'77 Merc 888 IT RUNS!!!!!!

[racinrc14]

Thanks to everybody over the past few months for the help with this rebuild. Turns out that the PO had the firing order backwards, and it was only running on 4 cylinders before. Although it seemed to be relatively smooth to me (first time boat owner), it was actually sucking in water on the 4 non-firing cylinders (bad exhaust shutters) and contaminating the oil (might be wrong about this). And the rod knock the local boat place told me about was actually a severely out-of-alignment motor/drive and worn out coupler. I am glad I took on the project, as I have learned a lot about my boat, and the systems that make it go. After the initial 20 min run to break in the new camshaft (1500rpm), and another 15 or so to check for leaks (that was my excuse for just the satisfaction of listening to it!), the oil appears clean and clear so far.

Special thanks to the following:

-mkast
-Bond-O
-Bubba1235
-Ziggy
-turborich
-Haut Medoc
-chiefalen
-reelfishin
-WizeOne
-Don S
-coastalcruiser
-haulnazz15
-jimbo3123
-gadget73

This place rocks!

 

[mkast]

Re: '77 Merc 888 IT RUNS!!!!!!

Outstanding.
If you are like most of the people I know with 302's, you'll be looking to replace it with a 351, as soon as you find it.
Be patient, the last one I pickup cost $100 and came with fresh water cooling.

 

[racinrc14]

Re: '77 Merc 888 IT RUNS!!!!!!

Thanks Mkast. Yeah, more power always has appeal. She's a relatively small, light boat, so hopefully the 'ole 302 will be enough for a while. I'm not sure I want to pull the motor again any time soon anyway.

 

[7designs]

Re: '77 Merc 888 IT RUNS!!!!!!

Thanks Mkast. Yeah, more power always has appeal. She's a relatively small, light boat, so hopefully the 'ole 302 will be enough for a while. I'm not sure I want to pull the motor again any time soon anyway.

As soon as you get passed you will be pulling the motor.

 

[WizeOne]

Re: '77 Merc 888 IT RUNS!!!!!!

As soon as you get passed you will be pulling the motor.

Stroke it! Mucho increase in torque, no extra size or weight or any of the other issues of conversion.

Glad you got it tickin' racin.

 

[racinrc14]

Re: '77 Merc 888 IT RUNS!!!!!!

So what does a 302 stroke out to? 377? Where's my PAW catalogue....

 

[WizeOne]

Re: '77 Merc 888 IT RUNS!!!!!!

So what does a 302 stroke out to? 377? Where's my PAW catalogue....

For ultimate duribility go with the 331 cid. For street, I would consider a 347 but not for the marine app. 331's have a better rod ratio, almost close to the stock 302 R/R. That means that the piston is not trying to push thru the sidewall of the cylinder on it's upward motion.

You not only get more cubes with the stroker, the piston stays at the top of the stroke longer, taking maximum advantage of the ignited fuel charge.

 

[mkast]

Re: '77 Merc 888 IT RUNS!!!!!!

I'm not sure I want to pull the motor again any time soon anyway.

Believe it or not, the more you do this, the easier it gets.

 

[Haut Medoc]

Re: '77 Merc 888 IT RUNS!!!!!!

 

[racinrc14]

Re: '77 Merc 888 IT RUNS!!!!!!

Believe it or not, the more you do this, the easier it gets.

I'm really fortunate to have a friend with an old John Deere 70 with a front end loader. If I had my own hoist that was tall enough, I would have had it done sooner, but I really appreciate him helping me out. I suppose, looking back, that it really wasn't all that difficult. Just time consuming and expensive.:redface:

 

[gadget73]

Re: '77 Merc 888 IT RUNS!!!!!!

The other plus to the 331 is that the wrist pin is not inside the oil scraper ring. On a 347, the wrist pin is part way through the bottom ring, so they have a habit of sucking more oil than a stock or lesser stroked engine.

Honestly the 302 is not a bad motor at all. In extreme cases the block will shift and they blow head gaskets. Mostly this happens when you spin them like mad, but since most marine engines never get over 5000 its not a concern. Crank it to 6500 or so, and they just don't hold up as well.

As for the backwards firing order, I've done that. Put a 351 in someone's car, got the firing order right, but forgot the distributor spun the opposite way from a Chevy. Oh well, no damage done other than to my ego. It did make a nice loud bang out of the open headers tho.

 

[WizeOne]

Re: '77 Merc 888 IT RUNS!!!!!!

..... On a 347, the wrist pin is part way through the bottom ring, so they have a habit of sucking more oil than a stock or lesser stroked engine.

True on the wristpin but the rest of it was truer yesterday than today. The ford 302 is inherently such a good motor that more and more aftermarket design emphasis is going into components for the now defunct pushrod motor. Even Ford Motorsport is still in the game. They have become real 350 chebby beaters.

The big difference, IMHO (331 vs 347) still remains the rod ratio.