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  #21  
Old 06-20-2019, 09:38 AM
DrPhil DrPhil is offline
 
Join Date: Jun 2019
Location: Temple
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Default DrPhil

Wow, thanks for the info. Got to get rid of 2? scats & use larger diameter scat.
Did your 17 row cooler fit Van?s mount or was that another project?
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  #22  
Old 06-20-2019, 12:02 PM
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Zuldarin Zuldarin is offline
 
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You have to modify the mount a little but its a very simple modification. I just did the same thing for my RV-10 build. My last post on my blog shows some pictures of the modification I made. For my RV-9 I had a home built oil cooler mount so I did have to modify it a little.
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  #23  
Old 06-21-2019, 05:28 AM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
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Default Numbers- you need numbers . . .

Upper and lower pressures are needed, also what are your CHT's? What are the conditions of test? Speeds - temps. Mixture - and YES check timing first.

Rest assured, you have plenty of flow area in and out of the cowl for cooling flow, it is something else, either too much heat generated (timing) or poor utilization of air - i.e. not crossing fins. Low pressure delta across the engine would be a symptom.

The SJ plenum is most restricted at the face of the heads. Looking at pressures will help diagnose the issues. Be sure the front of the plenum is not lifting and bypassing air.

Get an electronic manometer like DanH has suggested and pipe into the cabin. Tap into the static line for a reference point. Dan has used some of the rock aerators for small aquariums, so the measurement points should not present a large error.

Good baffle sealing thread http://www.vansairforce.com/communit...hlight=piccolo

Happy Hunting!
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  #24  
Old 06-21-2019, 10:55 AM
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Carl Froehlich Carl Froehlich is offline
 
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Location: Dogwood Airpark (VA42)
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Quote:
Originally Posted by DrPhil View Post
Having high oil temp issues with plenum and RV10-sized cooler mounted on firewall using the mount from Van's on my IO360 angle valve 200HP Lycoming. I modified the 4" flange on the mount to using 4 two inch scat tubes (2 of them off plenum over #4 cylinder and 2 from cowling mounted NACA ducts to outside air.

Put exit duct on cooler and placed a handheld sports anemometer in it that's BlueToothed to my phone. While in cruise, I am seeing 75MPH air passing thru the cooler.

Cooler has -8 hoses going to and from it and I have the Anti-Splat cowl flaps.

This is a RV7, SJ plenum and cowling, dual Emag's, Superior cold air sump otherwise engine is stock and zero-timed. BTW, when I bought the engine I hauled it to Barrett Precision Engines in Tulsa and it was placed on their dyno and run WOT for one hour. Had them install a new Vernathern and it ran perfectly after a 10 year pickling experience.

Please help me.....I want to fly!
Some thoughts:
- The high oil cooler exit air speed implies you are trading pressure at the cooler exit for velocity. This is exactly opposite of what you want as you increase the back pressure on the air going through the cooler - resulting in less pounds/mass of air. Try removing the exit plenum.
- The RV-10 firewall oil cooler mount is not the greatest setup for maximizing cooler air flow (several changes in cooling air direction, each increasing cooler back pressure). There are some ideas on how to modify this mount to mitigate so perhaps you can search the RV-10 posts. On my RV-10 I did not use this firewall mount.
- As been pointed out, verify your pMag setup. For this engine the most straight forward way is to set pMag timing at 5 degrees ATDC, with the jumpers in. The resulting advance curve will be (about) 20 to 30 degrees BTDC.
- I?ve seen others chase oil cooler temp problems by adding the outside NACA scoop. All proved less than successful unless you also increase exit air dimensions. After you remove the oil cooler exit plenum try a single SCAT hose to the rear engine baffle. If you can?t fit a 4?, then try 3.5?. For you engine and cooler a 3? hose should be adequate but you will need to test. The hose size is a consideration, but it is in series with the back pressure presented by the cooler itself. With your larger cooler you mitigate this.
- I assume you verified no issues with the cooler itself (like clogs). If you find you need a new cooler I recommend the Air Systems 2006X. This worked well on my RV-10 and am using it on my 180hp RV-8 (overkill but will have an oil cooler air butterfly valve).

