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Auxiliary oil cooler.

Auxiliary oil cooler

I added a second oil cooler plumbed in series with the primary. Works well with warmer summer temps in Northern Nevada.

Brad
 
Auxilliary oil cooler

If you would, please, the cooler part # and a brief description would sure help. Location, routing, etc. thank you.
 
Auxiliary oil cooler

Don't recall the cooler part number, purchased from vans several years ago. Maybe a 9 row size? Original cooler mounted on engine mount aft of #4 cylinder, top (outlet) of this cooler plumbed w/#8 hose to bottom inlet of aux cooler mounted aft of #3 cylinder also secured on engine mount tubing. Discharge from top of aux cooler plumbed to return oil port top left of accessory case. Two inch red (scat?) tube from the rear baffle on each side connected to plenum on each oil cooler. The plenums are from vans firewall oil cooler mounting kits.
 
The latest American Champion aircraft has a Lyc 390 and features dual oil coolers. Might be worth it to review that installation for new ideas.

That said, a Rocket should cool with a single cooler. I operate in a hellish environment all summer and don't have any issues. What kind of temps are you seeing (incl. CHT), and how are you setup?
 
Thanks, JBW for your ideas.
Toolbuilder- Running an Aerosport Power '540, D4A5, with the oil cooler aft of #6 cylinder, angled back about 20'. I've had a few aerobatic machines and worked them hard in airshows, but am just not used to the temps with a Rocket. I've been advised that its just the nature of the beast. Using Exxon 20-50 with a pint of Camguard. On a hot day I'll see 235 on the oil temp and the hottest cylinder about 400. I know this is within limits but would be more comfortable with a bit lower temps, if for nothing more than increased longevity. Thanks for your input.
 
Rocket oil coolers

I've been struggling with this subject also. I'll be hanging my engine in a week or two and working on firewall forward. I've concluded to use a genuine Stewart Warner cooler.

I also fly acro (Super Decathlon) and looked closely at friends with 540's. The Extra 300L uses 2 each Stewart Warner 84062 coolers if that helps any.

I got carried away and bought a SW 10631S; when I got it it's huge and heavy. I'll be returning it.

I'll be calling Pacific and asking which SW is best for this application; 10599R; 8406R; or 8432R (these seem to be the most commonly used in RV's).

That's what I know. Still don't have it figured out.

BTW; There is a strong chance I'll be making a new cowl; (changed thrust-line to straight and have a different cold-air-induction). If anyone has advise, parts, molds, whatever; I'd appreciate input.
 
Just as a point of reference ? I did a formation flight over the weekend chasing a buddy?s F-1. I was usually WOT and 2600+ RPM trying to stay with him. After nearly an hour of extended trail acro, low level, etc, (working the airplane hard) my oil temp was 190 and my hottest CHT was 388. His oil temp was 200, and CHT a touch lower than mine. This was an 85+ degree day at 2600 feet, and I have a stock D4A5 to his 10-1 ?boutique build?.

Both airplanes have a single cooler in the standard location behind #6
 
I have built several rockets some will cool ok, others are marginal may be due to some engines have piston oil squirters others do not yours does.I have installed 2nd coolers on several rockets.Yes I know there are many rockets that cool ok but there are others that need help. the ones that got 2nd cooler have been installed ethier in front by #2 cyl. or behind #5 cyl. depending on room if installed in front a brow needs to be installed to direct air through cooler, cooler in rear cools best. The 2nd cooler I have used is vans stock 4cyl cooler I think it's 6 row plummed in series with main cooler,also on my airplane changing from exxon 20-50 to aeroshell 100 plus dropped temps.My rocket aeio540dab5 before 2nd cooler 230 degrees after cooler 190-195,before going to the trouble of 2nd cooler be sure your baffles are good If you would like to contact me call 909-393-1538 daytime please.
Good luck JERRY (Finishig 10th rocket)
 
Forgot to mention checking vernatherm for operation and proper sealing also I normally enlarge cowl exit .the stewart warner coolers seem to cool best
Good luck Jerry
 
Auxiliary oil cooler

Baffling is good and tight. Even put a little Red RTV where air might be tempted to squeak out. Vernatherm operation is normal. If you're cruising at altitude with an oil temp of 215, and you point the nose down and reduce power marginally, the temps come down pretty quickly. I'm going to add a Stewart Warner 4 row by 6" wide second cooler, mounted on the right side engine mount. Planning on delivering the air off the right rear baffle through 3" scat to the cooler, with the air exiting towards the cowling outlet. Also thinking of two small aluminum baffles to be incorporated into the lower cowling to add exit area.
Thanks to all for your input.
Michael Wigen
RV-3
Pitts S-2A
Z-250
"Cyclone"
Hughes 500D
DHC-2
F-1 Rocket kit #97
 
What oil cooler do you currently have? If it is a stock Van's cooler you will be much better off just getting a larger SW oil cooler instead of adding a secon cooler. Made a huge difference in my RV7. Dropped my oil temps by 30 deg. My oil would routinely get up to 220 at which point my prop would start to overspeed and I'd need to pull off the power because there was no oil pressure. Once I switched oil coolers everything was perfect. On the RV8 build there was no question of just going with the SW8432R from the start.
 
