Bullet Proof Diesel

[FlyingCloud1937]

My engines native color was Blue as in Perkins 6-354 III, they were the dark blue unlike the Range series IV which are a much liter shade of blue.

As usual I was leaving Friday Harbor, after picking up Guest. I did my normal ER Check. In doing so I notice what appeared to be a hairline crack on the white oil cooler where the high pressure fitting connected. A close inspection varified the faintest of oil, with just a little pressure applied to the hose, the fitting breached.

Now had this been it's native color, it's likely I would not have been able to see this failure coming, and it would of gave way spewing all the oil from the engine, possible resulting in a catastrophic engine failure.

I do have oil/water alarms, but a 3/4 hose at 60 psi can shed 4 gallons of oil in a quick hurry.

Lloyd

Originally Posted by captain58sailin

I knew if I offered that outlandish piece of wisdom, someone would come along and counter it. Regardless the color, if you perform a careful inspection before start up you will catch things before they become catastrophic.

[captain58sailin]

a64pilot, you should go to a reputable prop shop and tell them the differential, most good prop men can tell you what needs to be done to get your prop right so you run right. My one experience with an over propped vessel, even though we were running at a reduced rpm, we melted a hole in a piston and then bad things happened, and that was the second occurrence. I believe you can over stress your engine and shorten it's life.

[FlyingCloud1937]

The potential harm will come when you are pushing against a strong tide/current for hours. If you don't have pyros, you won't see the engine running hotter EGT. This can lead to piston, valve, and head gasket problems.

Lloyd

Originally Posted by a64pilot

How bad is overpropping?
My engine should turn 3600 RPM, full bore, but will turn only 2700. Tach has been verified accurate and prop is spotless, so it's obviously over pitched.
I cruise it at 2000 and it seems happy there, full throttle you can tell she is straining, but even then, no black smoke.
I know I'm giving up significant HP by not letting her turn up, but are we sure this is damaging? What specific harm does it do, she's burning all the fuel as evidenced by lack of smoke.

[Pauls]

There is nothing inherently wrong with over propping. If you want to run your engine at lower RPMs, and you have the horsepower available to do this and still deliver the power the boat needs, it can be a good thing.

The problem with over propping is that some people run the engine as if it was propped normally. Meaning if you have a 3600 RPM redline engine, have it propped so that it can only turn 2700, and then run it at 2700, the engine life will be very short. As has been said before, if you keep the RPMs 20% or so below the engine/prop combo redline it will be fine.

And, to be clear, if you're headed into a 50 kt headwind and 8' seas you must check what the max RPM is under those conditions and modify your running RPM accordingly. By the way, this applies to all engine/prop combos. Overloading can kill a diesel quickly. As long as you don't do that it can be a happy motor.

[darylat8750]

The best way to tell if having more pitch than recomended is hurting your engine is by looking at one of the fancy gauges that will give you a % of power under various rpm/manifold pressure combinations. Like the new John Deere's have. Absent that Exhaust Temp Gauges are very good second choices. Prop your engine so it will turn up rated rpm and run it at full throttle and note the EGT. Then no matter what you do with the prop never exceed that EGT. Another good way on a turbocharged engine is to use a manifold pressure gauge. There should be charts available from the manufacturer that shows the combinations of rpm and manifold pressure that is appropriate.

[nhschneider]

Originally Posted by colemj

I can find no other info other than your posts corroborating this placard and the 1,000hrs.

What I have been able to find is that Volvo-Penta warranties that engine for 1,000hrs or 2yrs, whichever comes first.

Are you sure you haven't misinterpreted that placard? It would be strange that the warranty period on the engine was placed so close to a known end-of-life. I mean, if it died at 999hrs, Volvo would have to replace it. Doesn't seem likely to me.

Further, the identical Perkins engine does not seem to have that either. Volvo simply resells the Perkins in a different color.

Mark

This is a photo of the tag that's on the engine of my brother's Volvo Penta D2-75. He gave me permission to post it here as long as I didn't say bad things about his engine.

[Jim Cate]

Originally Posted by nhschneider

This is a photo of the tag that's on the engine of my brother's Volvo Penta D2-75. He gave me permission to post it here as long as I didn't say bad things about his engine.

Astonishing! Why would anyone buy an engine with that label on it?

That just boggles my mind...

