Anybody else ever make concrete engine mounts?

Winger Ed.

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I've been carrying this around for awhile. I wasn't sure if it should go here, or on 'Stupid Human Tricks'.<br /><br />I used to have a early-mid 70's 23' (tupperware)daycruiser with a Mercruiser behind a 351 Ford V-8. As it aged, the engine mounts under the block turned to mush. The engine settled downward & ate the gimble bearing.<br /><br />I scrounged up a Oak beam approx. the same size as the 2 'glassed over boards mounted in the hull under the engine. This thing was huge, a rough cut 6 x 8 or so, and about 10' long that I intended to cut & fit in as replacement eng. mounts. <br /><br />To do this:<br />I figured I could just put a beam across the gunwales, and use it to hold the weight of the engine up a inch or two after I levered the block up and tied it with a rope. Then, I could cut out the old mounts, put in the new board, 'glass it over like the original, then just lower the engine back down a few inches and live happily ever after.<br /><br /><br />The plan worked great. I got the weight of the engine up a bit, tied it off, and started to remove the old mush engine mount...... Then I noticed, the engine was hanging from my new mounting beam/boards.<br /><br />So, in desperation, I cut the top off the stringer looking old motor mounts. They were 2 beams about 6 x 8, and ran 3 feet or so from the transom board up to a bulkhead that ran across in front of the engine mounts, and held up the back end of the floor.<br /><br />I scooped & cleaned the rotted, wet sawdust out of the fiberglass 'mold' that used to cover them. <br /><br />I then got a bag of cement, mixed it up & poured it into the fiberglass shell that used to incapsilate the engine mounts. I pushed about 4-5 re-bar rods down into the wet concrete, and let it set up.<br /><br />------<br /><br />Now, before the pureists start pounding thier pitchforks, gathering firewood, and lighting thier torches in preperation to come after me like they did the Frankenstien monster.....<br /><br />I gotta say it worked great.<br /><br />The cement probably weighed 25 pounds more than wood does for that size & length. On a 4,000 pound boat--- that's no big deal. <br /><br />All those mounts needed to do was hold the engine up at the correct level in relation to the Gimble bearing & outdrive's drive shaft without crushing or breaking in half and folding up.... which the concrete could do quite easily, especially since it had several re-bar rods inside it.<br /><br />Plus, transfer the forces of fwd. thrust to the hull from the outdrive on the outside of the transom board. Being poured in the old fiberglass 'mold' that was left from the original wooden mounts,, it did that real well too with no pressure points due to the solidified mount not 'fitting' just right (as a board might) in relation to irregularities in the bottom of the hull where they sat up against the center section of the inside of the transom.<br /><br />A added feature was that my new mounts would never rot out like replacement wooden ones eventually would have. <br /><br /><br />I'd never recomend this engine mount replacement method to others, but I just had to tell the tale never-the-less.
 

G DANE

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Re: Anybody else ever make concrete engine mounts?

I like innovative people.<br />Could have been done with seacast too, to avoid the housebuilding methods. Did you ever use bricks anywhere ED :D
 

Bondo

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Re: Anybody else ever make concrete engine mounts?

I've been accused of some Over the Edge Creative Engineering ...................<br />But,<br />You've got Me beat all to He!!................... :D
 
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DJ

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Re: Anybody else ever make concrete engine mounts?

My view is that it was "brilliant" idea.<br /><br />Dang cheap, dang strong and should outlast the boat.<br /><br />My "hat's off" to ya.
 

Winger Ed.

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Re: Anybody else ever make concrete engine mounts?

Originally posted by G DANE:<br /> Did you ever use bricks anywhere ED :D
Well, no---- not yet anyway......<br /><br />But I'll bet they'd make great shims if ya needed something to help support a soft spot in a stringer or something under the floor.
 

Realgun

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Re: Anybody else ever make concrete engine mounts?

You do know that they make canoes of all things out of concrete?<br /> HAH there you go!!!
 

a_bullfrog_a

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Re: Anybody else ever make concrete engine mounts?

when will it crumble. No rot but when will it vibrate in to a pile of sand?
 

Winger Ed.

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Re: Anybody else ever make concrete engine mounts?

