Diesel engine design: glow-plugs vs ether vs batteries

[Birdseye]

My Case 580se was manufactured around 1985 and came installed with a one touch starting fluid injection system. As I look at all the parts necessary for this cold-start system, I wonder why didn’t they just put in glow plugs and/or larger batteries. The battery box is configured for single or dual batteries so that was a designed on option but not so for glow plugs which would have provided easier starting on a single battery without starting-fluid injection into the intake. This glow plug technology was available, just wondering why it wasn’t standard.

Maybe Case backhoe designers thought backhoes aren’t used much when it’s freezing cold. Or it was an expensive additional feature and wouldn’t be use much especially since a large number of backhoes go to climates where it doesn’t get below 40F year round, so just throw on a optional cold start ether dispenser which is relatively cheap. Etc.

Any thoughts? I wish my Cummins 390 had glow plugs.

 

[Birken Vogt]

Traditionally, glow plugs were used for indirect injection engines. That engine (Cummins 3.9) is DI so no glow plugs in 1985. They might have put an air intake heater on it, in fact you still might. But I am not sure if air intake heaters were really a thing until a little later than that.

Those engines are known to start very easily in all types of weather without any assistance. Does yours not?

 

[Delmer]

There may be direct comparisons out there, that is, direct injection engine models available with glow plugs and without, but I'm not familiar with any. I'll guess that ether is MORE effective and cheaper than glow plugs, but that's not really the point, the engine was not designed with glow plugs, end of story. A block heater is cheaper and simpler too.

 

[OFF]

I don't know what the temperatures get to in Kansas, but in extreme temperatures, ether is the only thing that works. Glow plugs work much better than an intake heater system however. And there comes a point when all the battery in the world isn't going to get you going. All you're doing is using the starter to warm the block, and starters are expensive.

 

[DB2]

Fact is glow plugs draw a lot of amps and you’re depleting your power source before you even attempt to crank. DI engines have generally higher compression and are better starters.

 

[John C.]

The 6.0 and 7.3 diesels in the Fords were glow plug engines and were problematic. When the glow plugs didn't work, the engine wouldn't start. The plugs would go bad, the timers would go bad and the starters would go bad when the plugs and timers were bad. In my experience glow plugs are a sign of low compression engines with some added complexity to make up for the poor design.

 

[Tyler d4c]

The 6.0 and 7.3 diesels in the Fords were glow plug engines and were problematic. When the glow plugs didn't work, the engine wouldn't start. The plugs would go bad, the timers would go bad and the starters would go bad when the plugs and timers were bad. In my experience glow plugs are a sign of low compression engines with some added complexity to make up for the poor design.

Good time when the glow plug solenoid goes on the 7.3 get you screw driver and off to the races

 

[Birdseye]

Are you saying that in 1985 the technology for glow plugs on DI diesels didn’t exist so the only option was an ether system ?

Found this on wiki, according to the author the minimum starting temp on my Cummins DI 390, would be 32F since it doesn’t have a glow plug. That seems about right:

“...The minimum starting temperature without using glowplugs is 40 °C for precombustion chamber injected, 20 °C for swirl chamber injected, and 0 °C for direct injected engines. ”. Main article is here.

 

[Truck Shop]

Small pre-cup PC engines are not as big a problem as large pre-cup engines on emissions. Large pre-cup engines usually have poor fuel mileage and dirtier emissions. Plus pre-cup cylinder
heads are way more expensive to manufacture. Maintaining the glow plug/starting system is a added task and can be expensive, plus more to manufacture. The simplest idea is the intake
air pre-heater. The old A model cat was a good engine with pre-cup, when Cat changed them to direct injection it made the early 3406's a great engine. 1/2 to 3/4 a gallon advantage/ increase
in fuel mileage.

 

[Swetz]

An air intake heater could be added. I have thought about adding one to my Ford 445A, but it is a project that I haven't gotten to so I haven't done it yet.

Anyhow, if your intake does not match the bolt pattern of existing heaters, there is a company that makes an add-on unit. This is the one I have been thinking about.
Here is a link:
https://www.rattlintruck.com/i-1626-sure-start-inline-universal-grid-heater.html

 

[Bluox]

Are you saying that in 1985 the technology for glow plugs on DI diesels didn’t exist so the only option was an ether system ?

Found this on wiki, according to the author the minimum starting temp on my Cummins DI 390, would be 32F since it doesn’t have a glow plug. That seems about right:

“...The minimum starting temperature without using glowplugs is 40 °C for precombustion chamber injected, 20 °C for swirl chamber injected, and 0 °C for direct injected engines. ”. Main article is here.

