28 Foot Force Project

CK Marlin

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Oct 28, 2014
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Ken
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Patti
You should always have the coupler faced with the shaft. Even if its brand new.

KC
 

HelluvaBoater

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Mar 7, 2012
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Maka
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Force 28
Not too much this week on the boat. Waiting on the prop shaft and some trailer parts to arrive before I go further with the tunnel glassing. Did a little planning tonight. I'm gonna simplify the layout compared to what I had before. Basically going to put in two big fish boxes that can hold the longest onos I ever plan to catch. With the fish boxes being 5'2" long, I figure I can fit a 6-foot ono in there diagonally.... There will be a compartment for the engine box with engine battery storage in the middle of the boat and a compartment for the rudder/house batteries in the stern. The rest of the voids will be converted into fuel tanks. Going convert the engine to a high mount turbo which is better anyway because it gets the turbo higher above the water line.

I will have twin forward tanks that will be connected with a balance line as well as twin stern tanks that will also be connected with a balance line. Going to put an electric pump with a filter on it so I can transfer fuel fore and aft. This will allow me to trim to the boat according to the sea conditions.

Still need to figure out the bait tank... Thinking it should go on the centerline, aft of the engine box but above the waterline so it drains naturally. Could possibly just make a flat deck and do the bait tank on top of the battery storage area but we will see. I can figure out the bait tank later as long as I get the fundamentals right now.

I have been making wood templates for everything inside of the boat but I don't have any good pics. Here is a rough sketch of what I'm planning....

 

Kinaiahi61

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Jan 17, 2012
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Lihue, Hi
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Kalani
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Looking good. Are you going to have a large fish box on the deck? If not, the 5'2" box will have a hard time fitting them big ahi that you're gonna load up.
 

HelluvaBoater

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Not planning on having an above deck fish box. There is already a huge fish box forward of the engine box in case I get something really big. That will fit most of the fish I plan to catch. I might end up moving the aft bulkhead towards the transom a few inches which would gain me some more length. Not sure yet.

The shaft comes in tomorrow. Gonna set the v-drive in place, glass in the stern tube and then make a wood template of the engine. Gonna build the boat around that....

I think this design layout offers a lot of versatility in trimming the weight of the boat. If I need weight somewhere, I can transfer fuel from front to back or use different fish boxes depending on the sea conditions. I wish the aft fish boxes would be a little longer, but I need to have a bulkhead somewhere... ya know? They should be big enough for 99% of the fish I plan to catch.

Stoked about how much fuel I am going to be able to carry. Gonna have a ridiculous range. Maui to Kauai should be possible I would think, or perhaps around the Big Island....
 

Kinaiahi61

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Kalani
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Nice, that's some sick range. Kauai has no fuel dock so if you're coming this way you'll need to arrange for delivery. Sounds like a lot of room, good luck and keep trudging on, you're making good progress. Aloha
 

HelluvaBoater

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I think this layout has a lot going for it...

-increase range
-keeping the battery weight low
-no more "sealed compartments" that are actually full of water
-allows transferring fuel fore and aft for ballast weight
-new holds can be used for bait tank, cooler, scuba tank storage, etc.
-if the shaft or rudder ever leak, it _should_ be confined to single compartment. I am not counting on this by any means, but it's a nice thought. I doubt the boat would stay afloat with full fish boxes, full fuel tanks AND a flooded engine box, but with a light load it _could_ help I guess.

The engine access isn't ideal right along the sides of the engine, but I will go wider with the above-deck portion of the engine box to make access better. I am leaving enough room aft of the engine so that a person can fit in there. The width between the engine stringers is 30 inches. I think I will be able to access the engine pretty good. Might bolt a wooden jig of the engine to the gear once everything is glassed in place so I can design the boat around that.
 
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HelluvaBoater

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Sharpened the edges of the tunnel with a 60 grit sanding block and 80 grit air file. I think it looks pretty good. Going to radius the edge slightly more. I want to put a few layers of glass on the outside of the hull, but it looks so damn good I don't want to mess it up. Thinking I might just do a few layers of fiberglass cloth and then a light layer of mat over top.





