Motor mounts

[stomp10]

I'll try to keep this as short as possible....
I am considering replacing my 38 year old 470, 170hp merc. Parts are just getting too expensive, I don't want to be screwing with it in my retirement. I just wanna hitch her up and plop it into the lake and go. I am the second owner and my Da was the first.

Overall the hull is in great shape as it was garaged since new. It has been rained on a few times during vacations, (It never fails it seems!) Floors are still solid.

Considering a v6 as replacement among other options.

Don't mind some work to obtain that objective as long as I only have to do it once.

I attached a photo of the engine bay. The horizontal member is the existing front motor mount base for the 470 and you can see the base of the engine mount in the photo. Looks like it is attached to a front to back glassed in 1x4?

Same deal both sides of the engine.
I don't think the 1x4 is enough to hold the six, nor is it high enough. Maybe its a 2x4 bedded in fiberglass?

Provided the 1x4 isn't rotted out, (doesn't seem to be.) can this be built upon to get the desired height or does it have to come out? I don't mind the fabrication aspect as long as I can get expert advice in order to do it right. Pitfalls along the way don't scare me either. I don't mind making the engine bay wider if need be. (If it's even feasible.)

Center to center horizontally across the hull on the front to back stringer thingys is 17.5". The engine bay is 26" wide. Have some room at the front of the engine but I don't think this is an issue with a six.

And is it just me or is this a kind of cheesy fiberglass job? Looks like a bubble on the motor mount member.

Let me know if'n ya'll need more info

Your input is greatly appreciated!

Thanks much!

 

[Chris51280]

isn't the 470 front mounted? the v6 are side mounted. need new engine mounts. And while at it, a 38 year old boat will in 95% of the cases have rot somewhere. I can see a screw going in the wood there which is in the bilge and most likely water got in there. While the motor is out, check the transom since they are most of the time bad because they were not sealed everywhere.

 

[Woodonglass]

If it's been in the garage all these years and only wet from occasional rain showers then you may have a dry boat. Re-configuring the engine well for different motor mounts should be an easy procedure I'd recommend looking for info on how your proposed motor actually mounts to a boats hull and dimensions required to see if your proposal is feasible. More than likely it is. Some core sampling of the mounts and transom will tell you the condition of the inner wood core.

 

[Bondo]

The engine bay is 26" wide.

Ayuh,...... V-6 motor mounts will just fit in that distance,.....

Total motor width is 'bout 32",.....

 

[stomp10]

I appreciate everyone's input. Helps me devise some kind of a plan which is still thinking of the easiest way to meet my objective.
At this point a straight six 165hp seems to be the best way to go. I would possibly only need to rework the stringer at the front of of the engine but maybe not. I suppose a measurement from the transom front to the stringer at the front of the engine would help. Looks like 43" from the transom where the engine mounts are to the backside of the stringer. This would probably entail the least amount of modification. Hafta figure out dimensions for installation of that. I'm guessing the 470 front mount isn't far enough forward to accommodate the 165hp. So may need to install a new one at the front of the new engine. Seems like the heads would be hanging over the existing deck on a v6 installation, making it close quarters to work on.

Chris, your point about "rot somewhere" is well taken. I still feel strongly that this known quantity is still further ahead of an unknown quantity of a purchase of another used boat. Does anyone know what the build quality is of Viking hulls? There aren't a lot of them around. Unfortunately, Dad isn't around anymore to ask..... Pretty sure he did his homework before he made the purchase. It's just the kind of guy he was. And, yes the 470 has a front mount...

At one point, Dad told me he really wanted the v6 option. Long story as to how he wound up with the 470, which I won't go into. But this is initially why I asked about the v6. Right now the straight 6 seems the best option.

Thanks so much, everyone. I feel like I'm making progress.

 

[stomp10]

I
I would possibly only need to rework the stringer at the front of of the engine but maybe not. I suppose a measurement from the transom front to the stringer at the front of the engine would help. Looks like 43" from the transom where the engine mounts are to the backside of the stringer.

Oops, I said Stringer, but I really meant the cross member thing running side to side...
Still learning new to me terminology.

 

[Chris1956]

On my Searay, the stringers were about the right width to support the motor mounts of the 4.3L V6. The motor mounts were lagged onto them. In your case, If you have stringers running perpendicular to the transom, about the correct width,the V6 motor mounts could be made easily.

You should be able to find the specs on the web.

If the stringers are a bit wide, simply bolt pressure treated 2 by lumber to the existing stringers and cover with fiberglass.

if too narrow, bolt 2 By lumber to top of stringers to increase width, provided oil pan will fit between existing stringers.

An IL6 motor is just about obsolete these days.

 

[stomp10]

Thanks Chris, I did finally figure out that the IL6 is obsolete just today, so now I am back to the 4.3 plan. I knew it was too good to be true....

 

[steve_h7]

Oops, I said Stringer, but I really meant the cross member thing running side to side...
Still learning new to me terminology.

Side to side and perpendicular to the stringers are called bulkheads.
I understand your pain... it's hard to know what to call different pieces.