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Messages - Flusher

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Boat Showcase / Re: Hallett Mini Cruisers...Lets see em!
« on: August 24, 2021, 11:14:48 AM »

Flusher, it's all good! I know you know what your talking about! So again it's a 6.0L iron block LS With aluminum heads. The build should make 450ish peak HP at 5800. That's what the last one I built did. All three shops I talked to know my hull. In fact one of them just did the exact same LS setup for a customer with my exact 18.5ft Hallet Mini.  Customer said it was perfect and brought it in with an A cut.  I guess I really won't know until it's all together and it's in the water. It's a tough call because the jet needs a rebuild and everyone is saying B/C or B+. I'd like it to be right on the first shot. But I understand it doesn't always work out that way.  Also, I'm planning pro-charger only because I'm trying to keep everything within an enclosed engine compartment and yes, I prefer the power up top.

Why do they recommend a BC or a B+?  Why not a B and split the difference?

Why do you "prefer the power up top?"

Just trying to inspire thought on the topic.

Honestly, I was expecting a 19' or 20', not an 18.5'.  It makes a difference, especially after powerlifting my bare hull around last weekend.  I can lift a 19' bubble deck and place wood between the hull and trailer bunks by myself.

Boat Showcase / Re: Hallett Mini Cruisers...Lets see em!
« on: August 23, 2021, 07:58:13 PM »

So, the engine is supposed to Dyno around 450HP.  It's not done yet, but based on the build, it should be pretty close.  I built another engine like it a while back with the same components and it came in right there.  I've talked to 3 different Jet shops and all of them said "B/C or B+".  I'm also going to ditch the original rear transom cover and go with the customer setup to make getting the bowl off faster so if the cut is wrong, it won't be a pain to switch to another impeller.  I'm not trying to build a rocket since it's a Mini day and decently heavy.  I'm looking more for a family cruiser.  If it's not fast enough or struggles, I'll add the pro-charger.   

I don't mean any disrespect, its your money and your boat.  However, I don't see any mention of RPM.  I also have to ask, are the three shops that recommended a BC and a B+ impeller aware of exactly what hull you have, or are they assuming a lightweight bubble deck?

As you mentioned, you have a heavy hull.  A larger boat neads a larger impeller to help get it out of the hole.  Once you start adding horsepower, the problem gets worse, you will run into problems blowing the pump dry.  I think you will be happier with a larger cut impeller to increase out-of-the-hole response and better fuel economy.

On a side note, if you have the option of an aluminum block, that would make a great lightweight running package.

Just running some numbers, a BC impeller is going to absorb 450 horsepower between 5400-5500 RPM.  A B+ impeller will absorb 450 horsepower between 5100-5200 RPM.  A 30-degree A cut, or "small A" impeller would be at 5000 RPM.  In contrast, a C cut impeller would absorb 450 horsepower at 5600 RPM.  I would strongly recommend against going that small.

If you are making your 450 horsepower at a higher RPM, the impeller will never allow the engine to turn that RPM.  It's all about WHERE you are making the power.

All I am saying is, try the impeller you have BEFORE you cut it down.

The ProCharger is a good call if you decide to go forced induction.  I think a centrifugal is best suited to a jet boat.  Compared to a positive displacement blower, a centrifugal blower comes on when you want it (upper RPM).

I have the 20.5' posted a few pages back.  It had an MPD fully detailed B+ impeller when I got it.  The B+ allowed the engine to RPM way up where it wanted, but I had to backpedal a lot to get it there.  I definitely didn't get the "shot out of a cannon" feeling until I put in the AA.  The AA hooks right now and cruises at 50 MPH at about 4000 RPM.

I want to play too.  My '91 20.5' 454/Berkeley JG-AA.  I don't have any recent pictures on the water as it has been on hold for some family matters, but now making progress.  Once I get a computer online, I will post a build thread.  Shooting for TPM

Boat Showcase / Re: Hallett Mini Cruisers...Lets see em!
« on: August 23, 2021, 02:14:35 PM »
Very nice!!  I'm going Mild 6.0L LS just to get it in the water. After a little time I'll likely add a procharger. I'm already rebuilding the berkeley and having a new impeller cut to match the LS.  I know once I go procharged I'll have to dump more $ in the pump. For now it should be fine for the family.  Hopefully I'll see you guys out there next season.
What are you having the impeller cut to?  That boat is not going to like anything much smaller than an A cut out of the hole.

