Alternative to marine manifold

badman

Petty Officer 2nd Class
Joined
Dec 29, 2008
Messages
117
Hi.
Badman here with the V4.

Just wondering if anyone has tried an alternative to the marine exhaust wet cooling manifold.

Due to the rusted out state of my existing manifold, plus the slim chance of me finding a replacement (1963 V4), i have an idea!

1: Locate standard auto exhaust pipes for the head from the scrap yard or internet.
M2: ake a new blanking plate to cover over the water jacket channels (where the manifold would connect) but allow the exhaust.
3:Add a radiator with FRESH NON SALTY WATER! to the rig with 2 electrically controlled fans (common these days) on a thermo.

Loads of room in the engine bay for a rad. Might even pop it somewhere else?

Has anyone tried this?
Can anyone see any flaws in this evil plan?
Cheers
matt
 

superpop

Master Chief Petty Officer
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Mar 5, 2006
Messages
869
Re: Alternative to marine manifold

If this was a valid idea it would have been done long ago, the problem with a radiator is that it will not work in a closed environment. That is why most car radiators are at the front of the car with lots of air inlets. Besides you do not want the heat that manifolds will generate in a closed area, you will overheat very fast. The way it was designed is the proper way to do it.
 

Don S

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Messages
62,321
Re: Alternative to marine manifold

Can anyone see any flaws in this evil plan?

Big time flaws.

The biggest reason for marine manifolds is to keep the heat out of an enclosed engine room. In cars and trucks you have wide open spaces under the engine and plenty of airflow thru the cars grill and radiator. Not near what you would have in an enclosed engine compartment.
Those automotive manifolds also get around 1400? and glow red in cars, not something you want in a boat.

Go marine, and stop trying to reinvent the wheel. There re reasons (and most from a safety standpoint) of why things are the way they are.
 

Bondo

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Staff member
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Messages
71,241
Re: Alternative to marine manifold

Ayuh,...

I looked at your pictures,...

Any reasonably competent Welder/ Fabricator can build a Copy of the simplistic design that's on there now...

Matter of Fact,... You otta be Learning to be a Fabricator,...
You're going to have to build Everything to get that tub running again...

Btw,...
Your current line of thinking is Definitely a Bad Idea....
 

badman

Petty Officer 2nd Class
Joined
Dec 29, 2008
Messages
117
Re: Alternative to marine manifold

Hehe.
seems i have had to learn to weld all sorts lately!
Will attempt the manifold then... probably try to fab it out of existing similar diameter tube etc.
Seems the general concensus is the rad is a bad idea.

The local military engineer who services my truck thinks its a good idea. I think he is alone though!
reason being, he bulit a 6x6 truck where the rad was in the back, like a lot of the 4x4 trialers have, so they don't get damaged.

The landrover radiator is so effective it doesn't need wind blowing through it, it just needs to be in the open etc.
They were developed in the desert and are so effective at cooling they have to be covered over 95% in winter (diesel engine rad).
But certainly.. why change a good design eh?
If i can get the maifolds off i will try and Fab em.
Had a go at the bolts today..... Hmmm!
Looks like i'll be heating this lot up with the torch to try and free it.
Thats okay, i have time, the desire to try and make it work, a radio and a flask of tea!
:)
 

Bondo

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71,241
Re: Alternative to marine manifold

Looks like i'll be heating this lot up with the torch to try and free it.

Ayuh,... Get the Nuts Red Hot,+ throw Cold Water on'em....

They come off like you Just screw'em on...

Btw,...
I've got a series IIA with a diesel,+ a series III sitting in my backyard...;)
The Radiator is Still a Bad Idea...
 

Don S

Honorary Moderator Emeritus
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Messages
62,321
Re: Alternative to marine manifold

But certainly.. why change a good design eh?

Who said anything about it being good. There you are in London, England with a 1963 boat, with a motor never heard of here in the states, trying to build parts for it without knowing how or why anything on a boat is even there. And it's hooked up to an OMC outdrive that didn't come out till 1964 and OMC went out of buisness over 10 years ago.

Your best bet if you want to keep that hull, is to pull the engine and drive off the boat. Rebuild the transom and find a Mercriser or Volvo (whatever is easiest to find there in London ) and install it.
What you are getting yourself into is crazy.
 

badman

Petty Officer 2nd Class
Joined
Dec 29, 2008
Messages
117
Re: Alternative to marine manifold

Ayuh,... Get the Nuts Red Hot,+ throw Cold Water on'em....

They come off like you Just screw'em on...

Btw,...
I've got a series IIA with a diesel,+ a series III sitting in my backyard...;)
The Radiator is Still a Bad Idea...

