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Engine Warm up Period- from a cold start

jakeslim

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I have a 383 and let it warm up for around 5 minutes from a cold start. Even as the choke kicks down, i still let her run for a bit before driving. Is there a warm up rule that needs to be followed?
 

big jimmy 91

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I make it a rule to not run my hot rod car hard until it gets to full operating temp.
btw. I have driven this car like I am at the drag strip for 12 years now with no major failures (engine wise anyway , the rest of the drive train is another story lol)
Warm it up , then hammer down
/forums/images/graemlins/thumb.gif
 

dyeager535

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Probably in for a bunch of speculation here, but I'll bite.

I read somewhere once (owners manual for something perhaps) to let the vehicle warm up for 15 seconds.

I would assume this probably applies to fuel injected vehicles, because idle typically goes to normal pretty darn quick. More than anything anymore, they are more likely afraid some idiot will not completely depress the brake and inch forward into their garage wall, and sue.

Anyways, I don't think a long warmup is probably necessary. It may help, but I have a feeling proper maintenance (oil, filter changes) is the key to longevity, not extended warmup. Lots of the internal lubrication of the engine is by oil being slung, idling is typically claimed as being hard on the engine. Besides. Look at the way most people drive their vehicles that are lasting at least 150,000 miles. Hop in, throw it in gear, and go. (yes, newer engines are different, but IMO not THAT different)

I like the 15 second rule, makes me feel good. haha. Not that long to wait, and as long as you aren't lugging the transmission down with an overly high idle (also probably not really a problem) I say move out. /forums/images/graemlins/smile.gif
 

tRustyK5

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Even my 6.2 in cold weather I don't let it warm up that much before driving. 15-30 seconds max...then drive it 'nicely' until it is warmed up. After it's warmed up completely it's fair game. /forums/images/graemlins/smile.gif

rene
 

big jimmy 91

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The "15 second" thing is the recomended time that the "eco nazi's" are advetising to combat air pollution /forums/images/graemlins/deal.gif
Personally I think its better to idle for a few minutes(2-4} before you drop it in gear , longer in colder climates
But what do I know lol
 

4xcrazy

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Well being that my motor has over 211k miles on it now, i usually let it idle for at least 5 minutes, alittle longer in the winter, i even let it idle for a bit during hot summer months out here in Arizona, mainly just to make absolute sure that all parts are adequately lubed and somewhat warmed. Just trying to prolong the engine life i guess. I did live in a semi cold climate for awhile (Flagstaff,AZ) during winter, the coldest i saw i believe was 2 degrees, i always went out ant started it up and let it idle for about 15-20 minutes, one reason was just to get the damn heater warmed up /forums/images/graemlins/doah.gif.
I did this once and when i was pulling out of the driveway, i happened to look at the temp gauge and it read 220, i said waaait a minute. Shut it down and checked everything, the engine was hot, the radiator was cold. (Was frozen) But anyways, off topic, sorry.

I personally think you can get away with a short warm up time, depending on climate conditions, as long as you are not hard on the engine until it reaches normal operating temps. Get the components heated up so they work and ride like they were meant to.
 

m j

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oil temp is an indicator of whether the engine is warmed up
you are trying to get the pistons to operating temperature before hitting them with big loads
when cold the aluminum pistons are looser in the iron bores
 

CyberSniper

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I usually wait until the temperature gauge reaches 100°. By then there is usually enough heat in the engine itself for things to be their proper sizes. The oil has also warmed up a bit and started to go through the engine a little better. Getting to 100° can take 5-7 minutes around here though. And I have electric fans.

I always tell people never less than 90 seconds on a cold motor and 30 seconds on a moderately warm motor. On the first start of the day it can take more than 30 seconds for the oil to even make one pass through the motor.

No matter what, if your fool-injected vehicle is still on high idle then it isn't time to drive off yet.

I know a lot of people that have their vehicles in gear practically before the starter even finishes its cycle of starting the car. They also happen to have some of the noisiest running motors when cold that I've ever heard.
 

