pm on a couple deals. As far as pressure. Down in the Shoemaker section Sleeper was saying 20-30 lbs is good and 30-40 is better? Is that a pretty good rule of thumb? Anyone?
Actually I was told for a "Gullwing" and my experience is that 30-40 psi is good, and I was told that 40-50 is better.

I don't know if it's possible to achieve 40-50 psi without hanging the hardware under the boat. I won't do that with the CP it needs to shut down safely for river racing and playing.

As far as pressure goes for a 19' Daytona style boat I'm clueless ( even more so than info on Gullwings).

Sleeper CP
Big Inch Ford Lover :D
 

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Discussion Starter #8
Sorry if I mis quoted you. It just seems like a pump is a pump, and that correct pressure wouldn't vary that much just because of the hull, but if you say it does I'll take your word for it. Any daytona help in the crowd???
 

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Angry American
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here's what Timm from TuffeNuff Marine suggests-

I BELIEVE the best places(yes two!) to put the pressure taps are as close to the wear ring that you can on the top (right up next to the hand hole 10 or 2 o'clock) and the bottom as close to the bottom as you can (the 5 or 7 o'clock position). This is because the shoe controls most of the bottom load and the loader grate controls the top load. These two pressures are quite independant of each other and should be roughly equal. Having only one tap in the middle (3 o'clock) only reads the average of the load and can't discern top from bottom.
 

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mo balls than $cents$
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now someone please explain to me how to check ramp and shoe pressures if there's a loader whipping around at 6500rpms and slinging h2o at those 2 taps? i don't see how the average lake hotrod would benefit from the 2 taps when there's always gonna be a inducer installed? seems as if taking the reading behind the inducer would be the only way to take the average and have it be a steady reading to judge hardware changes by. i'm taking readings behind the inducer now, but if its necessary to take them in 2 other spots, i'll do it. the 2 and 5 oclock positions in frt of the wearring are already tapped on my housing, i did that last spring.
 

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Discussion Starter #12
Thanks for the read there cas. The topic of will the average joe weekend guy(like me) really ever gain anything from 2 taps has come up before on hb. Sounds like timinator had a 21 daytona that read 35 # at 3 o:clock. When he tapped it top and bottom the top was 15-17 # and the bottom was 55#. By adjusting hardware and getting top and bottom 15-17# the boat picked up 7-9 mph. Most the daytona guys here are running a backcut shoe, before I buy and try one of those I wanted to see just where I'm at. I had my loader hanging a little below the keel the time before last at the lake. So I took it out completly last time and went slower. I wish my jet was already tapped so I could have seen what was going on the last 2 times out.
 

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mo balls than $cents$
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Thanks for the read there cas. The topic of will the average joe weekend guy(like me) really ever gain anything from 2 taps has come up before on hb. Sounds like timinator had a 21 daytona that read 35 # at 3 o:clock. When he tapped it top and bottom the top was 15-17 # and the bottom was 55#. By adjusting hardware and getting top and bottom 15-17# the boat picked up 7-9 mph. Most the daytona guys here are running a backcut shoe, before I buy and try one of those I wanted to see just where I'm at. I had my loader hanging a little below the keel the time before last at the lake. So I took it out completly last time and went slower. I wish my jet was already tapped so I could have seen what was going on the last 2 times out.
are you runnin a inducer too?
 

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Thanks for the read there cas. The topic of will the average joe weekend guy(like me) really ever gain anything from 2 taps has come up before on hb. Sounds like timinator had a 21 daytona that read 35 # at 3 o:clock. When he tapped it top and bottom the top was 15-17 # and the bottom was 55#. By adjusting hardware and getting top and bottom 15-17# the boat picked up 7-9 mph. t.
Wow, I need to loan him the CP for a couple of weekend's to see what he can do. I never read that before; what thread did you read that info from ?

That's some good fine tuning right there. I have given some thought as to why more pressure would be better than say 10 psi. If you have 10 psi positive pressure on the face of the impeller and just for kicks lets say the face of the impeller is 8.5" in dia. The total surface area ( forget about the shaft for now ) would be 56.75 sq. inches. At 56 sq. in. that would be 560 lbs of pressure. If that same 56 sq. inches has 35 psi pushing against in that would be 1,960 lbs of pressure.

My question would be, does that extra 1,400 lbs of pressure have an affect on the speed of the boat ? Or am I looking at that wrong ? I would seem that you should just need enough pressure to keep a positive charge on the face on the impeller. I know there are a lot of people here that know a lot more than I do, I wonder if I'm just full of Sh*t ?

Just asking a dumb question :)bulb

Sleeper CP :D
 

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Discussion Starter #17
No inducer here. As far as the thread .click on the bottom one Cas put up then go to page 2, and it's like the 3rd post down. As far as the intake, outtake deal.....is it the suction housing? Would that be the correct term? If any one see's me using an incorrect name or anything, please correct me I hate sounding like a dumbass.
 

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clear your schedule for 2 hours and give timm a call at 623.877.8553.......he had his 21 daytona dialed in for sure
oh and he tapped my suction housing for me...i can't wait to see whats going on :D


:)
 

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mo balls than $cents$
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No inducer here. As far as the thread .click on the bottom one Cas put up then go to page 2, and it's like the 3rd post down. As far as the intake, outtake deal.....is it the suction housing? Would that be the correct term? If any one see's me using an incorrect name or anything, please correct me I hate sounding like a dumbass.
i think the outtake statement wasn't applying to jetboats;):D but yes, suction housing is a totally different part than the intake. the intake is bolted to the boat, the suction housing is bolted to the intake.
 

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Owner/Crew Chief
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The critical psi is that which comes out the nozzle as that is #'s Trust ..... and, 1,400 psi there would make one hell of a difference it terms of quickness & speed.

By the way, if you know of an impeller that has an eye of 8.5 inches, I would like to know who it is who makes it as I want one. The biggest eye of an impeller made today (in terms of the kind we're talking about here) is the new Hi-Helix which is exactly 7 inches.
 
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