Mercruiser Motor Mounts

[boxers21]

I have a 1988 Bayliner 2150 Capri. It had a 3.0L OMC in it. With the motor mount on the front. I have taken the outdrive off and sold it. Took the 3.0L OMC out, cause it froze ( not my doing was like that when I bought it). Got a donner boat. It had a 4.3L Mercruiser in it. I took the engine out the throttle cable, the control box, the Gimble Housing. I took everthing off this boat even the dash and all the gauges. Less the out drive it was already gone. My question is sense the motor mount was in the front on the 3.0L and on the side on the 4.3L. The supports are there for the mounts. I have the mounts on the motor that has the fluid in them. What do I need to do the the boat part to give it the right height? Do in need to glass in motor mounts on the boat side and if so what do I make them out of plywood peanutbuttered together and if so do I need to test mount the engine to get the right height then mark it and go from there? Thank You Randy

 

[Bondo]

Re: Mercruiser Motor Mounts

Ayuh,... Welcome Aboard,.... I just explained the process to this fella,...

No sense in typin' it twice...

 

[wellcraft-classic210]

Re: Mercruiser Motor Mounts

If you are going to use lag screws be careful about going into end grain plywood as it will have a low holding power an tend to split.

I recently fabricated some engine stingers on my 5.0 litre Merc out of dry pressure treated 2x10's and capped them off on top with 1/2 inch aluminum to spread the load and a smaller 2nd piece of Aluminum under the mounts to make 1 in. thickness & hold the 1/2 in. bolts. Using epoxy to seal each piece and seam.This was overkill but made a good winter project and I do not expect to have to do it over any time soon. Even if the wood starts to rot it will have to get pretty bad before the Aluminum shifts.
I have read of others using hardwood such as Ash or White Oak hardness & ability to hold around lag screws. This would most likley be less labor & cost than the the approach I mentioned above but more than plywood.

Perhaps the experts can offer some advice on alternate methods.

 

[achris]

Re: Mercruiser Motor Mounts

If you are going to use lag screws be careful about going into end grain plywood as it will have a low holding power an tend to split.

I recently fabricated some engine stingers on my 5.0 litre Merc out of dry pressure treated 2x10's and capped them off on top with 1/2 inch aluminum to spread the load and a smaller 2nd piece of Aluminum under the mounts to make 1 in. thickness & hold the 1/2 in. bolts. Using epoxy to seal each piece and seam.This was overkill but made a good winter project and I do not expect to have to do it over any time soon. Even if the wood starts to rot it will have to get pretty bad before the Aluminum shifts.
I have read of others using hardwood such as Ash or White Oak hardness & ability to hold around lag screws. This would most likley be less labor & cost than the the approach I mentioned above but more than plywood.

Perhaps the experts can offer some advice on alternate methods.View attachment 132228

I used Jarrah for my engine beds. An Australian hardwood that you can't just bang a nail in, you have to drill a hole for it first, just like steel!!!

Chris.....

 

[boxers21]

Re: Mercruiser Motor Mounts

Thank for the opinions. Where in the world does someone get Jarrah?

 

[achris]

Re: Mercruiser Motor Mounts

Thank for the opinions. Where in the world does someone get Jarrah?

I just go down to my local timber merchant or hardware store and they have it by the truck-load....