Got the 1.75" AQ22 prop shaft today. They sent it UPS to hawaii and at 60 lbs it wasn't cheap.









This is with a 22" prop. The prop isn't pressed all the way on the shaft yet. It still has an inch to go. This is the first mockup. I think the shaft length looks dead on. I have about an extra 1/2" to remove the prop without removing the rudder and the shaft is about 2 inches off of the forward engine box bulkhead.

Since my ideal prop is probably 20 or 21 inches, I am going to go with a 1.5" clearance with this 22" prop. It is my starting point because I got this prop cheap and bigger props generally mean better fuel economy. I am not going to run this prop if I cannot reach the recommended RPMs. The recommended prop tip clearance is about 2-2.5 inches and that's what I'll have when I change to the recommended prop size. Even with a 21-inch prop I will have a 2 inch clearance which I think is acceptable.

Next steps are to get the gear in place, install a strut, then glass in the stern tube.... Might be looking for someone on maui to weld a strut if I can't find something off the shelf...
 
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HelluvaBoater

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Had the local machine shop resurface the flywheel where the CFR damper plate will mount....



Going to clean all the mounting surfaces up with a Scotch Brite pad before bolting it all back together.
 

HelluvaBoater

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Met with a local boat builder and was told the last custom strut they made cost $5000. That's not going to work for me. If I can't find something "off the shelf", it is going to be cheaper for me to just re-glass the flat spot on the roof of the tunnel where the strut attaches. Good thing I haven't glassed it all to a completed thickness yet. It is only 1/4" thick right now. Hopefully I will find something that fits, but I might have to cut out the flat spot and re-do the angle if it saves me $5000.

So my next goal has become to get the strut in place. Today I got a lot done. I started bolting things together even though they are going to have to be un-bolted later.

The 22" prop I bought for $300 had a good amount of corrosion in the bore. I strapped the shaft to a table and proceeded to lap the prop using a valve grinding compound. I checked the fit with prussian blue and a Sharpie..





I lapped it by hand for 40 minutes adding compound 8 times or so. It is showing pretty good contact to the shaft, but I am going to clean the small portion of the prop bore with a dremel before it all goes together because there is a lip of grime on the skinniest portion of the prop bore.

Cleaned the ZF63IV output flange with a Scotch Guard pad and WD40. The shaft coupling looks brand new but the whole gear looks really good I'd say.

Proceeded to bolt the shaft coupling to the gear, although I will have to go back later and add Loctite 243 as per the ZF63IV manual.







I'm going to leave the black paint on the gear the way it is since it looks good already and the case is aluminum. Less paint will make it easier to rebuild when the time comes.

I aligned everything up to within 1/16" and within .05 degrees to take some pictures and get an idea of the stern tube placement. I will be widening the hole for the stern tube, but I want to get the strut epoxied in place first.





In the meantime I can measure the strut, do some glass work on the tunnel, reinstall the flywheel and think about moving the turbo to a high mount.
 
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HelluvaBoater

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I sent the specs to half a dozen "foundrys" for quotes on casting a custom bronze strut. Nothing off the shelf was going to work right because the "A" angle of the strut is more than anything off the shelf (because of the tunnel roof). Marine Hardware AKA Algonac Marine Cast won me over on price and confidence that they will deliver a quality product. They are going to build me a custom pattern that exactly matches my specs. They are saying the casting will take 4-5 weeks for the pattern design and casting and will cost a total of about $2200. Strut will exceed ABYC standards. Not cheap, but I think I feel like I am getting a good deal for what I'm getting. It's not like I didn't shop around. Spent a couple weeks on it... Excited to see the strut and get it epoxied in place.

Not gonna glass in the stern tube until the strut is epoxied in place. Looks like I am doing other projects for a while until I get the strut.
 
