1978 Formula restore thoughts?

Hi all!
I have a 1978 Thunderbird Formula I got on a trade a couple years ago. Looking to now fix it up. Trying to decide what to do with the engine. When I traded for the guy told me it ran for him but had been a few years. I've done cars but this will be my first boat project. I pulled it out a few months back and it turns over, and after a bit of trying, got intermittent spark. Went to then change the points as they were toast.

I don't want to just change the points out and then have another issue come up when I'm on the water so considering a complete rebuild or replace of the engine. Plus when inspecting it, found a missing freeze plug which I know could indicate a cracked block. I don't want to just replace the points to find the whole engine is shot.

Trying to think through my options to determine what's best. Options I'm considering are just replace points, get it running and hope for the best, rebuild this current engine, replace with an auto engine. Replacing with a new or already rebuilt marine engine is a bit out of the price range so not considering that.

I'm used to cars, but I don't know what I don't know on this project. Open to thoughts from guys who have been down this road.

From my research on using an engine out of a car/truck you have to swap out cams, and make sure all items with spark are contained and correct parts are used there. Also, possible wrong rotation issues. Outside of that, anything to think through? Will that been a money saver in the end? I'm seeing guys saying both ways... do it, and don't do it.

What would you do/consider if this was your project. Looking for wisdom from guys who have been down this road.

Ayuh,..... Ya really oughta reconsider this project,....

What motor is in it, V8,..??
Ford,..?? or Chevy,..??

Yer hull has the Stringer drive, which is obsolete, 'n parts rarely available for it,....

I figured that was going to be the response. It's a 351 Ford.

What about converting it to an outboard?

Alot of those old stringers out there working just fine. BOAT break out another thousand. The cost of points is peanuts if you need them for a thorough diagnostic. Do a compression test and get back with the results. Baby steps! If it turns to be serviceable run it till it pukes. IMHO

FIRST ( IMHO) do a thorough inspection of the hull concentrating on

1) Stringers... are they fiberglass encapsulated wood or hollow fiberglass. If the latter all good, if the former, inspect the wood for dry rot. If dry rot, consider scrapping the boat.

2) Transom... inspect to see of the fiberglass skin is delaminated from the core. To do this, get a plastic faced hammer and gently tap the transom... if the hammer bounces, the skin is delaminated in that area. The area around the hull drain plug usually delams first followed by the area around the thru transom boot on the drive. Small areas of delamination are fixable. See West system book for details.

3) Check decks... if solid glass, check for cracks... if cored, check for dry rot especially around any fittings or screw/bolt holes. Fixable, again... see West System book

You can break the bank trying to fix hull issues. Materials costs for fixes are usually not the issue.. Labor often prohibitive... even if DIY

While Formulas are good boats, they aren't Bertram or Hatteras.

Super helpful[FONT=Arial, Verdana, sans-serif] [/FONT]kimcrwbr1 & sandkicker. I'll check those items and get back. I love taking on projects and breathing life into things but I just don't want to end up stranded somewhere on a lake with my family lol.

The body and such does seem to be in very good condition, but I have not checked in detail (because I didn't know how to not having done a boat before) so that is very helpful on where to check and how to check.

A large rubber mallot will help find dryrot you will hear the difference in tone kinna sounds like thunk? A drill and a ice pick works good just penetrate fiberglass with a 3/16 bit and poke the wood with the pick helps tell you the extent of the damage.

..........................

tmantiller said:

Hi all!
I have a 1978 Thunderbird Formula I got on a trade a couple years ago.
Since you posted this in the OMC forum, you likely have an OMC Stringer Drive.
As mentioned, these are no longer being produced and have not been for years and years, plus they were NOT a good system to begin with.



I don't want to just change the points out and then have another issue come up when I'm on the water so considering a complete rebuild or replace of the engine. Plus when inspecting it, found a missing freeze plug which I know could indicate a cracked block. I don't want to just replace the points to find the whole engine is shot.
These are "casting core plugs" aka welch plugs.

Trying to think through my options to determine what's best. Options I'm considering are just replace points, get it running and hope for the best, rebuild this current engine, replace with an auto engine.
The auto engine will be incorrect for Marine use.

Replacing with a new or already rebuilt marine engine is a bit out of the price range so not considering that.
In my opinion, that puts you in the DO NOT DO THIS category!


From my research on using an engine out of a car/truck you have to swap out cams, and make sure all items with spark are contained and correct parts are used there.
That is a portion of it, but certainly not all!

Also, possible wrong rotation issues.
Most any single engine boat built in 1978 w/ an OMC stern drive will be a Standard LH Rotation engine.

Outside of that, anything to think through? Will that been a money saver in the end? I'm seeing guys saying both ways... do it, and don't do it.
Again, in my opinion, I would not spend one dime on this boat...... unless you were willing to re-build the transom so that a real stern drive could be installed!
Often the OMC Stringer Drives were installed in hulls that did incorporate a Structural Transom. The Stringer drive did not require that!

What would you do/consider if this was your project. Looking for wisdom from guys who have been down this road.
The old Formula boats were well built. I owned one years ago!
However, the Stringer drive on this boat is the downfall!
I would NOT go forward with a resurrection........ and again, unless you absolutely love this boat, you are looking for a project, and if you were willing to completely over-haul the transom (closing in the large OMC cut-out area so that a real stern drive could be installed) and to re-build the stringers!
You would be much better off if you were to find a boat with a good hull and an existing Volvo Penta stern drive!

Click to expand...

It's a 351 Ford.

Click to expand...

Ayuh,.... Stringer drives were discontinued in '85,....

Ford left the marine industry, Entirely in '95,....
Merc dropped Ford power in, I believe, '78,.....

For ease of findin' Parts, 'n service,... Chevy power with a Volvo, or Mercruiser drive is the Only way to go now-a-days,....

What size is this Formula Thunderbird ? How about a picture of the boat, engine and outdrive ?