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Which Oil Cooler?
- Thread starter shiney
- Start date
RV7Guy
Well Known Member
S&W
Hi Shiney,
I live and operate out of the hottest environment in the US in Arizona. Cooling is absolutely critical. Last summer we had 36 days over 110 degrees!!!!
I went with the Stewart Warner 8432R oil cooler. This is a dual pass style and is mounted on the baffling behind the #4 cylinder. This provides me with under 200 degree temps (F) even on the hottest summer days.
Cruise temps are running 175-185. Your environment is certainly different and you don't have to deal with very high temps. Check out S&W. You could probably get one of the other models they make that isn't the dual pass version.
Hi Shiney,
I live and operate out of the hottest environment in the US in Arizona. Cooling is absolutely critical. Last summer we had 36 days over 110 degrees!!!!
I went with the Stewart Warner 8432R oil cooler. This is a dual pass style and is mounted on the baffling behind the #4 cylinder. This provides me with under 200 degree temps (F) even on the hottest summer days.
Cruise temps are running 175-185. Your environment is certainly different and you don't have to deal with very high temps. Check out S&W. You could probably get one of the other models they make that isn't the dual pass version.
tomcostanza
Well Known Member
Darwin,
Do you have any pics of your installation? IIRC, the 8432R has a different port arrangement than the stock Van's cooler.
Thanks and happy holidays.
Do you have any pics of your installation? IIRC, the 8432R has a different port arrangement than the stock Van's cooler.
Thanks and happy holidays.
gmcjetpilot
Well Known Member
SW and remote mount
As far as location I hate hanging it off the baffle directly behind #4. That is kind of the "plans" and I'm all for following the plans but here is the problem, the oil cooler, with oil in it, heavy duty braided oil lines also filled with oil, hanging off the engine, is heavy and begging to crack the baffle or oil cooler flanges. Builders have gotten smarter. Now builders reinforce and brace the heck out of their baffle. They also use long through bolts with spacers and washer/radius fillers, going through both flanges of the cooler to help distribute the load. Anything less and you WILL have a crack. My preference is off off the engine mount with as short of SCAT as possible. The duct flanges need to be "funnel shaped" not box shaped. The "G" force or acceleration of the engine as it starts and stops like a shaking wet dog, might be a lot. Also its going back and forth. Even in flight there's a buzz which is really hard on the cooler and baffle, fatigue wise. It's just un-stiffened flat sheet metal hanging off a few screws. Following the plans works but I guarantee it will be a maintence item before your first condition inspection or few 100 hours.
Do not use Vans std remote cooler kit. It's OK for a 320 at best and uses 3" SCAT, however for the RV-10 and 540 they now use 4". You really need at least 3.5"; 4" SCAT is better and gets the most out of a 8432R SW cooler for low OT in hot climb conditions. Remote mounting of coolers got a bad name because of the undersized Vans cooler kit. If you use it you will have a OT issue, so make your own. The Van kit works OK for 320's in moderate climates but not 360's in warm climates. Van uses 3" SCAT. It's way too small. Also the fitting/duct adapter that bolts to the cooler Van supplies, is a flat shallow bent up sheet metal box. It is really poor from a flow stand point (see pics in links below). There are several threads about how to do a remote mount cooler properly with pictures. Location is semi critical and you should make sure the cooler exit is in a low pressure area and air flow is not fighting the exit air out the cooler.
I did not take time to read everyone, there are 100's. Here is a good sample of threads about the subject. I used the forums archives SEARCH feature for "OIL COOLER" (you can hunt around with other key words and get more info):
http://www.vansairforce.com/community/showthread.php?t=19960&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=21483&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=2629&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=16249&highlight=oil+cooler (poll)
http://www.vansairforce.com/community/showthread.php?t=12939&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=12813&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=18322&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=19978&highlight=oil+cooler
As Darwin suggested, get Stewart Warner 8432R oil cooler. There is a direct relationship to money spent to oil temp. The more you spend the lower your oil temp will be. For a 360 get the best, a SW.I'm working on the FF prior to the arrival of the engine which is due in mid Feb. Which oil cooler would you recommend for the Superior IO-360 and where is its best location? Shiney
As far as location I hate hanging it off the baffle directly behind #4. That is kind of the "plans" and I'm all for following the plans but here is the problem, the oil cooler, with oil in it, heavy duty braided oil lines also filled with oil, hanging off the engine, is heavy and begging to crack the baffle or oil cooler flanges. Builders have gotten smarter. Now builders reinforce and brace the heck out of their baffle. They also use long through bolts with spacers and washer/radius fillers, going through both flanges of the cooler to help distribute the load. Anything less and you WILL have a crack. My preference is off off the engine mount with as short of SCAT as possible. The duct flanges need to be "funnel shaped" not box shaped. The "G" force or acceleration of the engine as it starts and stops like a shaking wet dog, might be a lot. Also its going back and forth. Even in flight there's a buzz which is really hard on the cooler and baffle, fatigue wise. It's just un-stiffened flat sheet metal hanging off a few screws. Following the plans works but I guarantee it will be a maintence item before your first condition inspection or few 100 hours.
