Perkins

[Guest]

A Perkins 510, which is a V8 diesel if it makes any difference or you can get variations I don't know about.

 

Had one parked up and run only infrequently for short times, for over a year. Starts superb, runs smooth and sounds all good. Took her for a big run today while pulling the boat out of hibernation.

 

All was good but when I pushed the revs up there was a little hint, nothing big at all but definitely there, coming out of what looked like a mesh vent thing (2 off, one each side) on the aft end of the motor up near what I know as a rocker cover if talking old school car motors. When tapering the revs back a bit it stopped or all but went away, maybe still just the tiniest hint. At the time the motor did sound like she was above cruising revs, doing 1750 rpm at the time.

 

3 questions -

1 - Are those vent things just vents?

2 - Is a hint of smoke a worry?

3 - If you answered 1 & 2 you must know something so Q3 is, what's causing it?

 

And another Q if I may. Perky runs very well and is pushing 30 tonnes of Pugh designed 58ft steel ketch, currently with a furry bottom but that'll be worked on over the next few days. Cruising revs are 1400. Anyone have any idea what fuel consumption rate would be good to work on?

 

She doesn't get used a lot, the owners penis dragged him to (in to? :) ) a lady in Chch and still looks to be in use so a return date is unknown, I don't want to overload her only to have 1000lts of dead fuel in 6 months. I'm guessing a R930 max fuel load of 22lts probably won't get me that far

 

Oh crap, I'm about to have to do what I laugh watching others do... stand for ages at a fuel pump

[grant 40]

this might help on the gas guzzling side

 

http://www.rpsmarine.com/rps_marine_fuel_calculator.htm

[Guest]

That's a cool site, very interesting.

 

One downside though, I don't know the Hp rating of Perky. Apparently it's a wide band depending on configuration.

[PaulR 3]

Google perkins engines 510

=> www.perkins.com with details about engine numbering etc.

[wheels 543]

The continuous rating of the 8 is SAE120Hp@2000RPM and peak power rating is SAE160Hp @2800RPM.

They are vents and any fumes can and should be sucked back into the intake manifold via a pipe fitted to the tappet cover. Maybe something I can do when up there.

1400 is way too slow an RPM for cruising. 1750-2000RPM should be more like it. But I imagine the prop will be well fouled and in need of a good shave.

Hp is depenadant on RPM and Fuel usage is dependant on Hp and Load. In otherwords, you open the throttle, she wants to obey her master and provide X RPM, which at X RPM she will provide X Hp and thus sucks X amount of fuel to produce that RPM. But dirty bottom and prop is going to make it work harder to provide that RPM, so because it wants to be faithful, it tries to suck more fuel to provide what it's master has asked of it. The result is the use of lots of fuel and a lot more heat generated and no more speed.

Off the top of my head, you are going to use about 10ltrs/hr ruffly at 1500 and probably 15ltrs/hr at 1700-2000. Over that and the fuel usage really starts to climb.

If you want exact, I can work it out exactly for you.

Also remember, she may suck lots of fuel, but can plough the harbour up at a faster rate, so it is all horses for courses in the end.

Running these engines all the time at low RPM is bad. They love hard work, but watch that you don't have lots of black smoke as that is a sure sign she is overloading due to dirty prop and bottom.

[Guest]

Sounds shite at much over 1700, just seems way too fast. 2000 and the word screaming comes to mind. I remember Capt K mentioning something that was along the lines of 'blaa blaa so it can't run at the right revs'. Prop pitch or something I think. As he doesn't move it much it's never been a worry he's need to sort out I suppose.

 

She's a nice boat but really needs someone to use it a lot more and tweak all the weird or knot quite right yet bits.

 

I'll see how she goes after the bum scrub. Judging by the lack of Ommph when kicking her in the slats I'd say the prop could just be a ball of weed. There was a large streamer coming out from under the stern yesterday.... then I put it in gear and it went away. 1st night away will be Motohie for a prop and as far as I can go on a battery load (hooker) clean. Like you I do suspect the 400mm long weed hanging of her around the waterline probably isn't the fastest :)

 

I'll chuck in 500lts and I'm sure we can burn that up over summer. I know a man and will speak at him about re-pitching the prop I think.

[Farrari 4]

How are you checking your RPM KM? From what I have read around the traps RPM gauges can be well out of whack. It might be worth while verifying the gauge. Screening at 2000 RPM does sound a little odd.

[wheels 543]

First thing, we need to check the Tacho is giving the real engine RPM. If it is a cable type then it should be close and not much you can do to tweak it. But an electronic one may never have been adjusted right and may need a tweeking. I can do that.

The next is that if the prop is dirty, then it could be cavitating and/or out of balance, which will make everything sound and feel bad.

KM, once you have cleaned the prop, Run the engine full throttle with it out of gear. You should be able to open throttle all the way and the engine should go to about 2600-2800Max if the throttle hasn't had the upper limit set low.

Then pull her back and drop it in gear and open throttle again. Normaly the rule of thumb is to get to within 10% of the max revs you obtained when unloaded. That means you have about the right pitch on the prop.

