VW diesel marine conversions [Archive]

sal's Dad

04-07-2006, 07:37 PM

A cousin has offered the motor from an '82 Datsun pickup - 4 cylinder SD22, as I recall. this and the sister SD33 (6 cyl) are used in forklifts and the like.

As it will be in an aluminum boat (no combustible material ), I was thinking to just run it hot, and maybe put some insulation around it if required.

In any event, I've scaled down the project for now, and the diesel is WAY too big for the 19' Atkin Rescue Minor. "She whose whim is law" has told me that if RM works, I can build a bigger one next year! So I have some time to figure out the diesel installation.

Sal's Dad

moTthediesel

04-08-2006, 12:15 AM

Funny that you should mention that old Atkin design --
I take it you saw the piece about the "Rescue Minor" in the current WB? I must say that artical is food for thought, -- I was mightily impressed.
I was thinking of a larger version of that bottom under a light and simple raised deck pilothouse cruiser of around 28'. Something that could be powered by a cheap and light diesel of around 40 hp, like - say, a 4 cyl VW?
And so a thread is born --

Re: The Nissan 4 pot diesel
I have no personal experience with them, but I've heard good things about'm. If I'm not mistaken, they were used in some mid-eighties Fords (Escort, Tempo, Ranger PU) as well.
moT

sal's Dad

04-08-2006, 03:51 AM

Yes! That's exactly my thinking - scale up either Rescue Minor, or "Shoals Runner" (WA's last tunnel design, very cool underbody) unless Mrs Atkin has another design in the mid 20' range that she's keeping secret....

http://www.boat-links.com/Atkinco/Utilities/ShoalsRunner.html

I don't have time for a full discussion now - but will be back Monday!

lucas12

04-08-2006, 07:09 AM

There are many ways to disipate heat from a hot source, they usually involve copper as being the most conductive, cheap, and maliable material.
If it is easy to copper plate the manifold, at a plating plant, (I'd have it bead blasted first) then further down the mainfold on the straightest section as close as possible to the exhaust ports, braze on a copper jacket with the water pumping through.
On the hot end where you can't fit the jacket, insulate it with ceramic wool that's used in furnace building, it's rated to 1260Deg C, the heat build up will transfer to the heat exchange further down.
Another way would be to leave it all alone and leave on the viscous fan to take in cooling air through a grill in the engine box and duct it out of the stern.
Another idea would be to simply cool the air in the box with honey comb aluminium lining the box and aluminium or copper tubes running through the honeycomb (just like a radiator) but very thin and with plenty of room for the surrounding air to circulate around.
Trust me an engine bay in a car doesn't get alot of air cooling, constantly cooling the surrounding air to 20deg C will be plenty.

Poida

05-03-2006, 08:15 AM

Trust me an engine bay in a car doesn't get alot of air cooling, constantly cooling the surrounding air to 20deg C will be plenty.

G'day Lucas
Should we trust a man who can't spell the name of his country properly?

An engine in an engine bay may not get a lot of cooling, but it gets enough. One area that tends to get forgotten is the cooling of the oil sump which gets a lot of air circulation. Also the radiator fan is not only there to cool the radiator but to blow air over the exhaust manifold.

The exhaust manifold on my boat is rather crude. The water return from the engine is sprayed inside the manifold and blown out of the exhaust.

One of the problems of this, evident from the top overhaul I am doing at the moment, is if your exhaust valves are not seating properly you can suck salt water into your combustion chamber.

lucas12

05-04-2006, 04:32 AM

So I did spell Australia wrong, who cares, we have the highest tax rates in the world, and the rest of the revenue collection which as around every corner, the last thing I could ever be is patriotic enough to care whether I spelt the name of a country that rips off it's residents and spends it on, fat pay checks, for people with the talents and skills of monkeys.

Ok, I don't quite get the water return system injected into the manifold, (sounds like a bad idea) I would get rid of it.
I'd say without having seen it that the water is ingested into the chamber when it cools down and creates a vacuum, sucking in the salt water that is strangely injected.
On my project, I'm going to have the radiator in a ss tank that has the salt water pumped in and out, in this tank will also be the trans cooler and oil cooler, with temp monitoring and water level alarm on the dash, That's pretty easy you just use a proximity switch and use the water as the completed circuit, when the circuit is broken the switch is activated to the alarm.
The Viscous fan will draw in air from the deck area via holes in the cover, the other end of the cover will have ducts to the transom under the decks. with slight rise to create a flue effect in drawing out the air, the longer the flue the better the draw about 8 feet is ideal.
Simon.

Poida

05-04-2006, 05:16 AM

Well Lucas I'm not the patriotic type either. All a country is basically, is a lump of dirt. So somebody's discovered a lump of dirt, called it a name and expect you to die for it.

My pay cheques not bad, but I spend most of it on bananas.

Yeah, pumping water into the manifold is not uncommon and I see your point in the cooling engine sucking the water into the combustion chamber if it was possible but the exhaust is vented to open air so a suction couldn't exist.

Incidentaly not all of the water from the engine is pumped into the manifold just enough to dissipate the heat. Most is pumped into the exhaust, the main benifit of this, is it helps to keep the exhaust fumes down.

