Engine bed modification

[howardm]

Hi,
I am looking for ideas how to bolt down my new engine.
This is an engine swap from a petter mini six to a Yanmar 2YM15.
The new arrangement will include an Aquadrive, so I can get the engine lower down. I have shaved the beds horizontal and am making a subframe from rectangular hollow section, so the engine can be slid out like an ambulance trolley.
My hesitance is with the subframe to bed ( 2-1/2" Maple ) I don't want coach bolts, but, thought of something like Helicoils expoxied in the wood.
I would appreciate any ideas on this fixing.
here are some pictures of work n progress.

http://s176.photobucket.com/albums/w...027%20project/

thanks
Howard

[michael pierzga]

I don't like wood engine beds, they split. I like your idea of being able to slide the engine out . Dont know if you can use helicoils with wood. you use "INSERT NUTS"

The last time I did an engine change on a small launch we fabricated a hat section of aluminum plate to dimensions that would fit overtop the old fiberglass engine beds. Thick aluminum engine mount blocks were welded to this aluminium hat section, the engine was mounted on this pair of hat sections in the workshop. The whole assembly was then lifted up, dry fit to the beds to test rough alignment.., shimmed, marked, then Lifted up again, disassembled sand blasted, primed, painted.... reassembled ,epoxy filler was then spread on mating surfaces of the old engine bed and the new hat section, then the whole assembly was lowered onto the old beds and into the epoxy bog. It worked well . This was a very small engine. We used aluminum because we had it...steel would work.

[wardd]

google "thread inserts for wood"

[messabout]

Wardd. (Off topic)You must be an old guy to even remember liberty ships. Many of them were concrete and served the purpose quite well.

[FMS]

I prefer thru-bolted metal upside-down L or U engine mounts which straddle the stringers.

[tunnels]

If the boat rolles 360 will the beds be strong enought to hold twice the full weight of the motor and gear box !!!

Wooden beds well glassed are ok .
For cruising /racing serious off shore roll over and upside down proof engine bolt down you need to bolt through the beds so its impossibe for the bolts in the mounts to fall or pull out .
we used to use square steel 1 inch X1 inch throught the beds from side to side inserted and then drill and thread down into the steel !! need to set the steel a good 3 inchs down from the actuall mount surface so need almost 4 inch long bolts .
Or use u shaped steel also through bolted and thread into the u steel !!!!,so has to have at least a 1/2 thick top for a good amount of thread for the bolts to hold .

[howardm]

Thanks guys,
I take the point about 2G inversion, but, I have to work with the beds I have inherited.
I have gone off vertical inserts for this reason, so I think in shear, horizontal bolts low down are the way to go.
Howard

[tunnels]

Originally Posted by howardm

Thanks guys,
I take the point about 2G inversion, but, I have to work with the beds I have inherited.
I have gone off vertical inserts for this reason, so I think in shear, horizontal bolts low down are the way to go.
Howard

You might find it easyer to use 1 1/4 steel shaft and just drill the hole all way though each bed have to be careful when you drill down that is as close to centre of the steel as you can get . Its a good way to use up and old prop shaft if you have a broken or damaged one