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oil not hot enough D1A

D

drmax

Well Known Member
Ok gents, so I'm only in mid indiana and it hasn't even gotten that cold.
I've only had my 9A for a couple months and flown maybe 20 hrs. I've noticed the temp don't get much up above 160, and pressure remains around 90 on cruise. 450 hrs on engine and all appears normal, so nothing wrong....yet. What have you northern/colder folks doing, taping over the oil cooler? Lycoming says there is some type of blocker panels for this. I'm really not into constructing anything. Anything quick? I'm running 20w50 xc with camguard, starting with a 50 degree engine. Oil is just over 6 qrts. I've heard some said to reduce oil amount to raise temp. That's just crazy and will not do this. My Reiff "standard" heater system is arriving in a few days...but that won't heat much beyond 100. Thx for the advice. DM
 
First thing you should probably do is to pull your oil temp sender and dunk it in boiling water to make sure your reading is at least close. If so, just try taping over like 1/2 your cooler.
 
aerhed said:
First thing you should probably do is to pull your oil temp sender and dunk it in boiling water to make sure your reading is at least close. If so, just try taping over like 1/2 your cooler.
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Howdy and yes...just got off the phone with lyc. Heat up some old oil to 160 and dump probe in to figure this out. If accurate, then tape. I suppose there are some that have created a box with a cable controlled door to vary the temp. Ideal, as if you screwed up with too much tape....$$$. Also should have mentiond my concern with my oil pressure, but lyc said 90-95 is perfect for cruise, with a cold start indication of 115, (for short amount of time) so I'm good with this....whew! Gotta love it!!
 
Same Thing

I have the same issue with my RV-4. After replacing the old gauge with a new one and a new probe that I tested for accuracy (within 2 degrees) I proceeded to tape over the oil cooler. With about 2/3 taped off I couldn't get above 145 degrees. With the whole cooler taped over, front and back, it holds steady at 150 degrees (in cruise @ 2300 RPM) with outside temps in the 20's and 30's.
 
Hi DR, I'm across town from you and ended up with a 9A as well. I've got my oil cooler completely blocked with an aluminum plate and I can get the temp to 180 only if I "fly it like a rental" 2450 - 2500 RPM. There are lots of other posts on this subject. I think Vetterman? put a ball valve in line to limit the flow to the cooler and as I recall was pleased with the result. Some have had luck blocking both sides of the cooler. I may try that eventually. My CHT runs low 300s all the time too. For now I'll just "suffer" with blasting around at 145-150kts where ever I go... ;)

Since all the 9s seem to run cold we could reduce cooling drag with a cowl redesign. Surprised someone hasn't done that yet....
GZ
 
GWZ said:
Hi DR, I'm across town from you and ended up with a 9A as well. I've got my oil cooler completely blocked with an aluminum plate and I can get the temp to 180 only if I "fly it like a rental" 2450 - 2500 RPM. There are lots of other posts on this subject. I think Vetterman? put a ball valve in line to limit the flow to the cooler and as I recall was pleased with the result. Some have had luck blocking both sides of the cooler. I may try that eventually. My CHT runs low 300s all the time too. For now I'll just "suffer" with blasting around at 145-150kts where ever I go... ;)

Since all the 9s seem to run cold we could reduce cooling drag with a cowl redesign. Surprised someone hasn't done that yet....
GZ
Click to expand...
Wish my CHT's were that low...i'm in the mid to upr 3's, especially on #3.
 