Projects / Re: 75 Cobra Jet... I think.
« on: August 17, 2021, 04:34:25 PM »
It looks like s really beautiful boat.  Can't wait to see pictures with the engine installed.

Jet Pumps / Re: Pump useable or paperweight?
« on: August 17, 2021, 04:32:01 PM »
Don't weld it, you risk warping and scrapping it.

The register doesn't have anything to do with sealing on a Berkeley.

Could you post more pictures?

Jet Pumps / Re: Pump useable or paperweight?
« on: August 17, 2021, 11:57:57 AM »
Don't know if it is my vision getting worse or the lack of ability to zoom in on my cellphone.  It looks like the register got a little dinged.

That register is critical because it is what locates the bowl bushings concentric with the thrust bearing.

It doesn't appear that it is too bad, as long as the bowl registers.

Could you turn the shaft without binding?  That would be a good indication of potential problems.

How do the bowl vanes look?  Are there any chunks missing?  If yes, it would never be as good as it could be

Jet Pumps / Re: Pump useable or paperweight?
« on: August 16, 2021, 05:53:15 PM »
Does the bowl still fit tight to the register?

Jet Pumps / Re: Intake machining question
« on: August 15, 2021, 09:38:29 PM »
Trying to do things more aerospace than hill billy

Jet Pumps / Re: Intake machining question
« on: August 15, 2021, 07:59:02 PM »
I hate gaskets!

In all seriousnes...

The reason bowls and droops are double drilled is not because the pressure is going to blow the pump apart.  It's because the gaskets push out.  The extra clamping force is enough to support the gasket over the wide span of the bolt spacing.  If you wanted to drill the bolt pattern per SAE specs in the Machinist's Handbook, you would add two bolts instead of just one in between each existing bolt.  An o-ring would solve the gasket fitment issue created and give us the cool factor needed to get all the chicks.  However, the added weight of the additional bolts diminishes our cool factor and we might not be the hero when that weed whacker bass boat tries to line up next to us.

The most problematic gasket is the suction to intake.  The clamping force is weak with the wide spaced 5/16" bolts.  If that surface is sand blasted and powder coated, you can brace yourself for gasket failure.

I set out to develop a "double-drilled" intake, but it had to be compatible with every possible intake/suction combination and combined with an o-ring.  B1 corporate decided that my overwhelming coolness needed to be stifled and the project was killed until now.

How I do it:

I could have simply just put the groove in the middle with some radiused corners and called it good.  Then it would be easy enough to just make the appropriate o-ring from cord stock, but that's just not the kind of machinists we are.  I manipulated the dimensions and arc lengths until the actual linear distance of my o-ring groove matched the circumference of a standard off-the-shelf o-ring.

The groove was machined per the Parker Hannifin O-Ring Handbook (my authority for o-ring seals) for a .139 diameter cross-section, .111 +/-.001 deep.  I wanted ease of installation, so I made the width so that it has a slight drag on the o-ring so that it remains in place during assembly.  The suction experiences both pressure and vacuum.  The process spec describes which side to offset the groove.  In this case ease of installation took precedence.

I made a fixture to hold the intake and cut it with an 1/8" endmill.

I don't really know what to say about an o-ring groove, I was trying to be humorous.



Jet Pumps / Re: Intake machining question
« on: August 15, 2021, 07:04:25 PM »
More great info thanks.
Different topic, tell me about the o-ring groove on the suction piece.

Sent from my iPhone using SoCal Jet Boats

Jet Pumps / Re: Intake machining question
« on: August 15, 2021, 09:10:34 AM »
Just in case...

ride plate or shoe and ride plate?

Jet Pumps / Re: Intake machining question
« on: August 15, 2021, 08:55:25 AM »
Yes helpful! Iíve been reading other threads here and on PB site that had some info but may have not completely answered the questions. I know one size does not fit all but I needed a little more clarification on these 3 before jumping in!
Iíll take pics as I go.

