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Quick survey - Lancer 23 outdrives cooling

December 16 2017 at 8:38 AM
Pierre  (Login cayuco)

Greetings all,
I am interested in knowing if there are any Lancer 23s (or 19s) with outdrives AND closed cooling. I've searched through the literature and I don't see CC having offered a closed cooling option for outdrives.

Thanks for the feedback and happy holidays!

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(no login)

I don't know the answer to your question, but it should not be difficult to install

December 18 2017, 3:41 PM 

It's a pretty basic flow diagram for the specific motor you may be dealing with. I would just run the water through a heat exchanger and then dump the cooling water out the tailpipes whether they are the above-the-waterlike tips or whether it is into the outdrive system itself. The latter may take a special dril and tap but that should be no big deal.

If you are going to do this send us a diagram if you want some help and we'll comment accordingly.


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(Login HenryRI)

Closed cooling

December 26 2017, 12:49 PM 

Paul and Pierre:

for some reason Network54 forgot me so I am now in under a new name.

I already posted a while ago about my 1968 Lancer w/IO repower project and intend to use closed cooling for the engine. I have gotten a lot of conflicting information/advice about the possible perils of doing a full closed cooling system and at this time am inclined to go block only.
I see a number of different vendors who make after market closed cooling kits and wondering if anyone has any opinions on sources good, bad or indifferent.

One thing I know for sure is I will be using a crank driven raw water pump and pulling raw water thru a hull fitting, not the Volvo I/O unit so I am sure I am moving enough water.
Since P/O had already installed two 3" exhaust outlets thru the transom I will be using them for exhaust, not the i/o unit. I do need to find or fabricate a plate to block the exhaust opening in the transom shield.

My previous thread ended with me fighting with the old PDS unit and retaining ring and fortunately I have been able to find a brand new replacement, that has quite the adventure.

Currently too cold for any serious work here in RI but will post more updates soon.

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(Premier Login FEfinaticP)

No point in running salt through a hot exhaust manifold

December 27 2017, 10:06 AM 

I would absolutely run the antifreeze through the exhaust manifolds too. If those fail they can take out the motor. There is plenty of cooling available to handle the heat.


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(Login HenryRI)

Full vs block only

December 27 2017, 4:59 PM 


Indeed a failure can take out the engine

What I have been cautioned about is that it is easy for the barrier between the exhaust manifold and the risers to leak and contaminate the closed system coolant with salt water. My first inclination was to go with a full system but have now heard from several sources that the difference in operating temp between coolant in the closed system and the raw water cooling water as it exits via the riser system means SS block off gasket may fail and you don't realize it happens until you disassemble the system at the end of the season.

I have looked at the so called dry joint exhaust systems that Mercury developed as an alternative but could replace the whole exhaust system at least once for the increase in cost over a generic system with a block off gasket.

Any opinions on best sources for a closed system either full or partial much appreciated. BTW I am taking your advice and going with a Davis Unified Ignition system.


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(Login cayuco)

Agree, not so simple

December 27 2017, 7:17 PM 

Henry, I'm glad you chimed in to this topic. It has been on my list for some time and I am still not comfortable as to the best approach.
I have studied the cooling diagrams and I see substantial differences between the closed cooling (CC) and raw water (RW) systems.


For starts, the thermostats are on opposite sides of the engine. In the RW system: water comes in, splits into the feed to the PRVs on the risers and the rest is immediately redirected to the logs by the recirculating pump and after the logs goes into the block.

By contrast, the CC system takes water in, goes to PRVs, to the heat exchanger, the thermostat, the engine block, and finally to the logs at the end of the cycle. Not an insignificant difference between the two systems.

So if one adds a heat exchanger, where should it go? before the cycle as in the CC system? After the cycle as in RW? Does it matter? Should the thermostat be relocated front to back? Can a Chris Craft Closed Cooling thermostat housing be sourced at reasonable cost?
The Chris Craft heat exchanger has one port in and six out. I have not seen an aftermarket heat exchanger with that configuration, if one where to try to replicate the Chris Craft closed cooling.

I have spoken with suppliers of "cooling kits" and got very tentative "wishy-washy" responses. My mechanic who is good at marine engines does not want to get into the subject. So given the expense and possibility to mess things up I am a bit cautious, reason why I started this thread to find out if there are ANY outdrives with closed cooling out there.

Given the lack of positive response, I conclude there are NO outdrives with closed cooling. Chris Craft does not seem to have offered the option for outdrives...

...And this bears some reason. What the inboard people on this forum may not realize is that a Q engine sits extremely close to the transom. The outdrive's steering tiller swings in between the risers and there would be NO room for the thermostat housing, associated plumbing, and never mind a heat exchanger, between the risers, the tiller and the transom as Chris Craft has it in their own Closed Cooling system. The picture below of my engine shows how tight things are.

Chris Craft possibly did not want to have yet another cooling system for the Q with outdrive configuration, so outdrive boats were produced with the standard Q raw water system only. My theory, I would love to be proved wrong.

Henry, if you want to email me ( pitjean1"at" ) we can share other ideas on this.. Thanks.


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Eddie G
(Login Gio0052)

Re: Full vs block only

January 2 2018, 8:34 PM 

A half system is much better, when running a full closed system you have more chances of a leak because on a closed system your risers are at a different temperature then the manifolds 50/50 chance it might leak, a half system the manifold and risers keep the same temp, so the chances of a leak is almost impossible, you still have to connect your hose to flush than go with a half system, i've had both and in my opinion a half system is better, but some might think the full is better, i just go with what i've experienced and also my friends that work at boat yards and marinas say

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(no login)

Interesting hands-on experience

January 5 2018, 10:46 AM 

Hi Eddie,

I certainly stand to learn more every day, and hope to do so. My comments are based around the standard Chris-Craft motor and manifolds, but I have recent experience with the more modern systems too. The NOS out of production aluminum Glenwood system I found in California was adapted to pre-heat water for the motor and I worked out the entire circulation system to do what I wanted it to do. It basically keeps the 327F flow system but with the updraft center discharge exhaust manifolds. I used a stainless steel block-off plate, and can't imagine how that would ever fail. I think the aluminum setup will need me to check the tightness of the long bolts from time to time, but it runs pretty cool (and fast).

Since I don't run in salt water I have no experience with it. My predisposition is to avoid salt in any hot metal because the corrosiion factor is increased, and to go with a stainless steel riser or final dump so you are not eating up cast iron (or aluminum). CC originally started with aluminum exhaust manifolds and I have a set of original 283 manifolds from 1959. Those would be long gone if they ever saw salt water. I guess it all depends on what type of exhaust system you have, what kind of metal is being used, cast iron or aluminum, or perhaps stainless steel, and how it is plumbed.


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