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'82 Mercruiser 228 cooling system

L

LX Kid

Regular Contributor
Hello to all. This is my first posting. I have a '82 Grady White with the 228 / V8 and have a question about the exhaust manifold gaskets. My engine cooling was, converted sometime before I owned it, to fresh water and they discarded the heat exchanger. I'm putting new elbows on and was wondering if I used the correct gasket. It had the free flow gasket, without spacer, and I will put put on the recommended restricted flow gasket. Is this something I need to do or go with the free flow gasket? (No spacer)

Old pics!

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1) Removing the heat exchanger converts an engine to what is usually called "raw water cooled". The term "fresh water cooled", normally applied to engines WITH heat exchangers, is somewhat of a misnomer since engines with heat exchangers are normally filled with antifreeze/water mixture, hardly fresh water.

2) If you remove the heat exchanger and run in salt water you need to change the thermostat to one in the 140 degree range.

3) Given that the previous owner is apparently a fan of hack repairs, I am concerned that the very new looking carb shown on the engine in another of your pictures, is not a marine carb. If its the "automotive version", it is not only illegal on your boat but a safety hazard.

4) Very often, when heat exchangers fail ( I assume the original one failed, else why remove it???) there is collateral damage to the engine. Check engine compression as a first check.
 
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I've been running a gutted thermostat in it. Here in Florida we don't have real cold water or outside temps. Yes I realize the thermo regulates the engine temp to a constant temp but has worked out fine for me. She runs about 170 degrees average. The carb is a Marine carb, I put on years ago, and got rid of that lousy Carter/Quadrajet or what ever that junk was and solved so many of my running problems.

Here's a link to Edelbrock Marine carb specs: http://www.edelbrock.com/automotive/mc/carburetors/marine.shtml

Here is a link to where I bought the boat in 2008 and have been restoring it. Carb and many other issues are there also. Long post.

http://forums.iboats.com/forum/boat...pair/282796-1982-gw-24-project-updated-w-pics
 
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If you have been running with no t'stat in sea water @170 degrees, you have two problems.
1) Insufficient cooling performance, running @ 120 is more what I would expect.
2) Running @ 170 in sea water in a raw water cooled engine is problematic. At temps much over 140 degrees, the minerals in sea water start to drop out of the water and deposits form. That's why raw water cooled engines run t'stats in the 130 to 140 degree range. My "fresh water" cooled 260HP 5.7 runs @ 170.
 
sandkicker said:
If you have been running with no t'stat in sea water @170 degrees, you have two problems.
1) Insufficient cooling performance, running @ 120 is more what I would expect.
2) Running @ 170 in sea water in a raw water cooled engine is problematic. At temps much over 140 degrees, the minerals in sea water start to drop out of the water and deposits form. That's why raw water cooled engines run t'stats in the 130 to 140 degree range. My "fresh water" cooled 260HP 5.7 runs @ 170.
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I think I'll put a thermostat back in maybe say "140 degree!" The two that I researched 18-3550 & 18-3551 don't say weather they will hold up in raw sea water. Do you happen to know? If not I call Monday and see what the sellers tell me. If not special material they will rust away pretty fast. Thanks for that tip.

My Grady has sat around for 3 years and only recently have felt guilty about letting her go this long that I have a renewed interest in getting her back in the water. I've already corrected a lot of electrical problems in the last 10 days and have put a new impeller and housing in the lower.
 
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Some background on my cooling problem three years ago she was running hot. Put new impeller and housing on and still no change. Removed elbows, on top of exhaust manifold, and they were badly fouled with corrosion. Bought new ones, install and still ran hot. Sooooo I let it sit for three years! Last week I got involved in cooling problem and pulled starboard exhaust manifold and found the elbow on the bottom completely closed. I pulled all the screwed in plugs and used spring steel wire on dill to open up all the passages and am satisfied they are letting water flow properly. This is why I'm wondering if I should use the full flow gaskets versus the restricter gaskets between manifold and elbow. I do not have a spacer between the two and is just manifold to elbow.
 
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I will preface this by saying I'm being a jerk here. I've watched this thread on two forums....

whatever you you do, do not put the right thermostat housing on it. That and the right temperature thermostat have nothing to do with cooling performance...
 
Dieter said:
I will preface this by saying I'm being a jerk here. I've watched this thread on two forums....
whatever you you do, do not put the right thermostat housing on it. That and the right temperature thermostat have nothing to do with cooling performance...
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???? Explain please! My problem was due to blockages in the cooling system restrictions in the elbows and exhaust on the starboard side. I had a similar problem some time ago with restrictions on the port side elbow. The thermostat will open, and stay open, at it's designated temp unless temp drops below it's design. They are mostly for cold engine starts and raising the engine to it's optimal operating temp for performance and fuel economy.