All, again thanks for the help.

Sent from my iPhone using SoCal Jet Boats
I would make a 3-degree back cut shoe with a 2-degree ride plate step.

The other dimension that you need to be aware of is the opening length.  Measuring from the front of the loader (rock grate) pad, a standard intake opening is 13.5 inches.  A standard opening is a good place to start for almost all boats.

The attached picture is for illustration purposes only, the pictured shoe is not the correct shoe for that intake.  It's just what I have available right now.

Lastly, make sure that the leading edge of your ride plate does not hang lower than your shoe.

Jet Pumps / Re: Intake machining question
« on: August 15, 2021, 08:23:47 AM »
The dimensions that should be different from the above posted diagram (posted here for reference) are as follows:

The 0.562 dimension should be .700-.718 inches.  There is a slight twist in the casting, if you measure at both corners, you will see that.  I usually measure in the middle (pictured), to split the difference.

The last two pictures show the area that if you haven't cut enough, the shape doesn't come in.  There will be an abrupt wall instead of a smooth transition for the water path.  Watch this area as you are cutting.

Cutting much deeper than .700-.718 compromises hole depth and possibly thread engagement.

The 7.375 dimension should be 7.875.  This provides for the front two 1/4-20UNC bolts and utilities a square 7.875" square shoe blank.

Jet Pumps / Re: Intake machining question
« on: August 15, 2021, 08:05:09 AM »
Yes helpful! Iíve been reading other threads here and on PB site that had some info but may have not completely answered the questions. I know one size does not fit all but I needed a little more clarification on these 3 before jumping in!
Iíll take pics as I go.

All, again thanks for the help.

Sent from my iPhone using SoCal Jet Boats
Sorry I'm slow responding, I don't have the millenial texting skills.

I'm not a fan of the above posted dimensions.

Attached is the bolt pattern developed by Jack McClure of MPD.

Keep in mind how much load is on the shoe, it would be a terrible thing if it were to come off at speed.

I would say the two 1/4-20UNC in the front provide substantial leverage and holding force, with the fulcrum point being about the two middle bolts.  This utilizes  an otherwise unloaded area to provide additional holding force.

The two middle 5/16-18UNC bolts are located for the widest achievable back cut surface width when used with countersunk bolts and are located at the beginning of the highly loaded area of the shoe.

The four-hole ride plate bolt pattern is less likely to break through into the water surface, just before the impeller.  Any disturbance in that area causes cavitation.

There are probably more of Jack's bolt pattern than any other pattern, meaning that you would be more likely to be able  to borrow or share hardware with your friends.  I have made shoes for every bolt pattern, in my opinion, Jack's is the best and has an elegance to it, and there is no reason to use any other pattern.  I will say that I have even seen people come up with their own bolt pattern and the reality is, they all work.  Any failure is due to installer error.

All holes should have 1" thread depth.  Ensure that the center two ride plate bolt holes do not break into the water surface.  Ideally, you want a minimum of two times the bolt diameter of thread engagement.  That means that a 1/4" bolt should have a  full 1/2" of thread engagement and a 5/16" bolt should have a full 5/8" of thread engagement.  Two times the diameter thread engagement is recommended because you are threading into cast aluminum.  You want to give the threads the best possible chance of success.  Depending on how many shims you use, it would be nice to not have to have custom length bolts for every shim.

Jet Pumps / Re: Intake machining question
« on: August 14, 2021, 08:39:28 PM »
Cole fire star with delta pad.

Sent from my iPhone using SoCal Jet Boats
I'll be honest, I'm not the delta pad master.

If you are really ambitious, I would consider making a thinner 5/8" shoe with more shims for maximum adjustability.  You really need to measure when the intake is set in the boat.

Delta pads don't load very well and need a slightly more aggressive shoe and loader.  Keep in mind, the more aggressive, the more brutal your shutdown will be.

There is also the issue of more drag.  More shoe depth eqates to more drag.  More shoe depth = more water loading your impeller = more thrust, but at the expense of drag.  The ambitious will find the best balance between thrust and drag for best performance.

