Oil cooler on FW instead of raw water side of the cooling system

I've been on a navy minesweeper that uses the same arrangement. I don't know the particulars, but they were running four engines into two prop shafts. Not fast, but very versatile. As the chief petty officer told my kid, "nobody wants to follow us where we go".

nomadwilly wrote:

Marin,
I would run your boat 10 knots IF fuel cost was not an issue. I think fuel costs are driving this under loading issue.

Click to expand...

Nope.* To get 10 knots out of our boat you have to run the engines at WOT.* I''ve tried it, and that's what you have to do.* Do that with an FL120 and you're going to make your local diesel shop very, very happy and they'll all be able to go out and buy classic Porsche Speedsters.

*

sloboat wrote:

Pushin' that bow wave. I think the older Grand Banks semi-displacement hulls are closer to their displacement kin than to the planing genre. Not much lift occuring at slower speeds plus a lot of wetted keel surface creating drag.

Click to expand...

Very true.* Actually I don't think the* shape of the GB hulls has changed at all until the introduction of the GB44 and now the GB41.* I see the newer charter GBs (mostly 1990s and early 2000 boats) in the yard in our marina all the time and the wetted portion of their hulls look exactly the same as ours.* In fact the molds for the GB36 and GB42 were only changed once in the almost 30-year history of the fibreglass boats.* They were changed in 1988 or thereabouts when both models got a wee bit longer, a wee bit wider, and noticeably taller.* In ours,*made during*the first year of fiberglass, my head touches the headliner in the aft cabin and I'm 6' 3."* In the 1991 GB36 we chartered, I had a few inches of headroom over my head in the aft cabin.

A GB with big engines can be pushed along at a reasonable clip, however. I recall the ads for the GB42 in the late 90s, early 2000s.* They had a fuel burn to speed chart in the ad, and if I recall the numbers correctly, with the stock Cat engines which I think were some 375 hp, the boat would cruise at about 9 knots with a fuel consumption of about*7 or 8*gph.* BUt it could also cruise at about 14 knots with a fuel consumption of about 23 gph.* So perhaps double the speed for three times the amount of fuel.

Based on our own boat, the*"standard"*GB hull can exceed hull speed by a relativley small amount--- a knot maybe--- without a big increase in fuel burn.* But push them up to 12 to 15 knots if you have engines powerful enough to do this and the fuel burn goes way up.

1600 rpm gives us a cruise speed just a bit above the theoretical hull speed (based on the LWL*formula).* At WOT (2500 rpm) the boat does almost ten knots.* But as you say, it's pushing a lot of water around and is VERY inefficient.

*


-- Edited by Marin on Monday 11th of May 2009 06:47:31 PM

For folks that need a replacement for the old Ford tractor engines , the closest you can come today is the International DT 360 or DT 466.

They have a good power output and don't die from the TT light loading as Skool busses and delivery trucks MUST do frequently.

These are superbly built (the guts I have seen are better than Cat or Cummins) and wonder of wonders there CHEAP!!!


At least there cheap at the truck wrecking yard , although to get a low time NON ELECTRONIC unit is getting harder to find. Were talking $3000 here for a good low time running engine.

Dry stack, keel cooler and a Twin Disc rebuilt would get another 10,000 hr engine in the Hell Hole at minimum cost.

Fully rebuildable the kit is about $750, 3 or 4 times a year on sale , otherwise $900 or so.

Today insulation is good enough that it is a simple exhaust manifold* option. (but not THAT! cheap for the good stuff, custom fitted )

Marine Exhaust of Alabama may have Ser50 or DT 360/466 wet manifolds , but insulation is good at keeping both the noise and heat in .

Since water would only be injected after the riser , common plumbing fittings could be used , or a "Universal" style , with sufficient diameter.

Either a std COTS belted water pump could be fitted , as most truck and industrial engines have air cond , you could mount the water pump where the air cond compressor was or a set of high quality Obendorfer not Jabsco DC water pumps could be used. The quantity and volume of sea water is not high , easily one skinny V belt.

