O435 oil temperature / relief valve

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krazymatt
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O435 oil temperature / relief valve

Post by krazymatt »

Can someone explain to me how the oil relief valve cooler bypass operates on o435. I'm wondering about the main relief valve that is also the oil cooler bypass located on the sump. My boat gets hot after about 30 minutes of riding (2100 rpm) temperature rises to around 220 so I pull over and drink a beer or 2 n let it cool down. Once I restart the motor temperature is around 180-190 and I can ride for another 15-20 minutes then it climbs up again. Oil pressure is good (50) psi when hot. After talking with justin Ficken we both decided maybe my oil cooler was too small so I purchased a Haden 1260 which is about 2x the size of the cooler I was running. This hasn't made a difference. I'm not sure if oil is circuitlatong through the cooler or not I forgot my temp gun last time I went out to check. I'm wondering if the valve isn't operating correctly. It almost looked like there was small amount of pitting on the plunger last time I had it removed. If I remove the plunger and spring will that allow it to flow to the cooler or block it? Motor has all been bored to take larger jugs, using o320 cylinders making it a straight valve 480 now. All new bearings, crank and rods overhauled by d&s Camshafts, 9:1 pistons, new rings, h290 grind cam and fresh ground lifters from justin Ficken. timing was set to 25degree btdc Per justin. All 6 cylinders were overhauled by mark @ don george aircraft. Have about 10-15 hours on tach since Motor overhaul. Boat runs excellent other than the temperature problem. Doesn't appear to be consuming much oil if any maybe half quart on last 30 gallons I burned. Could it be the rings arnt seated and having some blow by? Is timing too much? It was originally set at 15 degree btdc with 7.5:1 pistons before I bored the case. Motor turns 2800ontrailer and cruises around 21-2200 rpms. Has fresh Phillips 66 Victory 100 AW oil n only run avgas 100LL.
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John Fenner
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Re: O435 oil temperature / relief valve

Post by John Fenner »

Not very familiar with the oil system on that engine, if you have an infrared thermometer, good place to start.
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krazymatt
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Re: O435 oil temperature / relief valve

Post by krazymatt »

John Fenner wrote:Not very familiar with the oil system on that engine, if you have an infrared thermometer, good place to start.
Ya me either, it doesn't have a veneratherm valve or adjustable relief valve. I do know you can adjust the pressure by shimming the spring with washers. (There are no washers in it right now) I just don't know if that's what I need to do or not. I have IR temp gun I just keep forgetting it every time in the truck!
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Re: O435 oil temperature / relief valve

Post by John Fenner »

The vernatherm would have been in the cooler itself most likely.
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krazymatt
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Re: O435 oil temperature / relief valve

Post by krazymatt »

bump
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Slidin Gator
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Re: O435 oil temperature / relief valve

Post by Slidin Gator »

krazymatt wrote:bump
What's Bump mean? Did you find a control valve in the old cooler assembly?

Picture below is section from the O-435 rebuild manual on the oil system. This says the bypass oil from the pressure relief valve is supposed to flow through the cooler and back to the sump. It also references a back up relief valve set at higher pressure, but not where the bypass oil flows to. It's likely that the back up relief goes direct to the sump??

A lack of bypass oil flow to the cooler would create a hot oil situation. Lack of bypass flow would indicate high internal leakage and/or insufficient pump flow. Further, as the oil get's hotter and thins out, there would be less flow through the cooler, leading to even more heat. Any oil that does flow to the cooler would be hot, the question is how much flow?

Image
I still think I-10 is the Mason Dixon line.
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Re: O435 oil temperature / relief valve

Post by fl cracker »

Bump just brings the conversation back to the top of the list in the forum.
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Re: O435 oil temperature / relief valve

Post by Slidin Gator »

I don't know what the minimum hot running oil pressure should be for that motor, but 50 psi sounds a bit low, particularly with the higher load from the larger jugs. The 540 motors are 55 min, 95 max. I would be aiming for the higher end of whatever the rating is given the other mods.