Cheers
Poida

AShley5031

08-25-2010, 07:30 PM

My BRazilian converted Retipar VW diesel 1.6 is overheating and I really have tried everything I can think of.....reconditioning the head, putting in an orginal (and hard to get) head gasket, changing the fresh water pump and overhauling the Jabsco water pump, with a new rotor, overhauling the heat exchanger, checking the temperature dfference between the inflow and outflow of the heat exchanger...and lots more. It starts fine and then begins to throw water out of the cooling system when it has been running for about five minutes. THis saga has been going on now for 7 months. I have got to the point when I am about to take the engine out of the boat, a 35 ft Bruce Roberts sailboat, and throw it over the side into very deep water!

Before I take this drastic step, please do you have any suggestions?

regards

Ashley

Petros

08-25-2010, 09:09 PM

a cooling system is a realatively simple thing, and cooling problems in both boats and cars can sometimes seem impossible to solve. You have to approach it logically: coolant circulates via the pump, the coolant heated by the engine and it is cooled in some short of heat exchanger. Verify everything is working and narrow down possiblities. Do not randomly replace parts without dianosing the problem first, that is a waste of time and money and usually does not fix the problem.

Even a leaky head gasket or cracked block will stay cool without overheating until you loose enogh coolant to not allow it to cool. That normally takes longer than 5 min. If it get hot that quickly it sounds like it is not cooling at all, that is about how long it takes to heat up. Check you are not sucking any hoses shut on the suction side of the pump, check you radiator cap is good, and your thermostat is good (do not assume that it is good just because it is new, many are junk right out of the box).

In many systems that were not designed for a boat, you can trap large air bubbles in the system that prevents circulation or proper cooling. You have to bleed the air out before it will cool properly. Sometimes you can do this by removing a fitting or hose from the highest point on the engine and fill it from that point until it is full, and than quickly connect the hose without allowing too much air in the system (many cars have this problem too). Sometimes you can trap large amounts of air in the heat exchanger causing the same problem, if there is no easy way to bleed the air out you might try adding a bleed port (a simple plug or bolt in the correct place). If you are using a seawater to engine coolant heat exchanger you have two places that can trap air, in the seawater side and in the coolant side. You should also verify that seawater is circulating the way it is supposed to as well.

You might install temporarily some lengths of clear plastic tubing to see if the coolant is circulating. Some inexpensive thermometers attached to the various components (including the inlets and outlets of each component) will tell you if the coolant is being cooled as it runs through the heat exchanger, that will help narrow down the problems. You also might check the capacity of the heat exchanger (rated usually in btu/min or cal/min) to make sure it is large enough for your needs.

It is just a matter of narrowing down all the possible problems. It is usually not some exotic problem (like the wrong impeller on the water pump), but will become obvious once you do systematic testing of the system and narrow it down. You have already spent a lot of money NOT solving the problem, so instead of throwing parts at it, now take the time to find the problem and fix it once.

Good luck.

CDK

08-26-2010, 04:36 AM

I wrote quite a lot about marinizing VW diesel engines here:

http://www.boatdesign.net/forums/diy-marinizing/marinizing-vw-turbodiesel-engines-19118.html

If there are any more questions, feel free to ask.

baeckmo

08-26-2010, 06:00 AM

Ashley, the one thing you did not mention was thermostat. Has it been changed/checked? Can you describe the cooling system more "systematically"?

jonr

08-26-2010, 02:43 PM

If you are getting sufficient coolant flow, then I'd look for a clogged passage or an air bubble. You might have low flow and steam forming in one area while other areas are working fine. You might even use an IR thermometer to check that the heat pattern on the block is symmetrical.

AShley5031

08-26-2010, 05:44 PM

Thank you for your very helpful reply. I have taken out the thermostatic valve to see if the engine runs cooler......could this cause any problems?

AShley5031

08-26-2010, 05:47 PM

Thanks Baeckmo, yes I have changed the thermostat....three times! Today I took it out, to see if the engine runs cooler...do you foresee any problems other than taking longer to reach operating temperature, which would be a nice problem to have!

AShley5031

08-26-2010, 05:52 PM

Thanks Jonr,

I have not found any restricted passages in the cooling hoses, and I checked them again today. I have tried to get rid of air bubblesby squeezing the hoses, I thought I had got rid of them..but you never know. A friend told me today that his VW 1.6 gasoline powered car always chucks water out of the expansion tank until it is halfway down. So I will be filling up to halfway tomorrow to see if it chucks out any more. I have also fitted a pressure gauge to the fresh water system which stays steady at 1 bar.

baeckmo

08-26-2010, 06:13 PM

Taking away the thermostat will normally cause overheating, since modern thermostats have a shunting function. When the engine is cold, water is recirculated directly from the engine into the circulation pump inlet, connection to the cooler is closed. With increasing engine temperature, the shortcut into the pump is closed and the flow is directed through the outer cirquit where it passes the cooler.

Now, if the thermostat housing is empty, all the water will take the easiest way around, i.e. directly through the shortcut, and nothing passing the cooler. The result: overheating engine!! So never run an engine without a thermostat!!

BUT: if you change thermostat, beware that the "shunting valve" has the correct configuration, since if wrong it may leave the shortcut open when it should close.