Good luck,
Carl
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  #25  
Old 06-21-2019, 11:45 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by Carl Froehlich View Post
The high oil cooler exit air speed implies you are trading pressure at the cooler exit for velocity. This is exactly opposite of what you want as you increase the back pressure on the air going through the cooler - resulting in less pounds/mass of air. Try removing the exit plenum.
Velocity alone tells nothing about cubic volume, and ultimately mass flow rate. You would also need to know the area of the duct, at a minimum.

Further, an exit duct can be used to lower pressure on the downstream side of the cooler, increasing pressure drop across the cooler, thus increasing mass flow rate. Steve Smith pointed out one method recently, a diverging diffuser duct. Or, as I've been doing for the last 850 hours, a builder can duct to an area of pressure lower than that found in the vicinity immediately behind the cooler.

Not that it matters, if Dr Phil's duct was a temporary measurement device.
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  #26  
Old 06-22-2019, 10:16 AM
DrPhil DrPhil is offline
 
Join Date: Jun 2019
Location: Temple
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So, here?s what I?ve done over the past two days. I have removed the four 2 in.? tubing?s to the top of my RV 10 firewall mount and replaced it with a 4 inch duct coming off the top of number four cylinder and the SJ Plenum. Went flying this morning up to 5000 feet OAT was 69? and my oil temperature was 241?. Is my next move to put an airflow oil cooleR 15 row, model number 2006A?
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  #27  
Old 06-22-2019, 10:29 AM
DrPhil DrPhil is offline
 
Join Date: Jun 2019
Location: Temple
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So, I have replaced the four 2 inch tubing?s with a single four-inch duct off the top of my Plenum over number four. Went flying this morning and at 5000 feet the outside air temperature was 69? and my oil temperature was 241?. Is my next move to replace the oil cooler with the airflow 2007A? I have nothing on the exit side of the oil cooler in the way of ducting. It?s open to the environment. Am I to assume that the 13 row Niagara oil cooler purchased from Van?s is a piece of junk?
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  #28  
Old 06-22-2019, 11:53 AM
Marc Bourget Marc Bourget is offline
 
Join Date: Apr 2009
Location: Stockton, California
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Dr. Phil said: "Am I to assume that the 13 row Niagara oil cooler purchased from Van?s is a piece of junk?"

I'm not familiar with you, but reading the above made me question your understanding of the wisdom contained in DanH's (and other's) posts above.

Baseball bats used to drive circus tent stakes would be considered "junk" to the uninitiated.

Don't take it negative. I've sometimes had to read the "smarter" posts several times before I "grok" them!
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  #29  
Old 06-23-2019, 10:28 AM
N54SG N54SG is offline
 
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Location: Kansas City, MO
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Quote:
Originally Posted by DrPhil View Post
Am I to assume that the 13 row Niagara oil cooler purchased from Van?s is a piece of junk?
Actually, I'm of that opinion. The higher fin density of the HE series Aero Classics (like the Stewart Warner) works much better. Keep in mind the number of rows is not equivalent from a Niagara to an HE series, yet they can be dimensionally the same footprint. Meaning, fewer rows on HE cooler doesn't mean smaller oil cooler.

https://www.aircraftspruce.com/catal...soilcooler.php

All that being said, this is in no way saying your current installation isn't your problem either.. I don't waste my money on Niagara (or equivalent) coolers anymore.
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  #30  
Old 06-23-2019, 02:48 PM
DrPhil DrPhil is offline
 
Join Date: Jun 2019
Location: Temple
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Thanks for that info? Most helpful! So in your opinion would it be better to get an Aero Classics brand or the Airflow oil cooler (2007X) that is found on the Spruce website? I?m just trying to find which is best. I?m thinking because of the difficulty of removal of the Vans 13 row that I presently have on the firewall? I may add this additional oil cooler in series. Your thoughts?
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