ArlingtonRV said:
I have the same issue with my RV-4. After replacing the old gauge with a new one and a new probe that I tested for accuracy (within 2 degrees) I proceeded to tape over the oil cooler. With about 2/3 taped off I couldn't get above 145 degrees. With the whole cooler taped over, front and back, it holds steady at 150 degrees (in cruise @ 2300 RPM) with outside temps in the 20's and 30's.
Click to expand...
Darn, your is colder than mine. Maybe i outta be happy with my 160. I'll look into the gizzmo that the last poster posted...unless it's a small fortune, i'll most likely just use alum. tape
 
Does it matter where the OT probe is installed? I typically have 160°-170° temps on my O-360 in the RV-4. I was discussing this with a friend, thinking it was low, and he said that the temp was measured after the oil comes out of the cooler, so the oil in the engine is hotter. Therefore the temps I am seeing are desirable.

So, when OT values are mentioned, are they all measured at the same place, and is the oil in the engine a lot hotter?
 
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I also have the Van's shutter ($85 plus cable and terminal), it is a work of art (Art who?) and is very well made. It is going to be a slightly bigger project to install than I originally anticipated and before I get too carried away I want to have some experiance with the summer temps. I may install the shutter next year, but for now the tape works.
 
ccsmith51 said:
Does it matter where the OT probe is installed? I typically have 16?-170? temps on my O-360 in the RV-4. I was discussing this with a friend, thinking it was low, and he said that the temp was measured after the oil comes out of the cooler, so the oil in the engine is hotter. Therefore the temps I am seeing are desirable.

So, when OT values are mentioned, are they all measured at the same place, and is the oil in the engine a lot hotter?
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Makes sense. Maybe the oil in engine is 20 degrees hotter, which then it would be ok.
 
I'm sure one of our engine gurus will speak up shortly, but IIRC the guy who gives the engine presentation in the Lycoming tent at Oshkosh said the oil temp is generally about 50 degrees hotter in the engine then at the probe.

You want the oil in the engine at more than 212 in order to drive moisture out, and for that reason 160 is not where you want to be.
 
Mile High Relic said:
I'm sure one of our engine gurus will speak up shortly, but IIRC the guy who gives the engine presentation in the Lycoming tent at Oshkosh said the oil temp is generally about 50 degrees hotter in the engine then at the probe.

You want the oil in the engine at more than 212 in order to drive moisture out, and for that reason 160 is not where you want to be.
Click to expand...
If it is indicating 160 and probe/gage is correct, and the oil is actually 200 degrees in the engine, then this would be sufficient, for me. This is if the probe is mounted after the cooler. I don't know this, as I don't have the cowling off and not 2 familiar as of yet, with the layout.
** just found out that the oil temp bulb is right by the oil filter...so this would be the hottest point of the oil that is being measured**
 
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drmax said:
If it is indicating 160 and probe/gage is correct, and the oil is actually 200 degrees in the engine, then this would be sufficient, for me. This is if the probe is mounted after the cooler. I don't know this, as I don't have the cowling off and not 2 familiar as of yet, with the layout.
** just found out that the oil temp bulb is right by the oil filter...so this would be the hottest point of the oil that is being measured**
Click to expand...

I checked my probe and gauge recently because I replaced them. In boiling water the gauge indicated as best as I could tell 210?. The probe is next to the oil filter, and that is where my friend told me the oil was cooler there as it was coming from the oil cooler.

So, can an engine guru please chime in with accurate information. My oil cooler is 1/2 blocked off on the back and if the oil in the engine is indeed only 160?-170? then I am going to block off more....
 
ccsmith51 said:
I checked my probe and gauge recently because I replaced them. In boiling water the gauge indicated as best as I could tell 210?. The probe is next to the oil filter, and that is where my friend told me the oil was cooler there as it was coming from the oil cooler.

So, can an engine guru please chime in with accurate information. My oil cooler is 1/2 blocked off on the back and if the oil in the engine is indeed only 160?-170? then I am going to block off more....
Click to expand...

You need to block it off from the front, not the back. I always taped up the upper 2/3rds of the oil cooler and that worked well all winter in the midwest until early April.
 
