Warm up Temp before hammer falls
#17
Originally posted by sjsharks
You can qoute all the rocket scientist you want but anyone who "hammers" a GT3 right out of the garage is nuts.
You can qoute all the rocket scientist you want but anyone who "hammers" a GT3 right out of the garage is nuts.
#18
I never said anything remotely to 'hammer a car out of the garage'. I did say one or two minutes warm-up was sufficient.
It is interesting that some of you gentlemen are so worried [needlessly] about the temperature of the water in your engines upon starting up and yet think little of 'hammering' your engines thereafter. You opine that the water temperature is going to 'save your cookies' thereafter since it has warmed up. You totally forget all of the energies at work throughout the engine, some being severe. For example, how many of you knew that typical combustion temperature is approximately 4,200 degrees F? Be honest now. The point I am attempting to illustrate is that no matter what alloys are used in an engine, or how precisely it is machined and assembled at the factory, if it is not properly lubricated against friction the first minute or so, the engine will fail OVER TIME. If it is lubricated immediately, it will last many years even if you 'hammer it'.
Those of you who have torn down engines and re-built them will understand what I am talking about. Those of you who have merely driven automobiles may not.
It is interesting that some of you gentlemen are so worried [needlessly] about the temperature of the water in your engines upon starting up and yet think little of 'hammering' your engines thereafter. You opine that the water temperature is going to 'save your cookies' thereafter since it has warmed up. You totally forget all of the energies at work throughout the engine, some being severe. For example, how many of you knew that typical combustion temperature is approximately 4,200 degrees F? Be honest now. The point I am attempting to illustrate is that no matter what alloys are used in an engine, or how precisely it is machined and assembled at the factory, if it is not properly lubricated against friction the first minute or so, the engine will fail OVER TIME. If it is lubricated immediately, it will last many years even if you 'hammer it'.
Those of you who have torn down engines and re-built them will understand what I am talking about. Those of you who have merely driven automobiles may not.
#19
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Guys, I am mostly with Bentley on this one (with qualifications). If my car has been parked over-night and even with balmy temps (the three days of summer here) I follow the five minutes before soliciting the max from the engine. If my car has been parked for an hour at the track I figure the trip through the paddock and a warm up lap is adequate. In fact I am more concerned with getting my tire temps up than the engine temp. The three minutes that takes seems more than adequate.
In the fall it can be 30 F or even less and if parked overnight at those temps I give the car a longer period to warm up before enjoying full power. I cannot claim Bentley's expertise in molecular oil technology but on cold days my gear shift and clutch are rather stiff until they have warmed up for five mintues or more. This is a disincentive to full power application as far as I'm concerned. Perhaps the "5 minutes max 4200 RPM" in the manual is a generalization to cover all the temperature ranges? If the fluid is goeey (technical term) enough to make ky gear box stiff, perhaps it takes longer to find its way into all the important nooks?
I've had cars with oil temp gauges and I've noticed that the oil takes a lot longer to get to temp than the cooling system. The opposite is also true, i.e. temp reads at the low end but the oil is still warm after an hour or so. I just guessed that oil retains its heat longer in spite of having less density than water. That doesn't make me right of course, I graduated in SPITE of chemistry.
Cheers,
In the fall it can be 30 F or even less and if parked overnight at those temps I give the car a longer period to warm up before enjoying full power. I cannot claim Bentley's expertise in molecular oil technology but on cold days my gear shift and clutch are rather stiff until they have warmed up for five mintues or more. This is a disincentive to full power application as far as I'm concerned. Perhaps the "5 minutes max 4200 RPM" in the manual is a generalization to cover all the temperature ranges? If the fluid is goeey (technical term) enough to make ky gear box stiff, perhaps it takes longer to find its way into all the important nooks?
I've had cars with oil temp gauges and I've noticed that the oil takes a lot longer to get to temp than the cooling system. The opposite is also true, i.e. temp reads at the low end but the oil is still warm after an hour or so. I just guessed that oil retains its heat longer in spite of having less density than water. That doesn't make me right of course, I graduated in SPITE of chemistry.
Cheers,
#20
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From: Montreal
Ughh typos above. PLease note the "goeey" should have been "gooey" (the more correct technical term) and the reference to "ky" must have ben Freudian. Be assured I use the proper synthetic lubricants in my car! Why do I think I am gonna hear from Watt about this????
#22
the primary function of motor oil is to provide a molecular barrier between moving components in the engine; namely, the pistons and piston walls. this is why when you blow an piston ring, you score that cylinder b/c the oil getting pumped in there is burned up, and the "protective film" is eaten by the combustion process... mind the huge plum of smoke trailing your car.
first, motor oil blends, work to give immediate lubrication on start - up. hence they're 10 weight because you want the minimum amount of viscocity on start up to allow the oil pump to prime the engine quickly when cold. 30 weight when hot (for example) means the viscocity of the oil increases with rising operational temp. the reasoning behind this is actually quite simple: with increased friction, you have increased heat, and vice versa; therefore, you'll want a thicker oil (i.e., a more robust molecular barrier) present to cope with the increased thermal strees of it's operational environment. these stressors are also why you have things like zinc, etc in modern oil medlies as they provide a greater degree of protect -- considering the fact that they're "hard" ions. this is also the reason why synthetic oil provides a greater degree of protection, and why petroleum co.'s spend millions coming up with proprietary blends of anti-friction cocktails. we can also get into the new 0 weight oils, and the implicit reduction of sheering, and lubrication system parasitic losses and oil pump pressure reduction, but that's an aside.
in closing, you should do two things: 1. use a weight of oil that's sufficently thin at start up to allow your lubrication system to apply that coat of protection to all of the reciprocating parts of your engine in a facile manner, and 2. allow your engine oil pressure to build to the appropriate pressure as you want you system to be able to provide you with ample lubriaction under full load.
a comment on oil pressure -- you usually get ~ 75% of full oil pressure within seconds of start up. this is to allow for immediate lubrication of critical components (crank, rods, pistons, etc), the remainder of the oil pressure is built up within minutes after the initial start -up, but this is usually directly proportional to water temp (if your car isn't equipped with a oil pressure gauge). so, if you need to "eyeball" it, just wait until your water temp is up in the right range, and then feel free to step on the loud pedal -- this is to usually used anyway as an anecdotal empirical footnote anyway.
Last edited by Hubert; 01-29-2004 at 07:22 PM.
#28
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From: Montreal
Watt - Thank you for showing commendable restrait.
Steve F - KY is an adequate shaft lubricant. Thank you for noticing.
AS - Screaming, yes burning rubber no. That was when I was younger.
On the whole, this is more fun that being told I am stupid though ..
Best,
Steve F - KY is an adequate shaft lubricant. Thank you for noticing.
AS - Screaming, yes burning rubber no. That was when I was younger.
On the whole, this is more fun that being told I am stupid though ..
Best,