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sailorman
Well-known member
Re: Engine Mounts Advice
i re-engined & had to cut the mounts down in height by cutting the top 40 m/m i then cut ply to a close fit about 25m/m below the new top edge placed s/s plate on the ply, filled to the top with "West epoxy" thickened then applied layers of mat to lap around the sides of the existing beds & over the west filler.
then tap thread as req .
cut the top of the beds with a "Fien multi" no dust & very quick they r on e-bay
good luck
roger
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i re-engined & had to cut the mounts down in height by cutting the top 40 m/m i then cut ply to a close fit about 25m/m below the new top edge placed s/s plate on the ply, filled to the top with "West epoxy" thickened then applied layers of mat to lap around the sides of the existing beds & over the west filler.
then tap thread as req .
cut the top of the beds with a "Fien multi" no dust & very quick they r on e-bay
good luck
roger
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capsco
New member
Re: Engine Mounts Advice
Coachscrews should not be used
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Coachscrews should not be used
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kds
New member
Re: Engine Mounts Advice
My shipwright advised against coachscrews. He has had to replace them with someting else after they worked loose on other boats.
We used the West system. Drill for studding, clean thread, soak wood in epoxy, thread down into wood and let it set. Then use washers and nuts.
Works so far !
Ken
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My shipwright advised against coachscrews. He has had to replace them with someting else after they worked loose on other boats.
We used the West system. Drill for studding, clean thread, soak wood in epoxy, thread down into wood and let it set. Then use washers and nuts.
Works so far !
Ken
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tugboat
New member
Re: Engine Mounts Advice
Coach screws are tapered and have a coarse thread so are really unsuitable for this application. It would be difficult to make a tapered hole to suit the bolt, also the coarse thread would IMO tend to come loose with vibration. I believe the correct method would be to make new beds from angle which would be through bolted to the existing (glassed-in) beds. The top (horizontal) face is then drilled to suit the mounts for the new engine. When it's all checked out OK have the new beds galvanised (get them added to a load by your local engineering firm) and use galvanised nuts and bolts too. Hope this helps.
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Coach screws are tapered and have a coarse thread so are really unsuitable for this application. It would be difficult to make a tapered hole to suit the bolt, also the coarse thread would IMO tend to come loose with vibration. I believe the correct method would be to make new beds from angle which would be through bolted to the existing (glassed-in) beds. The top (horizontal) face is then drilled to suit the mounts for the new engine. When it's all checked out OK have the new beds galvanised (get them added to a load by your local engineering firm) and use galvanised nuts and bolts too. Hope this helps.
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steve6367
Member
Re: Engine Mounts Advice
I have to say I used coach bolts when fitting a Yanmar 1GM to my boat. Been there for 3 years so far. I have checked bolts each year and they have not worked lose yet. Does not means its the best way, but has worked for me.
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I have to say I used coach bolts when fitting a Yanmar 1GM to my boat. Been there for 3 years so far. I have checked bolts each year and they have not worked lose yet. Does not means its the best way, but has worked for me.
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bruce
New member
Re: Engine Mounts Advice
over here there appears to be conversion motor mounts available, if not, perhaps a subframe to connect old and new....bolt it down and mount new mounts on it. just a thought...
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over here there appears to be conversion motor mounts available, if not, perhaps a subframe to connect old and new....bolt it down and mount new mounts on it. just a thought...
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Keith
New member
Re: Engine Mounts Advice
I've never had a problem with coach screws, previous engines were VPMD7A's with over 6000 hrs on and present engines are yanmar 2GM's and never had coachscrews come undone yet, if you go this route use stainless ones as they make subsequent removal a piece of cake and cuts down on the amount of rust you will expereince..........keith
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I've never had a problem with coach screws, previous engines were VPMD7A's with over 6000 hrs on and present engines are yanmar 2GM's and never had coachscrews come undone yet, if you go this route use stainless ones as they make subsequent removal a piece of cake and cuts down on the amount of rust you will expereince..........keith
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sailorman
Well-known member
Re: Engine Mounts Advice
my beds are GRP & assume the Nic 39s r 2
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my beds are GRP & assume the Nic 39s r 2
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Mudplugger
New member
Re: Engine Mounts Advice
When re-engining in the past, (uprating to a 2-3cyl) advised to use s/steel bolts/ studding, drilled into engine beds, which had to have 4 sloping horizontal cut-outs that had 4 pieces of plate suitably drilled to take bolts. Twas only possible 'cos I could get to the side of each engine bed easily. after the bolts fastened down, filled cut-outs with P40. HTH... Tony W.