Thanks, Bob. Is it accurate then that the OT measurement at the filter is the hottest oil, not the coolest? This oil path I found for an (I)O-360 indicates that the oil at the filter, where the probe is located, is at the outlet of the oil cooler. If that is the case then it should be the coolest point. And if that is the case then the next question is how hot it gets going through the engine, and what is the minimum I should see on my gauge to ensure I am boiling off water...

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To reiterate one of the positions above ...

...I've been told by more than one respected A&P that the OT sensor near the oil filter is the coolest oil point, i.w. after the cooler. They say 170 to 180 there is perfect, since that virtually assures the oil is above 212 in the engine at the hottest points.
I too had a low OT problem ... I fab'd a simple .035 block off plate covering ~2/3 of the cooler's exit area ... it's held in place by an AN3 bolt in the center holes of the oil cooler flanges. I can't block the inlet side because my oil cooler is mounted low - behind #4 almost completely. (The Sam James plenum is low profile and forces the oil cooler low on the rear baffle.) Right now at 30-40F OATs I'm seeing oil temps of 172 to 178. I'm happy with that. :D
 
I build a hinged flapper door to cover the rear of the oil cooler in my RV-6, with a simple push-pull cable under the instrument panel to open and close it. With it fully closed, but with some air leakage past notches that had to be cut in the door to clear the engine mount tubes (perhaps the equivalent of leaving two full rows open), I managed to get my oil temps from 150 without the door on a cold day to only 155-160 with the door closed. :( Not enuff!

Second attempt... I have now made an aluminum cover plate that covers almost the entire cooler's face in the front, except for one row on the most outboard side, where my flapper door can cover it completely on the rear face. Haven't yet flown it to test yet but I hope this will help me get the temps up to 180 for cold weather flying.

My desired goal would be to have a system where I could shut off oil cooling to get the temps up to at least 190-200 or so during takeoff/climb, and then pull the control cable to open it up just enough to cool it back down to 180. That's what we have for winter flying on the RV-8 with the electric servo-operated oil cooler flap I made for it and it's working great.

This little O-320 just doesn't seem to produce a lot of heat... unlike the RV-8's ECI IO-360 which we had difficulty keeping the oil temps down! Maybe I need to put piston oil squirters into my O-320 :D That'll bring the oil temps up.
 
49clipper

GWZ said:
Hi DR, I'm across town from you and ended up with a 9A as well. I've got my oil cooler completely blocked with an aluminum plate and I can get the temp to 180 only if I "fly it like a rental" 2450 - 2500 RPM. There are lots of other posts on this subject. I think Vetterman? put a ball valve in line to limit the flow to the cooler and as I recall was pleased with the result. Some have had luck blocking both sides of the cooler. I may try that eventually. My CHT runs low 300s all the time too. For now I'll just "suffer" with blasting around at 145-150kts where ever I go... ;)

Since all the 9s seem to run cold we could reduce cooling drag with a cowl redesign. Surprised someone hasn't done that yet....
GZ
Click to expand...

Its not only the rv9's, my RV-6 D1A runs exactly the same temps with the oil cooler completely blocked. I block it below 70 degrees and with say 40f OA, oil runs 170 and cht's are 270-315f. New oil temp sensor also.

Jim
 
Rupester said:
...I've been told by more than one respected A&P that the OT sensor near the oil filter is the coolest oil point, i.w. after the cooler. They say 170 to 180 there is perfect, since that virtually assures the oil is above 212 in the engine at the hottest points.
I too had a low OT problem ... I fab'd a simple .035 block off plate covering ~2/3 of the cooler's exit area ... it's held in place by an AN3 bolt in the center holes of the oil cooler flanges. I can't block the inlet side because my oil cooler is mounted low - behind #4 almost completely. (The Sam James plenum is low profile and forces the oil cooler low on the rear baffle.) Right now at 30-40F OATs I'm seeing oil temps of 172 to 178. I'm happy with that. :D
Click to expand...
What is the difference of front or back? I'm leaning towards doing what you did. I have a piece of 4" wide .040 alum. stock from my rv10 tail kit that I can mount there. What's the width required?
 
