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Oil Cooler

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dweyant

Well Known Member
What are my options for an Oil Cooler?

I think I'm going to mount it on the fire wall rather than on the baffles.

Is bigger better? I assume it would be, but I'm not sure. Should I just go with the Van's recommended cooler for the 9a, or is there a better option?

Thanks,

-Dan
 
dweyant said:
What are my options for an Oil Cooler?

I think I'm going to mount it on the fire wall rather than on the baffles.

Is bigger better? I assume it would be, but I'm not sure. Should I just go with the Van's recommended cooler for the 9a, or is there a better option?

Thanks,

-Dan
Click to expand...

If you're putting an O-320 in your 9A, the stock cooler mounted on the baffles is plenty. I had to tape off 1/4-1/3 of my cooler to get oil temps up to 190 this summer.

If you mount remotely, it may or may not be as efficient. It's all an experiment from there. However it's easier to block off part of the cooler to remove capacity than it is to add capacity.
 
Depends a lot on what particular engine you're going to have. The standard, small 7-row NDM cooler Vans sells is generally fine for a stock Lycoming carbureted 160hp O-320. That's what's on my RV-6 (mounted on rear baffle aft of cyl #4) and it has always performed adequately even in the summer heat we get here in north Texas. I have seen my oil temps hit 210-220 in a climb however. One friend of mine with an IO-320 on his RV-6 says his 7-row cooler is marginal on his plane on a hot day. He even had to move his from the rear baffle all the way up in front of the #2 cylinder to get enough cooling out of his. Several folks here on VAF have reported acceptable performance with this oil cooler on a normal 180hp O-360 engine, but most of those are not flying in Texas summer heat either.

For a bigger more high performance engine, like another buddy's ECI Titan IO-360 with 9:1 pistons and piston oil squirter nozzles installed in the crankcase, the 7-row was woefully inadequate, within a few minutes after takeoff it was hitting oil temps approaching 240, so we ended up swapping it out right away, ultimately for a high-dollar Stewart Warner cooler that cost almost $700.

In my experience so far with oil coolers, it seems that when you mount one on the firewall and plumb air to it thru SCAT duct, that the cooler needs to be one or two rows larger than one that would be baffle-mounted.

When you do choose your engine, give Pacific Oil Coolers a call (www.oilcoolers.com) and they can help you with selecting the right size and brand of oil cooler to keep the engine happy flying in Texas summer heat.
 
I have the standard cooler in the recommended position on the baffles. I've been flying off my Phase 1 hours in the dog days of summer (it was 102F last weekend when I landed). Oil temps are no problem. Always around 185-195F.
 
cooler mounted on motor mount on Maule

My Maule 180 has the cooler mounted on the engine mount with a hose going over to the baffle. Anyone ever try that?
cj
 
Neal@F14 said:
Depends a lot on what particular engine you're going to have. The standard, small 7-row NDM cooler Vans sells is generally fine for a stock Lycoming carbureted 160hp O-320. That's what's on my RV-6 (mounted on rear baffle aft of cyl #4) and it has always performed adequately even in the summer heat we get here in north Texas. I have seen my oil temps hit 210-220 in a climb however. One friend of mine with an IO-320 on his RV-6 says his 7-row cooler is marginal on his plane on a hot day. He even had to move his from the rear baffle all the way up in front of the #2 cylinder to get enough cooling out of his. Several folks here on VAF have reported acceptable performance with this oil cooler on a normal 180hp O-360 engine, but most of those are not flying in Texas summer heat either.

For a bigger more high performance engine, like another buddy's ECI Titan IO-360 with 9:1 pistons and piston oil squirter nozzles installed in the crankcase, the 7-row was woefully inadequate, within a few minutes after takeoff it was hitting oil temps approaching 240, so we ended up swapping it out right away, ultimately for a high-dollar Stewart Warner cooler that cost almost $700.

In my experience so far with oil coolers, it seems that when you mount one on the firewall and plumb air to it thru SCAT duct, that the cooler needs to be one or two rows larger than one that would be baffle-mounted.

When you do choose your engine, give Pacific Oil Coolers a call (www.oilcoolers.com) and they can help you with selecting the right size and brand of oil cooler to keep the engine happy flying in Texas summer heat.
Click to expand...

Thanks!

I will give them a call. I've got a Superior IO-320 with PMags sitting in a create ready to mount :).

I've been told that the firewall is a better mounting location because the baffles will generally crack with the weight of the oil cooler.

-Dan
 
dweyant said:
Thanks!

I will give them a call. I've got a Superior IO-320 with PMags sitting in a create ready to mount :).

I've been told that the firewall is a better mounting location because the baffles will generally crack with the weight of the oil cooler.

-Dan
Click to expand...