The failure sequence often the following: First the original thermostat gets tired and the engine tend to run hot. Second a new one is installed, "thermo is a thermo, same same but different, it fits the housing flange and has the right temperature setting...". Third the iron still overheats, owner goes bananas as more and ever more parts are swapped in vain........!

AShley5031

08-26-2010, 06:22 PM

Hi Baekmo,

Reading your message again...here is a better description of the cooling system.

There are two basic circuits, one fresh water and one salt water. If the thermostatic valve is fitted, the following happens: The valve cold remains closed and the fresh water circulates through the block and head driven by the fresh water pump in a short cooling circuit, which does not include the heat exchanger. When the valve opens, supposedly at 80 degrees C, it forces the water through the longer circuit, which includes the heat exchanger. The fresh water passes around the outside of the heat exchanger tubes, while the salt water passes through the middle. The salt water cooling circuit is driven by a Jabsco pump with a rubber rotor. The water is sucked through an intake (1/2 inch) in the hull, passes through a filter, then goes to the pump, thence to the heat exchanger, then returns via the exhaust into the sea, the hot seawater mixing with the exhaust smoke. The outlet is actually slightly under water, which makes flow observation difficult, but the filter has a transparent top, through which one can see the water moving. If it is full, then the water is circulating OK. If not full, it means that there is a barnacle build-up on the intake.

What is happening is that once the engine has warmed up, it starts to chuch water out of the top of the expansion tank, and the engine heats up to 100 degrees and the siren goes off, when of course I switch it off. The cap is new and opens and closes correctly, keeping the pressure at 1 bar. The heatexchanger/manifold assembly showed no signs of water contamination on the exhaust side when I took it off, so I have assumed that there is no leak between the exhaust and the fresh water system. If the gas coming out of the expansion tank was combustion gas, surely it would be black and smell of smoke? It would also start immediately when the engine starts…but it doesn’t. The gas bubbles only appear once the engine as warmed up, so maybe this is just steam. But where is the steam coming from? The block has just been tested and reconditioned.

And there it is……any suggestions would be most gratefully received

Ashley

Petros

08-26-2010, 07:35 PM

with your system it does not sound like running without the thermostat would be a problem, it would just take longer to warm up (it is supposed to keep the engine within a certain temp range, but running it cool would not harm the engine). On modern car installations the t-stat circulates coolant through the heater core until it warms up, and the t-stat redirects the coolant to the radiator. Removing it causes coolant not to circulate properly since it will flow into all hoses, rather than where directed by the t-stat.

It sounds like there is a large air bubble trapped in the cooling system somewhere. I had an old Diesel Mercedes Benz that would trap air in the back of the head when filling it from empty. It would over heat even if everything was operating normal. I had to bleed the air out though a bolt in the head that leads to the water jacket (odd how the factory service manual did not make any note of this, I had to figure it out on my own). Than it cooled just fine. Once you are certain all the air is bled out of the system you have to determine if coolant is circulated though both sides of the heat exchanger. Are you sure the heat exchanger is large enough? Even so, if it was too small but operating properly it would only heat up under heavy load (high demand on the cooling system). So it sounds like you are not getting any cooling at all if it spurts coolant out in only 5 min. Something is preventing cooling of the water, likely air bubble, could be blockage somewhere (not very common).

Good luck.

thudpucker

08-27-2010, 12:11 AM

Ashley, start a new thread with your problem.

Check the outflow of coolant water. You have a blockage somewhere and it could be parts of the older Sea Water impeller that came apart and lodged in places you cant see or get to, in the Cylinder block.

baeckmo

08-27-2010, 04:40 AM

Right Ashley, the system you described is the standard configuration to which my comments refer as well. Unfortunately you didn´t understand the function of the "shunting". If you take away the thermostat, you leave both outlets from the thermostat housing open. One (often in the bottom) leads directly back to the circulating pump inlet. The other (often in the housing cover) directs the fluid to the cooler/heat exchanger.

So, with the thermostat removed, the cooling fluid will take the route of least resistance, which is directly back to the pump. ERGO: DON NOT RUN THE ENGINE WITHOUT THE PROPER THERMOSTAT, UNLESS YOU PLUG THE SHUNT LINE!

Now to the sea-water part. You have not mentioned how the reverse gear and engine oil is cooled. In basic systems, like yours, the water from the strainer goes to the impeller pump, then to the gear oil cooler and to the engine oil cooler, before it passes the main heat exchanger (if there is an intercooler, it should have the coldest water, hence be place directly after the pump).

The two oil coolers in series with the main heat exchanger are often full of minor barnacles; their larvae passing the strainer without difficulty. This is also where surplus pieces from a destroyed rubber impeller will end. Since this occurs on the pressure side of the pump, you won´t notice any disturbance just by looking into the strainer. First of all, then: make certain that you have full flow through the sea-water system!

And Thud: there is no connection where rubber pieces from the sw pump can find their way into the cylinder block!!!!

CDK

08-27-2010, 05:55 AM

Baeckmo, the 1.6 engine has no oil cooler, no intercooler and probably the gearbox also has no cooler installed.

