Help and advise wanted on foam engine bearers

[Jon Fuller]

It looks like merc, the rubber doughnut etc is identical to merc, even painted blick. I assume they custom make em for Steyr, or whoever wants to use their drives.

[Hydrostream]

Originally Posted by Jon Fuller

I now set things up so there's no thread showing between the motor foot, and mount, using washers/spacers as shims to achieve the correct height, (IMHO).

I like that idea! Still prefere clip ons though

Freddy, was searching for something else and came accross this, might be of use. Look at the PDF in the link...

http://www.freepatentsonline.com/4778420.html

[Jon Fuller]

Originally Posted by Hydrostream

I like that idea! Still prefere clip ons though

You're young, but you'll learn!

They're clearly the only logical choice for boats like those you build, but as they get bigger, or heavier, or both, clip ons are a bit fragile (IMHO).

[Hydrostream]

Originally Posted by Jon Fuller

You're young, but you'll learn!

They're clearly the only logical choice for boats like those you build, but as they get bigger, or heavier, or both, clip ons are a bit fragile (IMHO).

Agreed! Would love to play with turbines but thats a whole different ball game.
MTI I think do a diesel package with very respectable no's.

[PerformanceDodge]

Originally Posted by Jon Fuller

Your engine is lighter than what I'm used to, but the 16mm / 5/8" stud options from the mainstream mob (merc, R&D etc) aren't up to it. I've always used the 3/4" UNF option (19mm, but imp fine thread) As side landings, that sometimes can't be avoided, put that stud under enormous side load. I have bent countless 3/4"UNF ones when racing (and in my pleasure boat). I now set things up so there's no thread showing between the motor foot, and mount, using washers/spacers as shims to achieve the correct height, rather than a lower adjustable nut. This obviously increases the vertical member diameter to the size of the OD of the spacers/washers, making it very bend resistant. Bit more fiddly setting up engine alignment, but worth it (IMHO).

If your engine 'gets let loose' in the engine bay at speed, feck knows what damage will be done!

Hmmmm, went away and had a re think after your comments gained from your years of experiance and have now come up with the following solution.

As the foam bearer's are quite high and the engine sits quite low it was not really practical to sit the engine mounts on top of the bearers, also tacking into account your comments regarding a cross member to link the engine mounts I have made complete bolt in sub frame/cross member assembly from extruded aluminium U channel with 10mm sides and 6mm bottom.

The sub frame is bolted to the 8 spacers, 4 each side which are epoxied in to the original foam bearer's. Over the top of the foam bearer and spacers will be a layer of carbon kevlar woven cloth then coved by some 600g woven glass matt again using epoxy resin.

After you comments regarding up to 50 G's in race conditions and bending engine bolts and ripping the side of engine blocks out, I have fabricated new engine block mounts from stainless, welded webs onto the engine mount supports and on to the up right studs and the engine support brackets will be bolted to the rubber mounts bolt shoulder. To get the right engine height as suggested I will fit packing blocks between the cross member and the engine mounts.

Does any one think this will be Ok ??

[Jon Fuller]

Really nice work there!

Looks great.

[PerformanceDodge]

I am laying up my engine bay with epoxy resin (Reactive Resins, Sintac Standard resin) What is the maximum time allowed between layups to prevent delamanating in use or does it not really matter if it is keyed up between layups.

Many thanks is advance for any reply's. David

[PerformanceDodge]

Originally Posted by Jon Fuller

Really nice work there!

Looks great.

Do you think it will be strong enough for pleasure and poker runs, I doubt it will be raced.

Can you help with my above post Re: epoxy