I recently made a flapper door with hinge on the back of my oil cooler. Since it has gotten cooler my oil temps had gone from 200 ish to 180. After going to trouble of installing the door I am only seeing 5 or so degrees increase with it fully closed. Should have asked Rocket Bob first and put some fowl tape on the front instead. Will do that next though.
 
rocketbob said:
You need to block it off from the front, not the back. I always taped up the upper 2/3rds of the oil cooler and that worked well all winter in the midwest until early April.
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good ole duck tape won't melt on shut down, or taxing will it? i'd use this and skip the alluminum, if acceptable. Thx for the education...dm
 
I used Gorilla tape on my old Cherokee for years and it worked great, but the oil cooler was in the front cowl opening and not near a cylinder head where the heat might melt it.

I've secured my new front block-off plate on my RV-6 with Gorilla tape, across the top of the plate, and I think the tape is far enough away from the cylinder head fins to be OK.

On my friend's RV-8 with ECI IO-360, the rear flapper door alone will bring the oil temps up from a max of about 150 with door removed or fully open on a cold day, to over 200 with the door fully closed. It's really effective and really easy to fine tune the temps in flight since I used a Ray Allen trim servo to move the door. As reported earlier, the rear flapper door only on my RV6 has proved nowhere near as effective or successful as an experiment. The ECI IO-360 engine in the -8 is a heat-producing monster with piston squirters, and I think that makes all the difference in how much heat it dumps into its oil.
 
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Oil Temps

I fabricated a thin piece of alum the size of the oil cooler, slipped it in front of the oil cooler and it works great. You will need to drill holes where the bolts go thru the alum cover and it secures nicely in place. I also did the same routine on the back covering 1/2 of the back. Temps went from 150 to 185 (perfect). I have also bought Vans adjustable system and cable which allows you do adjust the airflow to the oil cooler from the cockpit. Will probably install that in the summer. I live in San Diego and it can get cold (30's) in the winter mornings and 90+ degrees in the summer so having the adjustable system makes sense to me.
 
blocking plate

I went for the alum. stock I had and made a blocker for fwd side.
I went complete blockage, as most are reporting this to be the better
bet. I will report finds saturday. DM
 
Oil cooler shutter

Anybody know if there is a [Vans style] shutter available for the larger 13 row coolers?
 
Welp, I got my cooler remounted with the alum. blocking plate up front. This fit is good. I installed .030 washer ahead of the cooler, as not to "mush" the front of the cooler. Anxious to fly her, as slightly worried of covering up the entire front end. I suppose my anal self will end up dropping the $ for the shutter design, as to have complete control over the situation. Hopefully I won't overheat, but as I read here...noone is getting that hot with covering over the entire unit. I'll post back after this Sat. flight. DM IND
 
Mile High Relic said:
You want the oil in the engine at more than 212 in order to drive moisture out, and for that reason 160 is not where you want to be.
Click to expand...

This topic seems to come up fairly regularly, and I've never quite understood this argument- my experience is that water will evaporate just fine well below boiling temperature. Heck, a swimming pool will lose close to an inch per week during the summer, at 80 degrees. FWIW, the minimum oil temperature (for "normal operation") specified in my Superior manual is 135*F. I'll agree that warmer is better, to a point, but 212? Really? Maybe someone can enlighten me...

Edit: Looked up the spec again and my memory was slightly off. From the Superior Vantage manual dated February, 2007; Appendix A, page 18.

Table 9 "Oil Temperature Limits" says:
Minimum For Take-off: 75*F
Maximum Allowable: 240*F
Recommended Cruising: 130-200*F

Can't help noticing that 212*F is outside the "recommended" range...
 
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update

With temps at 44, I got my oil temp up to 205 at 2350. This will work in the cold temp, but will either have to 1/2 plate it in the summer, or go with the shutter. I'm happy now.
 
