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Aluminum Intakes

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Sooner5151

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I do not use my boat in salt water, and I want to install an Aluminum intake on my 305 chev engine. I know cars use water for coolent mix with antifreeze and aluminum works fine, so how about boats? I am going to pull the Qudrajet carb off and rebuild it, and I thought I would just change out the intake at the same time. Any pro's or con's about this move?
 
The PH balance of river or lake water will definitely shorten the life of an Automotive aluminum intake manifold.
Salt water would be a big NO NO!
The PH balance of Ethylene Glycol and H2O (i.e., a closed cooling system) will allow the auto manifold to work. It won't even know it's in a Marine application unless you tell it.


Also, the Marine cruiser SBC prefers the Dual Plane intake.
Single plane intake manifolds will not perform as well.


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Filp Flop said:
How do you know this ??.

You'd have to test the river or lake to be sure. Your statement is FALSE and unfounded !.




Filp = Friends in low places + Flop. :)
Click to expand...

Rick is absolutely correct.
Coolant pH below 8.3 pH is not acceptable for use in engines due to its corrosive nature. The correct pH value should be maintained between 9.5 - 10.0 pH. Below 9.0 pH it is advisable to flush the cooling system and refill with a new coolant solution.

Most rivers and lakes pH levels are below 7 and are acidic.
 
Sooner5151 said:
I do not use my boat in salt water, and I want to install an Aluminum intake on my 305 chev engine. I know cars use water for coolent mix with antifreeze and aluminum works fine, so how about boats? I am going to pull the Qudrajet carb off and rebuild it, and I thought I would just change out the intake at the same time. Any pro's or con's about this move?
Click to expand...


I have used aluminum intakes on salt water. Especially on Pre-vortec 4.3 ltr engines. Those intakes are just hard to come by. Anyway, what I do is paint the water cross over tube with POR15 paint. A few coats. I have pulled a couple t-stats to check them after a season on the bay and no corrosion was present. The paint does it's job.
 
Thank you, Chris.
BTW, this has more to do with the bi-metal issues between cast iron cylinder heads and the mated aluminum intake manifold.


Filp Flop said:
1... How do you know this ??.

2... You'd have to test the river or lake to be sure.

3... Your statement is FALSE and unfounded !.


4... Filp = Friends in low places + Flop. :)
Click to expand...

1... Years of experience that obviously you lack!

2... No need to. The science fully explains it.

3... Un-true!

4... That makes perfect sense.


Just once, you should try contributing and adding something positive to a thread, rather than your usual.

.
 
Sooner5151 said:
I do not use my boat in salt water, and I want to install an Aluminum intake on my 305 chev engine.
I know cars use water for coolent mix with antifreeze and aluminum works fine, so how about boats?
Click to expand...
Sooner, just to clarify ...... you can use the "dual plane" aluminum intake manifold if you also have a closed cooling system on this engine. This reflects the PH balance mentioned in post #5.


bondo said:
Ahhh, yes, a new Troll, eh,..??
Click to expand...
Bill, this is the same Troll with a new name, and is the same person who disrupts threads on several other boating forums, and has been doing so for years.
He is incapable of offering any useful or helpful information. :mad:


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hystat said:
no problem - lots of aluminum manifolds on RWC boat engines in my area (all inland lakes). They seem to fare as well as any cast iron.
Click to expand...
It's the bi-metal properties that cause the corrosion issues....... fresh river/lake water or not!
The true Marine Aluminum Intake manifolds are bronzed lined in the forward coolant cross-over area, and I believe at the two rear "would-be" cross-over blocked-off areas.

I agree..... these will last for a while.
But if one was to fail, image where the coolant (river/lake water) ends up.
Is it worth the risk?

If you want to use the automotive aluminum intake manifold, what a perfect excuse to install a closed cooling system! :D


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Docksidemarineservices said:
I have used aluminum intakes on salt water. Especially on Pre-vortec 4.3 ltr engines. Those intakes are just hard to come by. Anyway, what I do is paint the water cross over tube with POR15 paint. A few coats. I have pulled a couple t-stats to check them after a season on the bay and no corrosion was present. The paint does it's job.
Click to expand...


I think if Aluminium is used then this is the way to go!! POR15!!

Solves the problem if done correctly..........no need to worry about all the technical/scientific stuff......coat it and forget it....

just do it and have fun..............especially considering it will be used in fresh water only..........by the time any issue arrises the boat will probably have developed a whole host of other issues.......lol


One thing I would reccomend doing above all is to change the exhaust manifolds from the square log type to the current center exit type.

This will help with cooling and make it a lot easier to deal with...much simpler system.
 
are they any lighter than the monsters I pull off. The ones I removed are full of rust and I am now cleaning them up. Boat - Bust out another thousand-and mine project is doing better than that.
 
This is what I would reccomend,

It would require to redo the hose routing and thermostat housing. I would use this system 1988 - 1995

This will bring the cooling and exhaust up to date......also completely elimanate the old rusty stuff you have now, This, if done will make for a fun experience due to no water circulation issues............My 1987 350 I/O still has the original exhaust manifolds, elbows, I have design II with a slighly different thrmo housing which has the two poppet balls.......But still all good (fresh water only since new)


Exhaust manifold and elbow:
http://www.marineengine.com/parts/m...anifold-and-exhaust-elbow-cast-iron-exh-elbow


Hose and thermostst housing design to use: Design III
http://www.marineengine.com/parts/m...0999/standard-cooling-system-design-iii-alpha
 
kghost said:
One thing I would reccomend doing above all is to change the exhaust manifolds from the square log type to the current center exit type.

This will help with cooling and make it a lot easier to deal with... much simpler system.
Click to expand...
I fully agree with Kghost.


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I like the set up. The center exhaust looks easier to take apart clean than the exhaust 90 at the end that put mine up under the back deck and you need a drop light just to see under there.
 
Yes it is a much more efficient set up....

If needed one of us here can supply the water flow diagram needed for which ever system you may need.

Also if there may be a marine salvage yard near by you maybe find some good used stuff suh as the thermo housing and hoses (just make sure it is fresh water use if possible) Marinas may also be willing to sell you some used stuff from repowers they have done if you ask nicely........
 
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