At what RPM Do You Start a Diesel ?

[boatman61]

First shot I open throttle in neutral about 1/3rd.... if no luck 1st turn go up to 2/3rds and she'll fire...
But... not on this boat.... its got an O/B

[wadda]

Originally Posted by goboatingnow

Nothing wrong with that just that unloaded idling of the engine to temp, while a common usage is in fact not the best way, especially in modern diesels. Once you've verified oil pressure and cooling flow your better off bringing the temp up
Under load. I tend to not leave the boat idling at the dock , but once I'm happy alls is well I motor out letting the work of that under medium revs get the temp up. It does not benefit on any way to slowly warm the engine. In fact in very modern engines the engines may never( or take a very long) to come up to temp , which is why car companies fit little webasto heaters to get the cabin heating working as soon as possible. ( particularly in urban settings)
<snip>
Diesels don't benefit from pampering, a good hard life of constant use is best. Most marine engines die of lack of use.

As I've said most diesels are designed to be available immediately upon successful startup, otherwise they'd be excluded from many applications.

Again on cool down engines can be turned off immediately. Turbos benefit from not going from full load to off . Outside of this again a diesel engine does not benefit fr a cool down idle period often many big marine diesels run too cool in near idle speeds causing excessive smoke.

I start the engine. By the time the anchor is up, the temp is too.

I had a traumatically expensive experience with the old 4107 where I took off 100 meters into the seaway at ramming speed and found the cooling system failed. Better PM has reduced the possibility of it happening again, but the emotional scars remain.

The cool down is a holdover from the warning for the horse I never had about being road hard and put away wet. But that also is immaterial because I leave the engine idling while I make sure the anchor is set.

My practice is not to pamper the engine, but to pamper myself.

[Seahunter]

Originally Posted by goboatingnow

Diesels don't benefit from pampering, a good hard life of constant use is best. Most marine engines die of lack of use.
Dave

What a bunch of crap. Did you actually read the manual from your supplied link? The manual clearly states (if you looked at the diagram indicates the IGNITION switch), meaning to turn the key all the way or to employ the option "HS" (heat start) that is connected to a intake heater (if installed). The manual states clearly that it was written for tractors and equipment NOT marine use. These instructions are for a gravity fed fuel systems (IE tractor). No marine versions were built with "HS". NEVER START A PERKINS AT FULL THROTTLE.
Clearly your knowledge is lacking; I for one would like to purchase a boat with 500 Hours on the engine rather than 5000.

[chadlaroche]

How many people start their cars and trucks at a higher rpm then idle ? Manual or electric choke will adjust as necessary to start.

[zeehag]

i start my perkins as LOW as possible. same my yanjnie-- i have 2 boats-- i start them LOW and raise slowly until engine is "happy"-- sounds awesome n purrs like a snow leopard-- around 800-1000 rpm for warming......AFTER the initial startup...

[goboatingnow]

Originally Posted by Seahunter

What a bunch of crap. Did you actually read the manual from your supplied link? The manual clearly states (if you looked at the diagram indicates the IGNITION switch), meaning to turn the key all the way or to employ the option "HS" (heat start) that is connected to a intake heater (if installed). The manual states clearly that it was written for tractors and equipment NOT marine use. These instructions are for a gravity fed fuel systems (IE tractor). No marine versions were built with "HS". NEVER START A PERKINS AT FULL THROTTLE.
Clearly your knowledge is lacking; I for one would like to purchase a boat with 500 Hours on the engine rather than 5000.

Sorry. I was looking at a mobo with two Perkins recently , funny the keys had HS for heat start. Perkins used the same engines everywhere in many forms with a couple of different heat start systems

Secondly you didn't read the " starting the engine " section. You read the " cold start " section regarding preheaters etc.

Lastly for me diesel usage is a function of time. A 20 year diesel with 3000 hours on it is far better then a 20 year old one with 400 hours. They need use , most modern marine diesels die from lack of use.

Lastly please don't be rude. You 'are quite mistaken in your views.

It's worth noting that many simplified marine manuals often recommended idle throttle starting purely as a safety as too many users misinterpreted the manuals and engaged the gearbox with some consequences. However the fact remains from a design perspective diesels like full fuel flow starts


Anyways I point you to my original reply to the OPs specific situation.

