Bruce Harris Sharcat 23” Project

[Grand_Marlin]

Nice work PROS!
Always good to see another Sharkcat rebuild.
I look forward to seeing how she comes up.

This is the link to the one we did a while back.
http://www.ausfish.com.au/vforum/sho...light=sharkcat

Cheers,

Pete

[PROS]

Gosh this brought back some great memories. This one I grew up on. It was an '86, we bought it from Currumbin Air Sea Rescue, hence the colours! Dad sold it in 1991, it went to Bribie but from there I dunno. Great hulls, the best trailerable in my opinion, until the tunnel slap gets to you on the troll in those conditions where you just can't bear off by ten degrees, say when you gotta get back to the bait. Gotta be a slight negative somewhere though I guess! Amazing boat downhill and in chop.

On yours, the turbo will will likely be getting wet, hence the replacement. We also had to replace a cracked tank, starboard side. The compartment was full of fuel. Congrats, great boat. I've only been on one with the Volvo diesel. Served a purpose, but they do genuinely sparkle with some horsepower.

Great to hear all memories mate.
Looking forward to spending some time with my little ones

Nah Max, that's a load of rubbish. Whether inboard (shaft drive), or inboard-outboard (like yours is), they don't need to be primed. If they do, it means there is something very wrong with the salt (raw) water system.
Cheers


Sent from my iPhone using Ausfish mobile app

Exactly my thoughts mate, thanks for your help

Nice work PROS!
Always good to see another Sharkcat rebuild.
I look forward to seeing how she comes up.

This is the link to the one we did a while back.
http://www.ausfish.com.au/vforum/sho...light=sharkcat

Cheers,

Pete

Great to hear from you Pete.
I reckon I read your thread at least 10 times before going ahead with purchase


Couldn't stay away without visiting the sharkcat last sunday.
Taken my little boy for a quick ride over the canals and run around to deception bay waters, bit rough in the bay.
Boat handles head on or quarter sea very well.
Bit of a different weird feeling with following sea, need to get used to it.

Anyways, couldn't spent too much time as wife was constant nagging but taking below pics of the floor.
You can see the raised section with inspection port which houses the tank.
Can anyone that knows the floor structure please comment that proposed red lined cutting are is good to access to the fuel tank or do I need to take off the side pocket first as well?

IMG_1178.jpgIMG_1181.jpgIMG_1182.jpgIMG_1183.jpgIMG_1183_1.jpg

[Noelm]

That raised bit is not standard, the tanks have been out/replaced/cleaned/repaired or something, the tanks do go under the pockets a bit, but you should be able to get them out easy enough without removing the side pockets.

[PROS]

That raised bit is not standard, the tanks have been out/replaced/cleaned/repaired or something, the tanks do go under the pockets a bit, but you should be able to get them out easy enough without removing the side pockets.

Thanks Noelm, tanks are definitely looking replaced at some earlier stage.
Stainless steel tanks in there with some average flow coat job on it, around 250litres each side.
That little black cap inside the pocket area is the filler cap.

I will empty the tank first and fill up with some clean diesel to see if contamination occurs again.
Need to see if the leak is from hoses rather than tank.
Tank is most likely leaking though, I can smell diesel when I open the inspection lid.

After cutting that section out, does it really need to be glassed back in?
Could easily be turned into a lid type removable setup. Would this affect structural integrity?
With the amount of glass in this boat, I cant see how it will effect anything structural.

[PROS]

Loving the boat and inboard setup. Cant believe the amount of extra space inboard is allowing to have.
Proper outriggers will see me attempting to get me on board with billfish next year.
Side windlass is great for pulling crab pots out from the depth effortlessly and use as an electric anchor winch.

After searching a month for a used trailer, what I found was either good condition but too expensive or total scrap metal.
Ordered a new trailer from Swiftco at a great deal, 3.5t dual axle gal trailer with tunnel guide ends suitable for an inboard diesel.

Taken the boat out couple of weeks ago, heat alarm come through immediately after getting on to plane.
Steam was coming out of the engine box.
Turned it all off immediately, opened the engine box to see coolant spraying out from heat exchanger. O-ring connecting one of the pipes pushed out.
Let it cooled down a bit, luckily had heaps of water in the boat so used it to top up the coolant and went back home on idle.

On inspection at the jetty, looks like impeller was in bits, running dry.
Heat alarm comes fairly early on these engines and temp gauge was not near danger zone, we concluded as no possible damage.
Ordered couple of impellers and installed one, keeping the other as a spare.

This issue looks like will keep happening though and I am having trouble to find a solution.
Raw water is picked up from the front of the leg grill, travelled along the bottom of the engine and upwards to impeller.
Just above the impeller is the filter box. From there on goes to oil cooler to aftercooler, heat exchanger, etc...
My problem I think is that "head of water" is way lower than the impeller height causing the impeller to run dry once engine turns off unless filer box is manually primed.

