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How Hot Is Too Hot?

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TXFlyGuy

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Oh Happy Day. Wish you all the best.
Fell in love with P-51's when every Sunday after WW-2 the AG would practice making runs on a hill about 2 miles north of my Grandfathers farm . After Sunday dinner, I would go to the front porch and wait for the string of P-51's and my private airshow.
Dan
Wow! How cool was that!
 

Pops

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Job out of high school I worked for a men that was a Flying Tiger with the P-40's and then flew 51/s in WW-2. We ate lunch together every day and had long talks. Would love to set and spend time with him again.
 

Rockiedog2

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Dec 11, 2012
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I had a new high dollar motor years ago. First flight there was a problem similar to TFG’s. Did everything possible to determine if there was damage and all seemed ok. Flew it a while and couldn’t get it outa my mind. Built up another one and mounted it up.
Whole new world...and that was on a cheap, forgiving airframe.
 

TXFlyGuy

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I had a new high dollar motor years ago. First flight there was a problem similar to TFG’s. Did everything possible to determine if there was damage and all seemed ok. Flew it a while and couldn’t get it outa my mind. Built up another one and mounted it up.
Whole new world...and that was on a cheap, forgiving airframe.
Thought about doing just that.
 

TXFlyGuy

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Peace of mind is money well spent. Then if things go bad we know we did all we could.
Yes, it certainly is. I have exhausted all avenues of diagnostics on the engine. Everything has come back positive in my favor. We will do one more compression check on a hot engine, vs. a cold check.

Hutter Performance is satisfied with what they saw during the borescoping of the cylinders.

A final decision will be made after we get everything put back together...new fuel system and coolant lines, plus do some full power runs.
 

Pops

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Sometimes your guarding Angels whispers in your ears.
All of my life, if I have a lingering doubt in my mind about anything in the airplane, I fix it.
The reason to never buy all the airplane you can afford. Buy less than you can afford and do a no expense spared maintenance on the airplane.
Airplanes are expendable , people are not.
 
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Rockiedog2

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Dec 11, 2012
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Yes, it certainly is. I have exhausted all avenues of diagnostics on the engine. Everything has come back positive in my favor. We will do one more compression check on a hot engine, vs. a cold check.

Hutter Performance is satisfied with what they saw during the borescoping of the cylinders.

A final decision will be made after we get everything put back together...new fuel system and coolant lines, plus do some full power runs.
You’ll probably be fine with all the pros you got on it. I only had one redneck to depend on.
Couldn’t get past it. Ruined the plane for me.
Good luck
 

delta

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May 26, 2011
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Brookside Utah
I hope your cooling issues get resolved with this engine. I'm personally more worried about keeping chips out of the prop governor. A few hours of touch and go's should let you know if anything else is going on.
 

TXFlyGuy

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I hope your cooling issues get resolved with this engine. I'm personally more worried about keeping chips out of the prop governor. A few hours of touch and go's should let you know if anything else is going on.
We share your concerns, and the oil will be changed at 4 hour intervals to start.
 

Mike0101

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Aug 24, 2020
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The main coolant lines from the bulkhead to the radiator are 1 1/8" I.D.
We are going to add larger lines from the pump to the firewall. These are the 3/4" lines.
Plus a larger overflow bottle will be added, 2 qt size.View attachment 103073

View attachment 103074View attachment 103075
In my previous post, I keyed in on performance shop's suspicion of "trapped air". As others have pointed out, your line size is your biggest issue... 3/4" lines are far too small, you are exceeding 200 ft/sec flow, which for a liquid is far too high (assuming 45GPM at about 4000-5000 RPM).
Also at idle or low RPM LSx (or LTx) pump jut doesn't have much head (pressure) and flow.

I've attached a pic of Evans high flow pump for illustration.
LS3 pump.jpg
When you have a severely restrictive path to and from heat exchanger (radiator), then path of least resistance is to simply recirculate coolant in block - which is, what is very likely happening.

When looking at pump, the bottom ports (2) are coolant return, and top 2 ports are coolant supply to block. Where thermostat is (bottom right), would be coolant return from radiator... Also notice cabin heater ports (2), the smaller is supply and larger one return.

Upsize your lines throughout, and preferably follow GM in which, return line size is larger than supply - this helps to compensate for pressure drop.
Also for testing, maybe go back to water, as viscosity will be cut in half or more depending on what coolant you are using... As mentioned by others, 10 PSI pressure drop is not out of the question (could be more, AN fittings don't have the best hose to fittings transition). Modern water/coolant pumps just don't have much extra pump head (pressure) built in, in order to keep parasitic losses low...
 

Doran Jaffas

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Jun 25, 2019
Messages
240
Sometimes your guarding Angels whispers in your ears.
All of my life, if I have a lingering doubt in my mind about anything in the airplane, I fix it.
The reason to never buy all the airplane you can afford. Buy less than you can afford and do a no expense spared maintenance on the airplane.
Airplanes are expendable , people are not.
Excellent words of wisdom.
 

proppastie

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Feb 19, 2012
Messages
4,701
Location
NJ
Sometimes your guarding Angels whispers in your ears.
I like to say "the engine is talking to you" or "someone was looking out for me" ......had it happen to me many times and twice in the last 4 months......I hope I keep listening and/or my luck does not run out.
 

delta

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May 26, 2011
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Brookside Utah
I don't remember if you have magnetic drain plugs and temp sensors in the reduction but at 4 hrs if it smells ok, I'd explore ways to filter the stuff and re use it. Clearly just a global warming thing and in no way tied to my personal cheapskate way of doing things...
 

TXFlyGuy

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Apr 25, 2012
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Republic of Texas
Yes, I have a magnetic drain plug in the oil pan, plus a temp sensor is installed in the gearbox (PSRU).

Not really interested in using my oil again, but it does get taken to the local auto shop for recycling.
 

wsimpso1

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Saline Michigan
Glad to hear the insides all come up clean. Vent the fight spots on that engine and get it flying.
 
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