Motorboat replacement engines project and a bit of a refit.

[burgundyben]

You will probably find that the centre of gravity of that arrangement is round about the engine back foot. A problem if on flexible mounts.
I had a four cylinder Ford Sabre with PRM box, on flexible feet, and the whole thing rotated about the after mount. I also had a raft extending a frame forward for hydraulics, I wish I had extended it aft to have a mount level with the coupling, (or even six mounts) to dampen the vibration.
I should have realised at the start, when the engine arrived, gearbox attached, I could rock it back and forth on the rear foot.

Yes. You are quite right. The flywheel is a big lump and it's right where the rear feet are. Plus the box hanging out the back.

I'll need new mounts, the old ones were replaced in 2015 but are shot already.

I'll call R&D marine before I order. I suspect a different mount at the rear. They will need to be shear mounts as there's no python drive or similar.

 

[fisherman]

In retrospect i would have had the engine on an angle or channel iron raft, extending well fore and aft, so the mounts had more purchase or mechanical advantage against movement. If the rear mount is exactly the same plane as the coupling face, then aligning the shaft gets easier. One of the many things I wished I'd thought of at the time.
As it was the engine gyrated madly around the rear mount, but remarkably the R&D never failed, nor the mounts nor the flexible stern tube inner gland, in 5000-odd hours.

 

[burgundyben]

In retrospect i would have had the engine on an angle or channel iron raft, extending well fore and aft, so the mounts had more purchase or mechanical advantage against movement. If the rear mount is exactly the same plane as the coupling face, then aligning the shaft gets easier. One of the many things I wished I'd thought of at the time.
As it was the engine gyrated madly around the rear mount, but remarkably the R&D never failed, nor the mounts nor the flexible stern tube inner gland, in 5000-odd hours.

Thats what's in the boat. Lengths of angle steel bolted to the hogs at the same angle at the shaft. She's 40 years old anddone 10 years commercial service in Scilly and Dartmouth, she's a tough tub.

 

[fisherman]

Thats what's in the boat. Lengths of angle steel bolted to the hogs at the same angle at the shaft. She's 40 years old anddone 10 years commercial service in Scilly and Dartmouth, she's a tough tub.

the point is to have the engine on long steel bearers, then those on flex mounts. Otherwise you have the two aft mounts at the flywheel which is the point of rotation, they need to be further aft. IMO.

 

[superheat6k]

Yes. You are quite right. The flywheel is a big lump and it's right where the rear feet are. Plus the box hanging out the back.

I'll need new mounts, the old ones were replaced in 2015 but are shot already.

I'll call R&D marine before I order. I suspect a different mount at the rear. They will need to be shear mounts as there's no python drive or similar.

Ben

I have a set of R&D spare from my recent debacle. I bought two sets, but only fitted the stbd. No plans soon to lift the port so make me an offer if interested. I can get you the weight ratings.

 

[burgundyben]

Ben

I have a set of R&D spare from my recent debacle. I bought two sets, but only fitted the stbd. No plans soon to lift the port so make me an offer if interested. I can get you the weight ratings.

Hi Trev.

Thanks. Let me know the weight.

 

[superheat6k]

Hi Trev.

Thanks. Let me know the weight.

Ben Details are for my 6BTs...

R & D Engine Mounting 800-026 on the forward. These have an active working range of 114 - 256 kg (250 - 562 lbs) STAMPED 562
R & D Engine Mounting 800-027 on the aft. These have an active working range of 136 - 310 kg (300 - 682 lbs) STAMPED 682

You will need to know that these mountings are preloaded and have a lowest mounting height before loading of 63.5mm (2.50")

I have attached a copy of our Engine Mounting literature for your reference. You will find this mounting on "Page 2", 4th style down from the top of that page. LET ME KNOW IF YOU NEED THIS

4 off 800-026 @ £43.53 Each + VAT = £174.12 + £34.82 (VAT)
4 off 800-027 @ £43.53 Each + VAT = £174.12 + £34.82 (VAT)

I have two off of each bought in October - make me an offer if you wish. They are sitting in my workshop looking very bored !

 

[burgundyben]

Ben Details are for my 6BTs...

