Bad first outing

[cowboy4]

Well did some stereo work and touch up to the interrior over the winter.
Went out Saturday for the first time since winter and was going to try out my new dry suit.
Well first the exhaust didn't sound right (no water in exhaust) so I pulled the dog house to find water coming out of a freeze plug that had popped out. So I knock it back in enough to hold pressure and run back to the ramp. As I was waiting for the trailer to be back in the oil pressure dropped. So I shut it down and found a nice white frothy substance had come out of the breathers (oil and water mixed). So now I have either a cracked block, heads, or head gasket.

What a way to start the season.......

So what all would I have to change on the motor if I found a junkyard jewel out of a truck or rv? Cam, carb, water neck accessories, intake, ???????


I'm praying it's a head gasket or head and not the block.
I leave town for work tom morning so can't do to much to it right now. I drained the water out of the block as soon as it was out of the water and filled it with diesel (recommendation of two different mechanics.).

[Salty87]

sorry to hear that cowboy. keeping my fingers crossed for you.

[csuggs]

Sorry man . . . . .

[wotan2525]

From a guy who's been there before..... sorry to hear it. Good luck!

[mapleleaf]

why does this thread immediately make me worried about my first inboard winterization up here in Ontario. I'll be pull'in for you and your motor. And hope'in my motor pulls me!!!

[michael hunter]

Sorry to here of your bad luck Pull the heads and hopefully you will see a gasket or
something simple. You might check with GM sometimes they have new older engines
at descent pricing .If you find a cracked block you might be able to save the heads.
Then you can get a long block?
What did you put in after you drained the water [Diesel?]

[cowboy4]

I found a junkyard with two 454's both still in the vehicles. He said one was low miles but he didn't have the exact number right then. So worst case I'm out 750 for a motor complete oilpan to intake. Just swap a few of the parts, check the bearings and get her back on the water. Then look for a closed cooling water setup!!!!!

[rickr]

Closed cooling must be winterized also.

There are a lot of different big blocks. Mark IV, Gen V, Mark VI, tall decks......
Yours should be a Mark IV w/ two piece rear seal, fuel pump boss,stamped steel timing chain cover.....
Merc Mag 454s of that era were based on the LS6 w/forged pistons and crank, high rise intake, retangular port heads.... I do not know about the Mrec base 454. I am not familiar with Pleasurecraft???????
Many different heads also.

[cowboy4]

But closed cooling is much easier and quicker to winterize.
Like I said I won't know much about the motor or the possible donors till I get back home.

[michael hunter]

Cowboy how did you winterize your boat ? You said you put Diesel in it was that Diesel
fuel? If so where did you put it?

[cowboy4]

at the end of the season I pulled the polugs in the water jacket did the fuel stabil and sprayed the fogger down the carb. IO used it in a winter parade thanksgiving. Then after that I pulled the plugs out of the exhaust, disconnected the water neck and hit it with a shop vac.

The diesel went into the crank case after the Saturday trip where the mayonnaise consistency mixture of oil/water was pumped out of the breathers. I drained the crank case of water and didn't have time to tear it down then. So was told to do that instead of using cheap oil to try to save what was left from rust.

I got the motor out last night pulled all the accessories one valve cover and the intake.
Intake gasket was fine, lifter valley has no cracks, and everything that is visible currently looks ok.

Casting numbers are,
Block 14015445 - 1975-87 454 truck

Heads 6272990 - 1971-94 454 2.19IN 1.88EX Open 118CC

According to some websites they say with that head it should be a 425 hp???

[cowboy4]

Got pics!!!
Side #1
http://i123.photobucket.com/albums/o287/cowwboy4/DSC00910.jpg
http://i123.photobucket.com/albums/o287/cowwboy4/DSC00911.jpg

Side#2
http://i123.photobucket.com/albums/o287/cowwboy4/DSC00912.jpg
http://i123.photobucket.com/albums/o287/cowwboy4/DSC00912.jpg

[cowboy4]

Old crack from previous owner??
http://i123.photobucket.com/albums/o287/cowwboy4/DSC00920.jpg
http://i123.photobucket.com/albums/o287/cowwboy4/DSC00920.jpg

My assistant.
http://i123.photobucket.com/albums/o287/cowwboy4/DSC00914.jpg

[michael hunter]

Cowboy
It looks like you have a good mechanic on the job.
Sorry about your engine. I live near Chicago when I winterize
I drain then put 50/50 antifreeze into the hose going into the thermostat
until it starts coming out the exhaust. Knock on fiberglass never had a
problem.
Thanks for posting this problem its a good reminder for all to remember
what happens to engines with water in them.
Good Luck with your repair.

[csuggs]

Has anyone ever tried using RV Antifreeze to winterize the engine? I used regular Ethylene Glycol this year but now I have to dispose of it or save it for next year. Sure seems like it would be neat to suck Rv antifreeze into the motor and shut it down when it starts coming out the exhaust - then in the spring just start it and let the RV antifreeze blow out the exhuast since it's bio-degradeable!

[tg0824SSVGG]

Around here, if you put any kind of anti-freeze in, it is supposed to be RV antifreeze,
the other stuff kills fish.

I put RV antifreeze in my heater line - but not the entire engine.

[wotan2525]

I pull out the thermostat and then suck 6-gallons of RV antifreeze in through the water pump -- it comes out the exhaust a little before this but I figure it comes in a box of 6, why not use all of them. In the spring, all I have to do is put a new thermostat in (cheap insurance) and start it up -- no muss, no fuss.

[cowboy4]

After doing some checking, looks like the motor they put in and say to only spin to 4200 rpm has heads(square port) that are more designed to turn 7k+. I've had a few engine shops actually refering me to switch to oval port truck heads as it would improve bottom end where I normally run.


So asking for opinions and maybe some support from supra techs as to why there is a motor installed that is set up for high rev for a low rpm application let alone the 650cfm carb put on it.

If i go to a small port head I can save a good cunk and just buy a junkyard motor and toss it in.

I don't want to loose performance but also don't want to spend un-needed money.