Injection pump question

[BruceK]

Hi TL, A reason I suspect 200 hours could be an update on 50, is that your boat and Marin`s predate my 1981 boat. It could also be an updated pump with longer change intervals, though the Manual does not mention that, but does mention ID plate location. What date is your Manual?

 

[Marin]

Our boat and manuals are from 1973 but the manual I scanned the page from off the Grand Banks owners forum is dated 1986.

 

[Capt.Bill11]

Thank you Marin. I had seen some of your earlier post on this and I could not understand it either. The hose is definitely plumbed into the return fuel line. I do have a small pin hole dilled into the fill plug. I am going to check to see for certain that it is the breather overflow plug. It looks to be slightly off from your picture, but the only port/plug on the bottom left side, below the two bolts on the above plate. I suppose I should find a plug and remove the hose. Thank you very much for your quick reply. Live and learn. Charlie

Can you post a picture of your pump?

 

[Marin]

It looks to be slightly off from your picture, but the only port/plug on the bottom left side, below the two bolts on the above plate.

The Ford of England Dorset diesel (base engine for the Ford Lehman 120 and a number of other marinized versions by other companies), was used in a wide variety of machines both in England and in the US. Initially trucks and then generators, cranes, pumps, agricultural equipment (some old-timers in England still refer to this particular engine as the "Ford combine engine") and other industrial applications. The Minemec/CAV/Simms injection pump was in production for many years and undoubtedly experienced a number of minor changes as these companies bought each other out, merged, changed ownership, etc.

So plugs or other details in different positions are not too suprising.

However the basic function remains the same, so it still seems very odd to want to make a connection of any kind between the body of the pump and the engine's fuel return line which normally goes to a fuel tank. You want to keep fuel out of the pump's lube oil, not put it in.

As a point of interest the in-line injection pump on the later Ford Dover diesel, the base engine for the FL135, does not have an isolated lube oil supply but instead is lubed from the engine's oil sump. So the oil dilution issue does not have the same significance as on the FL120 since any fuel leak-down is going into three gallons of oil, not a half a quart or so.

It is possible to plumb the FL120s injection pump to be lubed from the engine but according to the people on the Grand Banks owners forum who have seen or inherited engines set up this way, it's a bit of a Rube Goldberg setup and most of them recommend against it. The ones I have corresponded with in England changed their pumps back to being self-contained.

 

[Comodave]

I just took Bob Smith's seminar on the FL. He recommended 50 hour oil changes. He said that over time if the oil still is undiluted at 50 hours, then you could stretch the oil change out a little bit, but each engine is a little different and you need to establish the hours before the oil is diluted with diesel.

 

[jleonard]

I just took Bob Smith's seminar on the FL. He recommended 50 hour oil changes. He said that over time if the oil still is undiluted at 50 hours, then you could stretch the oil change out a little bit, but each engine is a little different and you need to establish the hours before the oil is diluted with diesel.

And for that reason I have stretched my change interval to 100 hours.

 

[psneeld]

And for that reason I have stretched my change interval to 100 hours.

a simple blotter test will show if fuel if starting to accumulate in the oil...I am not sure my nose isn't good enough.

Poor Man's Oil Analysis - The Motor Oil Evaluator

one of many explanations.

 

[Texas Lady]

Thanks to all of you for the comments. I spoke with Bryan at American Diesel. He was as confused about this as the rest of us. I will take a picture and send to him and post here. It sounds like I need to add the plug and drop the hose an ensure the fill cap has a hole drilled in it. The good news was that after the oil change the engine started, did not miss and ran great.


Maybe someone theorized any excess fluids would be diesel and it would not hurt to return it. Who knows.

 

[psneeld]

Thanks to all of you for the comments. I spoke with Bryan at American Diesel. He was as confused about this as the rest of us. I will take a picture and send to him and post here. It sounds like I need to add the plug and drop the hose an ensure the fill cap has a hole drilled in it. The good news was that after the oil change the engine started, did not miss and ran great.


Maybe someone theorized any excess fluids would be diesel and it would not hurt to return it. Who knows.

Heck if it was just venting a little oil from excess or expansion....the dang thing only holds 15 OZ so better to the fuel tank than in the bilge...unless you were capturing it to see if there was enough excess overflow to signal too much diesel dilution.

 

[Marin]

The leak down fuel from the plungers in their bores mixes with and dilutes the lube oil underneath. It doesn't float on top of it or anything. I would be more concerned with a connection from the pump breather to the engine's fuel return line putting fuel into the injection pump's lube oil. It's not going to carry any fuel away from the pump.

All in all, it seems like a very poorly thought through armchair theory to me. And the fact it was not done on the stock engine--- the fuel return and in-line injection pump are of course components of the base Ford engine, they are not part of the marinization kit-- would indicate that this is not a beneficial modification. Otherwise Ford would have designed it into the engine in the first place.

