Barrel coatings test

comnoz · Mar 10, 2015

The test in still air is done. The barrels were heated for around 5 hours at 375. Then they were carried to the 3 sided box and placed in the same position each time. The thermocouple was inserted and the measured temp went up to around 330 -335.
As the barrel cooled I started the timer at 300 degrees and stopped it at 200 degrees. The room temp stayed at 68 degrees throughout the testing and I was soldering up a circuitboard on the other side of the room so there was no movement near the box.
Here's the results. Jim

[video]http://youtu.be/OkVfF8b-5Jg[/video]

Anonymous · Mar 10, 2015

Thank again comnoz. Good stuff.

Hey baldy. My barrels are flat black pot belly paint - not that it makes any difference!

Hobot · Mar 10, 2015

Alrighty comoz way to go as free's us to go by taste in cylinder finishes. Oh yeah one more question remains, how much is it worth drilling the snot out of fins, with holes the same dia as fin is thick vs 1/4"+ size generally seen.

Brooking 850 · Mar 10, 2015

Thanks Jim, good stuff, I use VHT exhaust paint on my bikes, gloss black on the barrels and matt black on the headers of the race bike, silver on the barrels on the Roadster to keep it the same as that (my)model was assembled originally, only thing is I only preheat with a heat gun before I spray.
Did i hear you say you bake the VHT on?
Regards Mike

comnoz · Mar 10, 2015

Brooking 850 said:
Thanks Jim, good stuff, I use VHT exhaust paint on my bikes, gloss black on the barrels and matt black on the headers of the race bike, silver on the barrels on the Roadster to keep it the same as that (my)model was assembled originally, only thing is I only preheat with a heat gun before I spray.
Did i hear you say you bake the VHT on?
Regards Mike

Yes, I bake any of the paint I put on a barrel. That makes the paint tougher and more chemical resistant. Jim

comnoz · Mar 11, 2015

hobot said:
Alrighty comoz way to go as free's us to go by taste in cylinder finishes. Oh yeah one more question remains, how much is it worth drilling the snot out of fins, with holes the same dia as fin is thick vs 1/4"+ size generally seen.

I doubt drilling the fins has any more affect than different coatings do.

I suspect that the reason I am not seeing any difference between coatings is not because some coatings or surface textures or colors may have the ability to dissipate heat more than others -I am sure they do.

I think the reason is because any paint or powdercoat has the ability to dissipate heat much faster than the heat can be transferred through the cast iron and out to the fins.

One thing I saw when I had the heating element in the bore and the fan on was that if I turned the element off and touched the ID of the bore -it was sizzling hot -and yet the fins that were in the airflow were only warm to the touch. Jim

Hobot · Mar 11, 2015

One thing I saw when I had the heating element in the bore and the fan on was that if I turned the element off and touched the ID of the bore -it was sizzling hot -and yet the fins that were in the airflow were only warm to the touch. Jim

LOL good one comnoz. Basically showed Norton provided adequate surface area and cast iron mass for the expected hp output they sold. Wonderful unpaid research that's both a relief and a let down, meaning we is pretty much stuck with just so much internal fuel heat disapation which could limit intervals and amount on speical fuels. Epoxy rattle can is my favorite DIY through the various weapon coats are cheap enough and alcohol thin so like nothing there except vaious color tint and some rust protection.

Other forums explored holes - if the lost mass and surface area nullified the flow exposure to settle on studies stating if holes same dia as fin thickness it both lowers mass and improved surface area cooling. Ok get back to work.

mschmitz57 · Mar 11, 2015

Wow, beautifully done Jim.
It's nice when empirical evidence disproves anecdotal.

I must admit I tried to conduct a similar experiment several months ago (on a much smaller and crappier scale) with identical 1" cast iron pipe couplers painted black and white. I heated them to 250 F in an oven then I used an I.R. thermometer but I got erratic surface readings until they cooled to around 100 F. The continuous readout thermocouple is the way to go but beyond my project funding just to win a beer bet. Your videos should become very popular across many car/bike/engine forums dispelling the myth. I've searched YouTube for this topic and I think you're the first to actually do it (and do it so thoroughly).

Anonymous · Mar 11, 2015

comnoz said:
...One thing I saw when I had the heating element in the bore and the fan on was that if I turned the element off and touched the ID of the bore -it was sizzling hot -and yet the fins that were in the airflow were only warm to the touch. Jim

Not sure that I follow on this one. How could it be otherwise? The edge of the fin would be coolest and the liner would be hottest as per the heat flow direction into the convection path.

comnoz · Mar 11, 2015

needing said:
comnoz said:

...One thing I saw when I had the heating element in the bore and the fan on was that if I turned the element off and touched the ID of the bore -it was sizzling hot -and yet the fins that were in the airflow were only warm to the touch. Jim

Click to expand...

Not sure that I follow on this one. How could it be otherwise? The edge of the fin would be coolest and the liner would be hottest as per the heat flow direction into the convection path.

I guess I was just a little surprised by how large the difference was. I could make a wet finger sizzle on the bore but comfortably hold my hand on the top fin. Jim

worntorn · Mar 11, 2015

Makes one wonder how hot the bore is when a wet finger sizzles on the fin edge!

Glen

comnoz · Mar 11, 2015

worntorn said:
Makes one wonder how hot the bore is when a wet finger sizzles on the fin edge!