The strainer in the water intake may be a source of problems because it can become clogged. I did not install it but use brass scoops (Wasserlöffel) with a row of narrow gaps that can easily be cleaned under water with a wire brush.

Ashley writes in post #24 "The block has just been tested and reconditioned."
That means all hoses have been removed and reinstalled. The big question is: have they all be connected properly?

A $25 infrared thermometer can provide the answer by checking hose temperatures during warm-up. The loop through block and head warms up first until 80 C. is reached, then the heat exchanger joins the game.

baeckmo

08-27-2010, 10:14 AM

.... the 1.6 engine has no oil cooler, no intercooler and probably the gearbox also has no cooler installed.

Yepp I know this one has no intercooler, but as for the rest, it varies between "marinizers". Just last week we drydocked a boat with a naturally aspirated VW four, marinized with the Bowman manifold AND a separate engine cooler AND a cooler for its Technodrive gear.

jonr

08-27-2010, 10:48 AM

> I have not found any restricted passages in the cooling hoses

I was thinking inside the block. Some type of reverse high pressure or chemical flush might help.

I have a theory (ie, never tried it) that one can test for internal air bubbles by pressurizing the system and then opening a valve - if there is air in there, then water will squirt out as the air expands. If it is all water, then there is no compression (except for perhaps rubber hoses) to expand. So very little "squirt".

AShley5031

08-27-2010, 05:07 PM

Ok people, thanks for helpful suggestions from CDK, Baeckmo, Jonr, Petros and Thudpucker

Here is what I did today in light of your suggestions. I tested the thermostatic valve in a pan of water and tested the temperature with a laser thermometer. It opened at 85 degrees. I did this a couple of times and then fitted it back into the freshwater pump housing. I then filled up the system with water again, tried to get the air bubbles out by squeezing the hoses, and started her up.

So far so good, the thermostatic valve opened up at 85 degrees and the water circulated correctly in the cooling system on both the fresh as well as salt water side. There was a temperature differential between both sides of the heat exchanger, 70 going in and around 55 going out, so difference of 15 degrees or so (Retipar said it should be 16) so that seems OK.

BUT, and here is the problem, I pointed the laser thermometer at all four fuel injectors. The one nearest the front of the block, where the timing belt flywheel is, was the coolest at 45 degrees, and I shall call this number 1. Number 2 was hotter at 55 degrees, Number 3 was around 60 BUT number 4 was wopping 100.5 degrees. This being closest to the heat sensor, it set of the overheating alarm. So I turned off the engine.

From Petros’ comments, it seems highly likely that there is an air bubble somewhere inside the block or the head, so I suppose the answer would be to take off one of the connections that feed the fresh water into the head. There is one almost in the middle, and there is another one right at the end, which also houses the heat sensor.

I suppose that I should bleed it cold, to avoid getting scalded, but I really wonder whether this is the problem. The mechanic who helped me today, Brazilian, said that he thought it highly unlikely that the air bubble would stay in the system once the engine had been running for a while. This time the engine ran for ten minutes before the heat alarm went off. He is of the opinion that there is a crack in the block, but then I had this tested, and the company said that it was OK. But then in Brazil, it is difficult to trust anyone.

I should add that there was some diesel oil leaking out of number 4 injector, which eased somewhat after tightening. Perhaps I should put some sealant compound on the injector thread, I have a silcone compound which says that it is good up to 315 degrees. Anyway, could this leaking fuel have been the cause of the overheating in number 4? I think it unlikely but I thought I would mention it anyway.

Any thoughts anyone? Should I try and bleed the head cold by removing one of the cooling connections?

Any other suggestions…I seem to be making some progress at least.

AShley5031

08-27-2010, 05:08 PM

Ok people, thanks for helpful suggestions from CDK, Baeckmo, Jonr and Petros.

Here is what I did today in light of your suggestions. I tested the thermostatic valve in a pan of water and tested the tempertaure with a laser thermometer. It opened at 85 degrees. I did this a couple of times and then fitted it back into the freshwater pump housing. I then filled up the system with water again, tired to get the air bubbles out by squeezing the hoses, and started her up.

So far so good, the thermostatic valve opened up at 85 degrees and the water circulated correctly in the cooling system on both the fresh as well as salt water side. There was a temperature differential between both sides of the heat exchanger, 70 going in and around 55 going out, so difference of 15 degrees or so (Retipar said it should be 16) so that seems OK.

BUT, and here is the problem, I pointed the laser thermometer at all four fuel injectors. The one nearest the front of the block, where the timing belt flywheel is, was the coolest at 45 degrees, and I shall call this number 1. Number 2 was hotter at 55 degrees, Number 3 was around 60 BUT number 4 was wopping 100.5 degrees. This being closest to the heat sensor, thus set of the overheating alarm. So I turned off the engine.

From Petros’ comments, it seems highly likely that there is an air bubble somewhere inside the block or the head, so I suppose the answer would be to take off one of the connections that feed the fresh water into the head. There is one almost in the middle, and there is another one right at the end, which also houses the heat sensor.