Dry stack is a horror to contemplate on a built boat , BUT??? a good look would be required before ruling out the best exhaust method ,super KISS!.





-- Edited by FF on Tuesday 12th of May 2009 12:10:43 PM

Yea, Iv'e often thought of a one off marinization since there are so many great engines out there. Marinization of an engine is a piece of cake after you get past the exhaust manifold and the marine gear/bell housing adapter. I had a Sabre 120 (a British marinazation of the same British Ford engine the Lehman guys used for their 120) and I'm 99% sure it had a welded exhaust manifold** ..* I think it was stainless steel too. Can someone confirm that? Welding a manifold would be a project but I think it could be done. I would start w 2" (approx) exhaust stacks welded to flanges that fit the stud holes on the engine (a scrap cyl head would be handy). Purchase prefab 90 degree elbows and weld in place. Cut the inside box wall out of 2 pices (top and bottom) w half circle notches to fit over the port stacks. Weld, fabricate and assemble the rest of the box and water and exhaust ports. One may need to heat it and burry it in sand to normalize it, stabilize it or whatever it may require. Then the extra thick stack flanges should be milled all straight and flat. Now, I'm ready to be blown out of the water by someone that actually knows what he's talking about. Another very important part of the project would be to pre-engineer the installation to fit the boat. One of the engines I was considering for my Willard would have required cutting away a large chunk of engine bed/stringer to accomodate the starter motor in a fixed position on the flywheel housing. Thats interesting FF about the International Harvester. You mentioned wrecking yard. Is IH still in business ?

Eric Henning

nomadwilly wrote:

*I think it was stainless steel too. Can someone confirm that? Welding a manifold would be a project but I think it could be done.

Click to expand...

It probably was SS, 304 and 321 works well for a dry exhaust. Personally, I would not bother trying to fabricate a water cooled manifold but would design it to be insulated*then shielded externally. Beyond the manifold itself*I would use external insulation blankets to the point where the riser joins the spray ring.

You can use PVC tubing to mock up the system and if you aren't interested in TIG welding it yourself, take the mockup to a welding shop.

*

Rick,

*** The Sabre was wet

Eric

Eric,

My Ford Sabre 80HP has a fresh water cooled stainless manifold, looks like the original one and is still in good shape. Water cooled manifolds get fabricated locally here in Thailand all the time - marinised second hand truck and bus engines are the norm for local vessels. My regular machine shop even makes nice ones that incorporate the heat exchanger tube stack as well for the Isuzu four and six cylinder engines.

Cheers, Leon.

Sloboat---

This may not tell you all that much as it's a fairly crude illustration*but it's a page out of the Ford Lehman 120 parts manual.* It would appear that there are coolant passages in the sides of the manifold as opposed to coolant tubes running though the manifold.

I know in the case of the FL120 it's critical that the manifold coolant passages be completely full.* There is a petcock at the forward end to bleed air out (it's at the highest point on the manifold assuming*the typical*slanted-aft mounting attitude in a boat).* You never bleed the manifold with the engine running but with it off and cold.* When the header tank on the front of the engine has the proper amount of coolant in it, the level is higher than the front end of the manifold, so opening the petcock will bleed any air that has gotten trapped at the front end of the manifold.* You simply open the petcock a bit until coolant appears.* If the coolant level in the header tank*drops too low and allows an air pocket to form in the front of the manifold, the heat of the exhaust from the forward cylinder(s) can burn through the manifold.

This is not something that has to be checked before every engine start.* The petcock is ued primarily for bleeding the system when the engine coolant is changed.* The coolant level in the header tank, however, should be checked prior to each day's startup.



-- Edited by Marin on Thursday 14th of May 2009 09:38:58 PM

I've always wondered why the exhaust manifold has to be cooled at all. I've assumed that it's simply to prevent having an extremely hot component in the engine room. But what about dry-stack engines? Are their manifolds liquid cooled as well?