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Jitamon

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Dec 6, 2011
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Jita
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16' Alii Kai rebuild
Aloha, love this thread, thanks for posting with pics. I am starting a rebuild myself and have really enjoyed watching your progress.
 

HelluvaBoater

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Mahalo, thanks for the kind words. You should post a thread on here too. This thread has been invaluable for me too... I've gotten tons of advice from very knowledgeable people and it gives me a log of what's been done and where I need to go.... I even got hooked up with my engine from someone seeing the thread. I highly suggest doing it. Plus, I'd like to see it.
 

HelluvaBoater

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I've been waiting for my custom bronze strut to be cast and delivered, so I've had time to mess with my engine. Figured I should get the engine cherry before I get too far along with the boat.

I added coolant and soon discovered the engine had a head gasket leak...





I immediately got a thread going on Boat Diesel...

http://www.boatdiesel.com/Forums/index.cfm?CFAPP=0&Forum_ID=37&Thread_ID=59268

They had me do some tests and the head gasket was "confirmed" because when I pressurize the cooling system with air, the air noise coming out of oil filler hole does not change as I bar the engine over by hand.

I did an oil change, pulled the injectors, sprayed tons of WD40 into the cylinders and have been cranking the engine over religiously to feed new oil to the bearings. Hopefully I will save the bottom end....

We stripped all the paint off the top half of the engine and are preparing to pull the head. I might do one more oil change before we pull off the turbo because I'd like to crank the engine over some more with fresh oil in. Even with the oil change and all the cranking, I still see some milkiness under the valve covers...

While I have the head at the machine shop, I'm gonna send the injection pump, injectors and lines to an injection shop and have them reconditioned.

I'm pretty sure the block is good because the engine started up EASY from a cold-dead start with no blowby and no smoke. After stripping the paint, the engine definitely has some hours on it...











Since we pulled the injectors, I was finally able to measure the injector nozzle tips. They are 9mm which means this engine is pre-1991 because in 1991 they went to 7mm injector tips. Since it has the larger expansion tank, it is post-1987 so the engine is dated somewhere between 1987 and 1991. Probably not gonna get much more accurate than that.











When I get it all back together, the engine should be good because it will have...

-reconditioned heat exchanger
-new water pump
-new gaskets on the top end
-valve job
-new belt
-new hoses
-new raw water pump
-new water pump
-new thermostat
-new alternator
-new starter
-new pulley
-rebuilt fuel pump/fuel lines
-rebuilt or new injectors
-new filters
-etc-etc-etc

I also did some other stuff like acid wash the expansion tank, flushed the cooling system, etc.

I suppose I should be upset, but I'm actually stoked because now I know why the engine was probably pulled out of it's last boat.
 
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Kinaiahi61

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Kalani
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Kai Kea
Hope the seller reflected the condition of the engine in the purchase price. Boats gonna be solid, no worries once you're done, its done:)
 

HelluvaBoater

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I still think I got a "fair" price based on what was known of the engine, which was basically nothing.

If I have to rebuild it, I should still come out well under the price of a reman, which for me is a fair deal. I personally don't mind the mechanical work too much *knock on wood*. It's the fiberglassing that I really consider a pain in the ass. Engine work is fun compared to that.

Hopefully, it's just the top end I need to rebuild and the lower bearings and pistons are OK.

I got an oil sample report done for $20 and there was so much water that they could not accurately calculate the metals. They did find sodium which means the heat exchanger had probably been leaking into the coolant system. Not good. So the engine had a blown head gasket, leaky CAV pump, in addition to a leaky heat exchanger. No wonder they pulled it. I just hoping the engine wasn't ran too long with water in the oil. Hopefully it overheated and was shut down before any bearing or piston damage was done. That's what I'm hoping anyway.



I ordered a compression tester and if the compression is good on the engine, I'm just gonna roll with it and redo the head and hope for the best on the bottom end. In the meantime, I've done three oil changes. I've been cranking the engine over for 20 minutes or so (off and on to let the starter cool) between oil changes. The oil is finally coming out not milky anymore. Just using cheap $10/gallon Walmart oil to do the flushes. I'll switch back to Delo 400 when I really get the engine going.