Adding washers to the relief valve spring will increase oil pressure, but decrease flow to the cooler, adding to the problem. I suggest adding Lucas or other additive to increase oil viscosity. Without adjusting the relief, this should increase oil pressure and flow to the cooler, leading to lower operating temp.

Long term, I would be tempted to re-plumb the thing as that is a pretty poor design and does not leave many options for tuning oil pressure. One possibility is adding a cooler bypass assembly to the oil pressure screen?? (320H adapter :dontknow: )
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
krazymatt
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Re: O435 oil temperature / relief valve

Post by krazymatt »

Thanks for the replies. Bump was just to bring the post back up hoping for more input. (Bring. Up. My. Post.) This motor is a dinosaur and not a lot of people familiar with it. What would happen if I removed the relief valve assembly? Would it then just circuilate through the cooler and not the rest of the motor (path of least resistance)? I've checked how it's plumbed 6x everything is correct and hooked up the same as before. The one thing I wonder is maybe when I put the mags in they could have possibly too much timing? I'm not sure I "snapped" the impulse spring properly before I put them in? Both my mags have impulse couplings, not super clear on the snapping procedure when installing them, I believe they are right but just something maybe possibly could be contributing issue? Boat runs like a raped ape. Mags are set to 25 degree tdc and checked with buzz box. Turns 2800 on trailer and runs strong.
Last edited by krazymatt on Sun Oct 28, 2018 11:08 am, edited 1 time in total.
krazymatt
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Re: O435 oil temperature / relief valve

Post by krazymatt »

Is the h2ad 320 oil screen housing different than the regular one? I have a 150 hp o320 and I've looked at the oil screen, oil screen housing, vernathem, oil filter adapter and it doesn't look like any of it will work on my motor.
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Re: O435 oil temperature / relief valve

Post by krazymatt »

Going to try to get it to the river this week. Will try the Lucas, I did run it in the past as the old rings and bearings, and crank were worn slap out and it did help some with the oil pressure. Also gonna try to remember the IR temp gun.
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Re: O435 oil temperature / relief valve

Post by Slidin Gator »

Yah, the H model is different. There is a cooler bypass valve plate assembly that sandwiches between the accessory case and oil screen. I have no idea if it will fit.

Almost got a chance to get real familiar with the O435, but I talked the owner into selling it and moving on.

No, you don’t want to remove the valve, oil will just run through the cooler and into the sump. I found a schematic for the oil circuit, the temp control valve is normally in the cooler. The problem is that this circuit only cools the excess oil, not all the oil. If there is not much excess, then there is not much cooling.

I would heat it up on the trailer and then pull a hose off the cooler and stick it in a bucket. Crank engine with mags off and see if you have much flow. Oil needs to be heated up first, when cold it should have plenty of flow.

Also, I did not find oil pressure specs for the 435. But various O290 models call for 55 to 60 as minimum. Use IR gun on cylinders too.
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
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Re: O435 oil temperature / relief valve

Post by Slidin Gator »

Slidin Gator wrote:Yah, the H model is different. There is a cooler bypass valve plate assembly that sandwiches between the accessory case and oil screen. I have no idea if it will fit.
Matt,
Here is an image from the 320H manual showing the cooler bypass adapter that I am thinking of. IF the porting on this set of components will match up with the regular 320 pressure screen housing and accessory case, you might be able to tap into the full flow of pressurized oil and route it through the cooler and then back into the adapter block (I think) or back into a port on the accessory housing prior to the pressure relief valve.

Then take the existing outlet to cooler (which is relief valve bypass flow) and route it directly back to the cooler return to the sump. You could even add a small cooler for the relief circuit, but that is probably not needed.

With this configuration you get full flow cooling and adjustment of the pressure relief valve does not impact cooler operation, allowing you to shim the spring and bring oil pressure up to the high end of the specs.