Sloboat,
1st question* .. yes. On most manifolds these days the heat exchanger w many small (3/16 approx) tubes inside resides inside the top of the exhaust manifold. Ive never seen inside of the box but I'm sure it is and looks like set of hot rod headers. So you have the flues (tubes) of the heat exchanger above and the welded (tubes) of the fabricated exhaust pipes in the lower part of the box that surrounds the lot. Marins manifold isn't tall enough to carry the heat exchanger within so his heat exchanger is separate (on the top of the front of the engine)from the manifold. Mine is on the aft engine room bulkhead.
I've seen the "spray rings" that Rick mentioned and believe that to be an element of the most sophisticated exhaust elbows. Most are just a simple iron casting w sea* water entering through a right angle deflector (cast in) on the periphery of the outboard part of the upper bend in the "riser" part of the exhaust just aft of the manifold. The design uses gravity and the velocity of the exhaust gases to keep the sea water out of the manifold and engine. Some boats sink because this elbow is not high enough. For example if rain water were to enter the cockpit and find it's way to the bilge and then the engine room and get high enough so sea water can enter the exhaust port at the stern, run the length of exhaust pipe and up through the exhaust elbow one will have sea water in the exhaust header. Much worse the sea water finds an open exhaust valve and it's quite likely to almost certain to certain (depending on how many cylinders and other things) that the sea water will find an exhaust valve open as well and enter the intake manifold and then the engine room and sink the boat, all because a little float switch stops switching. My how little things can cause big problems.
My curiosity about such things is high also (wer'e like kids no?) and the part of perceiving the marine exhaust system that I can't understand is how they cast in the exhaust pipes inside the water jackets w wooden plugs.
Actually Marin I think it's important the whole cooling system be full of coolant. Mechanics have told me to add coolant very slowly to prevent air pockets from forming. I remember my old Sabre manual said the Sabre engine was especially designed to be able to be filled from dry without air pockets. Since it was the same Ford engine as yours your engine may have that same feature. I think the biggest problem in this regard is the thermostat. On most or all engines there is a small bypass port such that even when the engine is cold some coolant circulates normally throughout the whole engine. This may or may not be the reason for the port. One could argue that the port is there to aid coolant filling or even to relive back pressure on the pump. Hey Sloboat, there goes my curiosity.
Chris, speaking of curiosity how goes your experiment in green?

Eric Henning

nomadwilly wrote:

Mechanics have told me to add coolant very slowly to prevent air pockets from forming. I remember my old Sabre manual said the Sabre engine was especially designed to be able to be filled from dry without air pockets. Since it was the same Ford engine as yours your engine may have that same feature.

Click to expand...

According to the Lehman operators manual and the*people at American Diesel (Bob Smith was involved in the original marinization of the FL120 at Lehman Brothers), when the coolant is changed in the FL120 (it holds five gallons), the petcock at the top front of the exhaust manifold must be opened to allow trapped air to escape.* They said the process is to remove the header tank cap, open the manifold petcock and start pouring in new coolant (in our climate a 50:50 mix) until the header tank is to the correct level and coolant comes out of the manifold petcock.* Close the petcock, install the header tank cap, and that's it.

*

Marin,
Very yes except I don't think you need 50/50 coolant. BMW thinks 60/40 (heavy on the water) is ideal unless really cold weather is likely. 50/50 is good to -34 degrees F. You and I don't need that. 70/30 would probably be fine.

Sloboat,
2nd paragraph yes yes yes but what about the 3rd** ...** " air radiator " ?* Don't get that at all* ..* sorry. Yankee engines in Brit cars? Years ago I wanted to put a 401 Nailhead Buick into my XK140 Jag roadster. Now that I'm more practical and less romantic (if I ever was romantic) a small block Chev would have been better w a* much wider choice of transmissions. I'd like now to but a Plymouth Arrow gas engine in my Willard. They had a balancing shaft and were at least as smooth as a V8. Would need to fab an exhaust manifold for that one** ..* Hmmmm.