Dave

[Blue Stocking]

squarpeg,

Ya clear now?
When starting a Perkins you:
use no throttle
use 10% """
use 50% '''''
use 100% '''

You then:

let it idle
load it up immediately
"""""""""""" when oil pressure is up
run it hard , kick its ass.

You can do this because:
it's fuel pump delivers max fuel at 0 throttle
""""""""""""""""" doesn't deliver max fuel at 0 throttle.

Interesting enough, no-one has made reference to letting the engine lubricate itself sufficiently before revving.
Cam lobes and followers are lubricated largely by drain-down from the rockers, which means the oil has to get to the highest point of the engine before this can happen.
Likewise journals and big ends have to have oil pumped to them.

But then again, most Perkins I've worked on seem to pump the oil once around the engine, and then out thru every mating surface, and into the bilge anyway.
Had a friend with a Carter 39 with a V-drive 4-108. Never checked the oil with the dipstick, just looked in the drip tray.

No offence guys jus tryin ta help.

[cal40john]

Originally Posted by chadlaroche

How many people start their cars and trucks at a higher rpm then idle ? Manual or electric choke will adjust as necessary to start.

Well for a start diesels don't have chokes, electric or manual. They have a full charge of air at idle or at speed.

With manual chokes you had to step on the gas pedal to allow the stepped plate to rotate into place to prop open the throttle plate, and most times it was beneficial to pump the pedal a few times so the accelerator pump would put some extra gas in the manifold.

Only the newer cars with a bunch of dashpots allowed you to not touch anything. Electric chokes for years you had to give the pedal a kick to get the throttle to the fast idle position.

My diesel has no electrical components associated with controlling the engine. It does have an interesting governer that apparently sets the fuel to full open for starting, but the manual still says to set the engine speed control to 1/2 open which may or may not affect fuel injection timing as I haven't figured that part out yet.

There are probably diesels with electronically controlled fuel injection that control rate and timing of fuel dependent on temperature and other factors, but the older engines that are on many boats don't have this.

John

[cal40john]

Originally Posted by Blue Stocking

squarpeg,

Interesting enough, no-one has made reference to letting the engine lubricate itself sufficiently before revving.
Cam lobes and followers are lubricated largely by drain-down from the rockers, which means the oil has to get to the highest point of the engine before this can happen.
Likewise journals and big ends have to have oil pumped to them.


No offence guys jus tryin ta help.

Post #19

[goboatingnow]

It's a sad fact from a design perspective that many half baked usage patterns get developed overtime in the case of diesels often stemming from practices associated with semi diesels , gas engines etc. They enter the popular myth. Often when we were designing in features we had to back them out because marketing opinion felt that it's required changes in standard practices that would be hard to implement in the field. For example we had cylinder head bolts that we tightened to max clamp load ( max fatigue life) that took the bolt just to the start of the yield point. These often had to scaled back as service people were inherenty nervous of torquing to this point. ( yet from a design perspective is was the optimum) lots of " real world " procedures have little basis in reality.

Dave

[Jesse]

I had a 4107 with the H/S system in an old Irwin ketch. Anytime I used the hot start feature I was beside the engine where I could watch the operation with a fire extinguisher handy. Never had a problem with it but the concept of drawing raw flames through the air intake to start a cold diesel is as frightening as it is effective. It worked beautifully but I never was comfortable while operating it.

[rtbates]

Listen to your diesel. Use whatever throttle position results in as smooth a start as possible.

[Blue Stocking]

Originally Posted by cal40john

Post #19

Sorry John,
Missed that, in sorting the wheat from the chaff.

Found this very interesting. In my time in the fire service (20 yrs) we ran Macks with Schwietzer turbos on B-85 ThermoDyne engines.
It was absolutely Verboten to have your foot on the throttle at start-up.
I am also very involved in high performance saloon car racing where all vehicles use dry sump and Accusump type systems
It is generally accepted that 90% of engine wear occurs in that first 2 minutes of under-lubricated parts rotation.
But then again, I could be wrong.

[SvenG]

Originally Posted by Seahunter

No marine versions were built with "HS".

Our Perkins 4-108M has one.



-Sven

[gonesail]

with an older yanmar and cold temps .. i start at around 1500 rpms (or 30% throttle) and immediately bring down to 1000 after it fires. add more throttle if that does not work. my 3GM will not start at idle under 50 or 60 degrees. I thought there was a choke on the 2GM but not sure.