Running engines when its cold
10-28-2012, 02:06 AM
#1
Tech Master
Thread Starter
Running engines when its cold
Hi all.
I just had a talk with my very good friend about running our engines when its cold (-5º to +5ºC / 23 to 41F).
Will the lifespan of an engine decrease in cold ambient temperatures?
I know you'll have to retune (richen) your engine due to more oxygen in the air.
Lets say an engine normally is 110ºC in the summer. If you run it at 0ºC it will only be 80ºC - race tuned. Now, thats will ruin your engine, because the sleeve doesn't expans as much as it should. Next time you run your engine in the summer, the compression is gone... Correct?
I think its enough to wrap the head so you can keep an temp between 100 and 110ºC (212 to 230F) when the engine is tuned for race.
Roelof suggets using a on-road head to reduse the cooling of the engine. Smart
. Will such a head have the same effect as wrapping the normal head?
Thanks guys.
I just had a talk with my very good friend about running our engines when its cold (-5º to +5ºC / 23 to 41F).
Will the lifespan of an engine decrease in cold ambient temperatures?
I know you'll have to retune (richen) your engine due to more oxygen in the air.
Lets say an engine normally is 110ºC in the summer. If you run it at 0ºC it will only be 80ºC - race tuned. Now, thats will ruin your engine, because the sleeve doesn't expans as much as it should. Next time you run your engine in the summer, the compression is gone... Correct?
I think its enough to wrap the head so you can keep an temp between 100 and 110ºC (212 to 230F) when the engine is tuned for race.
Roelof suggets using a on-road head to reduse the cooling of the engine. Smart
. Will such a head have the same effect as wrapping the normal head?Thanks guys.
10-28-2012, 06:04 AM
#2
Wrapping the head is too extreme, no cooling will be made, this is only done when driving in the full rain or when running in.
We have made 5 different heads with a different cooling capacity and the theory of controling the expansion of the sleeve in several air temperatures with these different heads is working life on the track. If we think the engine is running with some pinch not getting the full rpm range we change the head to a lighter cooling capacity and the engine is running better on the track.
The tight pinch in such cold conditions can have an affect when running that engine in hotter conditions again.
We have made 5 different heads with a different cooling capacity and the theory of controling the expansion of the sleeve in several air temperatures with these different heads is working life on the track. If we think the engine is running with some pinch not getting the full rpm range we change the head to a lighter cooling capacity and the engine is running better on the track.
The tight pinch in such cold conditions can have an affect when running that engine in hotter conditions again.
10-28-2012, 06:49 AM
#3
Tech Master
Thread Starter
Wrapping the head is too extreme, no cooling will be made, this is only done when driving in the full rain or when running in.
We have made 5 different heads with a different cooling capacity and the theory of controling the expansion of the sleeve in several air temperatures with these different heads is working life on the track. If we think the engine is running with some pinch not getting the full rpm range we change the head to a lighter cooling capacity and the engine is running better on the track.
The tight pinch in such cold conditions can have an affect when running that engine in hotter conditions again.
We have made 5 different heads with a different cooling capacity and the theory of controling the expansion of the sleeve in several air temperatures with these different heads is working life on the track. If we think the engine is running with some pinch not getting the full rpm range we change the head to a lighter cooling capacity and the engine is running better on the track.
The tight pinch in such cold conditions can have an affect when running that engine in hotter conditions again.
Always nice to read your replies
Well, I did not explain myself correct: If we wrap the the heads, its only the upper fins we wraps. Otherwise the temps gets waaaay too high even if its freezing
My trusted old NOSRAM engine has been running several times at races in very cold ambient temperatures (the lowest was -8ºC). Never ran her lean and always wrapped to keep the temp between 100 and 110ºC. Sometimes I've wrapped two and sometimes 3 or 4 fins with a dry outer airfilter foam. The engine is still in great condition.
Its just this, that some Danish drivers don't participates in these winter races because "It will ruin my engine". That's a shame.
Last edited by Lille-bror; 10-28-2012 at 07:01 AM.
10-28-2012, 08:10 AM
#4
Thanks Roelof.
Always nice to read your replies
Well, I did not explain myself correct: If we wrap the the heads, its only the upper fins we wraps. Otherwise the temps gets waaaay too high even if its freezing
My trusted old NOSRAM engine has been running several times at races in very cold ambient temperatures (the lowest was -8ºC). Never ran her lean and always wrapped to keep the temp between 100 and 110ºC. Sometimes I've wrapped two and sometimes 3 or 4 fins with a dry outer airfilter foam. The engine is still in great condition.
Its just this, that some Danish drivers don't participates in these winter races because "It will ruin my engine". That's a shame.
