Urgent Help – Ideas Please

[Stephen Oliver]

HI Guys

So 3 of 4 engine mounts went on well – even though they had lag screws as fixing (buried about 3-4inches in the Engine mount turrets.)

Number 4 – nuts and lag bolts turned out easily – and they have been cut down – presumably due to the shorter distance from the top of the mount pillar face to the hull bottom – On putting them back in they turn.. so the holes are stripped. it looks like oil or something has been slowly leaching into the hole.. and I think the lag bolts have worked loose and chewed out the timber in the pillar.

These are not normal lag bolts they look custom made with a custom thread form. I really only have top access no side access due to the gearbox being in the way.

OK now my issue – I need to get the engine mount fixed back in and sharpish! We have a trip planned next week – Can I have some ideas please –

1, I can fill the hole with epoxy and add threaded stud – I reckon I can go to 3 inches in the pillar – but not sure on how well the epoxy will go as the timber may be saturated with oil or deisel.

2, Drill out much larger and fill with Epoxy and shredded glass – redrill and reuse the lag bolts or even add threaded inserts into the epoxy. This may get me into good timber, but not sure on strength I can cross drill (at an angle ) if needed to get some tie in to the timber.

3, Longer term – make a bracket up that goes over the pillar and fixed in various locations – could have a nut welded under the plate to bolt into. I can probably only go 1/4 thick max due to engine mount height.- Not an option to do for next weekend though

4 onwards – Any smart ideas?

OK pictures of the space attached.

Thanks in advance!

Topic

[Stephen Oliver]

Ah yes the ubiquitous helper!

My son is only 2 so not much help unless I want things chucking around, my son is only 2 so my wife is always running around after him if I’m in the bilge, family is overseas, and friends are at work when I’m working on the boat.. so have learned to cope by myself!

I’m not a small bloke but can get in and out of tight spaces, can twist my arms in a way cirque de soliel would be proud of and pay for it for a few days after. I also have no skin left on my hand and arms.. such is the joy of working on the port Cummins engine. Tony is right with his couch engineering comments. The designers who marinised this engine, albeit a great engine, need lining up and shooting for some of the decisions they made. Thank God for sites like this and guys like you lot who make things just that bit more bearable!

Anyway.. I have the base understanding of the alignment, so will attempt it soon. We have one trip this Easter weekend of 2 hours, and then about 4 weeks downtime.. so should be good to go.

Expect more questions!

Steve

[Rob Schepis]

Stephen Oliver wrote:

I was going to get a mechanic to do it………

No way! You’re on a role, it’s all you. Checking the alignment will be simple compared to what you just went through. Start a new thread, or keep this one going, when you get to doing it. But I will say, having a helper makes things SO much easier. Even if for nothing else than to pass a tool or such to you….

[Stephen Oliver]

Hi Rob

Thanks. Not the hardest thing I have done on this.. but if I hadn’t have already done the port raw water pump (which was the worst), it would have been a nightmare…

I didn’t release the couplings. I measured and diagrammed each mount before removal. I have reset everything back as it was for now and the shaft turns easily which is an indication it’s not far off.

I now need to check weight distribution on the mounts which if the sbmar mounts are the same as the Barry ones should just be a case of measuring the snubbers gap between snubber and pedestal. Once distribution is ok, I’ll start Proper alignment. I was going to get a mechanic to do it, but I find it hard to trust any of them, based on the work I have seen so I figure I best learn it myself. I just need the time and the window of boat trip downtime to actually start on it!

Steve

[Rob Schepis]

Kudos for getting that done. Not fun and not easy but certainly rewarding. Did you separate the couplers and check the alignment?

[Stephen Oliver]

Well holy crap!

I’ve just finished off after running out of.time yesterday (2year Olds do that) so just returned the mounts to the same height referenced from the top of the pillars so should be close enough for now. Shaft rotates freely and easily by hand, although stern gland is dripping a bit much so probably needs seeing to or the shaft is still a bit out.

Ran at the dock in gear (this is the holy crap bit) it’s like a new boat.. no vibration, engine seems quieter, and it’s just much much nicer. Apart from the noise you wouldn’t know the engine was running! I’m sure it’s a combo of the new mounts and that they are not loose any more! Either way it’s probably the best 1000aud and time I have spent on the boat so far of the non critical type stuff.

Now to get the SB engine mounts replaced which should be equally as much fun! I was going to hold off on them for a bit.. but no.. we have a bit of layup time coming with busy weekends and the winter weather (we still use the boat a lot through the winter as weather allows) so I’ll get some more ordered and get them done..!

Steve

[Mike Mason]

Thanks.

[Stephen Oliver]

So not the best pics but hopefully gives you an idea of the gearbox end. Doing one mount at a time leaves one connected so stabilises the engine.

This rig stayed like this from Friday although I had a block of wood under also in case the hydraulics gave way

Steve

[Stephen Oliver]

I’ll get some of the gearbox end support later. Other end is complete so will have to do pics when I do the other side..

Steve

[Tony Athens]

PICTURES please.

