`79 Glastron SSV-177 OMC to Mercruiser

[79Glastron]

The day has finally come, I decided to stop throwing money at this OMC and install a Mercruiser. I'm gonna try to document this process as best as I can and take some pictures along the way. I'll have to snap a few pics of the entire boat, but these first are just work shots. Here are some pics of what I'm starting with.


Here is the engine that will replace the "blue" one. Note, these engines are almost identical, only the Merc is from `74 and "older" one is from `79. Both 140HP


The first item was to remove the OMC out drive, nothing too bad, I've done it before to replace the water pump, its a little more complex than removing a Merc drive.

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

At this point I removed the middle section of the drive and the large rubber boot. I also removed the helm, and steering cable. All the wiring and plumping are disconnected and the engine mounts are unbolted from the stringers. The engine is ready to be pulled out tomorrow.
My transom looks and feels very solid, It looks like water was never in the bilge area. Now I need a great idea, what is the best way to fill this hole in? I really want to try to keep most of the wood since its in such great shape. Input please! More tomorrow.....

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

Got the engine pulled today, it went very well. I wasn't sure if my picker was going to be high enough to clear the boat, but I had a lot of room to spare. Other than pulling the engine, thats all I got done today. I'm still thinking about transom options.

 

[vi]

Re: `79 Glastron SSV-177 OMC to Mercruiser

How come the hole doesn't look that big with the out drive in place ? I am contemplating the same change. It looks like it may be a good idea to cut 4"s or so past the current hole to the gelcoat, scarf it out then make the plug so the area outside the keyhole has more wood to glass too, ie old transom. Just thinking out loud...

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

How come the hole doesn't look that big with the out drive in place ? I am contemplating the same change. It looks like it may be a good idea to cut 4"s or so past the current hole to the gelcoat, scarf it out then make the plug so the area outside the keyhole has more wood to glass too, ie old transom. Just thinking out loud...

Yeah, it looks a little bigger with the everything out. I'm starting to lean toward "seacasting" a new transom.

 

[Willyclay]

Re: `79 Glastron SSV-177 OMC to Mercruiser

I'm starting to lean toward "seacasting" a new transom.

I bought a "new-to-me" boat with a good sole and transom plus two feet more length for less than what Seacast would have cost me for just the transom repair. Research it before you commit to that option. The Mercruiser transom plate/gimble mounting system raises some questions in my mind about the structural integrity of a Seacast "plug" in your OMC hole. I am not an expert, just an interested member. You asked for input. Good luck!

 

[vi]

Re: `79 Glastron SSV-177 OMC to Mercruiser

Yes, as others have stated before wood/glass in my mind is better than seacast as that has to have glass on it as well. I was saying maybe 4"s past the existing hole would give a good bond to the existing strong transom to adhere to.

 

[wire knot]

Re: `79 Glastron SSV-177 OMC to Mercruiser

I repowered this fall with VP. No diff in the layup/hole cutout.
Here's how I did it.

http://forums.iboats.com/showthread.php?t=455808

Disclaimer:
I'm an electrician, Although i did ALOT of research before beginning, And I am confident in the work,
I'm not suggesting anyone use these methods......I'm just saying.

WK

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

I'm still unsure on my method. I haven't done any research on the "west system". If I was going to use seacast, I would remove all the old transmsom, and use seacast as the new core material. There is a guy on here that did that with his Glastron and a 350 Chevy. His hull and mine are very similar. If I go against seacast, I'll probably remove the old wood, and install new wood, reglass and cut out the new hole. I don't think I'll try to "doctor up" my current hole, unless I'm convinced other wise.
It seems if seacast is strong enough to hold up large outboards, you think it would be ok for an IO? An outboard being mounted high seems like it would exert a large force on the transom? Thanks for the feedback!

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

This weekend I started to remove my transom. It turns out a little harder than I thought. The design of the engine stringers and floor make it a bit tougher. I also had to removed a good bit of foam, I wouldn't mind removing most of the foam from the rear of the boat, but at this point I just want to remove what is needed. I'm going to have to cut back the floor and engine stringers to gain enough room to cut the rest of the transom out. I also need a tool to cut the fiberglass where the transom meets the bottom of the boat. What are you guys using? More pics in next post.

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

More pics from this weekend. I can't believe people finishing this job in one weekend. Can anyone recommend the type of fiberglass cloth I should use when I reassemble my transom? I'll be using poly resin, and will probably be ordering from us composites. It seems like a lot of poeple order from them. More to come later!

 

[Woodonglass]

Re: `79 Glastron SSV-177 OMC to Mercruiser

404 resin , 1.5oz csm and 1708 Biax

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

Stupid craigslist, it made me find this boat, and for some odd reason I had to buy it.....Great another project, like I needed another one.



It came with a newer model `rude 40 with a busted lower unit case. He got a good used case, but didn't put his parts in the new case. It seems like its missing some pieces and I'm not sure if its worth fixing. It does have power trim, and the power head seems great.