Auxiliary oil cooler

Will look for the model number next time I have the cowls off, but it's not a small cooler. Switched to Aeroshell 100 Plus- A fellow told me that this would lower the temps. Will advise after a couple of flights. Thanks.
 
Oil cooler is an Aero Classics "HE Series" pn. 10634R, 12 row by 6".
jo64bXu.jpg

Before I go and add another cooler I'm going to open up the bottom of the cowling a little, and possibly add some aluminum louvres on both sides right about where the oil cooler air exit would be.
Another thing--my heat muff appears to be dumping hot air into the rear engine plenum, as the valve is either hot air to the cockpit, or hot air into the plenum. Seems counter productive for getting hot air out of the plenum. If I put another valve on the rear baffle to stop the airflow, will I burn up my scat hoses?Anyone had any experience with this?
Tks, Michael.
 
Looking at photo of your baffles it looks to me you have some potential air leaks in cooler area and flexable baffle seal ( garlock) is not sealing properly.
 
Good eyes, man. The photo was taken prior to me filling in any potential leakage with RTV. I think the biggest problem is getting more airflow "Out" of the cowling. Going to open up the bottom of the cowl a little, and add a couple of aluminum louvres on the sides. eg, on the ground after landing with an oil temp of 200, by the time you taxi back to the hangar its at 218. Just needs a little more flow.
 
Yes, looks like poor rubber flap seals to me. I'd measure upper-lower delta pressure before cutting holes in the cowl. Leaking flap seals reduce pressure delta.

Here's the Lycoming chart. It tells us that on a 80 F day at 5000 feet density altitude, the pressure difference above and below the engine must be at least 7.5" H2O just to maintain 435 CHT at 75% power.

To push CHT someplace below 400F, the pressure delta must be more like 11" H2O.

You'll find air pressure charts in the Stewart Warner oil cooler catalog too.

 
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Sorry, Guys, those photos were old ones from when the baffling was just being installed. It is tight, and the separate pieces are tacked together with RTV.
Cylinder head temps are pretty good for an F-1 Rocket. In a 24 squared climb on an 80' day I'll rarely see 420 on CHT's. Cruise at 10,000' on a 60' summer day will see 375 on the hottest cyl. Its the oil temp that I don't like, hence the second cooler idea.

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A couple of pics showing the quite small cowling outlet area. You can see why I want to add some exit area. Also I believe that the "Indy" engine mount causes a bit of outflow loss with that horizontal tube in an unfortunate position for airflow.

Aa well, still would like to hear from anyone who has a heater installation that dumps hot air into the rear cowling when the heater isn't in use. Can I restrict the flow in the summer without burning up the Scat hoses?
Thanks, Folks !
 
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OK, so how much/how little air can you get by with? 50%? What's your guess?
Tks, M.

I am going to start with mine with a 1" hole on my 7 just because it will increase the temperature rise of the heater discharge in the cockpit. This from some history on 7's that I remember, but can not quote. I am not flying, so no data.

You could just take off the heat muff to verify the maximum benefit. If it is not huge then don't worry about the flow as it would not be enough anyway. Just a thought.

Question: With the bottom of that cooler sitting below the head, do you block off the side fins on the head so air won't just flow through and heat up on the way to the cooler? You might consider some RTV impregnated fiberglass cloth to manage the air flow so the proper amount goes through head, and the remainder does not preheat going to the OC. Easy enough to try. Not sure that tape would work though.
 
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Good idea to remove the muff entirely. Thanks.
From memory there's aluminum baffle material between the bottom of the OC and the cooling fins. Will take a pic next time cowl is off, but I believe the way it's done there's little if any hot air to the cooler.

Oh, and one more thing. Anyone have any tiny Tinnerman washers for sale in the -4 size? That's what's on my cowling. Tks.
 
Maybe I can help

Hey Mike:

Enlarge the cooler inlet to the lower edge of the baffle rubber, and make the transition from the inner sfc of the cowl to the cooler duct as smooth and gentle as possible. Smooth flow into the cocoler duct is important - I suspect you have significant turbulence in the duct now.

Installing a plenum top would also help your temps - - by quite a bit! .032 6061T6 is easily formed to make this cover. If you do this, put the plenum top attach angle on the top - not one the sides - so you can still get at the spark plugs.

Contact me offline to get access to pics of some really nice plenums and ducts.

This ain't Rocket science! :-0

Carry on!
Mark
 
A couple of pics of the oil cooler installation. Comments, gentlemen?..]

First off, resize that picture! I cant even see the words anymore!

