IO 320 Oil System

[Kevin Bolender]

Does anyone know the correct size of the oil hoses in and out of the oil cooler? I/O 320's
At the ICS Convention maintenance seminar this past weekend, Cliff from Heritage Aero (a very
Good seminar presenter) warned of the prop governor oil line being the correct size, including
The fittings that could be restrictive if incorrect.
Well on myway home from Seattle ( 16hours to Florida in hot, hot conditions) I was contemplating
what I could do for the high oil temp on the left engine on 8871Y. Maybe a larger oil cooler, certainly
I could improve the baffling. Today I opened her up and applied the logic that was in my notes from one
From the two seminars paid for by CFF at the convention, in particular the oil line to the prop governor.
Sure enough the oil out on the engine to the oil cooler appears to be 3/8 And is bushed down to 1/4, then
an aluminum Fitting (I believe should be steel) further restricts to 3/16 and then 1/4" hose with
The same on the other end. The return oil line has the same restrictions.I don't have access this weekend
to my parts manual!
PLEASE can anyone recall, or look up what size these hoses should be ??
I am betting the 1/4" hoses should be 3/8 and the restrictive fittings is my high oil temp problem!

[N3322G]

Hey Kevin,

Wish I could help on the line sizes - agree on Cliff - he also presented at the Clifton seminar - always something to learn.

[Kevin Bolender]

Pat good to hear from you, I missed you in Seattle (sounds like a tittle). Anyway I awoke recalling that or manuals are on line and I'll begin researching. You have more experience than I (or anyone else in the world) in long range Comanche flights
Do excessively long flights in short periods of time effect ones brain. Maybe it is my reoccurring. CRS!! Thanks KB.

[MULEFLY]

Kevin... I printed out your post and will try to take a look today at my PA39. However, FWIW, I had witnessed hotter oil temps on the left engine for several years... +10 to 15F. My baffles are (Hans' term) frog butt tight and I have the plenum on the back side of the oil coolers that increased the velocity of the air flow thru the cooler and should contribute to lower oil temps.

My fix was to replace the cooler from Pacific Oil Coolers on the left engine... evidently it is/was partially clogged. The new air cooler immediately dropped the left engine oil temp to match the temps on the right engine.

http://www.oilcoolers.com/

All the best!
Jim

[Kevin Bolender]

J.C. Thank you for the response, I am not sure I understand "The plenum on the back side of the oil cooler". I have already replaced the oil cooler to no avail. I have identified some deficiency with my baffles up front on the sides of the cowling inlets, I'm hopeful. I also was looking at the engine air intake on the side of the cowling mod that are on some turbo comanches which would give another inch or two of manifold with the outside air instead of the hot engine air off the rear baffling that we presently have. Thanks KB

[MULEFLY]

Kevin.. some are of the opinion that the NASA scoop intake mod is snake oil. Send me your email and I'll send you pictures of the plenum. Caution it will not work until your baffles are frog butt tight.

Are your oil lines of similar size and configuration on both engines?

jim dot covington at inwave dot com

All the best!
Jim

[md11flyer]

Kevin, Just another thought about the stock air intake at the rear of the baffles, This air is not hot air as many believe.
The air in the top of the engine is being forced downward over the cylinders and any air that does not go inbetween the cylinders and into the hose that cool the fuel pump and the air to the oil cooler as well as the air into the air intake is ambiant temp air or close to it.
The only time the air going to the intake will be warmer is during ground runs with little cooling being forced over the clyinders.
So I wouldn't spend money for the external air scoop, Just tighten up your baffles fir the money.

Gary

[Kevin Bolender]

Thanks Gary, that makes perfect sense now the way you explained it,so I'll cool my jets on that one. I'll concentrate
On tightening up the baffling and make that area tighter than a crabs ________!! The hose size is still an issue, I couldn't
Find the size information in the manuals. Thanks again!!

[MULEFLY]

If the hoses and fittings are the same... that doesn't fit for the difference... keep looking.. I'll try and take more pics tomorrow... didn't get there today.

Jim

[Kristin Winter]

I replaced those hoses on Maggie a number of years ago. IIRC, those are -6 hose.

[Kevin Bolender]

Thanks Kristin, that is what I'll do.
Did I mention that 8871Y won "Best Twin" at the Seattle convention last week!!
Also took away the best raffle prize, a "EI" fuel flow instrument for single engine.
I would be remiss if I didn't mention that our new ICS president was gracious enough
to decline that prize when he was asked to draw and he drew his own ticket.
Thanks Bob for being the perfect gentleman that you are and good luck, we are in good hands.
I turned to the people at my table and said "I'm going to feel funny when he now draws my ticket"
and walla !!!

[N3322G]

Kevin,

Congratulations on the Best Twin! ... I know from personal experience that the emergency gear box is kept really clean.

BTW on tightening the flexible baffles - I didn't keep good enough data but did seem to see 50 degree temp drop when baffles were replaced. Kristin has the best example as she did one engine and then photo'd the engine monitors in flight - 50 degree delta and she said Maggie flew faster.

[Kevin Bolender]

I'll try and note difference when I finish with the tightening up of the air leaks around my baffling.
I might have that clean gear box that you speak of but I learned a lesson when we bet on whose was
the cleanest. I didn't know at the time who or how tough my competition was, (N3322G)!