Jet Pumps / Re: Intake machining question
« on: August 14, 2021, 08:21:10 PM »

Iím looking to install a shoe/ride plate on my intake before I put it back in the boat and have a few questions.
1) when machining for the shoe, is the shoe mounting plane (yellow line) parallel to the hull mounting surface (red line)?

Almost always, yes.  That will also make the shoe surface 4-degrees to the suction housing gasket surface.

2) letís say my shoe is 1/2Ē thick, so I only remove 1/2Ē of material from the intake? That way Iím starting from 0 when adding shims.

That's really not the right way to think about it.  EVERYTHING is relative to the keel.  Again, what kind of boat?  Every intake install is different.  If you wanted to start with a guess, a 5/8" shoe is a safe bet.  I wouldn't do a half inch shoe, but it comes back to what is the hull?

It sounds to me like you have the technical savvy and the tools and machinery to do the work.  I would not make the shoe until after you have the intake set in the hull.  That way, you can actually measure your biting edge depth and make the shoe accordingly.

Ideally, for a back cut shoe, you would want the end of the back cut, just in front of the ride plate, to be even with the keel.  This is a "safe" yet aggressive setup.

You should also make a selection of shims to increase your biting edge depth.  Your shim set should also include ride plate shims.  Whatever change you make to your shoe shims, you need to make the same change to your cradle and ride plate, otherwise your ride plate angle changes.

You will want enough shims to bring your biting edge depth even with your keel.  Typically shims are 1/32", 1/16", and 3/32" thick.  How many shims you need are relative to how ambitious you are about "dialing in" your boat.  Most people are satisfied with the "safe" setup and never add any shims.  A few people will end up with a whole case full of shoes and shims.

Be advised, DON'T start out with every shim installed.  Gradually add shoe depth and thoroughly test to verify that your boat is safe and wants more shoe depth.  The more shoe depth you add, the more dangerous your boat becomes.

3) as far as the ride plate, any angle will be determined by the cut on the rear of the shoe?

It depends on the type of boat.

A V-bottom hull will start out with 4-degrees (safe) ride plate angle and may approach a 6-degree (kill) ride plate angle.  I would most likely start out with a 2-degree ride plate step in the shoe.

In a tunnel hull, the step would probably be zero or 1-degree max.

These angles are guidelines and many factors need to be considered.  There is no such thing as one-size-fits-all.  There is "good enough for most" and "pushing the edge of performance" as well as all levels of in between.

Thanks in advance

Hope this is helpful.



Jet Pumps / Re: Intake machining question
« on: August 14, 2021, 06:29:46 PM »
What kind of boat is this for?

I'd fix it

Jet Pumps / Re: Split Bowl Conversion
« on: August 11, 2021, 11:47:19 AM »

So just getting clarification in a yes or no answer? Will a jg bowl fit a jc pump?


The No Wake Zone / Re: Ford explorer
« on: August 08, 2021, 07:43:21 AM »
Recently saw this video and thought it was worth sharing.

The video did mention an unofficial rule (in Australia), that is apparently law here in CA.  I had to make a donation to local law enforcement for towing a 1500 Durango on my car hauler with my Jeep XJ.  The issuing officer stated that it is illegal to tow a load that is heavier than the tow vehicle.  I would look into the legalities, where you will be towing, and weight ratings of your rig.

One other thought regarding tow vehicle weight. While launching my 21' Hallett at an unusually steep launch ramp where sand and gravel had gotten kicked onto the dry ramp.  The weight of my boat did pull my '83 Suburban around quiet a bit, causing the front tires to slide around like on ice.  A few passengers and 4-low calmed that down.

I'd hate to be the guy who sinks his tow rig at the launch ramp, or worse yet, the guy who rolls his boat on the Interstate.

Engine Mechanical / Electrical / Re: 454 Tunnel ram
« on: August 01, 2021, 02:11:50 PM »
Also depends on which top plenum you have.  You may only be able to fit Carters or Center Sqirters.  If you are able to turn the carbs sideways on the manifold, that will open up more options for you.

There is not a huge selection of metering jets and rods for the Carters, but the rods can be modified easily.  I used to turn the small diameter, of the metering rods, smaller on a lathe, but I saw a video (that I now can't find) on YouTube where:  they just grind or file a flat on the small diameter.