Always nice to read your replies
Well, I did not explain myself correct: If we wrap the the heads, its only the upper fins we wraps. Otherwise the temps gets waaaay too high even if its freezing
My trusted old NOSRAM engine has been running several times at races in very cold ambient temperatures (the lowest was -8ºC). Never ran her lean and always wrapped to keep the temp between 100 and 110ºC. Sometimes I've wrapped two and sometimes 3 or 4 fins with a dry outer airfilter foam. The engine is still in great condition.
Its just this, that some Danish drivers don't participates in these winter races because "It will ruin my engine". That's a shame.
) head other reasons not to run in Xtreme cold is : plastic parts break much easier , fluids need to be adjusted on car requiring alot of work and your hands get so dam cold you cant feel em!
Youre a diehard Bjarne
Boy though , engines sure make alot of power when the air they breath contains alot of cool oxygen though
10-29-2012, 02:55 AM
#5
Tech Master
Thread Starter
Wtvr works , roelof has the perfect solution of using different size/style of cooling (or in this case "heating" ) head
other reasons not to run in Xtreme cold is : plastic parts break much easier , fluids need to be adjusted on car requiring alot of work and your hands get so dam cold you cant feel em!
Youre a diehard Bjarne
Boy though , engines sure make alot of power when the air they breath contains alot of cool oxygen though
) head other reasons not to run in Xtreme cold is : plastic parts break much easier , fluids need to be adjusted on car requiring alot of work and your hands get so dam cold you cant feel em!
Youre a diehard Bjarne
Boy though , engines sure make alot of power when the air they breath contains alot of cool oxygen though
. I'll have no worries racing when its cold. I drive XRAY so no broken parts there. Hope to be able to convince other drivers.Diehard?.. Yearh... Remember Danes are Vikings!
10-29-2012, 06:22 AM
#6
We run a winter series around here and temps are usually in the 35-45F range. Tune the engine right and it runs well. I always preheat my engine when it's that cold outside no matter how old it is. Then I usually take those same engines to the nitro challenge and run them there. I don't see any performance loss by running them when it's that cold outside. I think as long as you preheat and tune for performance you are good.
10-29-2012, 12:30 PM
#7
Tech Master
Thread Starter
We run a winter series around here and temps are usually in the 35-45F range. Tune the engine right and it runs well. I always preheat my engine when it's that cold outside no matter how old it is. Then I usually take those same engines to the nitro challenge and run them there. I don't see any performance loss by running them when it's that cold outside. I think as long as you preheat and tune for performance you are good.
. Actually this preheat stuff is like a religion. Some believe and some don't. I'm a believer.
10-29-2012, 01:52 PM
#8
Even when pre-heated it takes some time to get the engine on full operation temperature:
http://www.youtube.com/watch?feature...&v=cwkVENYaK-k
You can imagine how long it takes when starting it cold.....
http://www.youtube.com/watch?feature...&v=cwkVENYaK-k
You can imagine how long it takes when starting it cold.....
10-30-2012, 12:00 AM
#9
Tech Master
Thread Starter
Even when pre-heated it takes some time to get the engine on full operation temperature:
http://www.youtube.com/watch?feature...&v=cwkVENYaK-k
You can imagine how long it takes when starting it cold.....
http://www.youtube.com/watch?feature...&v=cwkVENYaK-k
You can imagine how long it takes when starting it cold.....
Preheated to 80ºC.
After starting the engine the temp drops to 71 or so, because of max ½ throttle the ½ minute? = If you preheat your engine, go out and run race pace from the start?
The engine temp is raising because of less fuel in the tank, right?
What happend at 4:20? Ran out of fuel?
10-30-2012, 04:49 AM
#10
I think the cooling of the fuel has someting to to with the lower temps after the start and the combustions is heating it up again.
I always do take some care in the first laps before going on full.
On 4:20 I putted the car on the starting grid for a full acceleration. It hits in no time the 100km/h with max 2G of acceleration forces. Because there was no airflow you can see the temp going out of the engine going in high ranges.
With a cold start we have seen it can take 2 up to 3 minutes when the engine is on a resonable temperature to go on full. For sure that will take some life of the piston. The piston is small and so is quick on temperature while the sleeve is large and has the influence of the outside cooling, during warming up at a cold start the piston has to work through the pinch before all is on temperature.
I always do take some care in the first laps before going on full.
On 4:20 I putted the car on the starting grid for a full acceleration. It hits in no time the 100km/h with max 2G of acceleration forces. Because there was no airflow you can see the temp going out of the engine going in high ranges.
With a cold start we have seen it can take 2 up to 3 minutes when the engine is on a resonable temperature to go on full. For sure that will take some life of the piston. The piston is small and so is quick on temperature while the sleeve is large and has the influence of the outside cooling, during warming up at a cold start the piston has to work through the pinch before all is on temperature.
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