There are two versions of this engine. The V8 and the TV8. The TV is T for Turbo, but they brought the max RPM down to 2600, but even then it is muscling out 238Hp. The V8 should rev to 2800RPM. It's continuous working RPM was designed for 2000RPM. That is because this engine was mainly desinged for Tractors and Dozers and needed to work it's guts out all day and have the ability to provide short burst of extreme power under the Vehicle govenors that were used.

[wheels 543]

I should also add, Idle speed should be around 650-750RPM.

If you need to give her an oil change, use a Mono30 grade. And she will gobble up nearly 18ltrs of the stuff.

[Guest]

Old school looking gauge on dash. I seriously doubt anything electronic, no signs of any, and no Turbo is fitted.

 

But you may have a point as when you pull the throttle right back it says it's idling at 200 rpm, which I though was rather slow, mind you it does sound bloody slow. Maybe we have a under reading thing happening all over in which case the 1500rpm reading may actually be higher in true rpm.

 

Gawd, at 2800rpm I think she'd explode or at least sound like it's about to happen. 2000 sounds bad enough assuming we don't have a dodgy gauge. Maybe another hint towards the gauge is under reading. I really wouldn't even like to try to get to much above 2000 using the gauge numbers. I'm OK even if at a basic level on diesels, but have used many over the years, much above 1800rpm just sounds wrong to my ear. And don't forget I spend a lot of time around outboards screaming and aircraft motors running at red line, they sound a lot better than Perky at 2000rpm.

 

At 1500 odd on the gauge she's purring nicely and seems happy as a pig in pooh.

 

Anyone know what 'idle' revs should be? At the moment at full idle, even a bit above that, you can chuck it into gear and you don't notice squat, certainly no thunks, clunks, bangs, or neck snapping leap of acceleration. There is a very very slight hint something happened thru the level but that's about it.

 

I'm starting to think the gauge could be out, which may explain a few things. I think I'll run at 'sounds OK' revs until someone with more clues as a suss. I'm sure there is some meter that can read the true RPM off something on the motor.

 

It was all done back early 80's may a bit earlier and since them things have only happened that needed to happen i.e. no upgrades, just problem fixing, which have been bugger all as I understand it. So we aren't talking NASA levels of technology by any stretch.

 

OK, Wheels, just saw the 650-750 idle speed you posted. Which leads now to 'We have a gauge reading issue Huston'. So assuming the gauge is out a set amount across the broad my 1500rpm could actually be 19-2000. Which would explain the bloody awful noise when the gauge reads much above 1800 odd.

 

Could Perky actually run as slow as 2-300rpm?

 

Back to house patching before we go. The digger chopped the old water main feed while putting the new drive in so the newly laid but 'will be connected later' water main feed had to be rushed into use sooner than expected. Now we have mains pressure we are suffering collateral downstream issues. The dunny refills in about 3 seconds but this morning blew the tap washers apart. Bathroom vanity pushed out so much more it won't drain fast enuff so pulled the waste apart only to find Fort Knox. One of those basins with the slot overflow at the top and I suspect the kids have been using it as a piggy bank, chocker with coins. Had to readjust the mixers to suit. Now just waiting for the 1960 water cylinder to explode. Maybe I shouldn't have told the plumber I wanted a mains feed big enough to empty one of the damns in 1 hour :)

[wheels 543]

Could Perky actually run as slow as 2-300rpm?

Probably not. One sure sign would be that the engine Oil pressure would drop so low, that the Alarm or light (if fitted) would flash/buzz, whatever. It would be a ruff as hunting idle and most likely, dropping from high revs to Idle while under load, would cause engine to stall.

It is quite possible it is electronic gauge. They usually are. I have a hoodacky that I can check and adjust that when I get up there.

The other thing is that if at it's current idle, if it sounds sweet as and not too fast for an idle, then wind the Tacho up to say 700. Then see where that sits are normal operating noise.

 

On the back of the Tacho, there should be a small hole. Inside that hole is a little plastic adjustment screw. Moving that will change the point the Needle sits at. So at idle, just wind the screw till the needle sits around the 650-700mark.

 

Re the Revs, yeah it may sound bad at full RPM, but the beauty of a Diesel is that they are governed, so you can open them right up and they will go to max RPM and sit there for a short time OK. You won't damage anything, weven though it sounds like it wants to climb out of the engine room and then explode all around your ears, just so it can say Har, that'll learn ya.

[Guest]

When you pull the lever hard back the gauge reads 200-250 odd rpm but Perky sounds OK, knot ruff, super slow, struggling to stay alive or anything like that. You can engage gear at that rpm and it'll slow a small tad more but doesn't sound like or give any impression it's about to stall. No warnings and oil pressure stands up. 650-700 on the dial it sounds 'too quick' at which to engage gear.

 

It's looking very much like we have a dodgy reading dial doesn't it. Going deep..........

[wheels 543]

Yup. Sounds mighty sus to me.

[PaulR 3]

I'm sure there is some meter that can read the true RPM off something on the motor.

 

I have a mecanical REV counter measuring instrument. It has a series of changable tips to push onto moving parts to read the RPMs of that item e.g. flywheel, shaft, water pump or alternator polleys etc.

 

No batteries required, no wiring etc