Image
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
krazymatt
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Re: O435 oil temperature / relief valve

Post by krazymatt »

Update on what has been done and I have found. I lowered my timing to 22 btdc as suggested to try by gmac. I put 2 ball valves and a pressure gauge inline with my oil cooler so I could moniter the pressure and also cut off flow to the cooler and crack the other ball valve to see flow through the circuit. Took the boat out for a short cruise. Here is what I observed. I rode all way from Florence to moccasin without stopping, (cruise around 2100) temp was around 200 when I got there where before I'd have to stop halfway at old man camp and let it cool down before I went rest of way. This is progress. I remembered my temp gun this time time and verified my oil temp gauge was right. I checked it multiple times and everytime it was really close to what I was seeing on the IR gun (within 5 degrees or so) head temps were around 360-380 on the back 4 cylinders the front 2 were obviously cooler... I don't know if this is from the timing change or the fact that it was also about 50-55 degrees out vs 80 or so last times I was running it. As far as the oil cooler, at the trailer and the landing before we left (engine cold and oil cool/thick) the gauge I put inline with the cooler line followed exactly what I was seeing on my pressure gauge off the motor. However once the engine was warmed up I was still seeing 45-60 lbs of pressure on my gauge but the oil pressure to the cooler was reading 0 psi. I cracked the ball valve open with it running, very little amount came out (whatever was in line gravity draining) no pressure to it. I also discovered the source of a pesky oil leak I been trying to find. It is the plug in the oil galley that feeds the lifters on top of the motor... after more thinking and scratching my head could the be heating up thinning out and just leaking out there and not bulding enough pressure to open the relief valve to the cooler? There is flow and pressure to the cooler when the oil is thick and cold... Going to seal up the leak source good and try running it again and see if anything changes- hoping it might allow enough pressure to build and open the relief valve to the cooler. Looked into possibility of changing the spring to the relief valve also. The one in the 435 is a pretty heavy duty one. Was thinking maybe one with lower spring rate might allow it to open earlier. Not going to try that though until after I try it once the leak is sealed. Boat still running excellent aside from this.
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Re: O435 oil temperature / relief valve

Post by krazymatt »

Again this motor does not use a vernatherm / temperature to open and close the valve to the oil cooler. It has a spring loaded bypass valve for the oil cooler and then also has an auxiliary oil pressure relief valve in the block. The spring in both valves is the same (p/n 65703) It says it opens at 17-19 lbs of oil pressure. So it should be open pretty much anytime the motor is running. I have around 20 lb of pressure even at idle.... I do have a couple of different springs here if I do go that route...
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Re: O435 oil temperature / relief valve

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That’s a roger on your thinking, your bearings etc. are loose enough that they take all the flow and the relief stays closed, so no oil to the cooler. Your motor is worn. Put in a weaker spring until it stays cool. Your oil pressure will run lower. Eventually you will need a rebuild.

Add Lucas to help increase viscosity to help.
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
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Re: O435 oil temperature / relief valve

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PS the spec for the spring you have is 17-19 pounds of load, not lbs/in^2 (psi). You want a lower load spring, but load does not equal pressure.
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
krazymatt
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Re: O435 oil temperature / relief valve

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The motor should be tight! The motor doesn't have more than 10 hrs of tach time since being overhauled. Crank was cleaned up to standard within tolerances, rods were overhauled and fresh grind cam and lifters from d&s Camshafts. All 6 cylinders were overhauled by mark at don George's shop. New rings were also put in along with the 9:1 pistons... correct on the spring rates, I didn't know how that equated. Wonder what the actual pressure is that it will allow to valve to open. Also was thinking if I change the spring I need to change them both to the same.
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Re: O435 oil temperature / relief valve

Post by Slidin Gator »

No need to change the backup relief in the block, just the cooler valve. Don’t know about the condition of the motor, but it’s taking all the oil leaving none for the cooler.

