Low oil presure on rebuilt c90-8
- Thread starter sibbeston
- Start date
Noo, we dont changed to the -12, its -8F originally and we kept the oil gallery open in the accessory case!
Tempdoug, its a 72inch`s of diameter with 42inch of pitch.
With that prop we got 2250 of static RPM, but on takeoff roll the engine dont get any rpm more, so we changed to other prop with 72inch of diameter and 43 inch's of pitch!
Here some pics of the baffles finished.
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kase
SPONSOR
Billings MT
I had a similar problem with a C90-8 in my PA11. Sent crankshaft to Rick Romens. They reground and sent back yellow tagged. What they did wrong was took out oil transfer tubes and didn’t put them all back in. Number 3 rod journal was getting any oil. Hard to notice unless you know what your looking for. Had good oil pressure cold but when it warmed up went down to 25 ish. Good lesson that a yellow tag doesn’t mean shxt.
mike mcs repair
Registered User
chugiak AK
That thing In galley sounds like a restrictor, probably good... what’s the deal with the hose you added??? It sounds like a lack of volume issue. Must that hose be installed??? What’s its purpose???
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Hi Mike!
Yes, our doubt was about if that restrictor restrict the oil to go to main bearing galey and flow trough to the left oil galley, so to do this "bridge" besides right and left gallery we added this hose...
mike mcs repair
Registered User
chugiak AK
That’s what I mean. You have too much flow, not enough volume to keep up with it. Is it common to add that hose? Or is that hose likely your problem?
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I dont think man, because there went the oil coller and with oil coller there are much more volume then only the house...
I dont know if its a good idea try to remove the house and dont have oil trough right gallery...
Hello guys!
Today we tried to remove the front hose that we put to "bridge" left to right oil gallery, and nothing change... So we took off the oil pressure indicator and oil line, i flushed with air to clean and nothing too... So now im assuming that my instruments are ok and the problems wasnt in oil hose, so now im na look the oil sump tube and oil pump...
Here some pics...
Here 1.4kg/cm2 is the same as 20 psi and 2.8 is 40psi, and in that moment we where with 6minutes running engine, 5 minutes at 1000 to 1200 rpm and then 2000 rpm with 25psi and less then 40C temp....
Today we tried to remove the front hose that we put to "bridge" left to right oil gallery, and nothing change... So we took off the oil pressure indicator and oil line, i flushed with air to clean and nothing too... So now im assuming that my instruments are ok and the problems wasnt in oil hose, so now im na look the oil sump tube and oil pump...
Here some pics...
Here 1.4kg/cm2 is the same as 20 psi and 2.8 is 40psi, and in that moment we where with 6minutes running engine, 5 minutes at 1000 to 1200 rpm and then 2000 rpm with 25psi and less then 40C temp....
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Mark Lund
FRIEND
Jewell, Iowa
I purchased a C85 from an estate that had been assembled from "yellow tagged" parts including the case halves. I was given the yellow tags with the engine. It had good oil pressure until the oil warmed up and then it dropped drastically. Long story short, it took planing the case halves and line boring them to solve the problem.
cubdriver2
FRIEND
upstate NY
cubdriver2
FRIEND
upstate NY
Send it to Divco and have them put bushings in. If they say it can't be certified tell them you don't need a yellow tag you just want it to work. Mines been fine for over 1000 hrs
Glenn
Glenn
Is that lower gear loose and moving around when you slide it into position without the other gear installed?
By any chance was it installed dry on inital installation? If so that's probably wear marks from running without oil.
Show us a picture of the oil pump cover, and where it was leaking from.
By any chance was it installed dry on inital installation? If so that's probably wear marks from running without oil.
Show us a picture of the oil pump cover, and where it was leaking from.
do what glen says and then it looks like you used some kind of a sealer between the cover and the housing, dont do that. i see a line there of some type. divco or aircraft specialties will make sure that surface on the case is flat, you need to make sure the cover for the gears is flat. looks like a aluminum case instead of magnesium which can be fixed, but the bottom gear bore and the sidewall of the pump cavity is toast. then ask yourself if the cam to case tolerances and cam follower to bore tolerences are in good shape also. fixing the accessory case will help but it might not be a total fix.
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Hello men!!
Ok, im gonna see what i will do in this case, put bushing on gear shaft or change this case to another one..
I m gonna be sure that oil pump is ok and then if the problem persist open engine again!
I made a movie but i dont know how to put here...
Thanks guys for your help!!!
Hudson
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cubdriver2
FRIEND
upstate NY
Tempdoug it makes sence, next im gonna to use anything there! But if the parts are plain, it wouldn't lick any oil right??
Glenn, i need to send my case to someone that does this service or there is some way to lap it??
Thanks guys for your helping!!!
Hudson
these guys do excellant work, http://www.divcoinc.com/ but find out what it costs to fix first, could you show a higher up picture of your accessory case, if its magnesium and not aluminum i dont think you can get it fixed anywhere and will need to look for another. do you want to spend any money on fixing it or not??
TempDoug tomorrow im gonna see if a find other case, one friend of mine has one and if it looks good im buying it, if not i would need fix it!!
I just had a similar problem , we overhauled my c90-8 . It started up with good oil psi but after flying, oil psi went to next to nothing on approach and landing (washers don’t work for this issue) . I sent a different accessory case to divco. It was not repairable, so I bought an overhauled one from divco. I bought a new oil pump, new plunger and spring. All is well now. The seat on the New case for the plunger is much more pronounced then the other case. They can repair aluminum cases but not magnesium ones. They said mine was to saturated with oil and wasn’t weldable . Good luck.
Hi Elizair!!
Good to know that!! Tomorrow im looking other case with good pump housing and will try again!! Yes, washer dont work (at true at first start the pressure go up with wasjer but after return to same pressure). Did you used any kind of seal in your pump plate and housing???
Thanks!!!
Hudson
I wouldn’t waste my time I’d get a yellow tagged accessory case. When I first started this problem they had some at fresno airparts. They may have more now. Divco may have more in stock. But i wouldn’t buy one that looked good . It just takes too much time. I paid 875 for the yellow tagged one.
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Hi Elizair!!
Good to know that!! Tomorrow im looking other case with good pump housing and will try again!! Yes, washer dont work (at true at first start the pressure go up with wasjer but after return to same pressure). Did you used any kind of seal in your pump plate and housing???
Thanks!!!
Hudson