I suppose that I should bleed it cold, to avoid getting scalded, but I really wonder whether this is the problem. The mechanic who helped me today, Brazilian, said that he thought it highly unlikely that the air bubble would stay in the system once the engine had been running for a while. This time the engine ran for ten minutes before the heat alarm went off. He is of the opinion that there is a crack in the block, but then I had this tested, and the company said that it was OK. But then in Brazil, it is difficult to trust anyone.

I should add that there was some diesel oil leaking out of number 4 injector, which eased somewhat after tightening. Perhaps I should put some sealant compound on the injector thread, I have a silcon compound which says that it is good up to 315 degrees. Anyway, could this leaking fuel have been the cause of the overheating in number 4? I think it unlikely but I thought I would mention it anyway.

Any thoughts anyone? Should I try and bleed the head cold by removing one of the cooling connections?

Any other suggestions…I seem to be making some progress at least.

AShley5031

08-27-2010, 05:36 PM

Just an added thought, which I had forgotten, a propos Baeckmo, there are no coolers for any of the oil, either in the engine or the gear transmission. Just fresh and salt water cooling systems for the engine as described. Really quite crude, which I why I find it so hard to see why the problems are persisting in such a simple system. By the way, apart from the overheating around Number 4 injector, everything elso was fine, and the temperature gauge remained steady at under 80...around 76. But the alarm sensor went off all the same. Really weird.

Petros

08-27-2010, 05:52 PM

The fact that the back of the head is running hotter means only one thing; there is no coolant circulating there for whatever reason. Most engines have the cooled water from the bottom of the radiator, get sucked through the pump and enter the engine low on the block around the cylinders. From there it pushes up past the head gasket into the head, and than flows around the combustion chambers, ports and valves to the outlet near the top of the head (usually at the front of the head in the older engines, can be anywhere on the head of the newer engines), and than back to the top of the radiator.

So either you have a large air bubble trapped in the head at the number 4 cyl location, or something is blocking the water from circulating there. The wrong type of head gasket can cause this, but it appears to me it is an air bubble. This is exactly what happened to my old Mercedes, the circulating coolant did not force the air out. I had to bleed that part of the head.

One thing you can do is see if you can tilt the engine to allow the air bubble to go out the inlet (or weigh front of the boat enough to get the water jacket in the head level). The other might be to feed a small tube in from the outlet to the area where air might be trapped and allow it to vent out, or even fill it through the tube.

It likely is the way the engine is installed so the back of the head is higher than the outlet, trapping the air. In the car install it was level and did not trap the air. It would not be difficult to drill a hole in the high point of the water jacket on the head and install a bolt to allow it to bleed when you fill it. I would not do that unless you have a sample to head to examine exactly where to drill it. You also might find a factory plug or fitting nearby that will allow you to bleed out the air.

once cylinder running lean because of a fuel leak should not affect temp on a diesel (this is not true in a gasoline engine, lean means runs hot). It will mean that that cylinder will produce less power than the other three, so it might run rough, but I do not think it will affect anything.

Just so you know, a lifetime ago I designed the water jacket and cooling system that went on a 900 hp race car (a factory sponsored team). Getting the coolant to circulate evenly to all parts of the engine, especially the head around the combustion chambers, is critical to preventing overheating. We actally improved the cooling of the head over the factory Nissan engine. The car was undefeated in the IMSA race circuit back in the 1980's

AShley5031

08-27-2010, 06:10 PM

Thank you Petros. Actually the engine is at an angle so that the part of the block that is hottest is lower. The slope is around 15 degrees. The end of the engine connected to the propeller transmission is lower than the end connected to the water pump and timing belt. So you would have thought that the bubble would come out by itself. I think my best bet will be to take off the connection at the back of the block and fill the block up with water from there with a siphon tube. This is not the highest point on the block though. One would have thought that the air bubble, if that is what it is, would be at the highest point, which is precisely the coolest end.....weird.

AShley5031

08-27-2010, 06:34 PM

One thing further Petros, the gasket simply can't be wrong, it is an original VW part with the correct part number proscribed in the manual. By the way, sounds like you had fun in the racing world. I am ex-British army, former Lt in the Blues and Royals, a lifetime ago. I moved to Brazil about 15 years ago.

But one has time to breath in Brazil, quality time, and that means time for sailing, learning the piano...etc. I never had that luxury in England. Here I am a freelance translator in the financial markets, working wherever I have my laptop, be it on the boat or up in my cabin in the mountains!

dskira

08-27-2010, 08:54 PM

VW came with the same idea:

http://www.vw-marine.de/index.php?id=33&L=1

Their marine engines are based on blocks used in cars, perhaps you can find a dealer somewhere near and spy on how they did it.

Ho yes, their marine engine came in the US. With a extremely high price tag. I don't know if they continue the distribution, they seams to have fade away.

Daniel

baeckmo

08-28-2010, 02:58 AM

Ashley, good job with the IR thermometer! The water is distributed in the cylinder block through calibrated openings from a manifold channel. It seems that the openings for the no 4 cylinder are blocked. You say this is the lower end of the engine ok? Then I suggest that the problem is debris collected in the cooling area around this cylinder. I understand you are in Brazil, and never worried about freezing; could it be that you have no additive in the fresh water, such as glycol with a rust inhibitor? If yes, then there are corrosion products in your fresh water cirquit.