Replumbing for a full flow cooler system at the screen is the other, and probably better option.
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
krazymatt
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Re: O435 oil temperature / relief valve

Post by krazymatt »

Ran the boat today went from Florence all way to halfway lake before it hit 230. Oil leak is fixed but oil is still heating up. Oil pressure is good. Going to try lighter spring in the oil cooler valve and see what happens and put fresh oil in it
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Re: O435 oil temperature / relief valve

Post by jopete »

probly ought to bring that motor to somebody who knows what they are doing before you get it too hot and ruin it. i'm just tryin to help, no disrespect meant.

good luck!!
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Re: O435 oil temperature / relief valve

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jopete wrote:probly ought to bring that motor to somebody who knows what they are doing before you get it too hot and ruin it. i'm just tryin to help, no disrespect meant.

good luck!!
I don't think there has been any damage done, max oil temp rating is 235 and max cylinder temp is 500. That said, something is not right and jopete has a point. I've mulled this one a bit, for this system to work right the oil pump has to make a lot more flow than what is needed to hold pressure. Either the oil pump is not making enough flow or there is something wrong leaking too much flow elsewhere, there is not enough to hold good oil pressure and send flow to the cooler.
krazymatt wrote:The motor should be tight! The motor doesn't have more than 10 hrs of tach time since being overhauled. Crank was cleaned up to standard within tolerances, rods were overhauled and fresh grind cam and lifters from d&s Camshafts. All 6 cylinders were overhauled by mark at don George's shop. New rings were also put in along with the 9:1 pistons... correct on the spring rates, I didn't know how that equated. Wonder what the actual pressure is that it will allow to valve to open. Also was thinking if I change the spring I need to change them both to the same.


Might be time to talk with Don George a bit. My thinking on dropping oil pressure spring setting is based on keeping an old motor running vs. straightening out a rebuild right.
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
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Re: O435 oil temperature / relief valve

Post by krazymatt »

i put a lighter spring in there have not tried it yet, going to change oil and run it, but im having some suspicions and i dont want to run it and starve the bearings of oil by redirecting the reduced amount they maybe getting to the oil cooler.... might need to pull the 3 jugs on the right side and check where the case was bored... oil flow diagram shows oil passage way running down lower right side of case. wonder if broke through wall anywhere and allowing oil to dump back into the case/sump... see picture. if oil passage is punctured anywhere it would allow oil to dump back to sump (internal leak), not sure how close that oil gallery is to the jug openings. looking at the aux relief valve on back of case looks like its inline pretty close with the lower side of the bores... anyone familiar with boring these cases have any idea?
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Re: O435 oil temperature / relief valve

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krazymatt wrote: I remembered my temp gun this time time and verified my oil temp gauge was right. I checked it multiple times and everytime it was really close to what I was seeing on the IR gun (within 5 degrees or so) head temps were around 360-380 on the back 4 cylinders the front 2 were obviously cooler... I don't know if this is from the timing change or the fact that it was also about 50-55 degrees out vs 80 or so last times I was running it.
Where are you measuring your head temp at? You should aim the IR gun at the area where the CHT would screw in. I just installed CHT probes in my motor and I find around 150 degree difference between the CHT sensor and the cooler upper spark plug area. The lower plug area reads around 40 degree low and I get reasonable agreement aiming right on the head just above the CHT port on the bottom of the head.

For your reference, I just measured the following cylinder temp readings at 75 degrees this evening: 350, 380 and 290 for cylinders 2, 4, 6 at stable idle warm up and oil temp steady at 140. This is all at nothing more than full warm up idle. Just trying to re-enforce that your issue is oil flow to the cooler not cylinder issues.

I can't help on the possibility of break through during case work, but that's worth looking at :scratch: It would not take a huge hole/crack etc. to flow enough to use up the cooler flow.

Just to cover all the bases, did you rebuild the oil pump during the process? The manual calls it an "Impeller" type pump, could it be a bad rubber impeller? Any possibility it was not put together right?
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.
krazymatt
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Re: O435 oil temperature / relief valve

Post by krazymatt »

for the time being i think i am going to put the original heavier spring back in and add some lucas oil stabilzer to the oil to try to thicken it up someuntil i get some time to pull the jugs. this may let me ride a little longer before having to stop to let it cool down. im just worried with the lighter spring the oil may take path of lesser resistance (through the cooler vs to the main bearings) and thats a risk i dont want to take. will also probably put 2-3 washers in the aux. relief spring to try to keep it from just dumping back to sump.
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