Karl,
Have a look at this link.
http://www.gates.com/brochure.cfm?brochure=1020
It explains very much why a worm clamp is the worst choice for hoses
which experience big temperature changes.
Spring clamps are in my opinion the best readily available choice but
must be carefully selected for the right clamping size. The polymeric
type mentioned in this article might be a great system but I am not sure
if easily available and if we could easily apply them in our application
so the spring type will get my first vote.
Michael Grass
A266 TriGear
Detroit
----- Original Message -----
From: Karl Heindl
To: europa-list@matronics.com
Sent: 2008-07-02 18:16
Subject: RE: Europa-List: Coolant Temps.
Thank you. I'll go easy on that. But changing the cap back is easy. I
am changing all clamps again to narrow stainless worm clamps, and I am
also changing the hoses to the cylinders to a smaller i.d. silicone for
a tight fit (next week).
I see on the glycol container that the 50/50 mix boils at 129 C, and
the 70/30 at 135. So that is a guide for setting my limit on my EIS
warning light.
Karl
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From: budyerly@msn.com
To: europa-list@matronics.com
Subject: Re: Europa-List: Coolant Temps.
Date: Wed, 2 Jul 2008 17:09:48 -0400
Careful on the 1.2 bar cap. The reduction in boiling over with the
extra pressure is not worth the potential for leaking hoses. Unless you
replaced all the spring clamps with worm clamps, I would not do that.
As for the inlets, I leave mine the size they are due to ground
cooling. It's a trade off.
Bud
----- Original Message -----
From: Karl Heindl
To: europa-list@matronics.com
Sent: Wednesday, July 02, 2008 3:43 PM
Subject: RE: Europa-List: Coolant Temps.
Hi Bud,
Thanks for your recommendations. I am only concerned because I don't
recall a coolant problem from previous years.
I did make anumber of changes to the way the air flows over the
engine (Ihave a trigear 912S), but they should all
help with the cooling and reduction of drag:
1) I cut back the aluminum duct tail end to the radiator and this is
the main air outlet to the bottom of the fuselage.
2) I sealed the gills.
3) I taped over the main stbd Naca duct.
4) I closed the outboard 60% of the two round inlets. I don't see
the point of cooling the exhaust pipes.
5) I closed the gap between the round baffle inlet and the baffle.
6) I reduced the height of the main inlet by about 30mm, streamlined
the interior of the duct, and made sure that
there are no more gaps either at the front or around the
radiators.
7) The radiators are mounted just as you described.
8) The hoses all have a smooth run, and the two main ones to the
radiator are silicone and preshaped.
In essence, I have reduced the cowl openings by 50% and doubled the
exit openings.
The performance improvement in the cruise is considerable. The
temperature under the top cowling is around
15 degrees C above oat.
I see your note about coolant mixture, and that concurs with a
note in the Rotax handbook. I think I will try that
and maybe change the pressure cap to 1.2 bar.
Karl
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From: budyerly@msn.com
To: europa-list@matronics.com
Subject: Re: Europa-List: Coolant Temps.
Date: Wed, 2 Jul 2008 09:53:38 -0400
Karl,
Sounds to me like the duct sealing may have been compromised.
Another culprit can be the hose running from the top expansion tank
to the radiator. Sometimes that bend gets pinched a little.
I don't know what engine you have, but my experience here in Florida
with the XS cowl and Rotax engines follows:
1. Lower the oil cooler as far down as you can get it. Typically
1.5 inches is easily attained. That lowers oil temps nearly 15 degrees.
2. Make sure the cowl seal rubber is doing its job to include
around the top front of the duct. Any high pressure air getting from
the lower duct into the cowl cuts cooling. The engine is partially air
cooled also.
3. Seal the gaps on the side and below the oil cooler. The duct
works best when entering air stacks up and slows down in front of the
coolers so as to get efficient heat transfer. I bend a piece of
stainless which I attach to the oil cooler bottom and bend it to make a
nice tight seal underneath also. When taxiing, that really makes a
difference. I also continue the seal back to the cowl exit.
Other techniques:
4. For info only, I run 70/30 Dexcool which doesn't boil until 276F
vs. 265F for 50/50.
5. Taxi with coarse pitch to get more air in the duct.
If you have a mono, I do a number of other mods too numerous to
email about.
Bud
Custom Flight Creations
----- Original Message -----
From: Karl Heindl
To: europa-list@matronics.com
Sent: Tuesday, July 01, 2008 5:06 PM
Subject: Europa-List: Coolant Temps.
After changing all coolant hoses and coolant 50/50 I am now
getting much higher coolant temperatures while taxiing and climbing,
typically 25 C above the oil temperature. In the cruise the temperatures
are all within 2 degrees of each other. I don't think I had this problem
before. The radiator sits in front of the oil cooler. What could be the
problem ? The pressure cap is .9 bar.
Any suggestions ?
Karl
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