Off with the head again and clean out the block, watch out for forgotten rags and dead frogs! Good luck!

thudpucker

08-28-2010, 04:05 AM

Make a slender stainless tubing out of an old brake line.
Connect that to an air hose, and to some water.
Poke it way down the holes into the block and run the Air/water hose down that same hole .
It will crackle and Pop loudly, but the flakes of rust etc will break up and come flowing out.

Use a small (Ultrabrite LED) lite to make sure you got it all.

CDK

08-28-2010, 04:35 AM

jonr

08-28-2010, 09:20 AM

I'd take the head off and then pressurize the cooling water passages and make sure that the flows out of the block are all symmetrical. Then do something similar with the head.

AShley5031

08-28-2010, 09:30 AM

Hi Baeckmo,

Well I have pretty much ruled out the air bubble idea, because the freshwater intake is fitted with a bleed line which goes back to the cooling reservoir thus maintaining pressure, precisely to bleed out any air trapped in the block. But just to be sure, I tookoff the hose and, yes, it is full of water, and no air. As the block has just been cleaned and reconditioned, the water passages in it should not be blocked. So that means that it really has to be some kind of blockage within the block, according to your reasoning, which makes perfect sense. So off with her head, again, to misquote Henry VIII!

AShley5031

08-28-2010, 09:32 AM

Just a last desperate thought...what about putting in some radflush to see if that loosens up anything?

AShley5031

08-28-2010, 09:51 AM

One last observation worth mentioning Baeckmo, the hotspot of 100.5 degrees is ONLY ON THE INJECTOR. The areas around No. 4 cylinder and the end of the block are relatively cool. So I am wondering why the heat should be concentrated JUST IN THE VERY SMALL AREA and not around the cylinder jacket as a whole

thudpucker

08-28-2010, 11:01 AM

No chance that will work, Thudpucker.
The coolant entry point is a flange between cyl. 2 and 3 in the head; the brake line cannot follow the 90 degree angles.
Besides, debris drop in the block and end up in the water pump where a plastic impeller is waiting.

I'm afraid Baeckmo's solution is the only correct one.

I forgot to mention that kind of work has to be done with the head off. Sorry!
You'd almost have to tip the block so the debris would run out by itself too.

I had two VW Rabbits. The Diesel didn't give much trouble at all, but had no power. The Gas was a pile of problems but it would scoot right down the road.

CDK

08-28-2010, 11:05 AM

Ashley, you started this thread because the engine overheats and water starts leaking from the overflow. With just a small area reaching 100 C. there would be no pressure buildup because steam would revert to water the moment it mixes.
All symptoms point to a blockage and/or insufficient flow.

Is your cooling circuit only using the central port with the port next to cylinder #1 plugged or is that one used as well? It was intended for the car heater, which has a fairly high resistance.

AShley5031

08-28-2010, 12:41 PM

Hi CDK,

I have just had yet another mechanic look at the engine. In answer to your question, the connection is being used between cylinder 3 and 4 for the freshwater circuit. There is another connection at the end of the block (next to No.4 cylinder) which holds the sensors but also has a small hose connection.

This mechanic suggested swapping the injectors round to see whether the overheating follows the injector, and I will do that this weekend. But here is the thing, the temperatures around the rest of the engine seem to be all below 70 degrees, including where the sensor is attached to the cylinder head, but the temperature alarm goes off and water is thrown out of the cooling water cap. So yes, the engine is still overheating.

It also has now developed another problem. It started to accelerate on it own just now, and it wasn't that the throttle lever was stuck. I had to turn the engine off. The mechanic today said that he thought maybe the timing belt wasn't set correctly. When I restarted the engine after putting in more water, it was very difficult to turn over and I had to put by hands over the air inlet to block the air coming in, making it easier to turn over. Maybe the engine is retarded or advanced. If I understand correctly, the engine jams on the valves if the timing belt is not in the right place.

There is also a lot of smoke coming out of the exhaust, which is of course because of cylinder wear, which I knew about. I am really thinking that maybe I should take this engine out of the boat and re-build it. The trouble is that the boat was built with no access hatch to the engine so it has to come out and go back in pieces.

So even if I rebuild it, I would have to dismount it and rebuild it inside the boat.!!!

thudpucker

08-28-2010, 01:03 PM

Photos!
Some years ago I helped pull three engines out of an old Chris Craft. Three Chrysler Crown 8 cylinder inline engines and all the related parts.

It soon became apparent to the owner that he'd be better off removing the Decks above the engines. All the damage to his boat gangways and bright work suffered as four guys struggled with those heavy parts caused him to see the light.

We removed three Decks and lifted them out.

Your boat is getting older now. It may be time to overhaul the deck to give you better access to the engine compartment.

AShley5031

08-28-2010, 02:01 PM

Thudpucker, did you send some photos attached? If so I can't access them. Could you send them to my e-mail? ashley.huggins@terra.com.br

thanks

thudpucker

08-28-2010, 02:59 PM

No Ashly, I wanted you to send photos of your boat and engine. It would help my poor mind get an idea what your up against.

CDK

08-28-2010, 03:18 PM

This mechanic suggested swapping the injectors round to see whether the overheating follows the injector, and I will do that this weekend......