When impeller was out, I can poor water on to pick up line and it drains straight back out.
Seeing how high is the impeller from the sea water level, I was expecting a one way valve to keep the impeller primed along the line but there is nothing.
I would have thought there should be a cut off emergency valve somewhere just after transom also, but cant find anything.

As this is my first inboard engine boat, still in the early learning phase.

Let me know please what you think about solving the head of water height problem.

[Fed]

Surely the sea water pump can suck it up, if it can't I'd be looking for a blockage in the system or an air leak on the suction side of the pump.

[ranmar850]

I assume its a Jabsco-type soft impeller for the raw water pump? I've replaced many of these over the years ( used to be a commercial fisherman) and found they would pick up from dry and they were always mounted above water level. We would only splash some water on them as we installed, as much to make them easier to slip in as anything. And if the boat had been lifted out of the water, and sitting on the hard for extended periods, they would always pick up from dry with no problems. You've got to run them bone dry for a few minutes before they will fail. Your failure may not have been related to the installation, it may have just been ready to fail? Or there is growth inside your intake which is restricting flow? You did mention the boat had been anti-fouled, which means it could have spent long periods in the water, and that tubeworm/"coral" type growth, and barnacles, seem to love it inside intakes, where it may not be immediately noticeable. Certainly easy enough to replace at sea as long as you can access them. How high is it mounted above your water level with the boat sitting at rest?

[gofishin]

PROS,
Something is/was wrong with your raw water system, there should never be problems with seawater self-priming. Depending on the length of leg extension used (singles on cats sometimes needed large extensions else the centre pod would be too deep), your impeller may be under ‘water level’ anyway. A check valve creates pressure drop, and hence although a good one will keep water at the impeller, the pump will need to overcome this additional restriction to its ‘suck’, and hence it will reduce the quantity of water being circulated.

Maybe your impeller was cactus to start with? Start with the basics, check whole raw water system on the suction side. Start at the pickup/grill in the leg, also the aluminium leg fitting circled in attached. These corrode, which breaks the seal with the hose (under the hose clamp). This hose transfers seawater back to the transom shield pipe (and into the engine). At low speed, not a problem (the leak is under water), but at higher speeds the water is clear of this area and the raw water system then sucks in air through this ‘vapour leak’.

Problem could also be on the discharge side coolers/exchangers etc as per ranmar’s suggestions. Pull all the hoses/pipes off and visually inspect all that you can. Borescope cameras are very cheap these days too.

With my old man’s cat (twin Volvos, hence donks low in the hulls) we got rid of the leg pickups when we moved back to Oz and went thru-hull under the impeller (to remove the chance of sand/mud ingress in the canals/Broadwater etc). If I ever had a S/Drive again I would do the same, regardless of boat type. However, a single S/D in a cat may present problems with aerated water from the tunnel – unless you can pickup effectively from the very bottom of the pod?? Will need to seek further comment from people who have done this, or who know from others – if this is possible with singles in cats. Typical thruhull pic attached FYI.

We had one customer with a single Volvo S/D Sharkcat, that started with a 155 or 165, then went to a 200. Never a problem with water pickup with that (thru the leg as per normal).

Lastly, sounds like the donk got really hot!! Can’t recall the locations of the temp sensor(s), but if it was really hot and no water in the right places, your temp gauges may not have been indicating anywhere near the actual temp of the donk. Keep an eye out for signs of a cracked head! We had owners that cracked heads from one occurrence of overheating, and others that were more lucky – more so with the 155/165hp’s than 200’s although memory is getting very scratchy now as it was too long ago.
Cheers
Brendon
PS. Haven’t got round to looking for more ‘spares’ yet, maybe mid Jan +/-.

[PROS]

Previous impellerthat I destroyed was pretty much brand new.
I used aVolvo genuine impeller just in case and also purchased Jabsco matching unit asa spare.
Volvo genuineparts seem to be on par with gold pricing.

impeller1.jpg


(2) –Impeller location. Above black box is the filter where I prime before startingthe engine. Why they don’t simply make the cap transparent colour so runningwater can be confirmed visually?
Being a singleengine stern drive cat, engine is higher than what would be in a mono hull.
Impeller isway above from the floor height. Floor being self draining already above thesea water level.
A loteasier to make sure cooling system is working with outboard engine by seeingthe tell tale pissing, nothing like that on inboards. I am paranoid every timestarting the engine currently.

(3) – Rawwater pick up hose.
This hoselooks very sad actually. Feels too soft around the clamp attachment to impeller.Definitely needs changing. Cantaccess the transom side of this pipe unless I take off the aftercooler first.
Also sawsome half kinked hoses towards the rear left side of the engine what looks tome just before discharging out.
Thanks foryour feedback and I agree with all the comments about possible restriction onthe raw water cooling system and inspection is required.
Decided to change all the cooling pipes already.
I amassuming I can use matching size/shape radiator hose to replace these ratherthan forking out to Volvo genuine???
Can I usecopper (or some other suitable metal) piping instead of plastic hoses? Copper/StainlessSteel????
Ratherhave a metal 90 degree bend followed by plastic hoses clamped than a possiblekink on the corners.