That article should start "Once apon a time" if you read it carefully it contradicts it self several times .Who ever wrote that is basically clueless about diesel engines.
Bob

 

[kshansen]

If this machine is parked where electric power is available I would be looking into block heaters. If there is one available as an in-block that would be my first choice. Second choice would be a well done external tank type.

Some of the in-block types can be installed with a thermostat that control the on off of the heater to keep engine at a set temperature. Another option would be having a timer in the power source to have it come on a predetermined time before the tractor is needed.

To my way of thinking having a coolant heater of some kind has the advantage of having the combustion chamber warm at start up. Where the manifold heaters, ether injectors or even the glow plugs have the engine components cold at first start. And if machine is parked in say sub-zero temps an oil pan heater might also be something to consider.

 

[casey518]

In colder temps I used to have to crank my machine for a while if I did not plug the block heater in for 2 hrs or so before. Recently I realized the previous owner had snipped the wire going to the Thermostart system. Apparently It introduces heated fuel into the intake with the use of a glow plug. 20-30 seconds before cranking and it started at 30 degrees without trouble. I used to wear down a battery trying to do that before i fixed it. The block heater is still the best way to go though if i know I'm going to need to start it.

 

[Birken Vogt]

Glow plugs are a solution to a problem (the problem is: won't start when cold).

Your 3.9 engine is generally known as being a type that will start without any help.

Does yours have a hard time starting and at what temperature does the problem start?

A few extra seconds of cranking, using some throttle, and rough running and smoke would not have been considered a "hard starter" in 1985. So long as it could actually be started without burning down the starter, using jumper cables, etc. they would have been OK with it back then.

 

[Shimmy1]

A few extra seconds of cranking, using some throttle, and rough running and smoke would not have been considered a "hard starter" in 1985. So long as it could actually be started without burning down the starter, using jumper cables, etc. they would have been OK with it back then.

Best reply I've seen in a long time. We are spoiled rotten compared to what men had to deal with in the 70s-early 80s. Caterpillar had it figured out long before anyone else, their PC engines started as good or better than anything else of that vintage. When the B series Cummins came out, the best starter I knew of at that time was the Case 504 that had a rack magnet and starting grooves in the plungers. Deere didn't figure out cold starting until the mid 90s.

 

[Truck Shop]

Perfect example of a hard starting gold engine is the early Cummins 855. Fixed time-anything below 35* smoke like hell. Plug it in for a hour fire right up. When those engines
were common early cold mornings at truck stops you couldn't see across the lot for the light blue cloud of smoke hazing the view from 10 trucks firing up.

 

[kshansen]

Perfect example of a hard starting gold engine is the early Cummins 855. Fixed time-anything below 35* smoke like hell. Plug it in for a hour fire right up. When those engines
were common early cold mornings at truck stops you couldn't see across the lot for the light blue cloud of smoke hazing the view from 10 trucks firing up.

We had a 1979 W900 that I believe originally had a 8V92 that had been converted to a 855 Cummins. Believe we rebuilt that 855 with a kit and some parts for a NTA420 that we had sitting around from a canceled overhaul on an off-highway M-35 Mack. Like Truck Shop said if it got near freezing outside it needed heat or just a sniff of the ether can to start. A couple times I recall someone not familiar with it fire it up cold and try giving it too much fuel while cold and it could skip a little then fire in the exhust and blow the exhaust off. Most of the drivers did like it otherwise as it was gear so I was told that running empty on level roads it could hit 100 mph, but then I know how some drivers can stretch things a bit!

 

[old-iron-habit]

Fact is glow plugs draw a lot of amps and you’re depleting your power source before you even attempt to crank. DI engines have generally higher compression and are better starters.

My Cat 922A loader manual claims that at 0 degrees F, 2-1/2 minutes of glow plugs equal 10 seconds of cranking amps. That's a D330 engine. Cats typically have long glow pug hold times. 1-1/2 minutes at 30 Degrees. Below 0-F they recommend a external preheating source such as a block heater.

 

[56wrench]

when i used to run my 46a doing land clearing i used a propane recirculating coolant heater on 20lb bottle. i would start it after i shut it down and leave it on all night and in the morning it was nice and warm

 

[colson04]

I've never heard of a propane coolant heater, but I would bet that's the cat's meow for working out in the bush during a cold, northern winter.