........ If I understand correctly, the engine jams on the valves if the timing belt is not in the right place.

If you remove an injector you need to install a new heat shield disc, they are not reusable.

This type of engine doesn't allow more than 4 teeth timing error before the valves start hitting the pistons. When that happens, your overheating problem suddenly becomes very minor.

Maybe it is time to get a hacksaw and make a hatch.

AShley5031

08-28-2010, 07:49 PM

Hi CDK, I take it that the heat shield disc is the washer that goes in first, before the injector. I already took them out when the head was re-conditioned and have not replaced them...oops! Why are they not re-usable?

To answer your question about the fresh water cooling system, as far as I can tell, the route is like this. The pump has three hose connections, two small and one larger. The pump fits flush onto the block and pushes the water upwards inside the block. When the thermostatic valve is closed, the hot water comes out of two connections on the cylinder head, one between cylinders 3 and 4, and the other on the far end of the head, beside cylinder 4, the smaller of the two.

When the thermostatic valve opens, the valve shuts off the route to the connection between 3 and 4 and opens the larger hose connection, which starts to suck water through the heat exchanger. The small hose connection to the end of the block appears to remain open and seems somewhat redundant in the scheme of things.

Could the fact that the engine started to race on its own have something to do with the heat shield discs? Or the fact that one of the injectors is hotter than the others?

You say that there is error room of 4 teeth on the timing belt. If it is too hard to turn over the engine, is this because it needs to be advanced or retarded?

On setting the timing belt, two teeth back and it was jamming on the valves, so should I advance it one more tooth?

I will be taking some pictures over the weekend of the boat and the engine, which will make things clearer. Thanks for your help.

CDK

08-29-2010, 05:04 AM

The discs are the seals between the (pre)combustion chambers and the injectors. When installing an injector the disc is flattened because the center is pressed inwards by the nozzle. Once used there is not enough spring action left to cope with nozzle and bore tolerances.
With a non-sealing, wrongly mounted or missing disc, the injector heats up and the fuel boils. Then the needle valve gets damaged and the injector stays open, causing further overheating and power loss.

To properly set the timing, you have to follow a procedure for which you need 3 special tools: a gauge to keep the camshaft in position, a locking pin for the injection pump and a clock calibrated in 0.01 mm steps. Without these you don't stand a chance to obtain correct timing.

A source for information and tools is here: http://www.vwdieselparts.com/forum/

AShley5031

08-29-2010, 10:33 AM

Hi CDK,

I have entered the other site you suggested. What do these discs look like? Are they of steel? Here is the entry I have added on the other site, FYI.

Hi everyone,

My name s Ashley, I am English and live in Rio de Janeiro. My problem is the diesel on my 35 ft Bruce Roberts ketch. I have overahauled the whole boat since buying it in November, but have yet to sail in her because of problems with the diesel engine. I started an inquiry thread on

http://www.boatdesign.net/forums/diy-marinizing/vw-diesel-marine-conversions-11155-4.html

CDK says I need special tools to set the timing belt, plus also he says I need to replace the "heat shield discs"

When I took the cylinder head off and reconditioned it, I also took the injectors apart to clean them. I realize now that this may have been a mistake.

When the engine is running, the timing having been set by eye by the mechanic helping me, number 4 injector is running hot , 100 degrees C, and the engine started to race.

Firstly, to identify the heat shield discs, I need to indentify them...what are they made of and what do they look like?

What adjustments, if any, do I need to make to the injectors aother than merely tightening them up?

CDK says I need tools to set the timing correctly. He is probably right, but the mechanic showed me that if the groove on the valve cam rod is horizontal, the marks on the injector pump are lined up, with the mark on the pulley at the end of the main drive shaft in the most vertical position, then this is the right setting.

When we set the timing, two teeth back and the drive shaft would no longer turn because it was fouling on the valves. So I am thinking of advancing it one more tooth, because the engine is very hard to turn over.

Aside from this, if you look at the inquiry thread on the other site, you will see that my main problem is that the engine continues to overheat. That is to say that the heat alarm goes off, although the heat sensor when measured with an IR thermometer, actually shows a normal temperature of 85 c or so.

Any suggestions?

CDK

08-29-2010, 02:40 PM

I copied an image from the internet.

There are guys who can adjust VW diesel timing in the dark, without tools, by just listening to the engine. I am not one of them!

AShley5031

08-29-2010, 07:56 PM

Baeckmo, CDK, Petros

Here are some photos of my engine as well as the acess to it. The hoses to the pump and head are fairly visible

AShley5031

08-29-2010, 08:03 PM

Here is a photo of the engine...seems I can only upload one at a time!

AShley5031

08-29-2010, 08:08 PM

Another one from the other side

AShley5031

08-29-2010, 08:14 PM

One of the fresh water pump

AShley5031

08-29-2010, 08:19 PM

One of the salt water pump

AShley5031

08-29-2010, 08:27 PM

Here is a photo of the access

AShley5031

08-29-2010, 08:32 PM

This one just for fun

baeckmo

08-30-2010, 05:11 AM

Afraid that your observations regarding rpm increase and smoking exhaust indicate more serious trouble. The hot spot around the no 4 injector is a sign of bad spray pattern, or as CDK says, defect needle valve. It causes overheating of the pre-combustion chamber.

