Trimaran - Especially Searunner - Owners

[smj]

Originally Posted by Mark Johnson

I got mine from "Johnson's Supply" in Pensacola Fl. They are commercial suppliers for shipping. It is sold only in 5 gal buckets, and I forgot the price, but even with over $100 in shipping, it was about 60% less than the price of off the shelf counterparts. BE SURE YOU ASK FOR AN UP TO DATE CAN that is not expired. Ours was expired, but I called Ameron, and they said that after mixing, if it homogenizes OK, it IS OK!

We still like it, btw, and it has continued to get harder over time.

With your Sea Wind, you could go halves with someone...

Good luck,
Mark

Thanks of the reply Mark. I will pass this on.

[sassarassa]

Old 2GM20 finally died after 40+ years of service.

New low hours 3GM30F is the replacement. Random pics of the change over below.

Was very tempting to install some sweep oars and use the space for something better ... like a beer fridge

[sassarassa]

The old engine and shiny new PSS Shaft Seal

[Boatguy30]

that looks to be a 2QM15 made from 1978-81

Cheers,
Jeff

[clemon]

Nice installation. I'd never seen pictures of the "standard" engine location.

I just put a Beta 20 in. I've got the engine in the aft cabin under the companionway. Makes getting to the water pump impeller interesting, but otherwise has nice access to everything. We'll see how the Beta's do.

Chris

[Boatguy30]

Chris

I may mentioned to you before, but Mark Hampson is refitting the SR 34 I briefly owned up near the north end of the Gulf. He has a 2qm15 with a crazy belt drive setup I hope he won't keep.

cheers,
Jeff

[Roy M]

Here is my installation on a SR 40:

1st: Lifting the engine (3GM30F) for a trial fit.
2nd: The access port in the cockpit, the chain hoist and 2x4s. Engine instrument panel to the left.
3rd: Old engine room shell, formerly holding a Volvo MD2B, 25 HP, 500 lbs.
4th: Stripped to the hull, with original bed logs for engine.
5th: New shell with sound absorbing foam, modified bed logs for engine.
6th: Set up for placing engine. Lowered into aft cabin with halyard, set on greased plywood skid on timber, pushed by hand into engine room, lifted off skid by chain hoist, lowered into position.
7th: Jig for engine mounts, dowel to simulate shaft center for alignment with prop shaft.
8th: positioning engine onto mounts with chain hoist.
9th: detail showing engine mounts.
10th: Another detail of mounts in place.
11th: All the stuff packed in the engine room, but not dressed up yet.

[sassarassa]

Originally Posted by Roy M

Here is my installation on a SR 40:

1st: Lifting the engine (3GM30F) for a trial fit.
2nd: The access port in the cockpit, the chain hoist and 2x4s. Engine instrument panel to the left.
3rd: Old engine room shell, formerly holding a Volvo MD2B, 25 HP, 500 lbs.
4th: Stripped to the hull, with original bed logs for engine.
5th: New shell with sound absorbing foam, modified bed logs for engine.
6th: Set up for placing engine. Lowered into aft cabin with halyard, set on greased plywood skid on timber, pushed by hand into engine room, lifted off skid by chain hoist, lowered into position.
7th: Jig for engine mounts, dowel to simulate shaft center for alignment with prop shaft.
8th: positioning engine onto mounts with chain hoist.
9th: detail showing engine mounts.
10th: Another detail of mounts in place.
11th: All the stuff packed in the engine room, but not dressed up yet.

That is very neat job. I considered drilling an access hole in the cockpit floor but then just decided to manhandle it in. (I recommend drilling the hole for anyone looking at doing this job, it was a bit hairy scary going in.)

What prop size and pitch do you use, what RPMs do you rev to max and what speed in calm water do you get with the 3GM30? With the 2GM20 I was lucky to get 6 knots dead calm with clean bum. Any wind and we just stopped.

cheers

Jon

[sassarassa]

Originally Posted by clemon

Nice installation. I'd never seen pictures of the "standard" engine location.

I just put a Beta 20 in. I've got the engine in the aft cabin under the companionway. Makes getting to the water pump impeller interesting, but otherwise has nice access to everything. We'll see how the Beta's do.

Chris

I was going to buy a Beta 25 or 30 but then my yanmar 3GM30 with only 300hrs on it came up really cheap so had no excuse to buy new

Be interested in what you think of yours after you put some hrs on it.

It looks like you have a PSS Shaft seal or something similar. Do you run water to the seal or that hose just a vent? They say to run water to it but I've seen a few installs that are just vented and they dont have any issues.

Jon

[clemon]

Jon,

It's a PSS shaft seal. I've got a system that's sort of a combination of vent and hose. I've got a vacuum breakers line that has a tee off way above the water line to the PSS feed. When the engine gets up enough back pressure, some of the exhaust injection coolant water drains through the PSS seal.

I though of just having a vent, but this is about the same thing, and flows some relatively clean water through the system to washout any silt that gets into the cutlass bearing.

Chris

[Boatguy30]

a vent is all that is needed for "low speed" craft which I believe they consider under 12 knots motoring. At higher speeds apparently a vacuum develops which dries out the seal which then needs the feed line. PYI recommended a piece of bug screen over the top of the hose above the waterline to unsure nothing could clog it over time.

[Roy M]

I have a 17 foot long prop shaft, 1" diameter, supported every 40 inches or so with pillar block bearings, conventional shaft log and a cutlass bearing. No vibration to speak of (although the old MD2B used to shake my coffee cup on the sterncastle table) at cruising RPM of about 2300. Max is somewhere in the mid 3000 range. At 2250 in flat water with the centerboard retracted, I do a little over 8 knots and consume about 1/2 gallon of diesel per hour. I have sufficient power to punch through heavy chop and wind waves and make good headway.

