cold weather starting?

[Tx Jim]

That's good cold weather starting for a turbo engine that has lower compression(19:1) than a naturally aspirated engine according to DarkBlack!!!

 

[jaydee325]

My 2013 LS R4047 with a Mitsubishi diesel starts wonderfully. On the really cold days, I give it 2 cycles of glow-plug warming, and it starts right up. It IS barn kept though, but the barn is not heated. So, it's out of the wind, but not away from the cold temps. I don't have any type of engine heater installed. Very impressed with cold starts.

Same thing here for my '13 LS R3039H. Been in single digits here recently and no problems.:thumbsup:

Bob

 

[ME83]

Camshaft & timing I'm fairly positive won't have squat to do with compression ratio but I need to do so research to be positive.

The camshaft has a lot to do with your cylinder pressures. A blower cam typically has more overlap/duration and different centerline timings, it is beneficial in order to get more volume into the cylinder from the turbo. This also lowers the cranking pressures in the cylinders since the pressure is bled of slightly from the valves closing later. It is a whole static and dynamic compression ratio factor when dealing with forced induction.

 

[Tx Jim]

The camshaft has a lot to do with your cylinder pressures. A blower cam typically has more overlap/duration and different centerline timings, it is beneficial in order to get more volume into the cylinder from the turbo. This also lowers the cranking pressures in the cylinders since the pressure is bled of slightly from the valves closing later. It is a whole static and dynamic compression ratio factor when dealing with forced induction.

Is what you're referring to utilized on farm tractor engine TODAY or are you referring to sophisticated auto engines? Back when I checked compression on a tractor engine it had 2 valves per cylinder that must be closed and when piston reached the top of compression stroke then the gauge showed the compression in PSI. Camshaft & timing didn't affect the reading if correct.

 

[ME83]

Is what you're referring to utilized on farm tractor engine TODAY or are you referring to sophisticated auto engines? Back when I checked compression on a tractor engine it had 2 valves per cylinder that must be closed and when piston reached the top of compression stroke then the gauge showed the compression in PSI. Camshaft & timing didn't affect the reading if correct.

You are correct with the valves being closed at top dead center. I was referring to the start of the compression stroke when the piston is just starting to move upwards. Typical blower cams have more overlap so some of the compression is lost due to the valve being open yet (closing slightly later).

Also just to clarify, ignition timing won't do anything to compression, but camshaft timing can due to what I described above.

I don't know if tractor engines really get into this much, I kind of doubt it. Considering the TDI in my wife's car is a 2 liter and makes 140hp and 240 ft lbs of torque, and the torque is closer to 300 ft lbs with a simple tune to get rid of the CPU limiting it. Most tractor 2 liter engines make maybe 50 hp and 100 ft lbs of torque. Seems to be a significant difference.

 

[Tx Jim]

You are correct with the valves being closed at top dead center. I was referring to the start of the compression stroke when the piston is just starting to move upwards. Typical blower cams have more overlap so some of the compression is lost due to the valve being open yet (closing slightly later).

Also just to clarify, ignition timing won't do anything to compression, but camshaft timing can due to what I described above.

I don't know if tractor engines really get into this much, I kind of doubt it. Considering the TDI in my wife's car is a 2 liter and makes 140hp and 240 ft lbs of torque, and the torque is closer to 300 ft lbs with a simple tune to get rid of the CPU limiting it. Most tractor 2 liter engines make maybe 50 hp and 100 ft lbs of torque. Seems to be a significant difference.

1st camshaft timing will have nothing to do with compression ratio. What do the beginning of comp stroke have to do with comp ratio? That's similar to talking about who got out of starting blocks 1st in a 100 yd race.
2nd Compression and torque aren't the same either so how does your wife's car engine have anything to do with a tractor engine except it's an internal combustion engine?????? A lot of the difference in engine torque on tractor VS auto engine is the rpm's that the torque is measured at. I'll bet your wife's car will burn less GPM in fuel also than an equivalent tractor engine.

