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'86 Volvo 4cyl mounting

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SGF1

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A freind just bought a small boat with a Volvo 4 cyl motor. The only mounts on this boat for the engine and outdrive are where the outdrive mounts to the transom. I see no evidence that the engine ever mounted to the stringers. Is this right? Unfortunately the transom has rot and the weight of the engine is forcing the outdrive to separate from the back of the boat causing a major leak. He is looking into replacing the rotten transom, but I'm still baffled by the mounting of the engine/outdrive. I don't know much about these setups, so any help would be appreciated.
 
Some VP 4-cylinder installations have a cantilevered engine, but one of the dangers of such arrangement is precisely what your friend is experiencing. My suggestion would be that after repairing (replacing) the transom he should install front mounts.
 
My take is a little different, but I do respect Eduardo's!

The Cantilever Hung engines pose no issues until the transom core rots.
It doesn't take the weight of the engine alone to cause this damage.
If the engine had foward mounts, a soft transom core still poses an issue for a drive that is placing near continuous torque against this NOW structurally incompetant component.
Granted.... the engine moving UP/DOWN is not good on the fiberglass.
But the drive can pull down on the transom all by itself, simply from FWD prop thrust.

I say do a complete core replacement, and re-hang the engine.
It will go for another twenty or so more years.
Front mounts certainly won't hurt anything!

:D
 
So what is the procedure for adding mounts? I would assume that one would begin by setting an engine bed log athwartship under the engine in the appropriate spot?

What would one need to buy to finish the job? Does the cantilevered engine have the right bits to bolt on to?
 
The attached image shows what I have done with my AQ130C. There was always a rubber block under the right side and I added the very dense piece of foam under the left side. Note the metal plate which supports both blocks over the bilge. These are not really mounts, rather just supports but they seem to work well.
 

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Here are some pictures of the mounts that a very crafty member in your very same situation made some time ago.
 

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el_pescador said:
Ricardo, ever wondered why VP went from cantilever to front mounts and not the other way around?
Click to expand...
Eduardo, I must admit that the first time I saw this, I questioned it.
And I'm on record as having said that adding front mounts certainly wouldn't hurt anything. :D
Actually, wasn't this a Bayliner thing only? Did other manufacturers do this also?


film842 said:
............. Does the cantilevered engine have the right bits to bolt on to?
Click to expand...
Yes, the engine will have the necessary attachment points!
It's the hardware that you'd need to find.
You may be able to find a donor boat that did have the front mounts. Any larger hull with twin OHC 4's will have these.
And.... possibly some non-Bayliner boats.

Here is an OEM system that uses an isolator...... wonder if this would work.
7391.jpg


This too is an OEM set-up that uses an isolator, but is being shown with the 6 cylinder engine.... seems like I've seen this same sytem on the OHC 4's.
Here is more info if you scroll through the types of engines.
5270.jpg
 
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was'nt just bayliner, i've had 2 starline boats that were also made with no mounts 1 with the aq 131, and the one i run now with the bb140 which i've also manufactured a mount in the front of, i just don't trust them with no mounts, better safe than sorry.
 
eastcoastitalian said:
was'nt just bayliner, i've had 2 starline boats that were also made with no mounts 1 with the aq 131, and the one i run now with the bb140 which i've also manufactured a mount in the front of, i just don't trust them with no mounts, better safe than sorry.
Click to expand...
Interesting.... I figured I hear about one some day.
But prior to this, I was thinking that it was something that only B/L did.
Thanks for the heads up.
 
The 120/125 engines did not come with mounts from V/P. The 140 and 145 did. I don't think it was a boatbuilder deal to have or not have them. I have a family member who still runs around in his 125, actually 145 now that I put downdrafts on it, without mounts and all is fine.
 
Schematics show engine supports for the AQ131A, so it looks like I need to find boat "junkyards" that might have boats that had the 131 series or 140's or 145's. Guess I could start on ebay and go from there. This has been a helpful thread...thanks for the pics and info.
 
I agree. Thanks for the pics and diagrams. This has been very helpful. I've learned more about this boat in 20 mins on this site than I would have spending hours elsewhere!
 
