Engine marinising

[Hiptrip]

I have 350 Chev that seems to be marinised but am unsure. I don't know the differences between certain things to define if it's marinised.

I DO know that it has Diablo water cooled headers. But the carby, alternator & points I don't know about.

What do I need to have to be safe from explosions on this engine? How do I define if they are or aren't marinised? & maybe brands that would be suitable for this engine.

Thanks
Zol

[badges65]

Hi,
What are you using the engine for now???
don.

[Hiptrip]

It's going into a Savage Marlin 21 footer. And a Deon jet. I actually bought the boat with the engine but. Now it's near completion. So I'm doing the engine & fuel system. I wanna make sure I do it right the first time
Cheers
Zol

[gonzo]

These are the things to look for in a marine engine:
*carburator has bowl vent into the throat
*fuel injection system is of the closed type-no fuel return line
*starter is ignition protected
* alternator is ignition protected
*fuel pump, if of the diafragm type, has double diafragm and overflow fuel line into the intake
*gaskets with metal mesh or sheet are stainless steel
*coolant circulating pump has stainless steel shaft
*valves are stainless steel
*freeze plugs are bronze
*camshaft is of the correct torque curve design for the application
*Intake manifold, if aluminum, has bronze inserts on water passages
*oil pump is high delivery
*pistons are high performance-designed for extended high RPM service
*Marine blocks and heads have nickel added to the alloy for corrosion resistance and toughness-not necessary but desirable
*roller type timing chain
I hope this list helps you

[Ward]

One easy way to tell at a glance is to look at the water pump. Marine engine water pumps don't have heater hose fittings.

[Hiptrip]

Thanks for the reply fellas. I just found my thread as it's been moved cause it was in the wrong place so I didn't know if anyone replied.

Gonzo. Just a few questions on your response.
Can a normal...let's say an holley caby be changed to a vented bowl or do I need a specific model carby?
My fuel pump seems to be a one peice that doesn't come apart. Does that make sense to you?
How do you know just by looking at the starter & alternator that they are ignition proof? is there a seperate component that you add on or is it a built in thing?

Ward ...you're right it doesn't have heater hoses.

Cheers
Zol

[badges65]

Hi,
you havent stated whether it is salt water cooled or has a heat exchanger this can make a difference to what you have to have .
don

[gonzo]

Yes, it is possible to change the vent in a Holley. The automotive type has a straight pipe. Carefully twist and remove it. Then replace it with a curved one that ends into the throat. I use brake lines because they are the right diameter and bend easily. The other difference is that some of the automotive carburators have a hole in the upper plate for the bar that goes to the mechanical choke. Plug it and put an electrical choke. Marine alternators have a screen to make them spark proof. Starters are sealed. In the US they have a USCG stamp on them, I don't know what you guys have down there. Alternators can be marinized by installing the screen. The body on the starters is different, the marine has no holes. I assume you are talking of a mechanical fuel pump. Some of them don't come apart. A marine pump has two diafragms with a spacer plate in between. There is a small 5/16" od pipe for the overflow hose in it.

[Hiptrip]

Thanks Gonzo... I would assume that the sreen is sorta like a gauze type of screen. Sounds easy to make & place around the openings...yeah?

Don...I built a heat exchange unit out of pure copper & keeps the salt water away from the chambers.

Cheers
Zol

[gonzo]

The screens are made of fine tight brass mesh. I don't know what the mesh count is. Remember the carburator needs a flame arrestor too.

[Hiptrip]

Do you think that an electric fuelpump would be a better option?

[badges65]

HI,
hope you have made provision for heaps of zinc anodes, havent seen a copper one for years usually allybronze pipes and brass or alloy housings!!??
are your exhaust manifolds fresh or salt water cooled??
don

[Hiptrip]

Don...the anodes will be done when I do the wiring of the whole electrical system. Lot of theory reading there so I don't know a huge amount right at this point. At the moment I only have one big anode on the jet.

The manafolds are salt water cooled.The water is picked up through the jet, into a strainer, into the heat exchanger, into the exhaust manifold & the out of the exhaust. Is that not good?

Cheers
Zol

[badges65]

HI,
you must have anodes in all water circulating circuits, the more the better. as to the manifolds unless you flush the system after every use with fresh water you could right them off within 5 years and with a chance of water in the combustion chambers.
i have always used a bypass circuit for the manifolds take off from the front of the head to the back of the manifold then back to the fresh water pump. then injecting the salt water into the exhaust system after the risers.
don

[gonzo]

The water ciculation through the exhaust manifold and then the risers or elbows is standard. There have been many methods with complicated plumbing, but the simple systems work the best. About the electric fuel pump, make sure it is the right delivery pressure, 5-8 psi. Too much pressure will make the carburator overflow. Holleys are notoriously sensitive to fuel delivery pressure.

[Hiptrip]

Don
My manifolds aren not linked with the water camber on the engine heads. They're fully seperated. (Is that what you meant?????). It just flows from the front in & rear out

The heat exchange unit is something I'm gonna keep a close eye on since it is only copper. Though I've managed to suspend it on ruber mount to keep the dissimilar metals seperated. I was thinking about installing one of those "screw in" type anodes for the exchanger. One person said that I might not needed if I have rubber suspended.
Cheers
Zol

[badges65]

Hi Zol,
if that is what they are now that is salt water cooled!!
when you change them to fresh water cooling you take it from a plug in the head to one end of the mainfold then from the other end to the fresh water circulating pump ,, if your risers are in the cooling circuit you will have to modify them also, depends what sort you have!!
don

[gonzo]

Those zincs have to go on the raw or salt water side of the heat exchanger. They are a good idea. Your manifolds and risers are raw water cooled. I'm not sure I get the picture about the water coming out of the back of the manifold. Usually the water enters the end of the manifold and exits through the riser into the exhaust. There are some closed cooling systems that include the exhaust manifold. They require a huge heat exchanger. In salt water risers last three or four years. Most of the corrosion happens when the engine is not running. The hot salt water and oxigen are very corrosive. Flushing the engine with fresh water makes a huge difference. Mercruiser and VolvoPenta offer flushing kits that mix a neutralizing chemical with the water. I suppose there may be some aftermarket systems too.

[Hiptrip]

I was thinking that because I have suspended the heat exchanger on rubber it won't allow it to corrode & act as an anode.

Cheers
Zol

[gonzo]

There is salt water inside of the heat exchanger, that is what the anode protects.