HarryH3

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I'm typically backing out of the driveway in the amount of time that it takes me to release the key and put 'er in gear. /forums/images/graemlins/cool.gif The '91 S-Jimmy has over 148K on it, doesn't make any strange noises, has great compression, and still runs great. The '94 Suburban has 124K on it, doesn't make any strange noises, has great compression, and still runs great. /forums/images/graemlins/peace.gif I'm sure that running Mobil 1 in both of them has helped some. It flows well, even when the engine is cold. The S-Jimmy has an idle oil pressure of 60-80 PSI when cold, depending on how cold it is. The Sub has an idle oil pressure of over 40 PSI when cold. So I'm sure that it doesn't take long for either one of them to push lube through all of the vital parts. /forums/images/graemlins/cool.gif

The biggest change in the last 20 years or so has been the introduction of computer controlled machining equipment. The assembly tolerances on newer engines are WAY tighter than they were when everything was machined and assembled by hand. Just 25 or so years ago it was rare for a factory engine to go much past 100K miles. These days it isn't uncommon to find factory engines with 200K plus miles that are still going strong. /forums/images/graemlins/thumb.gif The tighter tolerances, better manufacturing techniques, and better materials have all combined so that warm-up just doesn't make that much of a difference on engine wear. /forums/images/graemlins/deal.gif
 

jjlaughner

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[ QUOTE ]
I'm typically backing out of the driveway in the amount of time that it takes me to release the key and put 'er in gear.

[/ QUOTE ]


AH, YEAH, DITTO.... The only time I sit in the driveway is when I'm waiting for the defrosters, adjusting mirrors or the seat when I get into a vehicle thats not mine.
If its my truck I'm usually in, turn the key, check the mirrors and the road as I'm putting it in gear, then I pull out the drive (just off idle) and down the road about 100 yards till I turn onto the main road.... then the hammer goes down /forums/images/graemlins/whistling.gif
 

m j

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I do not see much difference in a SBC in the 20 year span you are refering to in regards to materials and manufacturing
much has moved out of the US so perhaps you think Hencho en Mexico is better?
 

CyberSniper

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The biggest change has been fool-injection. There is no washing of the cylinder walls like there was with carburetion and chokes. There is also far less gas getting into the oil.
 

m j

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the computer warm up mode is better then a choke
but to say "no washing" infers that the old choke is grossly rich
at the high idle speed and the loose cold piston I do not think the washing problem is going to be as large a problem as you are making out
if it were there would be a much greater piston scuff damage problem that I have just not seen

lately I am very 'anti computer control'
been playing with mech FI

also in diesel engines the computer controls are very poor
I am back driving an old mechanical diesel and it is great after years of computer driving
 

CyberSniper

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OK, so please explain to me why carbureted engines rarely made it past the 100k mark before being in dire need of a rebuild? Perhaps why a 80s carbureted block needs at least a .030" overbore most of the time whereas an 87-94 block really only needs a good honing and ridge reaming with more miles?

Maybe it's pure coincidence that carbureted motors usually have a hint of a smell of gas in their oil after 3,000 miles whereas a fool-injected one smells uniquely oil-like.

Perhaps it was that one piece rear main that fixed everything? Oh, I know, it was those center bolt valvecovers that caused it. All those early TPI one piece rear main seal motors out there with 150k on them are anomalies by the way.
 

HarryH3

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[ QUOTE ]
I do not see much difference in a SBC in the 20 year span you are refering to in regards to materials and manufacturing

[/ QUOTE ]
Perhaps you should visit a GM plant... /forums/images/graemlins/wink.gif Or talk to their engineering folks about the things they have implemented over the years to improve engine manufacturing. /forums/images/graemlins/thumb.gif
 

fortcollinsram

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I let my 454 run about 45 seconds or so before I move..Then I drive it like a granny till I see the needle hit about 185* then it is bye bye rice boy /forums/images/graemlins/waytogo.gif

Chris
 

bryguy00b

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i let my truck run for a few minuts befor leavin in the mourning, but the way the carb is on it , i have to drive like a grandma or it will just stall out lol..even after letting it run for 2 minuts untill its good and warm
 

pauly383

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I wait until choke is done doing its thing. I do other stuff like seatbelts and checking gauges. About 4 to 5 minutes for me. /forums/images/graemlins/k5.gif
 

m j

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lots of carb'd motors exceed 100k
not at all unusual
 
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