SGF1 said:
I agree. Thanks for the pics and diagrams. This has been very helpful. I've learned more about this boat in 20 mins on this site than I would have spending hours elsewhere!
Click to expand...
Send Money! :D
Make check payable to.............................

Nope, no money needed........, that's what forums are all about. :)
 
I can't tell you how much time, aggravation and $$ I would have spent paying someone to do the job that this forum has saved me over the years. Big thanks to everyone who contributes!
 
If this was my boat... I'd buy a length of fiberglass rectangular tubing
http://www.mcmaster.com/#fiberglass/=71lwr7

This is a 5 ft length.

I'd cut it in half and mount each piece fore to aft under the engine, bedded and glassed to the hull ( clean very well and sand first).

I'd get a chunk of 1/4 " stainless that would fit inside each tube, drilled and tapped to take the mounting bolts,themselves.

I make two mounting "pads" that would prevent the metal vibration isolator mounts from chewing thru the tube from starboard (the name of the material, not the direction).

So, in cross section (bottom to top)

Hull
glassed in bottom of tube
drilled and tapped tube
top of tube
starboard pad
engine mount base...

Depending on distance from engine at front mount bolt holes to hull, some "adjustments" may be necessary. Tubing is available in several sizes.
You could also mount one short section of tube on top of another for more height.
 
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el_pescador said:
This is a very popular type of mount (vibration isolator)

http://www.bushingsinc.com/Acrobat/DF-206.pdf

They are about $51 each at Marineengine

http://www.marineengine.com/newparts/part_details.php?pnum=OSCDF-206&ptype=&Engine=&Model=
Click to expand...

So, do I have it right that I could attach these two mounts to the engines front mounting points and then bolt each mount into a suitable support (wood or fiberglass) that was glassed onto the hull?

Sorry about the obvious question, but I can be a real dummy about this stuff.
 
Yes. You need to fiberglass suitable wood blocks to the hull, the you need to install two mounting brackets between the engine and the isolators. The isolators can be fastened to the wooden blocks with wood screws. You will have to conduct some calculations to get this done correctly.
 
See picture below for the mounting of my engine ( a V8) to the hull)
The stringers (fore/aft structures on this boat) are hollow fiberglass
 

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el_pescador said:
Here are some pictures of the mounts that a very crafty member in your very same situation made some time ago.
Click to expand...

See the pics in post #9 in this thread. This is what I'd like do for my 131A, especially after pricing used brackets etc.

My question is how to go about making an accurate template for the three mounting bolt holes on the engine?

At first it sounded easy until I started thinking how to go about it after which my brain shut down.

Is there a process to make an accurate template with the boat in the engine? Thanks.
 
If you want brackets, check an automotive junkyard and find a Volvo with the OHC early engines. B21 I believe.

I have a 1976 Fiberform with the cantilever hung engine. Adding something after 30+ years without a problem just doesn't make sense to me.
 

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joe_merchant said:
If you want brackets, check an automotive junkyard and find a Volvo with the OHC early engines. B21 I believe.

I have a 1976 Fiberform with the cantilever hung engine. Adding something after 30+ years without a problem just doesn't make sense to me.
Click to expand...

I think it makes sense because it's 30 years old. The structural integrity of the transom is the issue since the motor and outdrive hang from it. I don't think my transom is weak, but the point is, I don't know for absolute sure.

I've never been impressed by how Bayliner uses wood in these boats or their general level of quality, so it seems reasonable to beef it up.

Thanks for the heads up on auto yards...never thought of that.
 
Place a "straight edge" against the transom (exterior of hull).
Have someone gently place their weight on the out drive as you watch for any movement or flex!
It's very simple to tell when a transom core is loosing it's integrity by doing this.
 
RicardoMarine said:
Place a "straight edge" against the transom (exterior of hull).
Have someone gently place their weight on the out drive as you watch for any movement or flex!
It's very simple to tell when a transom core is loosing it's integrity by doing this.
Click to expand...

Great idea Rick...thanks. That's exactly what I'm going to do. I'll post back here after I test it. If I get no flex, I am still going to plan on installing mounts, but will put that job further down the pipeline...as in next winter.
 
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