Eric Henning

Good morning Slobo,
In the interest of compactness most (I believe) modern engines have the heat exchanger inside the top of the exhaust manifold. Sea water flows through the small but many tubes in the heat exchanger that is emersed in engine coolant, thereby cooling it. I put my heat exchanger on a nearby bulkhead as I don't like sea water on or in my engine. Yes the "box" is filled w water** .. engine coolant. Usually the sea water goes first to the engine oil cooler, then to the transmission oil cooler (heat exchanger) then to the exhaust manifold (to cool the engine) and then to the exhaust pipe, through the muffler or lift muffler and out the stern of the boat. The engine coolant (when the thermostat is open) is pumped (by the centrifical water pump (usually oin the upper front of the engine) through the engine water jackets (block and head) and then through the exhaust manifold to be cooled by the heat exchanger that has lots of sea water flowing through it. On Marin's engine all is the same except the the sea water enters through the hull, goes through the engine oil cooler, then through the transmission oil cooler, then to the main heat exchanger to cool the engine coolant and then to the exhaust. His manifold is also flooded with water (coolant) but the heat exchanger is on the top of the front of the engine, not in the exhaust manifold (the "box"). What Chris wants to do is run the sea water first through the transmission oil coller, then to the main heat exchanger and then through the lube oil cooler after* it is warmed by the engine coolant. The sea water running through the oil cooler will be warmer, not cooling the engine oil as much, allowing him to run the engine at lower loads (speeds) and still have hot or warm enough oil to deal w acids and other problems associated w lube oil being too cool. When the engine is heat soaked the lube oil should be close to (and less than) 200 degrees. Some are running thier engines at such a low load that it may be nessessary to remove the oil cooler altogether. but thinking of what Kieth said then the lube oil may get too hot if the engine is ever run at heavy loads. Then we should pick up on what Rick B said about a product that by passes the cold sea water from the lube oil heat exchanger when (and only when) the lube oil is too* cool. Hows it look'in now Slobo ?

Eric Henning

"In the interest of compactness most (I believe) modern engines have the heat exchanger inside the top of the exhaust manifold. Sea water flows through the small but many tubes in the heat exchanger that is emersed in engine coolant, thereby cooling it. '

This is simply the cheapest way to convert an engine , if YOU have to pay for the construction of the wet manifold.
Starret did this with their cheap conversions of Izzsu in the 60's .

The exhaust manifold casting has to be created , making it a bit bigger and combining the heat exchanger has no virtue for the owner, besides lower initial cost.

This may become a new std , as BMW and M-B car diesels get stuck in light boats , that don-t need an engine with anything but a pleasure rating. OR can accept 1/4 the auto "rated" output as the "normal" power requirement.

FF

nomadwilly wrote:

*Then we should pick up on what Rick B said about a product that by passes the cold sea water from the lube oil heat exchanger when (and only when) the lube oil is too* cool.

Click to expand...

It's the other way around. The*thermostatic valve*allows the oil to bypass the cooler until it reaches set point temperature. This type of valve also serves as a pressure relief that will bypass the cooler if it becomes blocked and will*prevent oil starvation.

There are systems which control the water flow but*physically small units*are prone to more problems.

*

nomadwilly wrote:

Marin,
Very yes except I don't think you need 50/50 coolant. BMW thinks 60/40 (heavy on the water) is ideal unless really cold weather is likely. 50/50 is good to -34 degrees F. You and I don't need that. 70/30 would probably be fine.

Click to expand...

Cat says 50:50 for our climate, our diesel shop says 50:50 for our climate, my engineer friends at Northern Lights/Lugger say 50:50 for our climate, the engine manual for our boat says 50:50 for our climate, and American Diesel (the owner of which did much of the marinization work for the FL120, 135, etc) says 50:50 for our climate.* So I'm thinking I'm going to stick with 50:50

*

When its cold 50/50 is needed although I have heard of folks using even higher percentages of antifreez for even colder protection.

For non (or not very) freezing areas 35/65 is approved by most engine mfg.