Tony

[Stephen Oliver]

Hi Mike

At the timing gear end, I used as big a price of 1″ ply on the hull, a 1″ ply under the sump end and due to the hull being in close proximity to the sump used a hydraulic bodywork spreader, which is just jaws that open outwards. It lifts enough to change the mounts, which if everything is greased and easily removed doesn’t take long.

At the shaft end, similar arrangement using the spreader, but due to limited height I used 1/2″ ply under the gearbox and located it against the sump and gearbox or flywheel drain plug. The ply got indented by the drain plug so that it then rested on the gearbox itself.

I guess every boat is different, as out hull is over an inch thick of solid glass I was confident with the load spread it would take the load… Shame the rest of the install is crap!

Steve

[Mike Mason]

Can you post how you have the engine blocked while replacing the mounts. Thanks.

[Stephen Oliver]

HI Tony

I was going on West Systems recommendations for fastener embedding with a little less than 1/4″ ring of epoxy around it and filled with specific filler for fasteners and hardware embedding –

I guess a definition of Mayonnaise thickness varies per country – in Aus – Mayo is fairly runny.. and this ‘thickened’ epoxy was easily sucked up in a 10ml Syringe to then fill the hole and it squirted out like liquid. It definitely was soaking into the timber as I got a bit on the soon to be sanded teak deck and it soaked in! The stuff gets everywhere!

I’ll update you once I have the mount back in and the engine back in line.

I’m still amazed that with 2 loose engine mount stud nuts and 1 completely loose engine mount (where it bolted to the stringer) that the engine actually managed to stay inside the hull! This should be a huge improvement – and then I can get another set of mounts from you and start on the SB side! Access is a little easier on the SB though..

Steve

[Tony Athens]

Normally we prefer no thickening of the epoxy so it soaks deep into the surrounding material.. Or at the very lease, pour liquid 1st and let it penetrate for a while 1st before using “mayonnaise”.. ……But your hole was pretty loose, so you’ll know tomorrow.

Tony

[Stephen Oliver]

Hi Tony

Thanks for the input also. Work was completed today and we’ll see in a day or 2 if it has worked!

Studs made – 1/2unc Rod in 316 – 5″ long so 3″ in the hull then 2 above..

So I drilled out to 20mm (just over 3/4″) as some of the timber close to the glass was oil / diesel contaminated – it went away at 20mm so I know I was in good timber – Depth just over 75mm so 3″ – I dare not go any deeper as the hull bottom was getting close – I was still in timber so all should have been good as the bottom is around 1-1.5″ thick solid glass and resin.

I did notice in one hole that when vacuuming the shavings out that a small amount of water was appearing! – I thought I had holed the hull – but as soon as the vacuum was taken off the dampness disappeared – I assume that there is some water in the stringer area but very minimal and the vaccum was just pulling it out.. the boat is 22 years old and there are various screw holes along the stringer so doesnt surprise me!

I then counterbored to 22mm just over the depth of a nut to that I could add a nut to the stud at the top to keep it centred (recommended way in the book ‘The Gougeon Brotherson Boat Construction’)

I then mixed west 105 with 206 slow hardener and then added 413 (or 403 as you may know it) filler to mayonnaise consistency – Syringed it into the holes just short of the top – waited 10 minutes for any ‘soak’ and then wet the squeaky clean studs with resin and slowly inserted them into the holes – I left the overspil for about 30 mins and then scraped it level as I didnt fancy trying to level it off after it had set – given the access I dont have!

Now its just a waiting game and on Monday I’ll drop the engine mount in, which I need to modify again as I didnt check the original hole centres and they were out (I didnt notice the original mounts had been butchered) I only need to take a mm or 2 of the inner faces of the slots but something else to do that I could have corrected if I’d have checked!

Anyway I’m hoping its all good otherwise I’ll be drilling out and starting again!

Some pics attached for your viewing!

Thanks again for the help guys

Steve

[Tony Athens]

Drill the stringer material to 9/16″ inches as deep as you can.. Hopefully something is in there work drilling…..Figure out the depth you have to work with.. Add enough to cover the base on the mount plus a nut/washer and maybe about 1/2″..

Now, get some 1/2″ x 13 SS or B-8 threaded rod.. Cut it to length. Fill the hole up with liquid epoxy (West Systems or ??) about 1/3+ of the way.. Push the clean stud down SLOWLY and let the epoxy fill all 100% and flow out–Walk away for 24 hours. You are good to go…

Tony

[Stephen Oliver]

Thanks Rob

Any suggestions as to what size I should go hole wise? and is 3″ depth enough stud to hold? (I’m a mechanical design engineer but this is all new to me!)

Stud is 1/2inch (12mm) but can go to 14mm if needed as I had the slots extended (dont ask)

Would you glass fill (ie shredded matting) the epoxy and use something like west epoxy? Or would you use the 404 filler (apparently the strongest filler)?

Would you drill a few holes at an angle or try and inverse taper the hole so it cant pull out? (ie enlarge the bottom of the hole)

Finally would you add a nut or 2 to the bottom of the stud to give it a bit more grip in the epoxy?

Now just to find some 316 threaded rod.. and some west epoxy – I have some but its about 10 years old so may not be too good now!

Thanks again

Steve

[Rob Schepis]

Number 2 — overdrill and get into good clean solid material and epoxy in a stud

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