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Hello and 5.7 V8 Alpha One questions

N

NVTS

New member
Hello,

I am new to this forum. I have the following setup in my Reef Runner that is only used in salt water. I just purchased this boat and it had a plugged engine compartment during years of setting out side and the alternator was frozen and I assume the starter also. The exhaust manifolds are flaking off when touched by hand. No water was showing in the oil when checked by the dip stick.

My Motor:

5.7 V8 Alpha One – Thunderbolt Ignition / Power Steering
Model: MCM5.7 Litre, 350 CID, 8 BTDC, LH Rotation
Engine# 0F370428, Transom# OF476971, Drive # OF509647

I am looking for replacement parts to rebuild the motor. I am in the Tucson/Phoenix Arizona and hoping to find reasonable parts and supplier.

I am looking for recommendations or suggestions.

Also, has anyone setup a closed cooling system for this size of motor?

Thanks is advance.

Howard
 
Howard, any good automotive machine shop.... who has SBC Marine Cruiser Engine Experience ..... (note that I put that in BOLD type) can do this for you.
What you do not want to do, is build for more horse power using any conventional Automotive practices.
This is where the mistakes begin.
Also, the piston and cylinder head combination must remain complementary to one another, in order to maintain the correct C/R for Marine use.
You will find the dreaded full dished piston commonly used in many SBC Marine engines. This is NOT a desirable combination, but this is what GM does.
It also means that you must stay with the small chamber cylinder heads.
Likewise, the marine profile camshaft must be used. (water reversion is the issue)
Point being.... we can't arbitrarily swap these components without some knowledge as to what works with what.
Just an FYI on all that.

The Closed System cooling is great..... I'll not own a boat that does not have a Closed Cooling system installed.
However, there are some inherent issues when converting a previously raw water cooled engine over to CC..... and particularly salt water cooled.
Rust scale is the culprit...... because it will continue to dislodge and will end up in the E/G/h2o side of the tube bundle.
This leaves the potential that the tube bundle's heat removing ability becomes deminished.
This side of the H/E is in-accessible by average Joe.

It can be done, but there are some measures that must be taken.

.
 
RicardoMarine,

Thanks for the reply. Should I just stay with the current raw water cooling system then? Since this motor has been this way for a while. I plan on replacing the manifolds, risers, water pump and all hoses anyways.

What items would I need for this conversion also?

Thanks again...
 
If you are not going to use your baot in salt water then a NON closed cooling system is best and easieast to maintain.

If you are going to use it in salt water then a closed cooling system is best. Now as there is NO slat water in Tucson/Phoenix Arizona area can we assume it will be fresh water only?

Anything you may think needs replacement do it!!! Salt water is a boats worse enemy!!!
 
Conversion to full closed cooling is not difficult. Do a google search, I purchased my kit from I-net marine about 7 years ago, had no issues with it... $800 at the time. They may have kits available on this site as well.

I would suggest, since your manifolds are showing signs of corrossion on the outside, the inside is very likely much worse.
When you do the conversion, replace the manifolds, risers(elbows) and spacer blocks if you have them. This will save you a ton of time and money in the long run.

Also, when you do the conversion, expect a pretty severe 'crud' burst from the engine water jacket and any other components previsouly exposed to salt water that aren't getting replaced. Don't be surprised if the engine water pump craps the bed after the conversion as well. I would wait until after conversion to repalce this though. The small crud particles will likely trash the stem seal, so wait until you get the system cleaned up, otherwise you'll be replacing it twice.

Flush the cooling system as many times as it takes after running the engine a few hours in between flushes until you get it cleaned out. You'll be able to tell it's getting clean when you open the drain cock on the bottom-port side of the block and clean engine coolant comes out. If you continue to get black particles, keep flushing. It'll clear up eventually. At first, you may want to keep a length of solid 14 gauge copper wire handy to poke into the drain cock to help clear it out.
 
OK, Mr Pessimism here with his daily downer.
I would plan on a new engine and the reason is due to the fact that the boat was neglected for so long. You could maybe get away with a simple change of manifolds and pumps and all that but the real question mark is the water jacket of the engine itself. If the rust is flaking off in chunks on the manifolds, I would expect the same is happening on the inside of the engine. You can flush it but it will continue to barf rust for the remainder of its life. The only real cure for that is to disassemble the block and have it tanked. This is clearly well beyond the worth of that particular engine especially with Chevy small blocks being as plentiful and disposable as Pampers.
If the boat is worth it, and I mean really worth it like you are committed to keeping it for ten years or so, then take it to your nearest Mercruiser repower spe******t and have them put in a nice new EFI 5.7 package. You will be way ahead of the game if you do. Rebuilding is always more costly than a new engine especially if you figure in (here it comes) resale value.
 
Thanks to all for the replies,

Yes, I will only be using it in Salt Water in Mexico.

Yes, I plan on keeping the boat and the hull is worth it a new engine if needed.

Troym,

Thanks for the explanation and steps for the change over. I am trying to find a another salt water only motor to do this with and not have the cleaning process.

This boat was always removed from the water and flushed prior to storing. It was the storing and the storage unit that is were the damage happened. I suspect that the rain water filling the engine compartment and with the battery fully submerged is what caused the problems on the out side of the motor. This level and lower is were the damage is showing.

Has anyone put in a diesel engine as a replacement? A friend suggested this to me.

Thanks again to all...

Howard
 
If you go diesel then look at a Volvo Penta with Duoprop. Anything less is, well, less. It will not be cheap in any way. If you're using this in Mexico then it becomes a matter of personal safety and you must ask yourself how much your life is worth. Do you really want to be at sea in Mexican waters without the most dependable rig? Not knocking Mexico in any way but they don't have Sea Stallions and PJs to come get you if you get in trouble.
 
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Before you jump to the conclusion that the hull is worth the cost of a repower...

This thing has been sitting for a long time with a bunch of water in the bilge?
Get the moisture level of the hull checked.
Fiberglass can hide signs of pending failure right up until the point were the paint starts to bubble, indicating that the layerss of the fiberglass are coming apart (called delamination). In small localized areas, it can be repaired. If your whole engine compartment and transom have been submerged, you could have a real mess on your hands.
Did you buy the boat from a private party or through a broker? If through a broker, they should have recomended a complete boat survey, None-the less, they could still put you in contact with a surveyor who can at the very least check your hull out.
 
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