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DEWATSON

Well Known Member
Does it matter whether the pressure line from the engine is connected to the top or the bottom of the oil cooler when installed by the plans in a RV8? Mine is hooked to the top which forces the oil from the coolest part of the cooler to the hottest part and then back into the engine. I can't get this thing to cool properly and I have done everything in the book to seal it all up. There's no wasted cooling air. The only way out is through the oil cooler or down through the cylinder cooling fins. Does the direction of oil through the cooler matter?

David Watson
49FD
 
I believe standard practice is to have the supply (pres) on the bottom in order for the cooler to naturally purge itself of air. Makes sense to me and seems to work :)
 
It does make sense......I'll change mine and put the pressure line on the bottom. If I fly for 12 to 15 minutes now, the oil temperature will slowly creep toward 230 degrees. I've just started the phase one flying and this is the worst obstacle to overcome after 5 hours in the air 15 minutes at the time. Like I said, she is sealed up good enough to hold water and I've had no luck yet. I'd like to see the oil temperature no higher than 210 degrees. Thanks for your reply.

David Watson
49FD
 
I made about 20 changes under the hood on mine during the first 25 hours or so and nearly all of them helped a little. The one that didn't seem to do anything was swapping my oil input hose from top to bottom. I still feel it's worth doing just to guard against trapped air in your cooler, but when I did it, it didn't make any difference to my oil temperatures.

It's likely that you if you have a reasonably standard configuration, your baffles are well sealed, your wrap around cylinder baffles have the right size openings underneath and your oil cooler is a good one, then you are mostly just waiting on the engine oil rings to seat. When they do, you will see a dramatic drop in oil temps more or less immediately. I'd swap your oil lines as a precaution, but unless your engine "sets up" coincidental with your oil line swap, I'd be surprised if you see much of a difference. Just my experiences, others have seen it this way too, however...


Lee...
 
David,

The feed line must be at the bottom fitting of the cooler to get and keep any air bubbles purged out of the cooler core.

If you're using the Niagara (NDM) model number 20002A 7-row oil cooler as supplied in the Vans firewall forward kit, prepare to spend some more money upgrading to a bigger oil cooler. After looking thru your past posts (http://www.vansairforce.com/community/showpost.php?p=342167&postcount=1) it seems that you have the very exact same engine (America's Aircraft Engines-built ECI Titan IO-360) as we do on the RV-8 in my avatar. The little NDM oil cooler will *NEVER* be able to keep this engine cool unless you only fly in sub-50 degree Fahrenheit temperatures. It simply lacks the thermal dissipation capability.... period. It's really meant for no bigger engine than an O-320 or perhaps a low-performance carbureted O-360. We finally upgraded to an expensive $650plus SW 10599R cooler to get oil temps down to the 190-210 range in Texas summer heat and it's working extremely well. A cheaper alternative is the AeroClassic model #8000081 10-row cooler, which you can buy for around $260 from Aircraft Spruce. Another fellow here on VAF put that cooler on his similar-engined RV-7 in place of the NDM 7-row and achieved about the same results we did with the twice-as-expensive SW cooler. The 10-row will fit on the rear baffle of cylinder #4 on an RV-8, because I had a 13-row AeroClassic cooler mounted there for a short while, but the 13-row was just barely touching the inside of the cowl and almost wanting to rub the motor mount frame when the motor shakes during startup, so it had to go as well. 13-rows cooled too well --- 155-160 in Texas heat ;-) .


BTW, after reading your above-referenced post from July 2009 about your fuel injection issues, we had similar issues with the ECI fuel injection system after first startup, and found a mechanic who had a special set of fuel pressure gauges and hoses he had made for calibrating his Beech Debonair (very similar constant-bypass-flow Continental fuel injection system, from which the ECI design was derived) and he was able to calibrate the complicated ECI system for us according to the book, by using his gauges, and after that, the engine runs beautiful and hot starts are a complete non-issue with this fuel injection system. Getting the ECI system calibrated correctly for the particular engine it's installed upon, is absolutely crucial.
 
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I had a similar issue with my RV-6A which turned out to be that the oil cooler was not mounted high enough on the baffle. The plans called out for the cooler to be as high as possible, and I took this to be place the doubler (as provided) as high as possible on the baffle. I later found out that to locate it properly, you had to trim the upper left corner of the doubler off, raising the cooler about 1 1/2" from where I originally had it. This dropped my temperatures in the summer from 225F down to about 200F. On a trip to Charlotte 2 weeks ago, oil temp was only 165F in cruise. Now it looks like I need to cover a portion for the cooler months!
 
Just another data point for you David - my RV-8/ O-360 combination has the standard Van's 7-Row cooler, with the inlet to the cooler on the bottom, and the only time I have oil cooling issues is climbing out of Phoenix in the summertime after a quick turn fuel stop. Cools just fine all the rest of the time (unless I have been doing excessive slow flight). Houston climatology.

Paul
 
Paul, does your IO-360 have the piston oil squirters in it?

On these ECI Titan IO-360's, they're averaging 15-20 degrees higher oil temps than the engines without the squirters, but they're also getting way lower cylinder head temps out of this deal too.
 
Neal@F14 said:
Paul, does your IO-360 have the piston oil squirters in it?