Even though I am down here where it is much warmer (50 miles south of Indy,) I have routinely taped over the front of my O-320/160hp 9A oil cooler every winter, just to keep temps within reason. I use the adhesive aluminum stuff Van's sells for cowl heat reflector. I have threatened to make an adjustable shutter. I would put the control inside the oil door, not through the firewall.

When you consider how much surface area the engine has up there on top, and that the cooling air goes over it quickly, I think it is amazing we can get the temps up even with the cooler closed off. Besides, I think the 320 is designed to use all it's fuel for horsepower, not to heat the oil;)

Bob
 
videobobk said:
Even though I am down here where it is much warmer (50 miles south of Indy,) I have routinely taped over the front of my O-320/160hp 9A oil cooler every winter, just to keep temps within reason. I use the adhesive aluminum stuff Van's sells for cowl heat reflector. I have threatened to make an adjustable shutter. I would put the control inside the oil door, not through the firewall.

When you consider how much surface area the engine has up there on top, and that the cooling air goes over it quickly, I think it is amazing we can get the temps up even with the cooler closed off. Besides, I think the 320 is designed to use all it's fuel for horsepower, not to heat the oil;)

Bob
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Hello Captain Bob. I'm the guy from Martinsville that stopped in last Summer with my family (way back from TN trip) to look at your plane. I did end up with a 9A after all! Nice machine. I have the same HP eng as you and have one tank using Mogas, and the other mixed with mogas and 100LL.
Unsure if you've been doing this, but there is "no" difference in performance and she purs like a kitten. Take care....
 
CHT lower eng temp limits

I'm happy with my oil temp now at 190 ish. I've noticed now my cht's are also running cooler, as all that air is not rushing through the oil cooler. What i am seeing, though is a couple cht's running at mid to upr 200. Someone is gonna tell me this is too cool, but I'm not about to block off ram air. I don't have an eng. manual. What is the lower limits, if any? I will install the oil cooler shutter assy., in the future. With this I may be able to tweak this temp. Thx, DM
 
drmax said:
I'm happy with my oil temp now at 190 ish. I've noticed now my cht's are also running cooler, as all that air is not rushing through the oil cooler. What i am seeing, though is a couple cht's running at mid to upr 200. Someone is gonna tell me this is too cool, but I'm not about to block off ram air. I don't have an eng. manual. What is the lower limits, if any? I will install the oil cooler shutter assy., in the future. With this I may be able to tweak this temp. Thx, DM
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I wanted to c/p this outta the online lyc man...so I'm happy with my temps...!
"Minimum in-flight CHT should be 150˚ F (65˚ C), and maximum in most direct-drive normally aspirated Lycoming engines is
500˚ F (260˚ C). Some of our higher-powered more complex engines have a maximum limit of 475˚ F (245˚ C). Although these are minimum and maximum limits, the pilot should operate his or her engine at more reasonable temperatures in order to achieve the expected overhaul life of the power plant. In our many years of building engines, the engines have benefited during continuous operation by keeping CHT below 400˚ F in order to achieve best life and wear of the power plant. In general, it would be normal during all-year operations, in climb and cruise to see head temperatures in the range of 350˚ F to 435˚ F."
 
Oil temps

I have 6hrs on my new 0360 A1A and my oil cooler is mounted on the firewall with a naca scoop on my cowl right side. Because I'm running the engine in at 2400rpm 21" manifold fix prop, I have oil at 80-82 degree PSI and 160-162 degree oil temp in south florida. I maybe wrong, but thought this was good for now seeing that when it gets hot in the summer here, I have room for a hotter running engine.
 
shutter dimensions

Hello. I viewed a pic of the "shutter" off of Vans. It appears that it is sandwiched in place, as appears there are no mount holes. Does someone have the specific dimensions? A friend is making a couple of these.
Thx for any info. DM
 
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