Securing an engine in a rollover

[barnakiel]

Normally, mounts do not go in a roll-over event. Old one yes, undersized ones yes. But proper soft mount do not go.

No need for extra security.

PS You can add a removable T-bar OVER the engine.

PS What about the batteries? Do you have dry ones and how secure are they in an upside down scenario?

b.

[colemj]

We are not at all concerned about our engines in a rollover, but in the past on our mono, we installed the R&D mounts Gord links too - and I just always thought all mounts are made this way. Didn't realize that others could allow the engine to rip off them if not sitting on them horizontally.

Mark

[a64pilot]

The mounts are tougher than you think, they are essentially identical to automotive mounts, and it's very rare even in a pretty sever accident for the engine and transmission to be thrown form the car, happens, but rare.


Sent from my iPad using Cruisers Sailing Forum

[anacapaisland42]

Don't forget the batteries !

[deblen]

Thanks for the R & D link Gord May

I'm not too concerned about rollover,but if you look at the torn rubber in my VP 2003 mount,you can see there is no built in safety in this design.
The rubber is simply glued to the upper & lower plates-good glue(vulcanized),as the actual neoprene rubber tore on 3 of 4 mounts.
At near $200 apiece,just for the rubber,I was strongly inclined to put limit straps of some kind over the new ones-for no other reason than to protect them from future destruction.
Much research told me that Volvo & others used very flexible mounts of this style,back in the old days,as an attempt to soak up vibration from 1-4 cyl diesels.I can rock my eng. 1/2" with my hand & it is almost a blur at idle-8-900 RPM.
3/16 " chain was handy,so I made up 2 pcs 1/8 x 1" flat bar "tabs",with holes in the tab ends ,that fit under a eng mount block bolt & the bed bolt.
The chain was linked between 1/4" holes in the other end of each tab,using split chain joiners. Crude maybe,but I think it will fetch the engine,if another rubber lets go.
I believe the rubbers broke over the years from fouling lobster pot warps by PO & me & trying to "reverse" the warp out-very common on Maine coast & some what locally.

[GILow]

In theory the engine mounts will be fine in a rollover. Mine are not the fail-safe sort linked by GordMay.


But to trust THEORY, is, in my mind, a bit optimistic, particularly when it is so easy to add a layer of additional safety. Engine mounts age, mistakes are made during manufacture. The list goes on.


The engine weighs just under half a ton, as pointed out earlier dynamic loads are many times greater than static loads, a rolling boat is a VERY dynamic beast.


I'll add the extra security, regardless of what the theory states. And I'll sleep easier for it.


Matt

[GILow]

Originally Posted by anacapaisland42

Don't forget the batteries !

Yes, very good point too. Happy to report that if they can escape their current setup they can call themselves Houdini. Supported in ALL axis, up/down, port/starboard AND fore/aft.

Matt

[GILow]

Originally Posted by deblen

Attachment 96496

I believe the rubbers broke over the years from fouling lobster pot warps by PO & me & trying to "reverse" the warp out-very common on Maine coast & some what locally.

Deblen, you make a really good point here, and one that I forgot about.

Engine mounts failing from ropes fouling the prop are a serious hazard, and at 96 HP our engine has a fair bit of torque and rotational momentum when running. Another good reason to backup the engine mounts, and Neptune's Gear's solution looks more attractive to me now given that it limits the movement so well.

I'd still be interested in people's opinions on how well Dyneema rope will last in the engine bay environment.

Matt

[delcrest]

Originally Posted by GILow

Hi Cruisers,

I have just finished fitting soft engine mounts to our engine, which was originally hard mounted. Call me a a whimp, I just could not handle the vibration and noise any longer.

Now I need to be sure that the 450 kg monster stays in the same position if we get rolled. There seems to be a number of ways of solving this one, from steel angles over the engine mounts, to chains, rope, sky-hooks, fairy dust... I simply do not trust the soft mounts to support the weight when upside down.

Does anyone have a preferred smart way of solving this that they can recommend? I am likely to be able to fabricate anything required for the job, the new engine mount brackets proved to be reasonably straight forward though I had to farm out the welding after tack welding the bits in place as my welder could not handle the 12mm plate.