The lower thermostat housing, in my engines instance, routes water up from the block and when thermo opens and lets water up thru the thermo's bottom and on out the top to the two hoses going to each of the exhaust manifolds.
 
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1. Re read iboats forum thread you posted and Bondo references above. I belive he outlines why the looped hoses are strange, I assume these were supply and return to manifolds in previous closed cooling.

2. http://www.marineengine.com/parts/m...6218462-thru-0b525981/standard-cooling-system

was as guessing your year and serial off info provided, but look at the parts diagram shown and note the differences vs your current set up. There is a t up front that supplies cold raw water to the risers at all times to cool the exhaust. This is plugged on yours.

If if you put a thermostat in you will have no water going to your exhaust until the thermostat gets hot and opens. Depending on incoming water temp the thermostat will regulate the flow of water into and out if the engine to keep it at the correct temp.
If you keep the current non standard set up and install a thermostat you will most likely smoke your exhaust rubber couplers, flappers bellows etc.

3. Sand kicker is dead right with no thermostat to restrict the flow the engine should be running real cold, so there is something else wrong here. Hence the recommendation to get back to the factory set up, but it's your call. Also given your mentioned manifold blockage have you looked what's in the block/ engine circ pump ? is it fouled with sediment

if you have the separate t feeding the risers the restrictor gasket is correct. I belive full open ones are for cold manifolds constantly fed with cool raw water.
 
"Now" I see your point about the thermostat! Good point about exhaust rubber couplers. Won't put the thermostat in so I'll have water upon starting. I removed the circulating pump couple days ago and it just fine. No sand & no restrictions. New elbows, no 3" risers, and both exhaust manifolds are clear and have a gutted thermostat. With this new info provided it would seem that I would need free flow gasket, which would normally be between the riser and elbow, so I would get plenty of water passing thru the exhaust manifold.

Restricter:
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Free Flow:
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I'm guessing this is the thermo housing that contributors would like to see me get. In "MY" application where would the right side hose fitting go to? I know the cir pump and two discharge hoses but don't know where the right side discharge would hook up. (Block it off??)

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The point I'm trying to make is if you are running 170 with no thermostat something is wrong here with the amount of water flowing into and out of the engine. I would suggest you verify

water supply to the engine. Remove supply hose at thermostat and check the volume coming up here. if this is inadequate check impeller in outdrive and for debris like pieces of old impeller or blockages in the hosing up to thermostat.

Compare the water routing in link to what you have going on with the center rise conversion-

https://www.google.com/search?q=mer...UICCgC&biw=1024&bih=672#imgrc=-KuFWTgz0qmWaM:

If you google center riser conversion there are some others with the exact issue as you- using the log thermostat housing with center risers and getting high ish temps.

Again if there is adequate water flow, no blockages in the engine, then I would recommend putting th correct thermostat set up on.
 
Just seeing the second post now. You can use that thermostat housing for cold manifolds or the one in the parts link I sent last night to feed the risers separate and have warm manifolds which are supposed to burn off condensed moisture in the manifolds better.


The right side would be the raw water supply from the outdrive / power steering cooler I belive same as on your current set up
 
Here is an (old) better pic of my hose routing. The outdrive hose comes in starboard side thru the power steering cooler and then to the bottom of the thermo housing. I could get longer hose and route back over the top of the housing and hope I don't get a kink in the hose cutting off flow from outdrive. Or maybe a "U" turn sweep coming out of housing.

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Yes, Jack is pointing you the correct way, same parts diagram as linked in earlier post.

Since you mention the cooling water supply is on the other side currently I would use hard wall hose like currently looped on your housing to get over the power steering cooler which is on the 'wrong' side of your engine.

Also ensure you have the correct water flow to the thermostat housing...

I cant throw a GPM but I think you can search threads or google the right water flow rate from your impeller.
 
I just found this 2013 post over on iBoats and the moderator "achris" indicates this is the way to plumb the cooling system for my application and using a full flow gasket and using the same thermo housing. This is the way mine is plumbed. I will probably keep the gutted thermostat and not use restrictive thermo.

Here's a link to the posting: http://forums.iboats.com/forum/engi...er-exhaust-log-to-center-riser-question/page2
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yes I saw that one too, but what I didn't see is the OP writing and saying it worked. Jack above writes how his set up with newer style thermostat is flawless, ultimately its up to you.
 
