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Do I need to relocate my oil cooler?

Recently bought an RV-6A that flew first in 1995. Now that it is getting hot in Colorado, I'm having trouble with high oil temperatures. We're going through the steps I've seen in other forum posts - checking the baffles for leaks (there are some places to tighten up), checking the oil cooler for flow (expensive to have it cleaned, but we may do that), checking the oil temp sender and gauge and doing a compression test (tomorrow after work). The one thing that seems odd about this aircraft is the position of the oil cooler. It's just inside the left hand intake, mounted horizontally with a piece of 5/8" aluminum angle behind it to help direct some of the airflow through the cooler. Seems that airflow would largely bypass the cooler mounted this way. Has anyone seen this kind of configuration? Do I need to change it to the more traditional firewall mounting with a SCAT hose from the back of the engine baffles?
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This was a very common location for the oil cooler on early RV’s - I have seen it there on all fo the very early -6’s I have seen. We relocated teh one on Louise’s -6 to the rear of the baffles when we did a new baffle kit, and I think we gained a little cooling. If you are having temperature problems, moving it might get you a little bit of relief.
 
Same location, no problem with temps in FL

I do not have that angle, on mine. --- I have O360 FI, CS, and have never had temp issue, even at the 95+temp/195%+ humidity :)D).

Ron
 
Side view pic you can see daylight above the cooler, below the baffle. Air going around your cooler does no good. Make it go through your cooler.
 
Side view pic you can see daylight above the cooler, below the baffle. Air going around your cooler does no good. Make it go through your cooler.

And where are the seals on the baffle wall behind the spinner?
 
I do not have that angle, on mine. --- I have O360 FI, CS, and have never had temp issue, even at the 95+temp/195%+ humidity :)D).

Ron
I was wondering about that angle and planned on experimenting with taking it off, putting a curved piece there to direct the air flow down, etc and seeing if that has any effect on cooling.
 
Side view pic you can see daylight above the cooler, below the baffle. Air going around your cooler does no good. Make it go through your cooler.

Thanks. I wasn't looking for air escaping around the cooler. Good catch. I'll seal that up and see if it makes a difference.
 
And where are the seals on the baffle wall behind the spinner?

Good question. I'm looking at images for RV engine baffles and most don't have seals behind the spinner. Makes sense to add these as I can imagine air escaping through the dead zone right behind the spinner if there is nothing there to stop it. Seems I may be losing quite a lot of cooling air that better seals will improve.
 
I do not have that angle, on mine. --- I have O360 FI, CS, and have never had temp issue, even at the 95+temp/195%+ humidity :)D).

Ron

Ron, do you have the 7-row Vans cooler, a larger cooler, or a high efficiency cooler? After I seal up the air leaks the best I can, if I still have heat issues, I'm thinking of replacing the original 7-row model with a high efficiency part.
 
Mine is there too

Mine is in the same location. My engine came out of a Musketeer with the original baffling which I adapted and used in my plane. The inlet ramp on factory planes tends to be much more vertical with the cooler facing the ram air more directly than with the 6A, so I fabricated a simple scoop over the oil cooler to catch more air. I think it works well. An added bonus is that it moves the weight of the cooler forward. John
 
Standard cooler on my -6A

I have the early, (1993) standard cooler, --looks like the one you picture.

Ron
 
Mine is in the same location. My engine came out of a Musketeer with the original baffling which I adapted and used in my plane. The inlet ramp on factory planes tends to be much more vertical with the cooler facing the ram air more directly than with the 6A, so I fabricated a simple scoop over the oil cooler to catch more air. I think it works well. An added bonus is that it moves the weight of the cooler forward. John

John, can you post a picture of your scoop and/or the dimensions?
 
pics

Boulderick, Those pictures follow. I'm not an aerodynamics expert by any means, just a builder, but I think the scoop is worth a try. I used bolts to attach mine, but don't see why blind rivets wouldn't work to hold yours in place. John

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Boulderick, Those pictures follow. I'm not an aerodynamics expert by any means, just a builder, but I think the scoop is worth a try. I used bolts to attach mine, but don't see why blind rivets wouldn't work to hold yours in place. John

I wouldn't bother with trying the scoop until until you resolve some of the serious issues with your baffle installation that are evident in the photo links you posted.
Compare what you have to some of the details discussed in the thread that Dan posted the link too.
 