The engine starts easy and runs good with no weird sounds, smoke or blowby (with no load). If the compression test checks out, I think the engine will be fine. What do I know though.............................

Today, I also received my custom bronze strut....





Time to get to work!
 
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HelluvaBoater

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... here we are after 4-5 hours of work.

Everything's looking lined up This whole time I have been measuring everything on the tunnel as accurately as I could "using the thickness of a Bic pen". I made a paper template of the strut base and centered it on the flat spot I made on the tunnel roof. Popped some bolt holes as accurately as I could, but allowing 1/16" of play to move the strut around over the flat spot (I drilled 7/16" holes and I'm using 1/4 bolts).

Looks like everything is lined up nicely with the strut centered on the flat spot. Less than a 1" gap between the prop and strut which is good considering it has to be "less than 1 shaft diameter".







 

HelluvaBoater

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A lot of thinking going on this week. Not too much work being completed, but I'm about to kick the glassing into high gear.

The only work I did was fitting the fiberglass shaft tube:



I thought I was ready to float the strut in with epoxy, but after thinking long and hard about it, I think the next best step is to finish glassing the tunnel to a completed thickness (3/4" to 1" thickness according to the guys on boatdesign.net).

As per Tony's advice, I am using the v-drive as a jig for aligning everything. Now that I know everything lines up perfectly, I am ready to finish glassing the tunnel.

I originally wanted to glass the shaft tube in as I built up thickness on the tunnel, that way it is all connected. I now realize that the only function of the stern tube is to keep water out of the boat and there will never be any real stress on it, especially since I am going to grind it off flush on the bottom of the boat. Because of this, I'm going to glass in the stern tube after I complete the tunnel. This will allow me to epoxy the strut and v-drive into place basically at the same time. I'll then do a feeler gauge alignment on the v-drive and then glass in the shaft tube.

But, first I need to finish glassing the tunnel and then stringers. If I had to do it over again, I'd have done the tunnel first and then stringers, but live and learn I guess.

I'm gonna cut a recession into the forward bulkhead to make it easier to work on the shaft coupling (for shaft alignment and shaft seal change purposes).

-----

This week, I ordered a few special tools for the engine. I know I have either a head gasket leak or a cracked head (or both). Apparently, Cummins went to 7mm injector tips in 1991 because the heads were cracking between the injectors and push rod holes. My injector tips are 9mm which means my engine is pre-1991. Going from 9mm to 7mm added more beef into the head casting.

I ordered the following tools which will be here in the next couple days:

-Cummins compression tester with adapter
-Cummins barring tool
-Dial bore indicating gauge (for measuring cylinder trueness once I pull the head)

Some of the guys on BoatDiesel say compression tests are worthless, but I'm gonna do a couple compression tests anyway before I pull the head. The compression test should give me an idea of the cylinder health relative to the other cylinders. This will give me a better overall idea of the engine health and the compression tester will be a good tool to have later on anyway.

Once I pull the head, I'll also measure the cylinders for trueness with the dial bore indicator gauge and then decide whether or not I will rebuild the bottom end too. The oil pump pressure tested good which is definitely a good thing and apparently these engines can get 30,000 hours on the bottom end without requiring a rebuild (for all I know, this engine DOES have 30,000 hours though....)

I did four 3 oil changes/flushes with cheap-o Walmart 10W-40 to get the coolant out of the crank case from the leaky head gasket. Been cranking the engine over religiously with the injectors out in 45 second spurts for weeks now. The oil is looking clean now. One last oil change today, a compression test and then I will pull the head.

Depending on the head condition, I might just bite the bullet and spend the $1800 on a new OEM Cummins head (complete with valves, etc). It sure would be nice to have a brand new top end. $1800 is extremely cheap compared to a Volvo or Yanmar head. We will see though...
 
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