The racing tendency indicates that there is a non-regulated fuel supply. The crankcase ventilation is connected to the inlet manifold, and with the increased blow-by of a worn (and possibly seized due to injector misfunctioning) cylinder there is enough lube oil mist carried into the #3 and #4 cylinders, to increase rpm. If you are lucky, it is unburned fuel from dripping injector that collects and ultimately ignites, but the result is often that the lube oil is washed off, causing a seizure anyway...., so either way, luck is not on your route here.

Since there has been no improvement from a new head and all the other paraphernalia you have changed, I'm sorry that you must face it: that engine has to come out of the boat for a thorough overhaul!

AShley5031

08-30-2010, 06:36 PM

Thanks Baekmo, I coming to that conclusion too. There is a guy here who modifies this engine to run on a 2 litre block using the 1.6 head, and a steel gasket.....appears to have had very good results. This 1.6 diesel was notorious for overheating in the Kombi. with lots of fires ensuing. This mode seems to have no problems, So maybe I will do it too. Has enyone tried this in the US?

thudpucker

08-30-2010, 08:02 PM

I felt pulling the engine and looking at everything was the answer too.
That's why I had the query for photos to see what's involved in removing or remodeling your deck to make that an easier process.

Out of curiosity, I'd like to know how large or heavy your vessel is, and how fast the little Diesel can make it cruise (at cruise throttle) and how much fuel it uses when your cruising.

The reason I ask is from back in the 80's when I test drove a VW Diesel. I felt like I had to open the door and help scoot it up the hills with my foot.
My 85 Rabbit (gas) would go pretty good at 25 Mpg.

I just wonder what your Diesel fuel mileage in a boat might be.

jonr

08-30-2010, 09:05 PM

I wouldn't pull the engine until you tried moving the injector to a different cylinder.

AShley5031

08-31-2010, 04:33 PM

Hi Thudpucker,

My sailboar weighs 8 tons and the engine will drive it through the water at a reasonable 7 knots. It is also reasonably economic on fuel, though I have ben able to ascertain this on a long haul yet because of all these problems.

I am thinking of pulling the engine, it will have to come out in pieces, and maybe trying a whole new engine, or the 2 litre VW block conversion which someone is doing in Rio, using the same head with a steel gasket.

Anew Yanmar diesel of the same power is a wopping 15,000 US$ here in Brazil....too much to spend!

AShley5031

08-31-2010, 05:52 PM

Petros

08-31-2010, 11:04 PM

Is there somewhere that tests and overhaul diesel injectors nearby? Perhaps a refurbished set of injectors is all you need. That would be an easy check compared to overhauling the engine.

I would not be so quick to overhual the engine just yet. You never ran it for very long, and diesel fuel does have some lubricating qualities so it would not wash out the cylinder walls as much as gasoline. At least not as fast. I once drove a rebuilt volvo gasoline engine for about 200 miles with two spark plug wires in the wrong cylinder so it was only running on 2 cylinders (I was wondering why it seemed so underpowered). That would have washed all the lube off the walls of the cylinders if anything did, but once the wires were correctrf, and it was running on all 4 cylinders, power was restored, it did not burn oil or loose any compression. Unless the VW is is so fragile it could not hold up to what must be only an hour or so of running with too much diesel fuel in one cylinder, I doubt it is damaged enough to matter. I do not know for sure of course, but I would not resign your self to overhauling it just yet. If it is that fragile of an engine (which I doubt), it is not a good candidate for being in a sail boat in IMO.

I do not recall replacing any heat shield/metal gaskets on any of my Deisels, but none of mine were VW. I have always reused these kind of devices without issues (even when I knew it was supposed to be replaced).

Give it a try (refurbished injectors), you really have nothing to loose now anyway. Anything short of an overhaul, that solves the problem, will save you a lot of time and money.

Good luck.

CDK

09-01-2010, 03:44 AM

CDK,

What are the heat shields you show in the photo made of? The ones I have here are hard steel and the local mechanics are telling me that they never replace them, and would be dificult to deform with a ball bearing and a vise-grip, as has been suggested. The shields in the photo look like they are made of some type of alloy. Anyway I spent all day lloking for new ones here in Rio with no luck.

regards

Ashley

The ones in the picture are probably gold, the VW heat shields are dull gray and made of steel.
When you buy new injectors from Bosch, the discs are included and so is an instruction sheet telling you never to install used ones and not to install them upside down.
Any VW dealer should have these parts in stock; the are mass produced so are very cheap. Reshaping them with a mallet and an old ball bearing is a possibility only if you know what you're doing and have an unused one for comparison.

I admit it is difficult to distinguish new and used ones, you need a micrometer to see the difference. A used cylinder head gasket looks very much like a new one, but the difference is that a new one seals and a used one leaks.
When installing an injector with a new disc, the torque builds up gradually during the final turn: that is the stage where the disc is compressed.

Converting a 1.6 to a 1.9 (I don't know if there is a 2.0) must be an expensive operation because they use different injection pumps. From the 1.6 engine you can only use the head and exhaust manifold. The only valid reason to do it would be the need for more torque or hp.