My gaskets came in the mail today so I installed the gaskets and elbows. Hooked the water to the foot and she started right up. I let it run for about 30 minutes and temp stayed right around 100 degrees. That being said there is now something clogging up the port exhaust manifold even though it passes some water. Putting my hand on the starboard manifold the elbow it is warm to the touch but dare not put my hand on the port side. It's "HOT!" It's passing some water but not like it should. Gonna have to get the sucker off and see if I can clear it as I did the starboard side. Problem is the bolt heads are rounded and hope the special Craftsman sockets will remove them after buying them. If I can't clear it, once getting it off, I'll have to buy a new one. Old boats just want to bleed you to death to keep them OEM correct.
 
Dieter said:
yes I saw that one too, but what I didn't see is the OP writing and saying it worked. Jack above writes how his set up with newer style thermostat is flawless, ultimately its up to you.
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Yes but what I'm saying is that mine has run cool for years until my manifolds and elbows started clogging up due to raw sea water. I could put a couple thousand bucks into this old boat to go back with the OEM cooling system but it's just not worth it. I'll keep nickel and dimeing it until it's ready to go to the bone yard or someone else wants it more than I do. It's always run good until the manifolds and elbows, that came with it when I bought it eight years ago, started corroding up. That and putting the new Edelbrock carb on.
 
Just spent 3 hours taking three bolts out of the port manifold. One good bolt and two buggered up bolts. I'm having a very difficult time with the fourth buggered bolt. It's 3rd bolt from the front and not very accessible. Seems it's rusted to the manifold but is loose in the heads threads. No way one of those special sockets will get a bite on it. Hate to think about using the cutting torch in that area but may have to.

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What might work us to take a grinder / cutoff and grind off head of the stuck bolt. U should be able to slide the manifold off it as though it were a stud. With the stud in the head you can apply some WD, PB blaster etc over a few days, heat it at the head and use a pipe wrench on what's left of the bolt.

On on the thousands $ , the thermostat housing is on this website(Sierra 18-1994) for $153 incl the t to feed the risers, 1" ID heater hose at Napa is $3/ft.
 
Dieter said:
What might work us to take a grinder / cutoff and grind off head of the stuck bolt. U should be able to slide the manifold off it as though it were a stud. With the stud in the head you can apply some WD, PB blaster etc over a few days, heat it at the head and use a pipe wrench on what's left of the bolt.

On on the thousands $ , the thermostat housing is on this website(Sierra 18-1994) for $153 incl the t to feed the risers, 1" ID heater hose at Napa is $3/ft.
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The bolt is loose in the head but the bolt head is rusted to the manifold. Gonna take some PB Blaster Spray and let sit awhile then use vice grips, which have been slipping off, and see if I can break it loose. Carbide grinder bit otherwise to see if I can make flats that the vice grips will hold.

I was just talking metaphorically about $2k to put everything back OEM. I've got $18K wrapped up in this old girl over the last 8 years and she's probably only worth about $7500. Just trying to keep her running without putting a lot of bucks into her.

Here's a little video from 2011 with my son at the helm and grand daughter enjoying the sea spray!

https://www.youtube.com/watch?v=zw77HOpkJzg

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Finally got the last bolt out of the port exhaust manifold. And it only took "5 hours" for one lousy bolt! As you can see from the pics, the manifold was plugged up pretty good. Only one little hole was letting a trickle of water thru the hose elbow and into the manifold. Been about an hour unclogging it. Show a pic when I get it done and passing acceptable water through it. If I still have the Grady next spring I'll go ahead and put new manifolds on. It looks like it's carbon fouled from the exhaust rather than corrosion. I'm going to test the exhaust flange, where elbow joins, to make sure it's not warped. If it is I'll grind it level so the gasket won't leak.

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This is a pic where I was half way done. Seems to be working out alright. While I have the manifold off I'll install a oil filter relocation kit, replace spark plugs and change the oil. No, I'm not going to stick the same old bolts back in! LoL

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Based on the scale that exist in those manifolds I would not wait until next spring to replace. EVen with all the effort to clean them.

If additional scale falls off and reclogs the water passages you will be right back at square one.



WHat does it cost for peace of mind and not needing TOW US............
 
kghost said:
Based on the scale that exist in those manifolds I would not wait until next spring to replace. EVen with all the effort to clean them. If additional scale falls off and reclogs the water passages you will be right back at square one. WHat does it cost for peace of mind and not needing TOW US............
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As little as my boat is used your scenario is not likely. (Famous last words!) Ha
 
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