Where are my glow plugs?

[skyflyer]

Just realised that my engine (Yan 3GM30F) does not have glow plugs for pre-heat (Well, if it does they aren't wired up!). My previous boat had a different engine with pre-heat position on the keyswitch. My current boat has the same key switch but nothing actually wired to it; this would explain why I never saw a voltage drop when I was "pre-heating"

Is this standard for these engines or do I have a 'warm weather' option?

 

[prv]

No glow plugs on the GM series engines. Still seem to start ok.

Pete

 

[Scotty_Tradewind]

No glow plugs on the GM series engines. Still seem to start ok.

Pete

are they slightly higher/lower compression to allow them to do this?

S

 

[prv]

are they slightly higher/lower compression to allow them to do this?

No idea

Pete

 

[savageseadog]

You set the "throttle" to 50% to help cold start.

 

[Scotty_Tradewind]

that's what I do with my Bukh which has no glow plugs.

savageseadog....Greek courtesy flag?

ta
S.

 

[<152587>]

Generally only indirect injection engines are fitted with glow plugs but saying that also some direct injection engines are fitted with them for start assistance in extreme cold conditions. If glow plugs are not fitted then assume the injection is directly into the cylinder and not the Ricardo chamber. Our local " engineer" said in the loosest possible terms, advocates fitting heaters in the inlet tract to combat poor starting, this is purely masking other problems such as low compression.

 

[earlybird]

Yanmar GM engines do have a pre-combustion chamber, despite having no glow-plugs.
When I owned a 2GM20, it started in most temperatures "on the button", but in very cold conditions, my experience was that starting was difficult irrespective of control setting.

 

[savageseadog]

Cold starts on diesel engines consist of three basic techniques. Glow plugs, fuel enrichment and air intake pre heaters. Glow plugs tend to be used on cars to minimise exhaust smoke on start. The Yanmar cold start with 50% throttle is fuel enrichment. The problems with starting any diesel engine in very cold conditions are multi-fold. The main two issues are oil viscocity and battery power. Cold oil is much more viscous, together with increased friction and stiction the starter has to work far harder to turn the engine over. This in turn leads to greater demand on the starter and battery, the battery is less efficient at low temperatures . The reduced engine speed means it's less likely to start. It's possible to use a hair drier or hot air gun on the air intake to assist starting, I've used burning newspaper as well.

 

[prv]

The problems with starting any diesel engine in very cold conditions are multi-fold. The main two issues are oil viscocity and battery power. Cold oil is much more viscous, together with increased friction and stiction the starter has to work far harder to turn the engine over. This in turn leads to greater demand on the starter and battery, the battery is less efficient at low temperatures . The reduced engine speed means it's less likely to start.

Certainly the only time I had any difficulty starting Kindred Spirit's 2GM20 was in the middle of winter with ice on the pontoons, first thing in the morning, with the boat having been closed up for several months and the battery probably a bit flat.

After a couple of attempts at normal starting, I opened the decompressors, span it up on the starter motor, then dropped the levers and the engine started straight away. As you say, probably more about cold treacle-y oil and sluggish battery than a lack of glow plugs.

Pete

 

[Keith-i]

Most modern cars only activate the glow plugs if the temperature is below 5C. Above that I presume the electronics compensate for it.

 

[kolster]

Cold starts on diesel engines consist of three basic techniques. Glow plugs, fuel enrichment and air intake pre heaters. .

My Petter Mini Twin has a pre-heater in the inlet manifold.

 

[charles_reed]

Generally only indirect injection engines are fitted with glow plugs but saying that also some direct injection engines are fitted with them for start assistance in extreme cold conditions. If glow plugs are not fitted then assume the injection is directly into the cylinder and not the Ricardo chamber. Our local " engineer" said in the loosest possible terms, advocates fitting heaters in the inlet tract to combat poor starting, this is purely masking other problems such as low compression.

The GM range had no glow plugs - started well enough in even freezing conditions.
To my knowledge Yanmar have not yet produced a direct injection, small-boat engine though the YM series do have pre-heaters.

 

[Lon nan Gruagach]

Farmyard techniques to start a tractor:

Light a smal fire under the engine nd leave it for an hour.
Blow torch down the air intake.
Wrap it in a blanket over night.
Blanket and greenhouse heater (low power)
Drain coolant at end of day and refill with hot in the morning.
Crank till the battery is flat, recharge battery and try again.