 

[psneeld]

True...seeing which way the fluids went would be important...the Lehman puts out so little return that open air to the tank might be the path of least resistance for both....


Not a mod I would do as I also don't think the injection pump is as big of a deal as most....some have run it for many hours with no oil...others have run it with almost pure diesel as a lube.


It will likely need rebuilding for any one of many reasons....not necessarily a lube oil issue.


Anyone have any stats on what failures are common for these injection pumps?

 

[Marin]

Anyone have any stats on what failures are common for these injection pumps?

I do not have numbers, only the experiences relayed to me by acquaintances in the UK who spent a good chunk of their careers dealing with the Ford of England diesels, including the Dorset.

One of the reasons the Dorset proved to be a monumental failure in over-the-road truck service, which is what it was originally designed for in the late 1950s, were weaknesses in the engine that were exacerbated by the very nature of truck operations--- widely and rapidly varying loads on the engine, constant rpm changes, and so forth. The engine's two greatest weaknesses according to these acquaintances are the head gasket, which is prone to blowing under high heat, high load conditions, and the in-line, jerk-injection pump.

Anecdotal problems with the pump included comments like "it needed adjusting all the time" to "it broke a lot" and so on. But these were mostly about the engine being used in hard service, like trucks.

Both the head gasket and pump weaknesses are mollified a lot when the engine is used in lower load, constant rpm service which is typical of industrial and agricultural service, which is what gave the engine a new lease on life after its failure as a truck engine. Marine service, is of course, in that same realm of operation as agricultural and industrial constant-condition use.

Interestingly this same engine also used a rotary injection pump--- its maintenance and overhaul are covered in the Ford of England Dorset diesel operation and shop manuals that came with our boat. But I have never encountered anyone with the rotary pump in a marine application and we've never discussed them with our acquaintances in the UK as we don't have them. So I have no idea if they represented any sort of advantage over the inline pump.

The inline pump is the single most expensive component on the Ford Dorset diesel. The last I heard an overhaul was about $1,000 and that was some years ago so the higher cost of labor these days has probably increased that cost.

I do not know statistically what the most common reason is for having to overhaul the pump. I was told a long time ago that plunger and bore wear was a cause as this gradually reduces the power of the injection "shots' going to the injectors and eventually this will begin to affect the engine's performance. As this kind of wear is affected by a lot of things--- how the engine is operated, fuel lubricity, and so on--- it's probably hard to impossible to attach a consistent hour number to the pump's TBO.

 

[Texas Lady]

Here is a picture of the injector pump with the hose connected to the overflow plug(?), and plumbed into the return fuel line.

 

[meridian]

That's not the overflow plug, it is on the lower right.

 

[Driftless]

Huh.

Here's another twist: On the Albin AD-21 engine, which uses the same type of injection pump, though obviously calibrated for a much lower horsepower and only two cylinders, the oil is supplied from the engine's lube oil system and overflows back to the crankcase, so no oil changes are needed. Just why CAV approved this system with Albin is a mystery to me, but there it is.

I contrasted the injection pump/governor setup on my AD-21 with the pump on a friends FL-120, and other than the number of cylinders and calibration, they appear identical.

I've still got the AD-21 (but not the boat - repowered with an Isuzu) and I could probably drag it out and take a picture if it's important.

Happy Holidays!

JS

 

[Capt.Bill11]

Huh.

Here's another twist: On the Albin AD-21 engine, which uses the same type of injection pump, though obviously calibrated for a much lower horsepower and only two cylinders, the oil is supplied from the engine's lube oil system and overflows back to the crankcase, so no oil changes are needed. Just why CAV approved this system with Albin is a mystery to me, but there it is.

The injection pumps on many/most 135 Lehmans are set up that way.

 

[Marin]

Here is a picture of the injector pump with the hose connected to the overflow plug(?), and plumbed into the return fuel line.

View attachment 47565

Based on the layout of our Simms pump (photo in my Post #25), the plug on the very bottom (barely visible) of your pump is the drain plug, obviously. The plug above and slightly forward of that on the side of the pump's "bell housing" is the oil level plug (right side of the photo). The higher plug on the aft side with the hose attached is, as you correctly say, the overflow plug (left side of the photo).

You say the other engine is not fitted with this hose. So is there an overflow down tube attached to the overflow plug on this pump? On our boat the original overflowl tubes were metal and had a single fairly tight coil in them about halfway down toward the engine's sump pan. They were open at the bottom and simply dripped into the pan.

The stock overflow plug itself is a hollow bolt with a banjo fitting between the head and the case of the pump to which the overflow down-tube is attached. This is why Bob Smith's instructions for blanking off the stock overflow plug are more than just putting a solid bolt in the hole.