I wouldn't bother with trying the scoop until until you resolve some of the serious issues with your baffle installation that are evident in the photo links you posted.
Compare what you have to some of the details discussed in the thread that Dan posted the link too.

Yup. There's an order to things to try here and I want to make a change, fly the airplane, make another change, and fly again. I'm new to this and want to learn as much as I can about airflow over the engine.
 
Good plan, but there are numerous things that are needed that wouldn't be an experiement/change, they are a given because your baffle installation is not even up to the typical standard installation.

As already mentioned, the seals totally missing on the fwd dam are a major error.

Another backwards seals for the inlet ramps. With them attached to the ramps they are probably not doing much in regards to sealing.
All of the inlet seals should be attached to the cowl and lap onto the inlet part of the baffling so that dynamic pressure pushes/seals them against the baffles.
In your case, dynamic pressure like pushes them away from the cowl.

Considering these major flaws in the installation, there are likely more that could be seen if you posted more photos of the entire installation.
 
Point of reference

Just as a point of reference with an oil cooler at the left inlet. I flew across Texas today from east to west. Started at 4500' and was cruising at 8500' by the time i reached Lubbock. Temps on the ground were in the high 80's and 60 to 70 plus at altitude. I was running at 2300 rpm/130 knots. My oil temps were about 183 most of the time. CHT at cruise was about 370 on the 3 cylinder which tends to run hottest on my engine. I have an 0320.

Should see some much higher temps in AZ next few days. Will let you know the effects on oil temp.

John
 
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Good plan, but there are numerous things that are needed that wouldn't be an experiement/change, they are a given because your baffle installation is not even up to the typical standard installation.

As already mentioned, the seals totally missing on the fwd dam are a major error.

Another backwards seals for the inlet ramps. With them attached to the ramps they are probably not doing much in regards to sealing.
All of the inlet seals should be attached to the cowl and lap onto the inlet part of the baffling so that dynamic pressure pushes/seals them against the baffles.
In your case, dynamic pressure like pushes them away from the cowl.

Considering these major flaws in the installation, there are likely more that could be seen if you posted more photos of the entire installation.

Thanks, Scott. I'll switch the seals from the ramps to the cowl as part of the first set of modifications.
 
Another comment

Made it back from AZ Friday. Mercifully, ground temps only got to about 90 degrees this year. The highest oil temp I saw was 192 with an OAT of 74 at 7500'. My MP was 19.7 inches and I was near gross. My cowl flap was closed.

I would rate my baffle/caulking job as average for RV's. I believe my oil cooler is a 7 row Positech. Not sure how this compares to other 6A's with 0320 engines with oil coolers at the air inlet. I've never flown my plane without the air scoop for the oil cooler, so don't know whether it really helps or not, but after tightening up your baffles if you still have high OT's, it might be worth a try.

I also got a good test of my new Anti-splat cowl flap on this trip. If I opened it in cruise it seemed to drop my CHT's by about 3-5 degrees. For me that's well worth the time and cost. I only saw 400+ degrees once during my trip, and was able to get the CHT's down easily with the cowl flap opened by dropping the nose slightly and enriching the mixture a little.

John
 
Cool it...

John/Rick,
I mounted my RV4's oil cooler in the exact same spot. After several iterations it was the optimum cooling for SE USA heat and humidity. 190 in summer, 175-180 in winter.

22 years later it's still flying and cooling well...
V/R
Smokey
 
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