Will do. Not heard the throw water on before. good tip.
A IIA and a III ! what year are they and length?
Whatr state are you in?
I have a Series IIA coming in Jan, a Series III 1984, a Series III military chassis and a 1977 Series III.
The 1977 Series III hybrid (was military leaf sprung, drum braked FFR petrol)
is now coil sprung, chassis stretched, disc braked, Massive tires with BF Goodrich classic Mud tread, Defender grill (to accommodate the TDI), high diff gearing, TDI diesel with three fuel tanks and a custom fuel switching system and custom pure plant oil heating system for power
(takes additional heat from the exhaust manifold as well as a heated fuel filter and a heat exchanger all with temp readouts)
. Cut the mid box out yeasterday (mid muffler) and welded in a straight pipe.
'Much better in 3rd and 4th.
:)
 

mphy98

Lieutenant
Joined
Oct 20, 2008
Messages
1,422
Re: Alternative to marine manifold

If this was a valid idea it would have been done long ago, the problem with a radiator is that it will not work in a closed environment. That is why most car radiators are at the front of the car with lots of air inlets. Besides you do not want the heat that manifolds will generate in a closed area, you will overheat very fast. The way it was designed is the proper way to do it.


i have often wondered this as well, however if you could fabricate a nice looking grill between where the two rear seats are, why would this not have enough airflow? especially when underway? with the electric fans these days you would think someone would come up with a viable radiator. i would be all for it, save on winterizing costs.
 

slasmith1

Lieutenant Junior Grade
Joined
Dec 2, 2008
Messages
1,028
Re: Alternative to marine manifold

see post above and think about the heat of the exhaust in an anclosed space.
 

badman

Petty Officer 2nd Class
Joined
Dec 29, 2008
Messages
117
Re: Alternative to marine manifold

i have often wondered this as well, however if you could fabricate a nice looking grill between where the two rear seats are, why would this not have enough airflow? especially when underway? with the electric fans these days you would think someone would come up with a viable radiator. i would be all for it, save on winterizing costs.

Absolutely. Why not?
Easy solution for the salt water problem of a wet cooling system like mine as it would be filled with fresh water.
Easy solution for lack of available replacement manifold.
I even have spare rads kicking about!
Weld a nice grill over the rad and mount it outside the engine bay.
Might even be a nice heater when the cool wind picks up!
:)
 

Don S

Honorary Moderator Emeritus
Joined
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Messages
62,321
Re: Alternative to marine manifold

Another "listen only to what you want to hear" poster. Facts mean nothing, but if someone that also doesn't have a clue also agrees, that's good enough for you.

I'm actually beginning to believe this is a prank post
 

badman

Petty Officer 2nd Class
Joined
Dec 29, 2008
Messages
117
Re: Alternative to marine manifold

Another "listen only to what you want to hear" poster. Facts mean nothing, but if someone that also doesn't have a clue also agrees, that's good enough for you.

I'm actually beginning to believe this is a prank post

Thanks Don.
All ideas and viewpoints.That's what Forums are for?
My family and i have had quite a few boats in our time and been involved with a lot more. All have had outboards, hence the questions on the inboard.
There's nothing wrong with a good debate about different ways to try custom setups...
I am sure there are many people out there who enjoy a challenge on a restoration or customisation project, rather than just whip out the old and drop in a new replacement.
Sure, to some people that might be the best way to go, but the reasons that would put perhaps yourself and others off this rebuild are the exact reasons that make me want to do it!
These projects are often rewarding when ideas are put into practice.
True, they don't always work, but when they do it's great.
All points made on this forum are valid and i appreciate them all.
Badman
 
D

DJ

Guest
Re: Alternative to marine manifold

Forget the radiator. You have an UNLIMITED amount of cooling water available. It's called the SEA. Use it. If you want a closed cooling system, that's another story.

Fabricating manifolds would be time consuming but very doable.

The easiest way would be to locate new "dry" manifolds and fabricate water jackets around them. Your risers would have to be 100% custom, I'm sure.

You're getting a lot of negative comments regarding the resurrection of that boat. While I somewhat agree, if you did get it going, you would have something VERY unique. If that is what trips your trigger, go for it.
 

abj87

Petty Officer 1st Class
Joined
Aug 4, 2008
Messages
354
Re: Alternative to marine manifold

You could use air cooled manifolds with dry exhaust. A few trawlers use this system. It uses a standard stainless steel exhaust with an larger tube over it which air is forced through to to keep the outer layer cool.

Also fiberglass wrapped exhaust will go a long way as well.
 

badman

Petty Officer 2nd Class
Joined
Dec 29, 2008
Messages
117
Re: Alternative to marine manifold

Ayuh,...

I looked at your pictures,...

Any reasonably competent Welder/ Fabricator can build a Copy of the simplistic design that's on there now...

Matter of Fact,... You otta be Learning to be a Fabricator,...
You're going to have to build Everything to get that tub running again...

Btw,...
Your current line of thinking is Definitely a Bad Idea....

Here are the pics of the replacement marine manifolds i have made to match the old ones.
Next stage to box the end to take fumes to the omc fume out port and cap the ends closest to the camera.
wasn't too hard. Taken about a day so far.
:)
 

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