Do not use Vans std remote cooler kit. It's OK for a 320 at best and uses 3" SCAT, however for the RV-10 and 540 they now use 4". You really need at least 3.5"; 4" SCAT is better and gets the most out of a 8432R SW cooler for low OT in hot climb conditions. Remote mounting of coolers got a bad name because of the undersized Vans cooler kit. If you use it you will have a OT issue, so make your own. The Van kit works OK for 320's in moderate climates but not 360's in warm climates. Van uses 3" SCAT. It's way too small. Also the fitting/duct adapter that bolts to the cooler Van supplies, is a flat shallow bent up sheet metal box. It is really poor from a flow stand point (see pics in links below). There are several threads about how to do a remote mount cooler properly with pictures. Location is semi critical and you should make sure the cooler exit is in a low pressure area and air flow is not fighting the exit air out the cooler.
I did not take time to read everyone, there are 100's. Here is a good sample of threads about the subject. I used the forums archives SEARCH feature for "OIL COOLER" (you can hunt around with other key words and get more info):
http://www.vansairforce.com/community/showthread.php?t=19960&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=21483&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=2629&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=16249&highlight=oil+cooler (poll)
http://www.vansairforce.com/community/showthread.php?t=12939&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=12813&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=18322&highlight=oil+cooler
http://www.vansairforce.com/community/showthread.php?t=19978&highlight=oil+cooler
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RV7Guy
Well Known Member
Remote didn't work
I had my oil cooler remotely mounted on the firewall with tapered plenum for 3" Scat tubing. It didn't work. Even in the winter I had temps well over 200 with climbouts reaching 225. Part of the issue is there is no real direct way to get the SCAT to the cooler. Everytime you make a turn or bend it takes away efficiency of the incoming air. Simple fluid dynamics.
I used a standoff box manufactured by Robbie Attaway, to mount the cooler on the baffling behind the number 4 cylinder. I also added two cross braces mounted to the rear baffle and triangulated to points on the engine. Now over 300 hours without problems.
I wish I would have done this from the start. I would have saved 2 days removing, fabricating and reinstalling in the new location.
The remote mount sounds good on paper and may work fine in much cooler environments, but it didn't work here.
I had my oil cooler remotely mounted on the firewall with tapered plenum for 3" Scat tubing. It didn't work. Even in the winter I had temps well over 200 with climbouts reaching 225. Part of the issue is there is no real direct way to get the SCAT to the cooler. Everytime you make a turn or bend it takes away efficiency of the incoming air. Simple fluid dynamics.
I used a standoff box manufactured by Robbie Attaway, to mount the cooler on the baffling behind the number 4 cylinder. I also added two cross braces mounted to the rear baffle and triangulated to points on the engine. Now over 300 hours without problems.
I wish I would have done this from the start. I would have saved 2 days removing, fabricating and reinstalling in the new location.
The remote mount sounds good on paper and may work fine in much cooler environments, but it didn't work here.
Where can you get this standoff box
Darwin,
Where can you get this standoff box you describe?
Thanks,
Darwin,
Where can you get this standoff box you describe?
Thanks,
RV7Guy
Well Known Member
SW is not for everyone.
PHX OATs in the 100s, ECI, oil squirts, high compression, angle valve, running high power settings..... these things all add to the thermal load. In that case by all means SW nothing else!
In my case I have a IO-360 8.5 cr, OATs 0-70 typical, run it 45-55% power, no oil squirts. I see CHTs below 300 often and oil temps around 140 with a SW. I swapped it out for a positech and sometimes still have trouble getting 170 on the oil.
The question was asked by someone in a mild climate.