Jim

[lonesoldier0408]

I have a Yanmar engine, from a John Deere golf course Greens Mower. I placed it in an 83 Mazda B2000. It's currently surviving, my 23 year old daughter and daily local commutes. Of course lots of RPM fluctuation and 40 mpg city & 50 mpg highway. At 76 mph, it failed to, "Slow her role," as much as I had hoped. Wish I had a, "Dr. Evil," emoticon to place here.! 😉


Sent from my iPhone using Cruisers Sailing Forum

[hellosailor]

Mark-
It is risky to assume that Volvo simply repaints a Perkins and calls it a Volvo. Consider that this is a contract business, and that it could be the same as any "white box" or OEM supply.
I used to buy "white box" (literally) 3M open reel recording tape and it was "exactly the same". Except, when tape exceeded 3M's own internal limits for the number of dropouts per thousand feet, it got white boxed. So it wasn't necessarily the same even though it came off the same line.
Or the GM divisions. You could buy a Chevy or a Buick with the "exact same" engine and front end as a Caddy. Except, the Caddies were built with a requirement that the front end parts have a tighter tolerance, so "the same" parts were a higher spec and the wash-outs went to the other divisions.
Heck, Seagate used to sell hard drives to OEMs on the same basis. If you bought a Seagate that was rebranded to DEC, it could have a limit of two bad sectors. Buy it under another brand name, it might have 20. "Exact same" device though.

You could have the same thing with engines built on contract. If the contract says the bearings or the rings or the camshaft only need to meet a certain spec, looser or tighter than the Perkins branded one...We'd need a spy inside one of the companies to actually read the contract and see.

The general numbers I've seen are that any small marine diesel, the kind you would find in 35-45' boats, is good for 5000 hours before major overhaul, and 5000 more before the next overhaul. In the radical assumption that the operators have all followed all factory specs. Proper maintenance, oil changes, fuel, thermal management, rpm range, load, and of course, not jamming the driveshaft into anything while operating, or even while not.

But how often do you think all that is going to happen?

[colemj]

Interesting. That appears to be an EPA sticker. I looked up the EPA submission for diesel engines. It appears that most engines from all manufacturers are given set ratings of 10yr/1,000hrs or 10yr/10,000hrs, with a only a few at 10yr/20,000 or 3yr/10,000. These last two ratings seemed to be unusual and required an explanation as to why they deviated.

I don't know what these ratings actually mean, but the Volvo above (note that it actually says Perkins) is in good company with many Yanmar, Caterpillar, Detroit Diesels, Cummins, Perkins, John Deere and many others also having the exact same rating.

Conversely, many Volvo models (and those from other brands) had one of the other above "higher" ratings.

To make it stranger, it appears that identical engines (identical model numbers, or model numbers that differed only by an added differentiating tag like "-A") from many manufacturers had different "useful life" EPA ratings. At first I thought it corresponded to the EPA category of "recreational" vs. "commercial", but then I noticed that some "commercial" rated engines were 10yr/1,000hrs and vice versa for "recreational".

Again, I don't understand the meaning of any of this - just reporting what I found.

So while that sticker on that engine may be mind boggling, there is a good chance that the non-Volvo engine in one's boat is also rated the same.

And one has to wonder about a 1000hr warranty on a 1000hr "useful life" engine. Doesn't make good actuarial sense...

Mark

[colemj]

Originally Posted by hellosailor

Mark-
It is risky to assume that Volvo simply repaints a Perkins and calls it a Volvo. Consider that this is a contract business, and that it could be the same as any "white box" or OEM supply.
I used to buy "white box" (literally) 3M open reel recording tape and it was "exactly the same". Except, when tape exceeded 3M's own internal limits for the number of dropouts per thousand feet, it got white boxed. So it wasn't necessarily the same even though it came off the same line.
Or the GM divisions. You could buy a Chevy or a Buick with the "exact same" engine and front end as a Caddy. Except, the Caddies were built with a requirement that the front end parts have a tighter tolerance, so "the same" parts were a higher spec and the wash-outs went to the other divisions.
Heck, Seagate used to sell hard drives to OEMs on the same basis. If you bought a Seagate that was rebranded to DEC, it could have a limit of two bad sectors. Buy it under another brand name, it might have 20. "Exact same" device though.

You could have the same thing with engines built on contract. If the contract says the bearings or the rings or the camshaft only need to meet a certain spec, looser or tighter than the Perkins branded one...We'd need a spy inside one of the companies to actually read the contract and see.

The general numbers I've seen are that any small marine diesel, the kind you would find in 35-45' boats, is good for 5000 hours before major overhaul, and 5000 more before the next overhaul. In the radical assumption that the operators have all followed all factory specs. Proper maintenance, oil changes, fuel, thermal management, rpm range, load, and of course, not jamming the driveshaft into anything while operating, or even while not.

But how often do you think all that is going to happen?

I don't know what to tell you, but note that the sticker on the Volvo engine above is a Perkins sticker describing a Perkins engine. Additionally, the letters "Perkins" are cast right into the block. Not to mention that you can buy Perkins parts for every single component of the engine (except the touchup paint).

Besides the green paint, the only thing that tells you it is a Volvo is the sticker that says "Volvo". It is placed over the sticker that says "Perkins".

Mark

[colemj]

The other odd part about that sticker is it lists the engine as a 2007 model. Volvo and Perkins state that the D2-75 went into production in 2008. Close enough, I guess, to imply that EPA certification was done in 2007 for an engine going to market in 2008.

Mark