Itinerant Air-Cooled

I just bought one of these beauties at Harbor Freight for a ridiculously low price. It's way cool, but I want to know the best way to use it when it comes to monitoring my air cooled engine.



I've done some pointing with it already, mostly aiming it at the oil sump, the valve covers, the cylinder fins and the head just beneath the valve covers. Does anyone have thoughts on where I should point this thing that will give me information that is relevant and meaningful? So far, everything I've measured, with the exception of the exhaust has all been under 350 degrees which I'm assuming is good. Thanks!

I like to get about 6" away myself.

Randy in Maine wrote:I like to get about 6" away myself.

I believe it said something to that effect in the instructions that came with it.

What I'm asking is where should I aim it (heads, cylinders, sump, filter?) and what does the reading mean to me?

dtrumbo wrote:

Randy in Maine wrote:I like to get about 6" away myself.

I believe it said something to that effect in the instructions that came with it.

What I'm asking is where should I aim it (heads, cylinders, sump, filter?) and what does the reading mean to me?

I have a little LED array that makes a circle of red dots to let me know the cone of reading area. It likes 3" cone which occurs about 6" away.

Your readings can be all over the engine as you see fit, you will develop baselines and variations that will be salient for you.

My highest readings have been as follows for the following components at 123* Baker CA 16 mile freeway upgrade in 2005:

Valve Covers (naturally get hotter towards trailing surfaces) . . . 285*
Exhaust Pipes (at curves just below manifolds front and rear) . . . 880*
Taco Plate (at trailing slope of dipstick bump) . . . 260*
Left corner of Case (just ahead of the filter) . . . 265*
Oil Filter Can (in the path of cylinder exhaust air) 280*
Intake Manifolds (carb cast iron carries more heat than your FI) . . . 161*
Fan Housing . . . (after a good heat-soak) . . . 165*

Death Valley this year at 125* hadslightly lower readings because there was no freeway driving and the engine is nicely broken-in now.

The left rear corner of the case has most closely followed the oil temp gauge that I borrowed from RandyInMaine, but you have to be about 3/4" above the fins which do a damn good job of cooling the case surfaces down there.

Please let us know what you find at what ambient temps and loads.
Colin

You can also see which cylinders are the strongest and which are weak by measuring at all 4 exhaust ports. Ainokea

I was doing this and had 580 at the manifold bends and thought...whoa!

But seeing the numbers in the 800s really sets me at ease.

Amskeptic wrote:

dtrumbo wrote:

Randy in Maine wrote:I like to get about 6" away myself.

I believe it said something to that effect in the instructions that came with it.

What I'm asking is where should I aim it (heads, cylinders, sump, filter?) and what does the reading mean to me?

I have a little LED array that makes a circle of red dots to let me know the cone of reading area. It likes 3" cone which occurs about 6" away.

Your readings can be all over the engine as you see fit, you will develop baselines and variations that will be salient for you.

My highest readings have been as follows for the following components at 123* Baker CA 16 mile freeway upgrade in 2005:

Valve Covers (naturally get hotter towards trailing surfaces) . . . 285*
Exhaust Pipes (at curves just below manifolds front and rear) . . . 880*
Taco Plate (at trailing slope of dipstick bump) . . . 260*
Left corner of Case (just ahead of the filter) . . . 265*
Oil Filter Can (in the path of cylinder exhaust air) 280*
Intake Manifolds (carb cast iron carries more heat than your FI) . . . 161*
Fan Housing . . . (after a good heat-soak) . . . 165*

Death Valley this year at 125* hadslightly lower readings because there was no freeway driving and the engine is nicely broken-in now.

The left rear corner of the case has most closely followed the oil temp gauge that I borrowed from RandyInMaine, but you have to be about 3/4" above the fins which do a damn good job of cooling the case surfaces down there.

Please let us know what you find at what ambient temps and loads.
Colin

I think Richard Atwell has some temps posted on his website and they are very similar to Colin's when outside temps and load are considered. When we were racing the Fiat 124 spider it was not uncommon to see the headers glowing cherry or orange - which is something like 1500 F - 1900 F. In fact brakes would be that color to sometimes when the car passed as one could see color thru the wheels. I remember changing pads one time while the rotors were still that hot. Quite exciting because one slip and you are screwed.

The image below is from his site so he gets full credit for it. He says it was 60F outside when these were taken. http://www.ratwell.com/technical/Temps.html

sgkent wrote:He says it was 60F outside when these were taken.

Wow. When I read the Road Warrior's old numbers, that made me feel better about the numbers I had to read this summer.
285* on the RW valve covers? 278* this year.

Eleven years later (I would have never guessed I would do Death Valley every summer for a decade) , I am far more relaxed about the capabilities of these engines, and a whole lot more humble about the fact that they don't care how special you thimk your driving "technique" is, they pretty much do what they want temperature-wise.

Last compression readings, 125, 125, 130, 135, valve adjustments all good, CHTs top reading 444* and 25,600 miles since I bought this car last October 26.

Set it up, maintain it, drive!
Colin