Leg hasbeen in the water without much movement over the last 12-18 months, front grillneeds to be inspected for marine life.
Cant see toinspect this unless I dive in with resident canal bull sharks.

(1)– Coolant leaking location.
That upsidedown L shape pipe is connection between heat exchanger and engine block.
There is aclamp on the pipe however only attached from one side so it doesn’t have enoughstrength to stop the pipe from moving if under pressure.
This pipeseems to be connecting to heat exchanger via only an O-ring.
I assume whenimpellor got destroyed, coolant temp started increasing as well as thepressure. Pressure caused outwards movement of the L pipe and O-ring pushed outspraying coolant.
The cap onthe heat exchanger never had enough pressure to release.
Oninspection this O-ring has some bright blue colour silicon like adhesive thatlooks like recently applied. Who knows what….

I will bereplacing all raw water pipes as well as inspect/clean heat exchanger andaftercooler just in case once I am on trailer at mid January.
Too risky forme to do this job while still in the water without a cutoff valve.

[ranmar850]

Not a bad idea to have a stainless bend in place of a bent rubber hose--this is common practice on larger installations. If a hose feels "soft" there is a possibilty that, if it is on the intake side, it can collapse on suction, but It looks like you have already guessed that. I can certainly see your point about not having a telltale--even on big boats with a wet exhaust you can look over and see the water running out.
From what you have said, this may just be a combination of a number of things which gave you the outcome--sounds like you are on the right track, and the only thing you can't fix easily is the height of the pump above your waterline.
How hard is it to prime the pump?

[Smithy]

My experience with Johnson/Jabsco style pumps is if it ain't broke, don't mess with it. I think I had one impellor that had done close to 2,000 hours and came out perfect. I have also done one at 24hrs. I think it all comes down to instal. Use the glycerine in the kit so it is lubed as it goes in. I've seen other guys use grease, so long as it is not harmful to the rubber. I am doing better with after market impellors from places like Victory Parts rather than genuine Johnsons which are a harder compound I reckon. I'd say my housing is a bit worn after 12,600 hours. Also prime the system up after an impellor change. Yes, they should have no problem drawing water up but prolonged running dry will kill them. I have heard mine sucking a bit and running dry when backing hard on marlin. That is when most marlin boats do their impellors too in my experience. The old owner said he used to get 400hrs out of an impellor before one would bug out. I certainly get better than that. He said mostly they go when cold as you first idle down the river. I may have had that once. Been random when they go for me.

[PROS]

Looks like manual priming until I get the boat out of water and overhaul the raw water system.
The engine cover lid weighs about 50kgs+, thinking of making a quick mould out of carbon fibre to reduce weight and sound.
I wonder removing 100-150kgs out of the boat would give me more speed or not?

On a good note, I finished couple of sets of seats for the boat as captain/crew chair.
Decided on the Charcoal/Beige modern colours.
Will also start building the bench seat soon after new year.

Black/Red seats looked a bit too strong so I turned them into CEO office chairs for one of my customer.
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[Mupster]

What's happened to your project 23 Max?

[PROS]

What's happened to your project 23 Max?

woowwww
I cant believe nearly 6 months passed since the last update.

Boat is still tied to jetty and this project will run 3 times longer than initially planned for, as usual....
I figured I will struggle drive in/out through my driveway gate, only about 6-8 cm spared per side.
Instead of altering the gate, I though why not get a large shed and store the boat there.
Searching, searching, searching later I signed a contract in February.
Since shed is large enough, I will move the business there as well.
29th May last week was the settlement and I started moving that late afternoon.
Very exciting times.
Ordered the trailer next day and picked it up last Saturday.
Work been busy, cars getting interiors done up.
Now I need to find sometime time to get the cat out of water.

Need to organise soda blasting asap to remove antifoul.
Does anyone have any contacts that is reasonably prices? even better if they need leather/vinyl interior work done for their car/boat/aircraft

image1.jpg

[PROS]

Busy with work, finally decided boat had to get on the trailer and out of water last Sunday.
Beached it early morning to clean up the marine forrest, a very dirty shovel and brush job...
Kept reminding myself don't forget to bring outriggers and antennas down.
By midday all cleaned out and boat final checked for the drive to nearest ramp.
Trailed goes in the water, tunnel width is good however guards are just scraping the bottom, forced it up on the trailer anyways, it had to go now or a month later.
Poor old car looks tiny compared to boat.
Drove just out of the ramp, heard a big bang going under a tree, cant be good.
Both aerials are snapped from the base... Did take off the outriggers but forgot to lower the antennas in the rush.
Uneventful drive down to Brendale.
I am glad Sharkcat is finally out of water so I can start working on it.

IMG_4622.jpgIMG_4623.jpg

Leg and diesel inboard will be removed first.
Stripping the boat and removing the top next.
Antifouling needs to be soda blasted somehow
Filling and sanding the whole boat
Painting and putting it all back together
Carpet, seats and interior
Furuno electronics

Hoping to finish it all by mid September but it will be most likely Xmas if past is anything to go by