<hr width=100% size=1>Tony W.
When re-engining in the past, (uprating to a 2-3cyl) advised to use s/steel bolts/ studding, drilled into engine beds, which had to have 4 sloping horizontal cut-outs that had 4 pieces of plate suitably drilled to take bolts. Twas only possible 'cos I could get to the side of each engine bed easily. after the bolts fastened down, filled cut-outs with P40. HTH... Tony W.
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jeffro
New member
Re: Engine Mounts Advice
just re engine ing my kingfisher 30 took out the engine bolts which were coach bolts and they were as good as the day they were fitted 30 years ago just lucky maybe ! Jeffro
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just re engine ing my kingfisher 30 took out the engine bolts which were coach bolts and they were as good as the day they were fitted 30 years ago just lucky maybe ! Jeffro
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oldharry
Well-known member
Re: Engine Mounts Advice
Just about to re-engine a boat - 25 years old original engine, and fastened with coach screws (in timber), and they are tight. Very! Until seeing this one, I would not have used them myself - but they seem to have worked, and worked well on this 40hp petrol engine heavy dispalcement sea going work boat.
PS: anyone got a use for a marinised Ford 105e (ex Ford Anglia) - starts and runs well, but quite rusty apart from a nearly new Wortham Blake manifold. No gearbox - thats died a death, hence the replacement.
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Just about to re-engine a boat - 25 years old original engine, and fastened with coach screws (in timber), and they are tight. Very! Until seeing this one, I would not have used them myself - but they seem to have worked, and worked well on this 40hp petrol engine heavy dispalcement sea going work boat.
PS: anyone got a use for a marinised Ford 105e (ex Ford Anglia) - starts and runs well, but quite rusty apart from a nearly new Wortham Blake manifold. No gearbox - thats died a death, hence the replacement.
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boatmike
Well-known member
Re: Engine Mounts Advice
It all depends on your engine beds. If they have glassed in wooden bearers it is fine and dandy to use coach bolts. Stainless steel ones are available and should be used in preference to carbon steel, galvanised or not. If they have glassed in aluminium or stainless steel backing plates you should simply drill and tap new holes. If the bearers are solid GRP and have helicoil thread inserts fitted (which sounds likely) you can still use stainless steel coach bolts but drill a hole about 30 thousandths of an inch smaller than the OD of the coachbolts before you screw them in to avoid splitting the GRP and ensure that the shank of the bolt does not enter the GRP (only the threaded portion) Better still fit new helicoils which is not difficult. If not confident any good marine engineer should be able to do it for you. In any case drill a small pilot hole in the bearer adjacent to the new mount to see what is under there first.
The suggestion of an adaptor plate is also a way out if the old mounts are not too near the old ones and I have seen it done. Should not be necessary though
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It all depends on your engine beds. If they have glassed in wooden bearers it is fine and dandy to use coach bolts. Stainless steel ones are available and should be used in preference to carbon steel, galvanised or not. If they have glassed in aluminium or stainless steel backing plates you should simply drill and tap new holes. If the bearers are solid GRP and have helicoil thread inserts fitted (which sounds likely) you can still use stainless steel coach bolts but drill a hole about 30 thousandths of an inch smaller than the OD of the coachbolts before you screw them in to avoid splitting the GRP and ensure that the shank of the bolt does not enter the GRP (only the threaded portion) Better still fit new helicoils which is not difficult. If not confident any good marine engineer should be able to do it for you. In any case drill a small pilot hole in the bearer adjacent to the new mount to see what is under there first.
The suggestion of an adaptor plate is also a way out if the old mounts are not too near the old ones and I have seen it done. Should not be necessary though
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Keith
New member
Re: Engine Mounts Advice
I suspect the engine mounts would shear off before the coach bolts let go, don't forget the coach bolts are "in shear" anyway so they will probably take a couple of tons per screw easily........keith
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I suspect the engine mounts would shear off before the coach bolts let go, don't forget the coach bolts are "in shear" anyway so they will probably take a couple of tons per screw easily........keith
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