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Author Topic: What is the HOT engine temp?
SCCA_Racer
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I am going to be installing a couple gauges into the car and was wondering what range classifies as HOT? I know this depends a little on the radiator type, water, radiator cap, overall cooling system flow, and such but what have you guys found? 200, 220, 230 higher?
Also, what oil pressure is to low that I should get worried something is wrong 30psi? 15psi?
Thanks again for the help guys.

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Joshua Fine
SCCA member 323214 since 2003
Novice Permit in 2010
Racing 2011

Frank Todaro
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After a race when I am sitting in the impound waiting to get on the scales, my temp goes to 210. If your running water as you should it can go above 220 under pressure with out a problem but if my temps went to 225 to 230 I would be concerned, especially with water in the rad. Someone else can comment on oil temp and pressure.

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Frank
Member: No Pain Racing

Keith in WA Verified Driver Made Donation to Website
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When my engine is full hot, I see my oil pressure go as low as about 19 but that's sitting in pregrid or waiting for scales. I have my warning light set for 30 and it doesn't go off when I'm on track. On track I don't get below about 39.

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Keith Novak
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Ken SM-94 Verified Driver
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I'd say at 230 deg you're in new head gasket territory, or worse.

The low end of the oil pressure at speed should be around 40-45. At an idle after a race in the hot summer all of the engines I've had would drop to the 10-12 psi range.

Ken

CP Verified Driver
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My water temp taken from the plugged port on the back of the head (hottest point before returning to the radiator) can hit 245-250* during a race.

Oil temp taken from a drain plug sender hits 300* regularly.

Don't bother with gauges. I'm ditching mine this winter as they don't help at all. If something goes wrong, the motor will be gone before I see the issue from a gauge. I try to duck out of a draft to get some air to the radiator as much as possible.

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-Cy
Supported by LTD Racing & Speed Shack - New England's Premier Auto Accessory Store
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Keith in WA Verified Driver Made Donation to Website
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I've discovered I had a water leak twice where the gauges saved my engine. As soon as the temp went from normal to a major spike on the track, I pulled off immediately, fixed the leak between sessions, and all was good again.

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Keith Novak
(Will work for tires)

Spence Gatrell
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In perfect condition the water temp shouldnt go beyond 210. After that the ecu retards the timing and you dont want that. As far as a high reading.. 240 is the point of no return if you have a cap that will hold the pressure.

A water temp guage sweep 100-240
An oil pressure guage sweep 10-70

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When in doubt.. Stand on it!

Adroitracer Verified Driver
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Cy brought up a great point. You can take the temp from a bunch of different points. The numbers people are giving you are all relative. I take mine from the hose going from the engine into the radiator since I want to know the hottest that the water gets. I know some that take it from the radiator hose flowing into the motor. Obviously these would both give you significantly different readings. Make sure you are considering where you are reading to determine whether your number is accurate or not.

Does anyone have the specific threshold numbers for water going into the motor vs. water coming out of the motor in relationship to the motor timing being retarded?

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wheel Verified Driver Made Donation to Website
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Something that you might also consider is a coolant pressure warning light. This saved my AS engine, and I lost an engine in the SM, for lack of a warning light. When the coolant system is pressurized, the light is off, when pressure is lost, due to a radiator hose, or heater hose, the light comes on.
If all the coolant is gone, the temp gauge will not record the high temps, but the light will warn you.
wheel

Dave Lewis
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quote:
Originally posted by wheel:
Something that you might also consider is a coolant pressure warning light. This saved my AS engine, and I lost an engine in the SM, for lack of a warning light. When the coolant system is pressurized, the light is off, when pressure is lost, due to a radiator hose, or heater hose, the light comes on.
If all the coolant is gone, the temp gauge will not record the high temps, but the light will warn you.
wheel

I have the same thing,3# pressure switch in the top hose, light on the dash.

wheel Verified Driver Made Donation to Website
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When you get the pressure switch, make sure you get the one specifically for water. The first one I got came apart in short order. They said, oops, that one wasn't for water.
wheel

Dave Lewis
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Mine has been in for a couple of years now, so I guess it must be the right one [Big Grin]

Keith in WA Verified Driver Made Donation to Website
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quote:
Originally posted by wheel:
Something that you might also consider is a coolant pressure warning light. This saved my AS engine, and I lost an engine in the SM, for lack of a warning light. When the coolant system is pressurized, the light is off, when pressure is lost, due to a radiator hose, or heater hose, the light comes on.
If all the coolant is gone, the temp gauge will not record the high temps, but the light will warn you.
wheel

That might be true for the temp sender on the radiator hose, but when I've lost coolant with my temp sender in the heater hose, it did spike the temp providing me enough time to pull off and shut down.

--------------------
Keith Novak
(Will work for tires)

wheel Verified Driver Made Donation to Website
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No matter where your temp sender is, if you miss the spike, the next time you look it may only read a little hot. Once the sender is not in the coolant, just in air, it will give a false reading.

Keith in WA Verified Driver Made Donation to Website
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Checking the gauges regularly must be a side benefit of having my engine in and out of the car a few too many times. It can take a couple sessions before whatever wasn't just right gives any sign of a problem, so I've picked up the habit of scanning the gauges regularly looking for any signs of my own asshattery following a R&R.

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Keith Novak
(Will work for tires)

CP Verified Driver
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Cheap engine insurance is new radiator and heater core hoses every winter, and all the small hoses every few years.

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-Cy
Supported by LTD Racing & Speed Shack - New England's Premier Auto Accessory Store
Rt1 AutoMile - Norwood, MA
http://www.speedshackonline.com

   

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