Glen

Exactly...

john robert bould · Mar 11, 2015

Jim
Is heat in the "Normal Running " a problem ? if so would a small fan positioned in front of the engine be useful , coupled to a thermostatic switch ?
I guess it's where one lives?

comnoz · Mar 11, 2015

john robert bould said:
Jim
Is heat in the "Normal Running " a problem ? if so would a small fan positioned in front of the engine be useful , coupled to a thermostatic switch ?
I guess it's where one lives?

I wouldn't say heat is a big problem with normal use. It's when you start pumping them up a bit that heat becomes a limiting factor. Jim

Nater_Potater · Mar 11, 2015

comnoz said:
It's when you start pumping them up a bit that heat becomes a limiting factor. Jim

So, I take it that, with the limited heat transfer capability of cast iron, the only other way to get the heat out is through the oiling system.
Correct me if I'm wrong, but isn't most of the heat actually going out through the head? If that's truly the case, maybe we should be looking at adding extra fins to the head!
btw, I like your taste in music!

Nathan

comnoz · Mar 11, 2015

Nater_Potater said:
comnoz said:

It's when you start pumping them up a bit that heat becomes a limiting factor. Jim

Click to expand...

So, I take it that, with the limited heat transfer capability of cast iron, the only other way to get the heat out is through the oiling system.
Correct me if I'm wrong, but isn't most of the heat actually going out through the head? If that's truly the case, maybe we should be looking at adding extra fins to the head!
btw, I like your taste in music!

Nathan

With the limited circulation of the oil system there isn't much available there.
So extra fins or an aluminum barrel are probably the best way to cool things. I want to do some aluminum barrel testing in the future. Jim

PS The music comes from my server where I have been collecting music for a long time. I think the play time is up around 60 days now.

Hobot · Mar 11, 2015

It's when you start pumping them up a bit that heat becomes a limiting factor. Jim

Harley did EXtensiveEXspensive oil cooling study to realize oil don't transfer heat as fast as H2O so to prevent 500'F oil required bigger radiator than a water cooled cycle and gallons of oil to match plus as comnoz says Cdo oil routes are not enough for mass cooling, so only worth while place to put a oil cooler is before the head.

Online clac's btu's of => 750 Combat ~125,000 on cam vs a 920 cc ~200,000 & with 50% extra mix blown in => *helllofALOT* of btu's flow to sustain. Saint Barnard solution is only way I know to get away with it and still be recognizable Norton. btw the real test of fins & finishes happens on the fly with heater left on hi.

http://www.endmemo.com/sconvert/btu_hhp.php

heater provides 360 of heat in a small and portable design. With variable heat output (30K/35K/40K), this versatile tank top heater is a good low cost solution for extra heat in many outdoor situations. Quiet infrared heat, no electricity and tough construction. Variable temperature control. Heats up to 1000 sq. ft. BTU Output: 30K/35K/40K

Mr. Heater MH80CV 30,000-80,000 Btu

120,000 btu rated

WZ507 · Mar 11, 2015

hobot said:
It's when you start pumping them up a bit that heat becomes a limiting factor. Jim

Click to expand...

Harley did EXtensiveEXspensive oil cooling study to realize oil don't transfer heat as fast as H2O so to prevent 500'F oil required bigger radiator than a water cooled cycle and gallons of oil to match plus as comnoz says Cdo oil routes are not enough for mass cooling, so only worth while place to put a oil cooler is before the head.

And HD addressed heat management in their air-cooled Twin Cam engines by increasing fin area and fitting them with piston squirters (oil cooling jets). The squirter has a pressure check in it that activates and begins squirting at 12-18 psi, so below that pressure (at idle?) no oil is squirted.

Hobot · Mar 11, 2015

Yep man WZ aircraft went with more fins in bare alu than more oil. Alas Norton oil pumps have nil extra capacity to feed even the tiny oil holes in comnoz cam so he had to make a new pump with a lot more volume to save his upgrade. To get significant piston crown cooling would require all the oil flow our pitiful pumps can feed crank sling out so that's what Peel will eventually tap. Low boosted engines start with ~ a gallon a minute and 3x's that per piston for the maxium boosted heat. So when fin edges begin to sizzle spittle holding WOT like the space heaters maybe finishes matter. In other words until the flow exceeds conduction, finishes don't matter any more than size of sink drain pouring a cup of coffee down compared to tipping over a 5 gallon bloody gut bucket.

Still black is proven faster than white so Combat's cheated a bit over the silver. A shadow can move faster than light too.
[video]https://www.youtube.com/watch?v=A5j1hYuYmDo[/video]

peter12 · Mar 12, 2015

Havn't read all the comments but a great experiment with an interesting result.
Sure this has been discussed many times but is there a real issue with the temp these motors run at.
I had my 850 motor in a reasonable state of tune in 1976, one of the hottest UK summers.
I thrashed it around all summer, fitted a T150 oil cooler w/out a thermostat only to find that the general consensus was that my motor was running to cool.
Also I don't recall seeing any Commando motors currently within the CRMC with oil coolers.
Discus!!

Barrel coatings test

comnoz

Anonymous

Guest

Hobot

Brooking 850

comnoz

comnoz

Hobot

mschmitz57

Anonymous

Guest

comnoz

worntorn

comnoz

john robert bould

comnoz

Nater_Potater

comnoz

Hobot

WZ507

Hobot

peter12

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