PHX OATs in the 100s, ECI, oil squirts, high compression, angle valve, running high power settings..... these things all add to the thermal load. In that case by all means SW nothing else!
In my case I have a IO-360 8.5 cr, OATs 0-70 typical, run it 45-55% power, no oil squirts. I see CHTs below 300 often and oil temps around 140 with a SW. I swapped it out for a positech and sometimes still have trouble getting 170 on the oil.
The question was asked by someone in a mild climate.
gmcjetpilot
Well Known Member
Well there is a way
short. One way is mount the cooler on the engine mount with adel
clamps and may be an angle or two. No argument, it did not work
for you, but what cooler? You had a tapered plenum not Vans
crummy aluminum box? hummm, interesting. What where the OAT's?
Even a Cessna has OT problems on +100F days.
3" SCAT is too small. However from a Fluid Dynamics standpoint, the
CFM/velocity are low, so duct loss is small, with in reason. You do want
to keep SCAT asap (s=short). They make SCAT with a second smooth
internal layer. Also people aggravate the problem by using the cheap oil
coolers.
Below are pics of ways to mount to cooler off the engine mount (solid)
with a short rectangular duct. This is a direct rip-off of what Mooney
did, as shown: top left and middle left pics. The other pics are two
Rockets, one left one right cooler mounts. You can do something
simular but use a round duct, aka SCAT.
least 3.5" or 4" SCAT. If you start with Van's 3" stuff you're at a deficit
already. See pics below:
Bottom right pic shows SCAT going from behind #4 to the cooler,
mounted on aircraft right. That's a little long. There is nothing wrong with
picking up behind #3, which does tend to be hottest, but that is because
the lower baffle chokes the air off to the lower part of the #3 cyl. Proper
baffle gaps allow good cooling so you can pick up air behind #3. There is
more room behind #3 but the battery, if mounted per RV7/8/9 plans, is in
the way a bit. The blue baffled RV (mid left), the air is off of #3 w/ SCAT
to remote cooler. The battery was moved up & over. White cooler plenum
(bottom left) could be longer & more tapered. Smooth inner surfaces of a
fiberglass part is better than SCAT. Also being low and in the corner may
or may not help the exit flow out the cooler? Remote mount coolers work
but short 3.5"-4" SCAT runs & tapered plenums are needed. Note top left
pic has a tapered flange at the baffle as well, which is good. Sharp/square
corners are BAD for flow. This is also why I like mounting coolers with
Adel clamps on the engine mouth to keep SCAT runs asap.
[Note: In pics above, the top right show a wedge shaped plenum; I'd make it
less so with a rounded deeper shape towards the bottom. The RV-4 pic (middle
right) has no plenum at all, just an open plate. This is the RV-4 paradox?
RV-4's tend to cool better than other "wide body" RV's, especially OT. Why
I don't know but its true. He could have mounted the cooler closer to the
engine baffle, still mounting on the engine mount, keeping the SCAT shorter.]
There are ways to fit the cooler in, while keeping the SCAT duct
short. One way is mount the cooler on the engine mount with adel
clamps and may be an angle or two. No argument, it did not work
for you, but what cooler? You had a tapered plenum not Vans
crummy aluminum box? hummm, interesting. What where the OAT's?
Even a Cessna has OT problems on +100F days.
You are 100% right, bends and length causes loss, but size does matter.
3" SCAT is too small. However from a Fluid Dynamics standpoint, the
CFM/velocity are low, so duct loss is small, with in reason. You do want
to keep SCAT asap (s=short). They make SCAT with a second smooth
internal layer. Also people aggravate the problem by using the cheap oil
coolers.
Steve Ashby
Below are pics of ways to mount to cooler off the engine mount (solid)
with a short rectangular duct. This is a direct rip-off of what Mooney
did, as shown: top left and middle left pics. The other pics are two
Rockets, one left one right cooler mounts. You can do something
simular but use a round duct, aka SCAT.
