Inline six closed cooling system

[seasaw63]

Hi I am looking for information on how to convert my Chevy inline six cylinder Mercruiser to 1/2 closed cooling system. The engine is rebuilt and has not ben run yet (no rust in the block). I saw a post from Bondo to Freebee Tony on April 30th 2009 but can't find the information in iboats.Thanks in advance for any help

 

[Scott Danforth]

Buy a heat exchanger kit with all the brackets, plumbing, etc

 

[Scott Danforth]

However unless you are boating in salt water, its not needed

 

[seasaw63]

Hi Scott Danforth thanks for the reply. I am going to purchase a new system from Sea Kamp. I had them email me the instructions and didn't like the set up. I would like to see how freebee Tony did it from a 470 set up. I would only use new parts. I have a local merc dealer with in 5 miles and the best boat bone yard with in 3 miles

 

[Bondo]

Ayuh,..... Welcome Aboard,..... I remember that conversation with Tony,.......

So,....... What's yer question,..??

 

[seasaw63]

Hi Bondo I am trying to see the post where freebee Tony did the something I am trying to do. I would like to go mercruiser. The sea Kamp exchanger only 3".

 

[Bondo]

Ayuh,..... That may, or may not be possible, with the various software updates that have happened since then,.....

FreebeTony might have a link, but I haven't seen Tony in awhile,......

As for doin' a search, I suggest ya ask GA boater, as my fellow mod is much more tech savvy than myself,....

What was Tony doin', that you wanta reread,..??

 

[Scott Danforth]

mercruiser purchased their HX's at the time from Monitor products for the 470, and then the upgraded HX's from Champ Products (Now alfa laval).

however, the first question. are you planning to boat in salt water, yes, or no.

if no, there is no need for a HX. the motor and exhaust will last well over 50 years

if yes, I recommend a full system.

just an FYI, if you are buying thru a Mercruiser dealer, it will cost you well over $5k for the HX, the T-stat housing, the hoses and all the brackets, etc. the HX is about $3200 alone thru the Mercruiser parts channels for something that my price is under $700, and Mercruiser paid less then $500.

Not to mention, most of the brackets for the 250 cubic inch in-line motor are NLA

so back to my question. where do you boat?

 

[seasaw63]

Hi Bondo I wanted to see how Tony converted his inline 6 to a closed fresh water system. I have an inline six that I restored 20 years ago and its time for a new motor ( milky white oil and low compression in 1 and 2 cylinders) I bought a new reman engine and I want a closed fresh water system. This will be the last motor I buy in my life time. any help would be appreciated. I'll try to contact GA boater. I'll keep everybody posted. Scott Danforth thanks for your replies. I would probably go new aftermarket if the 470 option is going to work. Im from the Northeast (not cheap frugal))

 

[seasaw63]

Oh Scott, I am out of Dorchester Yacht club Ma. 5 minutes from Boston harbor

 

[GA_Boater]

Why contact me? Contact Tony, he did it and I wasn't around in 2009.

Find a post by Tony, click his name and look at his started posts.

 

[achris]

Hi Bondo I wanted to see how Tony converted his inline 6 to a closed fresh water system....

https://forums.iboats.com/forum/engi...mercruiser-il6

You also need to look at putting an exhaust manifold water reversing kit on... If you don't you run the risk of cracking the manifold, and allowing seawater to enter the engine...

Chris......

 

[GA_Boater]

Chris - That is one of about a dozen FWC cooling threads Tony started. Also I'm not sure it worked out well for him. seesaw should PM Tony or FreeBeeTony

 

[Scott Danforth]

. Scott Danforth thanks for your replies. I would probably go new aftermarket if the 470 option is going to work. Im from the Northeast (not cheap frugal))

the HX used on the 470 will be marginal on the Inline 6. and if you go full system (recommended), then its undersized in two areas. first, in its heat rejection capacity. next, in its expansion volume capacity.

if your going to run a 4" HX on the inline 6, start with a 24" bundle and about a 4-pass unit. however I would be looking at a 5" bundle by about 16" in length in either a 4-pass or a 5-pass. I would also run a separate de-aeration / expansion tank.

 

[seasaw63]

Thanks GA boater for the link I have PM ed Tony. I clicked on his name and the archives only go back to July 2018.

Hey Scott do know a good source for the 5"x 16 HX. I don't know what you mean buy 4 pass or 5 pass and a dearation/expansion tank

Achris thanks for the tip on the manifold TSB I did do that when I originally built the engine

 

[GA_Boater]

Credit where credit is due - achris posted the link, not me.

Secondly, our archives go back to the very first post. Any search provides up to 200 results and you can use Descending or Ascending sort order, Ascending sorts from the earliest date. Advanced search allows for date range selection.

I looked at every thread started by Tony, but I couldn't find any "Here's how I did it" threads. It took him about 5 years to get it sorted out going by thread dates with mainly questions. That's why I didn't link any threads, I found nothing definitive.

 

[Scott Danforth]

Hey Scott do know a good source for the 5"x 16 HX. I don't know what you mean buy 4 pass or 5 pass and a dearation/expansion tank

I know plenty of good sources.

Alfa Laval - Champ (formerly Champ Products)
Monitor Products
Sen-dure
SeaKamp
San-Juan Engineering (SJE) / Orca (they merged in 2017)

the number of passes is how many times the raw water turns around in the ends of the heat exhanger

then there is the diameter and spacing of the bundle tubes as well as number of baffles and how much each baffle is cut. (that information is proprietary per each manufacturer).

each engine cooling system needs a fill system and a de-aeration system on it as well as an expansion tank.

as you fill a cooling system, you get air bubbles. those air bubbles must be allowed to travel up-hill to the de-aeration tank.

thermal expansion of coolant is about 6% of the coolant system total volume.
technically you need to allow for 10%, to allow draw-down without creating air pockets

however instead of re-inventing the wheel and designing brackets and plumbing, you could just buy a SJE/Orca 300076 system for the 165 hp 250 cubic inch mercruiser. http://catalog.orcamarine.com/item/...onventional-marine-cooling-system-kits/300076

 

[seasaw63]

Thanks for looking for me GA boater

Thanks for the info Scott I emailed orca marine