On these ECI Titan IO-360's, they're averaging 15-20 degrees higher oil temps than the engines without the squirters, but they're also getting way lower cylinder head temps out of this deal too.
Click to expand...

No, it doesn't Neal...but then I run CHT's in the lower 300's in cruise. Makes you wonder if the squirters are a good trade!

Different engine, different goals.
 
I really do appreciate all of the input from everybody. The forums prove that this is often a problem that isn't easy to solve. My cooler is as high as possible. Before I started the installation, I read everything I could find and determined that having the cooler installed high was very important. My engine does not have the squirters, but it does have 9 to 1 pistons. I'm going to change the pressure line to the bottom of the cooler and if does not do the trick, I'm going to go ahead and spend the money for a more efficient oil cooler; probably what Neal has suggested. I'd rather it be too cool than too hot. The vernatherm should keep it warm enough to cook out the moisture if flown for at least a half hour. I've also used Paul's suggestions in another post to brace the oil cooler to prevent baffle cracking, etc. It worked out very well.

Thanks to all of you and we'll see what happens.

David Watson
49FD
 
Ironflight said:
No, it doesn't Neal...but then I run CHT's in the lower 300's in cruise. Makes you wonder if the squirters are a good trade!

Different engine, different goals.
Click to expand...

In our case, I think the oil squirters are worthwhile. We've got the 9.2:1 pistons, and I believe having the pistons cooled by oil spray has got to have some benefit towards helping reduce some of the possibility of encountering detonation.

We're also getting really good CHTs too. Even in the peak north Texas summertime heat, I typically saw 340-360 cruise and 370-380 tops in extended climbs. With the cool autumn temps, I barely got 320-330 in cruise on my Arkansas sightseeing trip last weekend, and when I throttled back to ~50% power to slow down and enjoy the ride, CHT's went down to 300 and lower with the OAT in the lower 40's. I also discovered that the cabin heater shroud is pretty much worthless below 60% power settings, even though it encompasses two of the four exhaust pipes :eek:
 
David, were you able to swap you oil cooler lines? if so, did you get any better cooling?
 
Alton,

I've changed the lines but have not flown the airplane any since then. I've been much too busy with other things, plus I'm waiting on an Andair fuel selector valve from England!!!! Wow. They said four weeks before delivery. Anyway, I should be back in the air by Christmas. I'll post my findings when I get going again. Too much to do....too much to do.

David
 
DEWATSON said:
Alton,
plus I'm waiting on an Andair fuel selector valve from England!!!! Wow. They said four weeks before delivery.
David
Click to expand...

Probably too late to suggest this, but did you try calling Van's to see if they had your Andair fuel selector in stock? (I'm presuming the duplex valve, needed for the ECI fuel injection return line plumbing?)

When we bought ours this past summer, Van's had them in stock for cheaper price than Andair direct or Aircraft Spruce had them. Took only a few days to arrive via ground shipping.
 
Neal,

I ordered the valve that the ECI manual calls for but did not like the idea of reducing the tubing size from #6 to #4 on the bottom. I elected to send the original back for refund and buy the duplex valve that is #6 on top and #4 on the bottom. It makes for a more sanitary installation without the reducers, etc. I'll wait for the new valve......heck, it has been 4 years and 9 months.....one more month is OK. It'll be a nice Christmas gift and cost half what the original valve cost.

David
 
The Andair duplex valve we bought from Van's did have the male AN #4 fitting inserts on the bottom (return) portion of the valve and the male #6 AN fitting inserts on the top half (Van's part# FUEL VALVE FS 20X20-3). It was $180 cheaper from Vans too ($365 vs $547) over the FS-20-20-D2-M6 from Spruce)

The ECI install manual for the RV-8/8A does indeed list a part number for a duplex valve with #6 AN male fittings on both sections (FS-20-20-D2-6M), but then they show #4 AN fittings on the instructions for modifying the tanks to add the return line bulkhead adapters.... I guess that's just an inconsistency on their part. #4 return line plumbing is plenty big enough since I think the absolute max flow rate on the return line is less than 9 gph under the worst possible settings (2700 rpm w/ throttle closed).

When we called Van's to order the valve, we told them we were plumbing for an ECI fuel injection system and they automatically knew which valve we needed.

Still, nearly $400 for a fuel selector valve is a bit on the breathtaking side of costliness, but if ya gotta have one, ya gotta have one :eek:
 
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swapped lines

When I swapped lines to the oil cooler to have the pump output go to the bottom of the cooler it reduced the oil temp about 10 or 15 F. I did not think it would matter but it sure did.

I also changed to the Aeroclassics 8000081 oil cooler and that helped about 20 F. I also added a 1/4" shim between the baffle and the oil cooler to move it a little farther from the #4 cylinder and allow a little better air flow.

The changes together enabled me to do a 500 fpm climb to 8500 feet on a 100f surface temperature day without exceeding 400 on CHTs or 220 on oil temp. I wanted better and turned my attention to the baffles. Improving the front baffling had a large effect and some cleaning up of the rear baffles helped a little. Total effect of baffle improvements allow me to do the cruise climb and not exceed 380 CHT or 200 oil temp.
 
Bubblehead,

I've changed the lines, but like I said, I haven't had a chance to fly yet because I'm waiting on the fuel selector valve. If I have the temperature reuction that you had, I'll be in great shape.

David Watson
49FD
 
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