If you keep the duct work to a min you can use scat, but you need at
least 3.5" or 4" SCAT. If you start with Van's 3" stuff you're at a deficit
already. See pics below:
Bottom right pic shows SCAT going from behind #4 to the cooler,
mounted on aircraft right. That's a little long. There is nothing wrong with
picking up behind #3, which does tend to be hottest, but that is because
the lower baffle chokes the air off to the lower part of the #3 cyl. Proper
baffle gaps allow good cooling so you can pick up air behind #3. There is
more room behind #3 but the battery, if mounted per RV7/8/9 plans, is in
the way a bit. The blue baffled RV (mid left), the air is off of #3 w/ SCAT
to remote cooler. The battery was moved up & over. White cooler plenum
(bottom left) could be longer & more tapered. Smooth inner surfaces of a
fiberglass part is better than SCAT. Also being low and in the corner may
or may not help the exit flow out the cooler? Remote mount coolers work
but short 3.5"-4" SCAT runs & tapered plenums are needed. Note top left
pic has a tapered flange at the baffle as well, which is good. Sharp/square
corners are BAD for flow. This is also why I like mounting coolers with
Adel clamps on the engine mouth to keep SCAT runs asap.
[Note: In pics above, the top right show a wedge shaped plenum; I'd make it
less so with a rounded deeper shape towards the bottom. The RV-4 pic (middle
right) has no plenum at all, just an open plate. This is the RV-4 paradox?
RV-4's tend to cool better than other "wide body" RV's, especially OT. Why
I don't know but its true. He could have mounted the cooler closer to the
engine baffle, still mounting on the engine mount, keeping the SCAT shorter.]
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RV7Guy
Well Known Member
Several points
1) It was winter, temps below 60
2) I made my own tapered plenum
3) I used 3" SCAT with the smooth interior
4) There was no room for 4" tubing
5) There was no room to mount it on the engine mount. Also this would take lots of work to get it mounted and secured properly.
George,
Not sure if you've actually built an RV or not, since you always use pictures of other peoples planes. There isn't alot of room under the cowl. I'm going to go out on a limb here and say that Van's probably designed it to be mounted on the baffles because it WORKS and is simple.
I do not remember why I wanted to mount mine on the firewall but it was a lot of work and was ineffective. Bad decision.
The entire process of mounting on the baffle (retrofit) took about 4 hours. Would have been about 2 hours had I done that from the start.
FROM MY EXPERIENCE, remote mounting did not work. From an efficiency stand point and ease of installation I can see no reason to remotely mount the oil cooler. There may be one, I just don't know what it is.
Work smarter, not harder.
1) It was winter, temps below 60
2) I made my own tapered plenum
3) I used 3" SCAT with the smooth interior
4) There was no room for 4" tubing
5) There was no room to mount it on the engine mount. Also this would take lots of work to get it mounted and secured properly.
George,
Not sure if you've actually built an RV or not, since you always use pictures of other peoples planes. There isn't alot of room under the cowl. I'm going to go out on a limb here and say that Van's probably designed it to be mounted on the baffles because it WORKS and is simple.
I do not remember why I wanted to mount mine on the firewall but it was a lot of work and was ineffective. Bad decision.
The entire process of mounting on the baffle (retrofit) took about 4 hours. Would have been about 2 hours had I done that from the start.
FROM MY EXPERIENCE, remote mounting did not work. From an efficiency stand point and ease of installation I can see no reason to remotely mount the oil cooler. There may be one, I just don't know what it is.
Work smarter, not harder.
Airflow through the cooler
I just completed replacing the O320 in my RV6 to a TMX IO-360~M1b. It has Lightspeed on top, a cold sump, Silverhawk injection, RAM intake, an AWI 4-1 exhaust, a plenum, and a 3 bladed Performance wood prop. It turns 2400 rpm static and 2700 flat and level...WOT...all the way to 10,000' so far. The best guess is it puts out about 195 hp. Its empty weight is 1055. And yes...it is possible to get more acceleration, climb, and cruise when you add 40 hp and only 22 lbs of weight.
A flying buddy has an RV7 with an angle valve, CS, and 230 hp. He was running warm with his non-SW cooler mounted on the baffling. He sold me his non-SW and replaced it with a SW. He saw a 5 degree change mounting it just where his old oil cooler was. I figured since his old cooler worked on a angle valve, it would handle my new engine.
The oil cooler on the old O320 was mounted on the baffling behind #4. It had caused the baffling to crack after 400 hours..even with the stiffener. So I installed the new oil cooler on the top of the lower horizontal of the engine mount with the airflow going down and out the exit. I fed it with a 3" round scat from behind #4. I even built a shutoff for that 3" controllable from the cockpit. For the first 25 hours of flight, I tried not to chase numbers. But if I went over 2300 rpm, I saw the oil temp go over 210. I thought at first it was a breakin issue... but since the CHTs were always under 350, I started thinking about the amount of air flowing throught the cooler. This same oil cooler had nearly worked on an angle valve...mounted on the baffling. I just mounted it on the lower horizontal engine mount. The only difference was the size of the hole feeding it air.