Jet Pumps / Re: More out of pump
« on: August 01, 2021, 01:36:28 PM »

I am new to jet boat but from what I was told from another boater is a Jetavator is a place diverted but what they call "old style" i have a floor mount to adjust the angle of the nozzle. He saud the Jetavator is a brand specific place diverted made only for berkley jets. Truth to that who knows..

Jetovator is Berkeley Jet-Drive's adjustable trim mechanism.

Place Diverter is an independent company manufacturing jet boat trim systems.  Place Diverter is a much more elegant design and is currently or has been available for just about every pleasure boat jet drive system, most of which are Berkeley cloans.

I have hated Jetovator from the first time I worked on one.  Fortunately, I have only replaced Jetovators with Place Diverters.

The important thing is, apparently you have a Diverter.

You will get your best speed with the angle of the nozzle about 7-degrees +/- up relative to keel.  At least that is a good starting point.

Jet Pumps / Re: More out of pump
« on: July 30, 2021, 09:25:02 AM »

Just bought a  18ft semi V boat the other day and finally got the mpg. It is a 12jg berkley with B impellar, 4 degrees wedge and jetavator with se loader. With 3 grown men, ice chest and 20 gallons of fuel in the tank (tank in  the bow of boat) I gps it at 62mph it had a little left but not much. But I pulled 5800rpm and then 6000rpm after losing passengers but didn't get a GPS reading that time. My question is should I try out an A or AB impellar or go with a ss loader to see were that gets me before I spend the money on a impellar. I want to GPS 70mph.
Motor was just assembled mild 454
9:1 CP
540 lift 238 248 D @ .050 114 LBSP
049 larger ovals small port work 3 angle valve job
Weiand high rise tunnel ram with 2 600 carter competition
Howard roller rockers 1.7 ratio
Msd ignition with 6AL box
Cam operation rpm is 3000 to 6000.

Pictures of the boat, from the side, while making a pass would help.  When you are doing your testing, try to keep everything consistent.  Lose all the ice chest, passengers, and unnecessary weight.  Keeping the fuel level constant would also make things easier for you.

Your RPM should not change with different weights in the boat.  The only way the RPM will change is with cavitation or by sucking air (pseudo cavitation).

I'm assuming you have an aluminum impeller.  It sounds like the impeller is right where it is supposed to be, compared to your cam RPM range, assuming that there are no underlying issues loading your pump (slipping the impeller).

If the trailing edges of your impeller are "properly" detailed, it will drop your RPM by about 300 and your MPH might pick up.  But then again, your RPM might not be reaching peak horsepower.

I would start with a 2nd 4-degree wedge, getting your trim and attitude sorted out.  The two wedges can be 'clocked' to adjust the nozzle angle.  You didn't mention a Place Diverter.  If you were feeling spendy, it's worth it because you will ultimately end up with one anyway.  Although, you can still test with wedges.

Take a straight edge under your boat, holding it flush with the keel.  Check to see if your loader ramps are hanging below keel.  You didn't mention a shoe, so more aggressive loader ramps might be necessary to keep the pump loaded, at the cost of drag.  Maybe, shorter loader ramps could help you achieve greater MPH.  Try to hook up with some friends who might let you borrow a different loader for testing.

Lastly, make sure that you are actually getting full-throttle, because it happens.

There is a lot you can do with just adjusting hardware.



Hulls / Re: Eliminator Sprint questions?
« on: July 27, 2021, 08:10:26 PM »
Ill get pics tomorrow if it's not raining. The pump was built by George over at ARS Marine back in '11, but I haven't opened it up yet. Plan on doing that this winter (among other things) to inspect/freshen it up, although it looks brand new inside. Very low hours
Have you talked to him?  I was thinking that that's one of his cradles.  Maybe he has more insight into the work that was done.

Hulls / Re: Eliminator Sprint questions?
« on: July 26, 2021, 08:07:04 PM »
Have you opened the pump for inspection?  You may find a shop name stamped on the impeller or ride plate step of the shoe.  Is it an actual Dominator intake?  I would really like to see inside the bowl, to see which generation it is.  Dating the pump could also shed some light

Could you get a better picture of the cradle?

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