R & D Engine Mounting 800-026 on the forward. These have an active working range of 114 - 256 kg (250 - 562 lbs) STAMPED 562
R & D Engine Mounting 800-027 on the aft. These have an active working range of 136 - 310 kg (300 - 682 lbs) STAMPED 682

You will need to know that these mountings are preloaded and have a lowest mounting height before loading of 63.5mm (2.50")

I have attached a copy of our Engine Mounting literature for your reference. You will find this mounting on "Page 2", 4th style down from the top of that page. LET ME KNOW IF YOU NEED THIS

4 off 800-026 @ £43.53 Each + VAT = £174.12 + £34.82 (VAT)
4 off 800-027 @ £43.53 Each + VAT = £174.12 + £34.82 (VAT)

I have two off of each bought in October - make me an offer if you wish. They are sitting in my workshop looking very bored !

Hi Trev.

I'll message you.

I did some c of g calcs, 64kgs on my front mounts and 156kgs on my rear mounts. So I could conceivably use your 4 on my rears but I want both sides the same.

It's not clear to me which would be the better choice since my rear load is within the range for either the 026 or the 027.

 

[burgundyben]

If you feel the need to spout some irrelevant rcd bollocks kindly do it elsewhere.

One engine is a rebored block and a pile of parts. I could not use my engine hoist to get the block on the engine stand since the legs got in the way.

So I built a timber A frame .

 

[burgundyben]

Work on the engines continues, I now have all the parts I need, except gaskets and bearings, one starter and 2 alternators, I also now have a pair of down angle gearboxes that will allow the engines to be installed level. Nice.

However, you may note the addition of a few words in the title...matters unravelled a bit when I wanted/needed to paint the cockpit floor, I found the ply to have suffered and some extensive rot underneath. Given the plan is to make the boat good for 15 years, I decided to rip it up.

I have 3 jobs, my brokerage, my work in industrial turbo design and my work in the boatyard, which means this project is suffering a bit. Musn't grumble.

 

[burgundyben]

Aside from the rotten plywood floor, along each side, right on the waterline, was three 2" cockpit drains and 4 smaller ones, a few inches up was a pair of big scuppers. I felt it was a lot of holes low down that didn't really need to be there. If she was just a couple of inches low she would fast have been overcome....

The scuppers were plywood boxes and a bit grotty, so today I went banjax with a multitool. Never used one before, what a fab bit of kit.

 

[burgundyben]

As you can see the hull at this point is about 6mm thick. I guess if I want 1:12 chamfer then I need to grind that about 72mm wide.

Then I need some kind of flexy buck taped on the outside.

I understand that epoxy is best for secondary repairs to polyester hulls and that I need glass without binding agent.

I'm very familiar with epoxy having used it extensively on wooden boats.

 

[Gary Fox]

A very interesting project and photos, keep them coming.

 

[burgundyben]

First engine mostly built.

 

[DownWest]

Oooo, nice old school engine, none of that electronik rubbish.
Nice clean workshop too... I wish I could match it.

 

[burgundyben]

Oooo, nice old school engine, none of that electronik rubbish.
Nice clean workshop too... I wish I could match it.

Yes, Cummins B series first in production mid 80's, so relatively old school, but leak free and clean running. There is an eneegise to run solenoid on the injection pump, but I'll disable that and use a stop cable.

I might even fit a wind up starter motor.

 

[superheat6k]

Yes, Cummins B series first in production mid 80's, so relatively old school, but leak free and clean running. There is an eneegise to run solenoid on the injection pump, but I'll disable that and use a stop cable.

I might even fit a wind up starter motor.

Indeed - those solenoids caused me no end of grief a couple of years ago, and I certainly wouldn't ever use PB Asher again - charged me £400 to tell me there was nothing wrong with my fuel pump and missed the fact the stop solenoid was incorrectly assembled !

Simple enough to remove the solenoid pintle and Spring.

 

[vas]

+1, endless problems with energise to run solenoid on my yanmar generator.
No issues with energise to stop solenoids in main engines though. Push button activated next to starter key.

 

[burgundyben]

I've got a keel cavity, its about 2" wide and 12" deep, its a right bugger to keep clean. I've been reading threads about keels and water...

I'd like to fill it in and glass over it. Lead shot expensive. Iron slugs might rust. Foam might get soggy.

My proposal is mix up some resin, add plastic pellets, £5/kg delivered, stir, pour. Small batches to prevent a massive exotherm inferno cracking disaster.

Once filled glass over the top.

Then I can flow coat the bilge for a nice easy wipe clean finish.

 

[burgundyben]

If I did use foam and it went all soggy its no worse than it being full of crud, oil, water and pubes for the last 4 years.

Would it be really mental to use shingle?