I have this Merc I'm thinking about installing it and just running it like this for the summer. The cap should probably be popped and everything redone.....but not right now.

Hopefully I'll get something done on the 177 this weekend. I tore the gimbal housing apart for new bellows and gimbal bearing, and a new trim limit switch if I can find one. Stay tuned.....

 

[vi]

Re: `79 Glastron SSV-177 OMC to Mercruiser

Hello again! I used an air type cut off tool with a 4" or so disk high rpm , it had a tilted head which made it easier to get between hull and old stringers. on the transom I made some small grinds to get down to the glass (through the plywood) and used a hammer and chisel to separate the gel or fiberglass from the transom, then the grinder to make it smooth. Then fitted each half of plywood in with a joint in the center, what I see a lot of is people make a single piece fit.

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

I just got back from vacation and was able to work on the boat again. I got just about all the wood out. I just need to do a lot of grinding and prep work for the new transom, whichever material it may be. Still thinking about seacast.......Also, I removed the panel above the engine, makes it a lot easier to work on!!

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

If there are any people following this thread I figured I should do an update of some sort. Last weekend I sanded down the fiberglass transom and squared up the engine stringers and parts of the floor I cut out. I bought one of those porter cable oscillating saws, it works pretty good, but fiberglass is hard on the blades.

I also changed my mind about what Mercruiser drive system I am going to install. I was going to install a 140HP Merc one drive from 1974, after doing some research and a lot of thinking I have decided to install an Alpha one drive from 1986, still using a 140HP GM engine. I figured with all the work I'm doing, I may as well take advantage of the newer drive system. I'm still going to keep all my one drive stuff, because some of it is interchangeable, and plus I didn't pay a lot for it. Tomorrow I plan on removing all the stuff from the donor boat, hopefully that should go well.

Lastly, I have decided to go with seacast for the transom material. I have choosen to do what others have done and make a plug for the transom cut out, glass in the new outer wall to fill in the OMC hole, pour seacast into form, and glass over seacast transom. Thats the plan I am going to follow. I will post pictures of my progress later this weekend.
Thanks for your support!

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

Short update with some pictures. I got the engine and drive pulled out of my donor boat, a 1986 sunbird with some very serious rot. I didn't try to turn the engine over, I figured if it was free, good, if not ok. So I loaded up the truck and went home. I messed around a little with the engine, connected a battery to it and it turned over just fine and had a nice strong spark!!! This morning I connected my outboard gas tank to the fuel pump, primed it with the hand pump and it fired right off and sounded pretty good! However, it looks like the manifold was never drained and it has a large crack on the bottom. I'm not sure if the block was drained or not, the petcock was closed, but I haven't seen any cracks yet, and water wasn't leaking out when I had my hose hooked up, and water hasn't found its way into the oil yet....... I'll probably pull the manifold and check behind it, since it seems like they like to crack back there. I may try to fix the manifold if it looks ok inside, I'm not sure yet.

I went to town with the grinder today and pretty much have the hull preped for seacast. I just have to build my forms and install the keyhole template a fellow user is letting me use. I was a bit carless with the grinder and cut a gouge out by the bottom, probably close to cuttting threw the glass, I might try to fill that with resin and chopped glass to reinfore that opps. Hopefully things will move along pretty good once the seacast is in. Time is ticking away for the PA boating season, early October is about all we have, until April or so. I'm confident it will be in the water before that.
Stay tuned!

 

[Willyclay]

Re: `79 Glastron SSV-177 OMC to Mercruiser

If there are any people following this thread I figured I should do an update of some sort.

I'm still here, always learning. Good luck with the Seacast pour!

 

[79Glastron]

Re: `79 Glastron SSV-177 OMC to Mercruiser

Seeking some more information. Does anyone have a recommendation on what type and weight of fiberglass I should use to build my outer skin? The skin is just going to be the area around the keyhole and overlap to the existing outer skin. I will then pour the seacast into the mold, and add some layers over the seacast once its cured. For the outer skin I'm thinking one layer of CSM 1.5 oz, and 2 or 3 layers of 1708????
Thanks!

 

[Cadwelder]

Re: `79 Glastron SSV-177 OMC to Mercruiser

Seeking some more information. Does anyone have a recommendation on what type and weight of fiberglass I should use to build my outer skin? The skin is just going to be the area around the keyhole and overlap to the existing outer skin. I will then pour the seacast into the mold, and add some layers over the seacast once its cured. For the outer skin I'm thinking one layer of CSM 1.5 oz, and 2 or 3 layers of 1708????
Thanks!

I've read yourwhole thread twice to see what I'm missing here. I don't understand your using seacast. You have all the old transom out, why are you not replacing with plywood. How are you going to pour seacast with the inner skin removed.

All you need to do right now is mount the plywood and glass it in (cover the outdrive hole in the skin), and glass it all back in. The hole for the OMC drive is much larger than the Merc will be so you'll be recutting the hole anyway.

Actually I don't even see any rot in the old transom.....what made you need to replace it anyway? Guess I'm just not thinking the same way you are here??