Oil Cooler Questions

[N941WR]

Originally Posted by alpinelakespilot2000

Hi Bill-
Do you have any sense of how much your 10599R might have lowered your oil temps?

About 10 to 20 degrees. I did some baffle work at the same time I installed the new cooler. On a high 90's degree day I'll see 190 with the SW cooler.

[RViter]

Originally Posted by dave4754

Great pics of that firewall mount, however, wont that be pretty hot for the pilot on warm days?

Dave

Having the FW mount for an oil cooler does nothing that wouldn't happen anyway. The engine side of the FW is essentially exposed to the same air temps because it is the same air volume. In fact, it could be argued that the air mass coming into the mount is air that entered the front of the cowl, into a SCAT tube and into the mount before passing thru the cooler, or cylinder fins. Thus, it may be at a lower temp in the mount plenum then air that would pass thru the cooler on a baffle mounted arrangement before hitting the FW.

[hohocc]

Larry/LR172,
Out of interest do you have the part number for the oil cooler you used?
Thanks.

[DanH]

Originally Posted by Randy

My temps will not stabilize at 220F at best power setting but I can keep it under 200F with my cowl flaps closed running lean of peak. I am hoping I can run at ROP best power settings when I want to with the second cooler.

Will post results after testing with second cooler.

Randy, I know you're pulling your hair out at this point, but gosh, I've never heard of anyone needing two coolers on a non-turbo.

There's something whacked in that installation. It's just not been found yet.

Hey, early on I recall you mentioned measuring case pressure. It was quite high under some conditions; do I remember 4~5 inches H2O? You were still in break-in, so it was discounted at the time. Have you measured lately? Excessive blow-by is a huge factor in high oil temperature.

Originally Posted by N941WR

A friend installed his oil cooler on his firewall and ran a 3" scat tubing to it. That didn't work out very well so we made this transition for 4" scat tubing and his cooling problems went away.

Hear, hear! A common 8432 or 10599 has a finned face area about, what, 22 ~ 24 sq inches? If you mounted it on the baffle, you would cut a 20 ~ 24 sq in hole. So why would anyone think they can feed the same cooler through a 3"D ribbed hose with a nominal flow area of 7 sq in?

[N941WR]

Originally Posted by DanH

...

Hear, hear! A common 8432 or 10599 has a finned face area about, what, 22 ~ 24 sq inches? If you mounted it on the baffle, you would cut a 20 ~ 24 sq in hole. So why would anyone think they can feed the same cooler through a 3"D ribbed hose with a nominal flow area of 7 sq in?

One of his problems is that he used one of these on his oil cooler, which effectively gives him only 7" of cooling area (Area = 3.14?1.5?1.5). By adding the larger tubing and making smooth transition to the entire face of the cooler the air slows down and passes through the entire cooler, not just seven inches of it.

[Randy]

Dan,

You probably right about something whacked in my install and adding the second cooler is kind of extreme. Most of the experts I talk to tell me not to do this, it should not be needed etc.

I measured 10" to 12" WC differential across the engine and nearly the same at the cooler itself, which puts it high on the efficiency chart from Pacific Oil Coolers.

In my case, I had quite a bit of the stuff laying around for adding the second cooler so the job has not been very difficult, and I will be happy one day to take it back off and set it on the shelf after finding the real problem

Complexity wise, I have added two more flare connections to the oil system, had Tom make up some nice -8 lines, and I had a good space left on the pass side to mount it. If I put in one of those life po batteries along with it I can claim it lightened the airframe

I will also be happy if I have excess oil cooling capacity. Maybe I will remove it in the winter and put it back on in the summer..

ECI tech tells me not to worry about oil and CHT temps that I have experienced and just fly within the Lyc. recommended redline temps.

At this point the money and weight cost will be worth it to me if it can even temporarily solve the problem. I decided to do this after talking to others that have done the same thing with good results. We wil see how it does in a few days.

Compression checked good with normal blowby past the rings. All in the mid to high 70s, checked cold.

Randall in Sedona.

[jakej]

FWIW - was the Oil Temp reading ever checked against a calibrated instrument ? No mention of that in the posts & should be first port of call, if not done already. I know of a situation where Oil Temps were supposed to be too high & the guy went through the same dual cooler route, end result was the EMS software had a bug.

Jake J

[Pat Stewart]

Another vote for the Stewart Warner. I put squirters on my second RV, big mistake I won't make again however the Stewart Warner brought so the temps down.

[jay bell]

I have 290 hours on my AeroSport IO-375 without piston squirters on my 7A. I used the Van's stock baffling, cowl, and cooler mounted behind the #4 cylinder. I couldn't keep the oil warm until I blocked most of the cooler off with aluminum tape. I leave about 3 square inches of cooler exposed in winter, and 4 for Canadian summer to obtain 180-190 degree oil temp. Oil did hit 210 climbing out of Oshkosh this year. A flow shutter would be a good addition for me.

[ColoRv]

Angle valve 360, 10:1 Pistons, Pmags, SW8432R mounted on baffle behind #4. Despite the piston squirters and high compression, my oil temps are low...often too low. I install a shutter in the fall to keep temps up. The key is a tight baffle system and a good cooler mounted with plenty of air flow....note I said good air flow, not what someone on VAF you've never met and who has questionable engineering skill tells you is good enough air flow. I fly in Florida quite a bit. Mid summer, Florida Vy climb to 17500, no issues with cooling and I mean none. Tight baffles are the key (I have a plenum) ....and air flow through the cooler. If you have a 3" scat tube feeding an oil cooler....you're not pointing your nose up very often.

I'll be reducing cooling flow over the winter. I'm running too cold, while racing....wide open. I'll say it again.....tight, well sealed baffles. If you don't feel like you are seriously anal retentive when it comes to baffle seals, you're not doing nearly enough. That last 10%.....is everything.

FYI, I'll never own a lycoming without squirters.