Remember antifreez only has 5/8 the heat transfer ability , so if engine cooling is a problem LESS antifreez is better cooling.

Antifreez does other jobs , corrosion protection , and 35% is sufficient IF the antifreez mfg standard of changing every 2 years is followed.

The other big need for special coolants is to prevent the cylinder walls , exposed to the coolant to have cavitation prevention.Mostly a high power engine requirement.

SCA, supplimental coolant additives are required for these more modern engines , and if 50/50 coolant is what the block mfg wants , why not?

SCA, if required must be replaced at intervals and checked with a kit , not too little Absolutly not too much!

-- Edited by FF on Wednesday 20th of May 2009 04:53:10 AM

http://homepage.usask.ca/~llr130/physics/HeatCapcityOfAntiFreeze.html

Water - Thermophysical Properties

-- Edited by RickB on Wednesday 20th of May 2009 10:11:39 AM

FF, absolutely! I'll bet BMW specified 60/40 is because of the heat transfer issue.

Marin, It's a no brainer why they all say 50/50. Everybody can remember 50/50. If your'e sloppy there's lots of room for error. Seldom will it ever come back to bite you. Nobody ever needs to remember which percentage is for water. 50/50 is for average folks. Those of us who really care can read the back of the jug, measure accurately and achieve better results.

Rick, Much of the value of this forum is for reference material and you've just made a nice deposit. I'll try to remember it's there.

Eric Henning

nomadwilly wrote:

*Those of us who really care can read the back of the jug, measure accurately and achieve better results.

Click to expand...

Better results?* What better results?* If the engine goes 12,000- 14,000 and in some cases 25,000 hours with no need for overhaul on a 50:50 mixture, I dont' see how you can achieve better results than that.

You're correct, 50:50 is an easy number to remember.* It also happens to be a good ratio to use.* Seems like a win-win to me.* Maybe a 64.567 to 35.324 ratio will optimize the engine temperature by 0.1013 degrees.* But who the hell cares?

For every armchair theory someone throws out regarding the operation of the FL120 I'm gonna throw the same argument back at them--- forty-plus years of long-lived, reliable operation all over the world of countless FL120s running at moderate to low power settings, running 50:50 coolant, single viscosity dinosaur*oil,*and all the other "bad" operational practices the manufacturer, marinizer, and diesel shops say we should follow, says a whole*lot more to me than armchair theories about optimal power settings, coolant ratios, and synthetic oils.* I have no interest whatsoever in what BMW says about coolant ratios, for example, because I'm not running BMW engines.* For the same reason, I have no interest in what Steve D'Antonio says about optimal power settings for the*5 million hp, triple turbocharged engines he is apparently fixated upon.*

I DO have an interest in what Bob Smith says about running an FL120 because he was a principle contributor to the marinization of these engines and has been selling, installing,*servicing, and fixing them most of his working life.* So we run and maintain our FL120s exactly*like he told me to.* The fact that what he told me is echoed by our engine operations manual,*our very experienced diesel shop, and friends in the marine diesel industry simply confirms our decision to follow Bob's advice.

This is a 1950s-design engine pushing a 1960s-design boat.* We're not trying to*go to the moon here, folks.*


-- Edited by Marin on Wednesday 20th of May 2009 06:59:57 PM

OK Marin. 50/50 it is. I'll need to give up all those advantages FF was talking about. But I'm willing to do that to keep the peace.

Eric Henning

If you don't have FL120s you can put any ratio you like in your engine. For that matter, you can put any ratio you want in an FL120 if you have one. Maybe the type of engine in your boat is so touchy the difference between 50:50 and 60:40 will make a big difference in engine longevity and reliability. If this is the case I wouldn't presume to tell you to use something that is potentially damaging.

I'm just saying that getting all wrapped around the axle about coolant ratios other than the one recommended by pretty much everyone over the last 40-plus years in the case of the FL120 is a pointless exercise because it's speculation about something that's not worth speculating about. Unless, of course, one likes to speculate about things purely as an armchair exercise, which is fine.