The general arrangement looks fine to me, but the corners of the oil cooler plenum need to be sealed for sure. Looks like a lot of air getting by there. Also, the baffle flaps may not be all that effective if they are jusy laying on the cooler
 
oil cooler

John Harmon suggested that turbulence behind the air intake disrupts the air flow and using foam and fiberglass to fill and smooth the top inside of the cowling would improve cooling, it does.
 
Ramping the intakes is definitely on my list. Then taking a good look at anything which might cause turbulence into the oil cooler, then more exit area for the lower cowl. Thanks, Michael.
 
I'm going to throw a largely unqualified comment out there concerning "turbulence into the cooler". The cooler acts as a throttle to a large volume of air in the upper plenum, so the air really is not moving into the cooler at high velocity. Cowl inlets and exit, sure. But between those two events, you are really dealing with pressure differential in a relatively slow moving body. In my mind, once you add another plenum in front of the cooler (as in this case), you have pretty much eliminated the concern for "smooth" airflow. Bottom line, if you have the differential pressure then you are going to get the required mass flow through the cooler fins - no special aerodynamic tricks required.
 
A very sharp eyed I.A. found some large cracks on the inboard side of the cooler mount. Very hard to see. In flight the cooler was flexing, exposing a large gap which the air exploited. A rebuild of the cooler mount is underway, with the expectation (Hope springs Eternal) that the oil temps will be lower.
Will advise.
 
Data point from an extreme example- we took off after work last thursday from Mojave (**** on earth) to Phoenix (experiencing a record breaking heatwave). It was 108 when we took off. I was able to climb directly to 9500 at 145 knots and I just touched 400CHT and 200 on the oil at the top of climb. Enroute OAT was 68 degrees and the oil settled in at 185. Return trip today was even hotter outside with enroute OAT of 75 @ 8500. I had to step climb out from under the PHX Bravo, but even still, I saw 205 on the oil and about 410 CHT by the TOC. Oil settled in to 191 and CHT was 388 on the hottest.

Granted, I would not want to be doing touch and go's in this kind of weather, but for a typical transport mission I find the cooling satisfactory with a single oil cooler.
 
Thanks for the info. For sure my F1 rocket would be a hurtin' unit in those temps. Fixed the broken baffle leaks, replaced some .025 2024T3 with .062 6061T6, and hung the cooler off the engine mount rather than the rear baffle.
Lowered the temps somewhat. Still don't like how the cyl head and oil temps creep up, pretty much starting on downwind. I can have an oil temp of 185 on downwind, and by the time I land and have a very short taxi to the hangar I'll be over 215. Guess that's the way it is.
 
The quest for proper engine cooling, without losing speed, is usually not just one part of the system. A very good place to start, as the saying goes, is at the beginning. If you are able to take some close up pictures, about two feet away, of the right and left hand cooling inlets, I may be able to get you started correctly. If you like you can email them directly to me [email protected].
 
I received some very good advice from Tom Martin--Opened up the cowling inlets and ramped the upper inlets. Found a few more little cracks where air was spilling out of the baffling and sealed them with RTV. Will advise after flying.
 
After flying over two hours with the top cowls cut back and ramps installed, I'm amazed at the difference in cooling. After flying for an hour I did a touch and go then climbed hard to 6000'--- never even got close to 400 on the CHT's. Oil temp which used to push 235 now under 200. Thanks to all who posted and offered advice.
 
Micheal, now that you have your cooling issues under control you will be able to really enjoy, and to challenge, your aircraft. Good stuff!
 
After flying over two hours with the top cowls cut back and ramps installed, I'm amazed at the difference in cooling. After flying for an hour I did a touch and go then climbed hard to 6000'--- never even got close to 400 on the CHT's. Oil temp which used to push 235 now under 200. Thanks to all who posted and offered advice.

Pictures, or it didn't happen!
 
Oil Cooling

Mike:

Any chance you are able to provide pictures of the work you did to improve your oil cooling issues?

Thanks

Hom
 
Aa well, still would like to hear from anyone who has a heater installation that dumps hot air into the rear cowling when the heater isn't in use. Can I restrict the flow in the summer without burning up the Scat hoses?

Myself and several others use Tom Berge's slide valve for heat. When this valve is closed, there is no air allowed to escape i.e. the air inside the heat muff and associated tubing is stagnant. 600+ hours on my plane and more than that on several others I am aware of with zero failures.
 
Brad,
Where can I find Tom Berge's slide valve. I haven't been successful in locating the source.
Thanks.
 
Dual Oil Coolers on my F-1 Rocket

I just installed a second cooler behind cylinder #5. I have the original cooler behind #6. My temps do not exceed 215* F working low level and hard. Before, I would see temps climb to 240*F.
 
We recently removed the inverted oil system and installed a 2nd cooler in N14ZM. This reduced temps by 25 degs with no other changes.
 
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