Originally posted by a_Bullfrog_a:<br /> when will it crumble. No rot but when will it vibrate in to a pile of sand?
Good question. I never thought of that. I did that trick back around 1990-'91. I sold the boat a few years later to a buddy. I used it a fair amount, the guy I sold it to used it a fair amount and as of last Summer, it was still doing fine. He's never had to adjust the leveling bolts to keep the drive shaft/Gimbel bearing aligned. <br /><br />The cement was mixed like they say to, and it was poured into the 'molds' which were open only at the top. It wouldn't seem like it couldn't move around enough to crumble.
 

G DANE

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Re: Anybody else ever make concrete engine mounts?

I dont think it will ever crumble, as long as there is enough cement ( right word ) in the concrete. Actually the idea is far better than I thought first time read. Concrete won't schrinck or change, will not change with moisture and hold the bolts as welded in. Permanent repair, only disadvantage is weight which means nothing on that particular boat. Good idea. Alternative thinking. Over here some build sailing boats from ferrocement, very strong.<br /><br />Within the last ten years there has been an industri over here making glassfiber reingforced concrete building components, for outdoor use over here. Light and very strong. Unlimited resistant to elements. Maybe this technique could be transferred for boating world somehow. Again Ed - you REALLY are innovative.
 

ED21

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Re: Anybody else ever make concrete engine mounts?

What usually makes concrete crumble is a bad mix, using salt as a deicer or improper curing.<br />I think you'll be fine.
 

one more cast

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Re: Anybody else ever make concrete engine mounts?

I worked in a vintage paper mill for 21 years and never seen a concrete bearing support crumble. And you could even feel those old paper machines rumble from outside the mill.
 

swimmin' for shore

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Re: Anybody else ever make concrete engine mounts?

Fantastic idea, Ed. I've been wondering about something like that for awhile, but with fiberglass reinforced resin. As I haven't had the opportunity to use any yet, I'm not familiar with the qualities it would provide, but I may give it a shot. I have some rotted engine mounts to deal with, myself, when I get to work early this spring.
 

steve n carol

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Re: Anybody else ever make concrete engine mounts?

well, Have I ever used concrete for motor mounts?....No. <br /> I did make a concrete anchor when I was 14. It didn't work too well, probably should have added some rebar.<br /> I have seen polyester reisin with sand impregnated into it! strong stuff...<br /> W Ed? Are you half Cajun? haha. If you decide to re do the floor in your boat, might I suggest using light weight concrete.....have a Merry Christmas....sl
 

Scaaty

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Re: Anybody else ever make concrete engine mounts?

I was a Machinist in a large factory, and all our massive milling machines would shake the ground at times, and all were mounted to studs in concrete
 

BillP

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Re: Anybody else ever make concrete engine mounts?

Maybe using fibermesh in the concrete would make this system better. Might be the same stuff GDANE posted about. It replaces steel (which would eliminate any rust/breakthough issues) and spreads stress thoughout the pour (to absorb vibration). It's a proven construction method here in Florida and widely used for sidewalks. Sound like it could be used to replace transoms too.
 

Winger Ed.

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Re: Anybody else ever make concrete engine mounts?

Originally posted by BillP:<br /> like it could be used to replace transoms too.
I wouldn't have much of a problem using it for a I/O transom after a bit of testing. For a OB, as much as I like beating the system, I'd try to find some sort of sturdy & rot-proof building material to use rather than plywood.<br /><br />I think we use plywood because its easy to get, fairly easy to work with, doesn't weigh too much, is strong enough, and lasts long enough for the lifespan of most boats.<br /><br />But to do a transom permantly- I'd think there is some modern generation composite materials that would work much better,,, once ya got over the cost or could scrounge them.
 

BillP

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Re: Anybody else ever make concrete engine mounts?

Ed,<br />It's hard to beat pt ply in transoms for low cost and long life. Composites are way expensive and non treated ply might rot. At one time I thought about core drilling an old transom and setting ss bars down the holes with epoxy. Never tried it though. Your concrete method might be the low cost alternative to seacast resin. It needs to be developed!
 

flashback

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Re: Anybody else ever make concrete engine mounts?

Hey Ed. just wanted to clarify that you used concrete and not mortar mix... I've read enough of your posts to know you usually say what you mean but just wanted to make sure......thx :D
 

KaGee

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Re: Anybody else ever make concrete engine mounts?

Truly a great job of BackYard Hacking.<br />
4_17_3.gif
 

llfish

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Re: Anybody else ever make concrete engine mounts?

In time you will start seeing cracks. With luck that is all you will see. Never hurts to do something new.
 
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