What is "Cold Spec"? (1 Viewer)

[SupraTuRD]

I was at my local Toyota dealer to order some parts and I was asked if mine was "Cold Spec".

What is cold spec?

My 80-series is a '95... how can I tell if it is cold spec or not?

 

[skhochay]

when they asked you - how come you did not asked them what "cold Spec" is?

 

[SupraTuRD]

Parts guy didn't know and was asking me. =]

 

[Tools R Us]

Guessing starter parts? There are 3 different starters 1.4, 2.0 & 2.2KW, well for a '95 only two were available from the factory, 1.4 & 2.0 cold spec, which is the most common.

 

[CJF]

Hey OP, what parts were you asking for?

 

[skhochay]

I know what that is I just looked up my parts spec : and it is a TAG notation for North and southern hemisphere like Canada Norway, Russia, etc. where temperature is usual colder

 

[SupraTuRD]

Hey OP, what parts were you asking for?

CJF- fusible links. Mine aren't looking too good.

 

[Douglas S]

On my HDJ81 there are a few things included in the winter package...retractable radiator blind, fuel heater, heated seats, different floor mats.

I'm not sure if any of that applies to the USDM models, but it may just be part of their system.

 

[Corbet]

Parts guy didn't know and was asking me. =]

This is a strong indication that you need a better parts guy.

 

[Kernal]

^^^this^^^.

 

[Golgo13]

@Douglas S Can we see a picture of the radiator blind?
I just found the drawing for this the other day and wondered what the actual parts look like in place...

 

[Douglas S]

@Douglas S Can we see a picture of the radiator blind?
I just found the drawing for this the other day and wondered what the actual parts look like in place...

Absolutely. I can't show it to you installed because unfortunately it doesn't work with a transmission cooler in place. It did work well when I had it installed.

It mounts with plastic clips to "L" brackets that are part of the factory radiator so I imagine a retrofit would be difficult if those brackets aren't included on the USDM trucks.

 

[artech]

I knew deisels had to have a different radiator! I knew it!



So there!

 

[Douglas S]

I knew deisels had to have a different radiator! I knew it!



So there!

The core of the radiator is identical to gas trucks. Diesels create less heat so they don't need a larger radiator...

 

[artech]

I keep hearing that, but I just don't believe it. The math doesn't work out. If you express horsepower in terms of heat, then deisels should run a little warmer since the compression is higher and they make more power. NLXTACY's thread has a bunch of science related posts and generated a few side conversations getting into applied physics and thermodynamics, we talked about this quite a bit.

Maybe I'm wrong(wouldn't be the first time that's for sure) but it seems like the deisel fire trucks around here make more heat than the gas fire trucks do. When static pumping, with the rig sitting still and working it's butt off sucking up and spitting out four tons of water every minute for hour after hour, most commercial cab diesel rigs need the hood propped open to help cool the engine. Never had to do that with a gas truck, and we've had a few of those along the way.

 

[Douglas S]

The 1FZ-FE makes more power than the 1HD-T.

Diesels do create less waste heat for the power they create because they create the power more efficiently (diesel engines have the highest thermal efficiency of any internal combustion engine). The result is less heat for the coolant system to deal with.

 

[Golgo13]

@SupraTuRD sorry about the Hijacking.
However,this does seem like a fitting place for this discussion.
What is "Cold Spec?" Why do we need a Cold Spec?

Imagine, no matter which engine you have, you need the engine block to be at the correct temperature for efficient and reliable operation.
For that matter, the same goes for the transmission and even the power steering.

In the case of the engine, having the cylinder walls hot enough to promote fuel vaporization and reduce fuel condensation is very important. When the fuel condenses on the walls of the combustion chamber, it isn't really getting burned and the resulting vapors exit through the exhaust stroke or burn in the next combustion cycle. Also, for an engine with aluminum pistons, when they are cold, they are "significantly" smaller than the bore size and you get a slight increase in blow-by past the rings as well as a little more fatigue in the rings since their job is to close the gap between the piston and cylinder.

For the transmission, you need a certain amount of heat to keep the trans fluid at its proper viscosity. Same goes for power steering. The pump can wear out faster if it is trying to recirculate a colder, more viscous fluid. It also take more power from the engine to pump the colder, more viscous fluid.

Now, imagine you are in the frigid tundras of the North and the ambient temp is -40C. You manage to get the engine started, but it would take a while to warm up to operating temp. Much longer than it takes @NLXTACY to get to that point. Then you get to temp, and start driving and now you have a rush of this skin-peeling, cold air over the radiator. The temp starts dropping and you start to lose efficiency and in general you add more strain to the system. Something like a blanket over the radiator works quite well to prevent this.

Now I have to laugh thinking about the Japanese design engineer who was challenged up with this "Radiator Shutter." I imagine him trying to figure out a simple, reliable way to achieve this result. And then I imagine him looking at the roll-up window shade in his tiny apartment and tearing it down and screwing it to the front of the vehicle as a mock-up of the final product...

Here is a picture of his boss:

 

[artech]

In a wicked cold snap up heah we just block off the radiator with cardboard. (cahdbowahd, thet is...)

'Course, we don't have a supercharger with burnt bearings preheating our intake air either...

 

[NLXTACY]

@Golgo13 appropriate Satoshi Nakamoto image for the win