So I added a 2" feed from behind #3 to the fiberglass trumpet shaped airbox over the cooler. When I did that, my oil temp dropped to 180...and rarely goes over 190 with OAT ~80. The lesson learned (for me) is that the airflow through the cooler is more important than the cooler. A 4" from behind #4 would also work... but getting the scat behind the engine to the cooler might be difficult.
I had a chance to test this further. A friend with a Great Lakes biplane installed a new IO360 and was seeing oil temps over 220 with a non-SW cooler. His oil cooler was mounted on the firewall and had a 3" feed. Others suggested a SW solution which he did... and it made no difference to the temps he was seeing. I gave him an airbox I had built earlier that had two 3" inlets. We borrowed the heater's three inch scat and added that airflow to the existing 3" from behind #4. His oil temp dropped to 180-185.
If you think about it, a baffling mounted oil cooler has a rectangular hole through the baffling roughly the shape of the cooler. The number of square inches for that rectangular hole is quite a bit more than the square inches for a 3" circle. So wherever you mount whichever oil cooler you decide upon, give it plenty of air.
Rick Smith
Oxnard, CA
I just completed replacing the O320 in my RV6 to a TMX IO-360~M1b. It has Lightspeed on top, a cold sump, Silverhawk injection, RAM intake, an AWI 4-1 exhaust, a plenum, and a 3 bladed Performance wood prop. It turns 2400 rpm static and 2700 flat and level...WOT...all the way to 10,000' so far. The best guess is it puts out about 195 hp. Its empty weight is 1055. And yes...it is possible to get more acceleration, climb, and cruise when you add 40 hp and only 22 lbs of weight.
A flying buddy has an RV7 with an angle valve, CS, and 230 hp. He was running warm with his non-SW cooler mounted on the baffling. He sold me his non-SW and replaced it with a SW. He saw a 5 degree change mounting it just where his old oil cooler was. I figured since his old cooler worked on a angle valve, it would handle my new engine.
The oil cooler on the old O320 was mounted on the baffling behind #4. It had caused the baffling to crack after 400 hours..even with the stiffener. So I installed the new oil cooler on the top of the lower horizontal of the engine mount with the airflow going down and out the exit. I fed it with a 3" round scat from behind #4. I even built a shutoff for that 3" controllable from the cockpit. For the first 25 hours of flight, I tried not to chase numbers. But if I went over 2300 rpm, I saw the oil temp go over 210. I thought at first it was a breakin issue... but since the CHTs were always under 350, I started thinking about the amount of air flowing throught the cooler. This same oil cooler had nearly worked on an angle valve...mounted on the baffling. I just mounted it on the lower horizontal engine mount. The only difference was the size of the hole feeding it air.
So I added a 2" feed from behind #3 to the fiberglass trumpet shaped airbox over the cooler. When I did that, my oil temp dropped to 180...and rarely goes over 190 with OAT ~80. The lesson learned (for me) is that the airflow through the cooler is more important than the cooler. A 4" from behind #4 would also work... but getting the scat behind the engine to the cooler might be difficult.
I had a chance to test this further. A friend with a Great Lakes biplane installed a new IO360 and was seeing oil temps over 220 with a non-SW cooler. His oil cooler was mounted on the firewall and had a 3" feed. Others suggested a SW solution which he did... and it made no difference to the temps he was seeing. I gave him an airbox I had built earlier that had two 3" inlets. We borrowed the heater's three inch scat and added that airflow to the existing 3" from behind #4. His oil temp dropped to 180-185.
If you think about it, a baffling mounted oil cooler has a rectangular hole through the baffling roughly the shape of the cooler. The number of square inches for that rectangular hole is quite a bit more than the square inches for a 3" circle. So wherever you mount whichever oil cooler you decide upon, give it plenty of air.
Rick Smith
Oxnard, CA
Bubblehead
Well Known Member
Pictures?
Rick - great information. Can you show us some pictures of the successful application on your -6?
John
Rick - great information. Can you show us some pictures of the successful application on your -6?