 

[ME83]

1st camshaft timing will have nothing to do with compression ratio. What do the beginning of comp stroke have to do with comp ratio? That's similar to talking about who got out of starting blocks 1st in a 100 yd race. 2nd Compression and torque aren't the same either so how does your wife's car engine have anything to do with a tractor engine except it's an internal combustion engine?????? A lot of the difference in engine torque on tractor VS auto engine is the rpm's that the torque is measured at. I'll bet your wife's car will burn less GPM in fuel also than an equivalent tractor engine.

1st, I did state cylinder pressures and compression, not compression ratio. Compression ratio is just a calculation based upon volumes. I referred to pressure because this is what your starter is working against when cranking you engine over. An engine with higher compression ratio than another engine can have lower cranking pressures than the other due to the cam, because of what I described above.

2nd, where did I ever write that compression and torque are the same? I made the reference comparing equivalent size diesel engines to reiterate that I doubt tractor engine cams have any overlap. Their power is only a third of an automobile engine, not pushing any performance envelopes. Most automobile diesels have there peak torque around 2000 rpms, my Deere runs at 2600 engine rpm for pto work.

Maybe you need to read a little more carefully and slower...

 

[Tx Jim]

1st, I did state cylinder pressures and compression, not compression ratio. Compression ratio is just a calculation based upon volumes. I referred to pressure because this is what your starter is working against when cranking you engine over. An engine with higher compression ratio than another engine can have lower cranking pressures than the other due to the cam, because of what I described above.

Maybe you need to read a little more carefully and slower...

MAYBE but I doubt it. What ""tractor engine"" are you referring to that has higher compression but lower cranking pressure??

 

[diesel lover]

what starts when it gets cold and what has trouble? my old mf 35 diesel starts like a gas tractor,but its a 1962. how do the new tractors compare?

after being a truck mechanic for two years there are many things I can tell you, first when we bring up "cold start" that is not going to depend on engine specs, horse power, size, or compression as others have mentioned. I will give you my 100% professional opinion . A cold start will be starting at the battery. Every start of any engine relates and starts at the battery and it's where the source of all power for starting the engine comes from. Simply if the battery Is discharged at 0F and the engine won't turn over/ turn over fast enough, that will create a no start situation. * second is the battery cables and connections. All must be shiney and I will accept no less. If needed I can teach you how to preform a voltage drop test to find bad battery cables. * after the first two are good then is the starter, the starter needs to crank over the engine quick and reliably. REMEMBER ! There is a huge difference between almost starting and barely starting when it's cold. Not starting causes you to throw wrenches and also get very upset when you need a machine the most. * Very important here if the engine has a cold starting aid it relys on then it should be in 100% working order. Example if your engine has glow plugs, the all need to work well. If you have 2 go bad on a 4 cylinder engine than the engine will have trouble starting in the cold. Glow plug relays need to be energized when cold. Some engines have intake manifold heaters. Most are electric using a grid heater, others like my 1960 MAssey ferguson mf 25 have a thermostat. A thermostart creates a fire inside the manifold of the engine that runs off diesel fuel from the fuel tank. They work well. AGAIN what does all this go back to? The Battery. Remember that. Not compression or brand, not engine size but it all starts at the battery. Best answer to your question is that the best starting engines in the cold have a good battery, good cables and a good starter. Without these three the engine may have trouble cranking over at all. Block heaters: a block heater is a heated element that heats the coolant of an engine before attempting a cold start. Heating the coolant will cause the coolant to circulate in the engine. This warms the combustion chambers of the engine, followed by the engine head and injectors, followed by the entire block. Every little bit helps when it's cold. I have a freeze plug installed block heater in my half ton gasoline truck. I plugged it in at -14F and noticed quite a large difference compared to when the engine was cold for several hours at work than starting the engine. When plugged in for 4 hours some times the engine can whip over like it was just shut off and start up instantly. Again i am only going to give you my professional opinion as brands and engine size are not important compared to the importantance of upkeep and maintenance in the engine and the machine

 

[diesel lover]

KISS keep it simple stupid! I have had 15 liter truck engines start at 0F and brand new 12 liter engines that won't start in the cold. Keep it simple. Brands and compression are not as important as a well maintained machine for cold starts !! period