This is just boats. It's not 777s or A380s or FA-18s or stuff that's actually critical. Chances are the diesels in everybody's boat --- Lehmans, Hinos, Detroits, John Deere's, Luggers, Cummins, Cats---are going to be running (given proper operation and maintenance) longer than any of their current owners are going to live or at least be involved in boating. (Commercial operations are a different story.) All that's needed to get the best longevity out of them is to follow the manufacturer's and marinizer's recommendation for type of oil, coolant ratio, oil and coolant change intervals, operating envelope, etc. If they say put a 60:40 ratio of coolant in it, put a 60:40 ratio of coolant in it. If they say 50:50, put 50:50 in it.

The owner of the diesel shop we use once told me they LOVE owners who become convinced to do abnormal stuff like run their engines hard all the time or use synthetics in 30-year old engines that have not been overhauled for synthetics, or run so-called environmentally friendly non-toxic anti-freeze in their diesels because, he said, they make a lot of money off these people. The people they don't make a lot of money off of, he said, are the folks who run their engines conservatively (aka intelligently), use the fluids and filters recommended by the manufacturer, and follow the maintenance schedules recommended by the manufacturer and marinizer. He said they never hear from these people except when they call for servicing if they don't do it themselves, or to have components like motor mounts or exhaust systems that have worn out replaced.

But the folks that get all excited about every amateur expert's theory they hear or read, they're in here all the time with this problem or that one, he said. "Those guys are gold mines," were his exact words that I've not forgotten since I heard them some ten years ago.

" Lehmans, Hinos, Detroits, John Deere's, Luggers, Cummins, Cats---are going to be running (given proper operation and maintenance) l"

Very true but I'm willing to bet not one owner in 100 does "PROPER" maint.

The downfall of most boat owners is the period of NON OPERATION.

DD for example gas a long, detailed , expensive requirement for

"Out of Service for Over 30 Days"

Do you know anyone that has asked the engine mfg what their reccomendations are?

Anyone that actually follows DA Book?


The engines our yard has replaced were KILLED , not worn out.

But we specialized on M>M boaters , & yachties not the* commercials.


-- Edited by FF on Thursday 21st of May 2009 04:32:38 AM

So here's the result of my research:

1700 RPM, 180 on water temp gauge, 1.6 GPH on FloScan, 171 F on oil filter housing by IR thermo, 177-184 on side of engine and head depending on location. Raw water pump 56 F. Oh, and 8.2 knots. Maybe there was some tide action helping me along on this one.

If there is any condensation left in the oil after the 1-2 hour one way trips I normally take we'll have to call it Houdini water. I'm thinking the oil cooler doesn't need to be on the "hot" side of the system. It seems to be doing exactly what it should be.

Just my opinion.....

Ken

8.2K on 1.6 GPH is doing great !

The hull must be really fine to go that fast on perhaps 22 -28HP!

Congrats to the designer!!!

FF

1700 RPM is about 6.5 or 6.6 knots. I'm only a couple months into the new prop so my tables aren't exact yet. 11 feet of tide change into a dead end was good for the rest. And I'll take that same free ride out this afternoon. Who said there's no free lunch?

Ken,
I can see what kind of dog you have but what kind of boat do you have? I'd like a hull to match those numbers to. We have 23' tides and today I put it to good use changing my propeller on the grid. I went on w a 12.8' tide. Just barely squeaked on but I went off w a 14.7'. To get your speed you need to turn around and split the difference between the two speeds. Only place to get good numbers is on a lake. One can also get close by going across the current.

Eric Henning


-- Edited by nomadwilly on Monday 1st of June 2009 12:40:50 AM

Geez Guys , we can run the East river at 5K , with the engine off!

One just doesn't get to chose the time or Direction!

Do it enough and we will be getting 1000 miles with Zero fuel!!

Speed and fuel burn are usually measured in still water, or by doing a mile in 2 directions and averaging the results.