Don't forget these engines were designed to sit more or less level in a vehicle, not slanted aft as they are in most boats. This is one reason the pumps tend to blow oil out the overflow plug because with the engine slanted aft, the normal level of the lube oil inside the pump can be very close to or even at the overflow plug depending on the downward angle of the engine.

So with regards to your hose, as the Russian fire official said in response to a question about the cause of the massive fire in the Moscow television tower years ago, "Is big mystery."

 

[Xsbank]

The lube oil becomes diluted by diesel and runs out the breather pretty much constantly and makes a mess, that's why the drain and the frequent oil changes. You can remove the drain plug and replace it with a valve, then you don't have to worry about stripping the drain bolt threads nor will it ever again fall into the bilge. Plug the level-hole and just measure how much you need so it's not such a mess.

 

[RT Firefly]

Greetings,
Mr. X. I have considered a petcock in lieu of the drain plug on the minimec BUT the drain hole is so small (in the neighborhood of 1/4") I fear it would take forever to drain although it would indeed make changes easier. The only viable way I would consider a petcock would be to drill the hole larger to accommodate a valve with a larger orifice but that would mean pump removal to do a proper install.

 

[Marin]

Greetings,
BUT the drain hole is so small (in the neighborhood of 1/4") I fear it would take forever to drain although it would indeed make changes easier. .

There is also the issue of clearance for the valve. If one has the 1" Johnson raw water pump there is not enough clearance between the top of the water pump and the bottom of the injection pump to install any sort of valve system in the injection pump drain hole. Perhaps there is sufficient clearance with the 3/4" Johnson pump, I don't know, but we opted for the larger pump on our engines.

 

[BruceK]

Our boat and manuals are from 1973 but the manual I scanned the page from off the Grand Banks owners forum is dated 1986.

So the mystery of hours for changing the injector pump oil remains. At 50 or 200 hours? Marin`s 1986(50) postdates my 1978(200), being the most recent pronouncement seen could be Lehman rethought it.
I change the pump oil along with the engine oil, at 100 hours.

 

[Xsbank]

Hello RT - back before I got banned from the GB site for daring to contradict Bob Lowe, a very kind gentleman made a drain valve for me out of a ice maker valve with adapted threads that he turned on his lathe to fit right in the Simms pump drain hole. I will see if I still have it, I never used it as I sold the Simms pump (and the boat attached to it) so I could auction it for the food bank or, the same way I got it, I could give it away... wish me luck in the basement and I'll let you know if it turns up.

The small size is not an issue as the oil is very runny with the diesel content and it is always warm.

 

[Marin]

I change the pump oil along with the engine oil, at 100 hours.

Unless your pump(s) are experiencing significant fuel leakdown, which is easily determined by examining (and smelling) the oil that comes out of it/them, I suspect a 100 hour pump oil change is just fine.

I would confirm that with an experienced, credible source however, as this is just my assumption.

 

[jleonard]

There is also the issue of clearance for the valve. If one has the 1" Johnson raw water pump there is not enough clearance between the top of the water pump and the bottom of the injection pump to install any sort of valve system in the injection pump drain hole. Perhaps there is sufficient clearance with the 3/4" Johnson pump, I don't know, but we opted for the larger pump on our engines.

I have the 3/4 Johnson and had no room....until I realized I could rotate the pump in the mount. Now there is plenty of clearance.

 

[Marin]

Yes, the pump can be rotated a bit but we found this didn't really gain us much. We devised a method of draining the oil with no mess that works well with the minimal clearance.

 

[Texas Lady]

Thanks for all of the advice. I agree with Marin; Is big mystery. Even American Diesel had not seen anything like this. I think I can safely say I have a unique set up.........Now I need to fix it.

By the way I used the dust pan idea for this oil change and it worked well.

Charlie

 

[bgillroy]

I change lube on LE120 MiniMec every 100hrs. Added brass extension 3 pieces: screwed 90 to drain then 2-1/2 nipple extension terminated with nice quarter turn petcock. I Hang small cup from valve for easy waste oil change makes it a breeze.

 

[catalinajack]

I did the same but the brass nipple broke off due to having been work hardened by vibration. I strongly suggest you replace the brass fittings with steel.

I change lube on LE120 MiniMec every 100hrs. Added brass extension 3 pieces: screwed 90 to drain then 2-1/2 nipple extension terminated with nice quarter turn petcock. I Hang small cup from valve for easy waste oil change makes it a breeze.

 

[psneeld]

Also I think the pump housing is aluminum.

Brass and Al don't get along near salt water.

Though most of my pump is covered in diesel or oil.

 

[Comodave]

I did the same but the brass nipple broke off due to having been work hardened by vibration. I strongly suggest you replace the brass fittings with steel.

You beat me to it, I was going to recommend that same thing.