John
gmcjetpilot
Well Known Member
Gee relax we just disagree
[ed. All text here removed by Doug (unsportsmanlike conversing)
[ed. All text here removed by Doug (unsportsmanlike conversing)
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RV7Guy
Well Known Member
Listen to George
George,
Not liking you has nothing to do with it. Re read the original post. Did he ask how to mount it? NO. He asked what oil cooler to use.
My point after you had to mix things up by bringing up remote mounting was simple. UNLESS THERE IS A COMPELLING REASON TO DEVIATE FROM THE PLANS, WHY DO IT? it is additional work, success is iffy and doesn't really accomplish anything. With thousands of them out there mounted on the baffles successfully, why change?
Nuff, said but I'm sure you'll have more.
George,
Not liking you has nothing to do with it. Re read the original post. Did he ask how to mount it? NO. He asked what oil cooler to use.
My point after you had to mix things up by bringing up remote mounting was simple. UNLESS THERE IS A COMPELLING REASON TO DEVIATE FROM THE PLANS, WHY DO IT? it is additional work, success is iffy and doesn't really accomplish anything. With thousands of them out there mounted on the baffles successfully, why change?
Nuff, said but I'm sure you'll have more.
NeilMcLeod
Active Member
I used Vans stock cooler in the stock location, planning to go to the SW a la Dan Checkoway if I needed it. So far I haven't needed it. Temps about 180 to 185 in cruise. I fly in AZ but don't live in the hottest area. I do fly into the Phoenix area often though and that cooler works fine cruise climbing out on my way home, never over 200.
robertahegy
Moderator/Tech Counselor
I, too have the stock Van's cooler mounted behind # 4 per the plans. Works fine with my 0-360 A1A. I think the higher HPs and the hotter climates need the bigger coolers, but 180 or less should be OK with the standard setup. I've flown out west in 90 plus temps and was fine. But I will admit that I have not endurred the really hot days out there.
I used strut tubes with full length bolts and mades sure I used washers on the oil cooler mounting flanges (both sides). I think this helps so you don't stress the flanges and cause them to crack. Another thing to watch out for is enough clearance between the cowl and cooler so you are not beating it up against the cowl during startups and shutdown.
Roberta
I used strut tubes with full length bolts and mades sure I used washers on the oil cooler mounting flanges (both sides). I think this helps so you don't stress the flanges and cause them to crack. Another thing to watch out for is enough clearance between the cowl and cooler so you are not beating it up against the cowl during startups and shutdown.
Roberta
trawlergeek
Member
Oil Cooler Mechanical Failure - avoidable
The oil cooler on a club owned AA5A Cheetah also failed - cracked tabs, mounting failure, etc. This cooler was the correct device for certificated AC. Craft went through a engine overhaul and the cooler was "simply bolted to the baffle behind #4." It turned out that this is not the correct method of attaching the cooler. Undue stress was placed on the cooler and it failed within the first 15 hours. Dramatic? Yes.
Solution? Be sure that you are not "adding" stress to the cooler frame and that the baffle will transfer the load effectively. Normally, you should not be compressing the cooler frame when you attach it to the baffle.
My wife admits that size matters - but I will leave cooler size and model decisions up to the folks with their individual engines, cowls, etc.
One other thing, the temp sensor on that Grmman was 15 degrees hotter than actual - the break-in seemed to be going badly but oil consumption was reasonable - it wasn't hot. Replaced sensor and oil at 25 hours - nice temperatures prevailed even here in Florida.
Cheers
Jim
The oil cooler on a club owned AA5A Cheetah also failed - cracked tabs, mounting failure, etc. This cooler was the correct device for certificated AC. Craft went through a engine overhaul and the cooler was "simply bolted to the baffle behind #4." It turned out that this is not the correct method of attaching the cooler. Undue stress was placed on the cooler and it failed within the first 15 hours. Dramatic? Yes.
Solution? Be sure that you are not "adding" stress to the cooler frame and that the baffle will transfer the load effectively. Normally, you should not be compressing the cooler frame when you attach it to the baffle.
My wife admits that size matters - but I will leave cooler size and model decisions up to the folks with their individual engines, cowls, etc.
One other thing, the temp sensor on that Grmman was 15 degrees hotter than actual - the break-in seemed to be going badly but oil consumption was reasonable - it wasn't hot. Replaced sensor and oil at 25 hours - nice temperatures prevailed even here in Florida.
Cheers
Jim
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