Coolant Hose Touching Exhaust

[lv2plyguitar 172]

I have a problem I need suggestions with.  I have coolant hose wrapped in orange fire sleeve touching the exhaust. There is no room to move it and no way to re-route.  Will that be a problem?  The only solution I see is to re-weld the exhaust if it is a problem.  What are your thoughts or suggestions?

Thanks

[dholly 718]

I would not be comfortable as is.

[Dusty 126]

Hard to say without seeing a photo,but any of my hoses that go near the exhaust transition to copper tubes with croxed ends.   The copper won't mind the heat and will give a little more clearance.

[lv2plyguitar 172]

Copper is a great idea.  How do you accomplish the end connections with copper.  Do you have any pictures available?

Edited 6 Feb 2017 by lv2plyguitar

[Av8r3400 1178]

I used aluminum pipe. 

Can you separate enough to to put a metal heat shield on the hose?

I agree a photo would help us help you a lot. 

[lv2plyguitar 172]

Yes I currently have orange fire sleeve around it.  And then I half wrapped the fire sleeve with a piece of stainless sheet-metal.  So the exhaust touches the sheet metal at one tiny point not a length of the coolant line.   

[Geoffrey Thorpe 31]

A coolant hose melted through on mine before I bought it - the previous owner then put in a chunk of copper where it goes past the muffler. I don't think he did anything special to the ends of the pipe.

[lv2plyguitar 172]

Can the copper actually touch the exhaust and be okay or will the exhaust heat burn through the copper. 

[Av8r3400 1178]

If they are touching, one will fairly quickly wear through the other.

[EDMO 1078]

Would a copper elbow or 45 somewhere before the muffler give you a little clearance?  EDMO

[lv2plyguitar 172]

It probably would.  I was in a big hurry to fly and just went with it.  Thought it would be okay but after thinking about exhaust temp's its pretty important to check stuff before I head out into the wild blue yonder. 

[wypaul 448]

I have the same situation and added an aluminum shield that is tight against the firesleeve and the exhaust.  It has been working fine, I just keep an eye on it. 500 hrs so far.

[lv2plyguitar 172]

How thick is your aluminum shield.  Does it wrap around the fire sleeve.  Just plain aluminum?

[wypaul 448]

Mine is just thin aluminum flashing, a beer can will work and it wraps about halfway around the fire sleeve.  It is tight enough it holds its self in place.  Thinking about it, I have a piece of fiberglass cloth in between the metal and the fire sleeve.

Edited 6 Feb 2017 by wypaul

[lv2plyguitar 172]

One more question.  Where on your exhaust does the flashing touch.  My guess is the exhaust is hotter just as it exits the cylinder compared to maybe 6" down the exhaust pipe.  Just want to make sure we are comparing apples to apples.

Thanks

[TJay 1041]

Some one was talking about a product called Lava something a while back, guess its one of the best heat shield products on the market, But have no idea where to get it and how good it really is,

[EDMO 1078]

Any time two parts touch and one or both vibrate the softest part is going to wear first.  The addition to this is that if a part causes a hot-spot on an exhaust or muffler it can cause heat erosion inside and burning or breakage.   EdMO

Edited 7 Feb 2017 by EDMO

[Dusty 126]

I won't be near the hanger for a couple of days do can't supply photos.the copper is bent with a spring inside to prevent crushing.the ends are crox flared  and hose clamped to stop the hose coming off,make sure they Don't touch the exhaust or they will chafe.

[wypaul 448]

It is on the bottom of the engine probably 6" from the flange  Ii like the copper tubing idea if you can keep it from touching.  

Edited 7 Feb 2017 by wypaul

[lv2plyguitar 172]

Okay so I feel like a dummy.  I was able to tap the coolant fitting on the head and it turned enough to give me 1/4 inch clearance from exhaust.  So glad I don't need to solve this riddle anymore. 

[Av8r3400 1178]

It will now leak. The fitting may possibly be stripped, too.  Theses can not turn once the lock tite is set. 

You need to heat the fitting with a heat gun or map torch, remove it, clean the threads then reinstall it with fresh loc-tite 648 pointed in the direction you need. 

[lv2plyguitar 172]

It is not leaking thankfully. 

[akflyer 1427]

It is not leaking thankfully. 

yet... I thought we had talked about this one as I was building it and I had mentioned to you that you can get different fittings etc to clear the mount and exhaust.  I had also mentioned using heat to take them out and the use of the proper loctite to re-position them as I was worried about clearance issues as I was building it and the determination at that time was to build it and then we could change fittings etc if needed.

 

[lv2plyguitar 172]

Only a couple of the fittings were close so I experimented with it and everything looks good now.  If  problem arises ( I don't think it will) I can look at different fittings.

[Av8r3400 1178]

Okay.  This is my last post to the topic.

These fittings are SOFT aluminum.  Turning them without heating the loc-tite will very easily tear the threads on the tube.  They are very fragile.

What you have done is extremely risky.  You may very well have set yourself up to blow off this fitting once it warms up and pressurizes the coolant jacket.  Maybe not even the first time, it may take a few cycles.  Then you will have a catastrophic loss of coolant situation and at best a JUNK engine.  At worst a silent engine.  Over heating a 912 will ruin the temper in the aluminum making is a total loss.  Heating up the fitting, removing it properly and installing it again is easy and extremely inexpensive, by comparison.

You are in Alaska.  This is some very inhospitable terrain.  A loss of coolant failure may be a life and death situation for you.  Now is not the time to be dollar wise (convert to a 912) and penny foolish (wreck its fittings).