The baffle will *always* eventually crack from the weight of an oil cooler mounted there.

For your engine, with a firewall-mounted cooler, I'd recommend something like a 9 or 10 row Aero Classics cooler. Put some kind of valve in line with the SCAT duct feeding air to the cooler and you can control the airflow reaching the cooler from the cockpit.
 
Neal@F14 said:
The baffle will *always* eventually crack from the weight of an oil cooler mounted there.
Click to expand...

Well, since you used the word "Always".....

This isn't true if the baffles are properly designed to support the cooler. I've been building baffles this way for years now, and have yet to have one crack after a couple thousand hours.

Improperly designed and supported? Of course they'll crack, and I've seen that happen as well.

But it can be done, fairly easily.
 
My 6 row Stewart Warner cooler is mounted on the rear baffle. 1051 hours and no sign of cracking. By the way the 6 row SW cooler is more efficient than my stock Vans cooler was.

Bayne
RV-9A N910BJ
RV-7A N227DB
Rans S-19 in process
 
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I have the stock vans 0-320 oil cooler for my 0-320 d2a on the baffles and wish I had more cooling than it gives me. On 85 degree days I tend to see 200-210F in cruise.
 
Dual pass really helped us

Ours in on the baffle behind number 4. We had serious oil temp concerns when we first bought the plane. Upgraded to the Aero Classic dual pass cooler and it solved our issue. We also seriously beefed up the baffling to handle the stress and no cracks after 2 years. 0-360 180hp in RV7a.
 
It amazes me the difference in performance we see due to baffling (including oil cooler performance). I have an IO-360-M1B, the standard Vans cooler, and I am running it 1/2 covered with aluminum tape in the summer to get the temperatures up to 175F. Winter goes to 3/4 covered. Might go more this winter. I am quite confident that it would be fine in Texas if I removed the tape.

Also, no cracking here. I fixed mine with a piece of J-channel stringer across the back baffle (not connected to the engine).
 
Standard Vans oil cooler is fine ...

I have the standard Vans oil cooler mounted on the baffle behind #4 and have more cooling than I need. Anytime the OAT is under 90F, I'm lucky to see 180 on oil temp. In the winter months I install a blocking plate that covers 90% of the oil cooler outlet, and my oil temps are still too low.

I was worried about the baffle cracking issue, so I installed the cooler with an additional .063" doubler all the way around the opening. 160 hrs and no sign of cracking or undue stress. Methinks the doubler did the trick. :)
 
Dan you will be fine with stock oil cooler. I opted for an aftermarket one and during winter times my engine is cold blooded. Only when I block the front AND the back of the cooler I can get temps in the green Dec to Feb.





If you have time and an opportunity to watch factory RV14 video there is a very elegant solution on doubler. I don't remember on what minute the video is long.
 
Hang 'em High

Vlad's picture above shows the oil cooler mounted nice and high on the rear baffle so it's minimally blocked by the #4 cylinder. Perhaps one factor of good cooling with the baffle-mounted coolers is keeping them as high on the back baffle as possible.

Of course this is a tricky process because when it's time to rivet the baffle together you have to know where the cooler is going. But you don't know exactly how high the cooler can go until the baffle is riveted together and trimmed to fit the cowl.
 
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Vlad's picture also shows a SW/Meggitt style of oil cooler (welded tank ends), which is a lot more efficient than the stock Niagara/NDM coolers (drawn cup style) that Vans supplies.
aec_8000075.jpg

This is the stock Vans-supplied cooler my RV-6 has, it's the right size for a carbureted O-320. In the winter I have to block off both the front and the back to get oil temps up to 180. On really hot summer days (105+) I'll see 210-220 oil temps if I climb too steeply for too long, I'll still have under 400 CHTs then and my baffles are well sealed, plenty of airflow and pressure differential between the upper and lower cowl areas.

It's much better and cheaper to initially install an oil cooler that you positively know will have a surplus of cooling capacity for the hottest summer days than to install an undersized or marginally sized unit first, hoping it will be good enough and then have to change it with a bigger one later. You can always block off some airflow if necessary, for colder weather flying.

The 9-row Aero Classics is about $270 from Spruce and is also a "drawn cup" style, and is only about an inch wider than the 7-row Niagara and will have substantially more cooling capacity than the 7-row.
8000074a.jpg
 
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I have an O-320 with 9.5 to 1 pistons and hover around 200 degrees on a hot day with the standard Vans cooler mounted on the baffle so I think its adequate. A few suggestions: 1. Build well sealed baffles, mount cooler as high up behind the cylinder as possible, build in reinforcements for the cooler to avoid cracking including an additional doubler plate on side baffle :cool:and a support back to the engine from the top of the cooler. I'd stick with the plans to avoid complexity.:cool:
 
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