[PhantomBoatwork]

Roy, I have pretty much the same set up for my CC44- 1 1/8" shaft about 20 feet long with flange bearings every 44 inches or so, a standard bronze stuffing box, and a folding Martec prop, recently refurbished. My engine is a (soon to be installed) 44 horsepower Universal M-50 four cylinder diesel. I just got back from picking up the wood and ply for my skeg and rudder. I need to finalize the steering cables and sheaves and the shaft strut so I can finish all of the aft section. Anyone have any words or wisdom for fabricating and glassing my skeg and rudder? I'm going to put a stainless steel trim tab for the self steering, and probably run it off a tillermaster.
Oh, a little off topic, I just finished the dinette table and think it turned out rather well. 1/4" plywood with an oak core, and a resin top with shells, placemats and a chart or the local waters. What do you think?

[rossad]

Awesome phantom

[Mark Johnson]

My 2 GM 20-F Yanmar is in the "under the companionway steps" position. I think this is better, especially for the SR34, because the old "under cockpit" spaces drawn were for the long narrow Atomic 4s, of decades past. It is really tight in there for short fat little diesels. This is IF one was starting over anyway of coarse... Roy's beautiful installation may be an exception, as there is so much more room from the get go on a 40. If you haven't been on a 40, they're HUGE!

I have, and still like, my PSS shaft seal. The non vented model I started with was problematic, so I switched to the irrigated version, which is the ONLY way to go in my view. (Drawing water from the engine's up turned loop)... This way the bearing at the shaft log's end gets irrigated a bit, lessening debris and wear. If one has no bearing in the log at all, just vented may be OK, but if it was me, I'd still go with a properly irrigated set up.

BTW... My PSS rotor slid up the shaft once, (when we were on a date ashore), partially flooding the bilge of the main hull. If I hadn't had a trimaran... The grub screws just barely grab the hard Aquamet 22 shaft! It can never happen again. Now I back up the rotor with a doughnut zinc, with a "small" bead of caulk at contact points between them. (It is important to JUST make contact, and not push the rotor out of perpendicular to the shaft). I still like the PSS, and trust it... WITH a back up to keep the rotor from moving.

The CV joint with thrust bearing goes a long way toward extending the lifespan of transmission bearings, and engine feet. (None of the thrust goes on the engine at all). It also protects the installation if you grab a crab pot, AND since the shaft only spins, and no longer shakes with the engine, the stern tube's cutlass bearing last longer, and the PSS seal works better. It is a pricey little jewel, but over decades, more than pays its way in reliability.

Roy, your installation sounds and looks stellar. 8 KNOTS, EVEN IN A SEAWAY... DAMN!!!

My little 2 gm 20, (really 18 HP MAX), "just" pushes us at 6 knots, running our regular 2,900 RPMs, at the same consumption as you, 1/2 gal per hour. If there is a 20 knot head wind, we go in the low 5s, and with 25+ knots of wind and a really nasty seaway, in the 4s. Luckily we sail most of the time! It would be nice to have the bigger 30 HP, but I would loose too much space to go that route, (with the engine still in the middle), and I like the access I have there... Guess I will stay with the runt of an engine that I have.

Phantom Boatwork... On tips for glassing your rudder / skeg. First, you need a lot of homemade BIAS CUT glass tapes, in varying widths 2,3,4,5,inches wide, that are cut at a diagonal to the roll of 10 oz fabric, (With a pizza cutter type fabric knife). With these, ALL of the fibers go across the joint, vs just half of them. Also, they will compound bend around radii, even on a curve.

I would glass the faces of the foils about 1/8" thick, MIN! That's a number of layers. I don't remember... 4 or 5 at least. This is NO PLACE to save weight! On all of the edges, I used those bias tapes to glass to about 3/8" thick. Especially on the leading edges and lower collision with the bottom "nose". On the aft rudder edge, (sans trim tab), we let the glass run back about 3/4" past the wood, which was SHARP. Then doing the other side the same, so the aft edge is all glass, and only about 1/8" thick.

After shaping to perfection, with NO hollows or flat spots, (detected by rolling a straight edge around the foil), I put on 6 or more top coats of epoxy, so that after years of future bottom paint removal, I still never expose any glass fiber.

I don't know what John drew on your boat, but the best rudder / skeg arrangement I ever saw, was the "no metal" version on my previous SC 28. This had only one underwater metal part... a 3 to 4' long, single 316 grade SS rod. Since the polypropylene fabric/epoxy bearings were wrapped around the waxed rod as a mold, the fit was a PERFECT '0" tolerance fit. If heavily glassed... It was vastly superior to the clunky nuts & bolts and massive SS gudgeons & pintles, found on our Searunners. These are hard to build, paint, clean, and maintain in every way.

The trim tab idea is fine IF you will have a wind vane, and really need one, BUT tris with a skeg / rudder and CB, track sooo well, and staying level, hunt soo little, that a standard wheel autopilot like the Autohelm, (Ray Marine 4,000), can handle the loads just fine, while just sipping amps. On a monohull, you would need a really consumptive down below autopilot for SURE!

I have tens of thousands of miles on our wheel pilot, and meant to carry a spare, but never got around to it. If it was me, I'd skip the "trim tab to a small tiller pilot" idea, and use a wheel pilot. Having said that, IF you need the trim tab for a wind unit anyway, why not have both a wheel pilot and a tiller pilot. (You will find that the wheel pilot works a LOT better in a seaway though).

If you have built that nifty "all composite" rudder to skeg connection, however, I would definitely not muck up the concept by sticking metal under water that could otherwise be avoided. Just a thought...

LOVE that table! What a beauty. That is on my list. I want a longer, lighter, round ended table.

Best to all...

M.