There are four mounting points, the front two rest on a timber stringer running transversely, the rear two rest on lengths of angle running fore and aft, which are bolted to the original engine bearers. Everything is fabricated from 12mm steel plate or angle. Weight distribution feels about 45/55, with a bit more weight at the rear.

Ta,

Matt

Had a similar problem on a 800 hp hot rod, engine would rip the soft mount under hi torque, we drilled a hole through the mount inserted a bolt with nylock nut, not tightened fully , this allowed the mount to move as designed and stop vibration, and still remain intact with hi power, no more vibration no more broken mounts

[GILow]

Originally Posted by delcrest

Had a similar problem on a 800 hp hot rod, engine would rip the soft mount under hi torque, we drilled a hole through the mount inserted a bolt with nylock nut, not tightened fully , this allowed the mount to move as designed and stop vibration, and still remain intact with hi power, no more vibration no more broken mounts

VERY neat solution, I will most certainly consider it, given the way my engine mounts are constructed. Very much like the rods posted early on. But it begs the obvious question. What sort of boat does a person who plays with 800HP cars sail?

Matt

[Maine Sail]

A well designed marine engine mount will not allow the engine to dislodge in a roll over...

This is Westerbeke's design..

[GILow]

Alas, mine are not so well designed.


Matt

[delcrest]

Originally Posted by GILow

VERY neat solution, I will most certainly consider it, given the way my engine mounts are constructed. Very much like the rods posted early on. But it begs the obvious question. What sort of boat does a person who plays with 800HP cars sail?

Matt

Haha A wannabee cruiser that currently building a a Mike Waller designed cat....and getting to old and running out of time....hope to be on the water December.....and have a few years before health issues force me to stop

[Neptune's Gear]

GILow, my engine is the same as yours, VP2003T. You CAN get rollover proof ones for this engine - some were in lifeboat service- but they are horribly expensive. After breaking 3 sets of VP ones in about 6000 hours of engine use, I gave up on the VP ones and bought some universal roll proof ones. Custom made brackets to suit.
Longevity of Dyneema in engine room - my current loops have over 4000 hours - still look fine. Engine is 27 years old, but well maintained, and engine room is clean. Due to the change in mounts (above) they are really now superfluous, but still there anyway...

[UNCIVILIZED]

Originally Posted by GILow

I'd still be interested in people's opinions on how well Dyneema rope will last in the engine bay environment.

Matt

For anyone with Dyneema/Spectra in their engine rooms, this would be a WARNING!

The question about Spectra/Dyneema in said environ is a VERY Good one. As, if you want to get technical about it, it literally starts to lose strength at room temperature, although not to a serious degree until near 200'ish degrees (Fahrenheit)... or call it say 90 degrees Celsius/Centigrade - ballpark. However...
- The Advised Long Term Temperature Limit for it is 70 degrees Centigrade, per the Manufacturer!
See the links in post #28, here http://www.cruisersforum.com/forums/...ml#post1671808 And the story on the Warpspeed jacket color change "controversy".

Odds are you'd be okay using Kevlar or Technora to make similar types of restraints. As if memory serves, it starts to break down a bit at 350 - 400 degrees, & chars at about double that. However, it's worth checking, prior to going out & buying some.
Also, look into what the high end, Big Boat racers (including big racing multis) are using on their running backs, Main, & Jib Sheets. Especially the covers on same. As the loads on said lines are measured in TONS, & as such, melt standard fibers, & even some exotics, on the winch drums.

Here's a starting point, plus of course, the major line manufacturers also - APS - Cover Only Look for: Aramid, Kevlar, Technora, & Nomex
Some are better at dealing with flash heat, & others, longer term stuff. But if you're that concerned over it, the Steel option's a good one, as discussed.
- Oh, & I think that Vectran is somewhere in between the 2 mentioned general line types, when it comes to thermal resistance.

As to chemical tolerances, I have Zero idea. But those that make the stuff would. While most of the above fibers are derived from stuff for industrial apps, that doesn't mean that they're approved for use with "Chemical X".