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  #31  
Old 01-14-2017, 02:57 PM
rwtalbot rwtalbot is offline
 
Join Date: Feb 2006
Location: Sydney, Australia
Posts: 251
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Quote:
Originally Posted by Steve Melton View Post
some kind of grey sludge in there
Its lead, you are running a centrifuge there. The lead collects in anything that spins including accessory case gears.

To me it seems like that seal may not have been put in properly as there isn't much sealant and/or the sealant has not stayed on the seal.

The local engine guy we work with recommends 5 minute Araldite for experimental prop seals. He says it works a lot better than the Loaming approved stuff.
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  #32  
Old 01-14-2017, 05:58 PM
russ popel russ popel is offline
 
Join Date: Oct 2011
Location: Sidney BC Canada
Posts: 6
Default Rank case seal

The seal may have been pushed out by crankcase pressure due to vent blockage. Cold temps can cause ice to form in vent,so you must have a V notch cut in vent line as alternate outlet if this happens. I saw your vent line is rubber, if it's all rubber, you might consider puttting a section of aluminum tube in for a place to notch it.
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  #33  
Old 01-14-2017, 07:15 PM
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Steve Melton Steve Melton is offline
 
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Location: Cincinnati, OH
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Quote:
Originally Posted by russ popel View Post
The seal may have been pushed out by crankcase pressure due to vent blockage. Cold temps can cause ice to form in vent,so you must have a V notch cut in vent line as alternate outlet if this happens. I saw your vent line is rubber, if it's all rubber, you might consider puttting a section of aluminum tube in for a place to notch it.
the lower 8 inches is rubber the other is alum. I do not have a notch in the alum. I do fly when it's cold. the coldest was -27C. something for me to consider.
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Steve Melton
Cincinnati, OH
RV-9A, Tip-up, Superior O-320, roller lifters, 160HP, WW 200RV, dual impulse slick mags, oil pressure = 65 psi, EGT = 1300F, flight hours = 800+ for all

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  #34  
Old 01-14-2017, 07:18 PM
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Steve Melton Steve Melton is offline
 
Join Date: Apr 2011
Location: Cincinnati, OH
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Quote:
Originally Posted by rwtalbot View Post
Its lead, you are running a centrifuge there. The lead collects in anything that spins including accessory case gears.

To me it seems like that seal may not have been put in properly as there isn't much sealant and/or the sealant has not stayed on the seal.

The local engine guy we work with recommends 5 minute Araldite for experimental prop seals. He says it works a lot better than the Loaming approved stuff.
humm, it's the same color as lead. where does it come from, the oil or fuel?
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Steve Melton
Cincinnati, OH
RV-9A, Tip-up, Superior O-320, roller lifters, 160HP, WW 200RV, dual impulse slick mags, oil pressure = 65 psi, EGT = 1300F, flight hours = 800+ for all

Simplicity is the art in design.
My Artwork is freely given and published and cannot be patented.
www.rvplasticparts.com
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  #35  
Old 01-14-2017, 07:30 PM
noelf noelf is offline
 
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Location: Cary, N.C.
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I, and several others that run the Superior engines, have had front seal failures. We have all found that the front seal was installed with white silicone sealant. I am not sure what you mean by "the same color as lead" but white flakes is what we all had. New seals and plio bond adhesive were the answer.
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  #36  
Old 01-14-2017, 07:34 PM
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Steve Melton Steve Melton is offline
 
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Location: Cincinnati, OH
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Quote:
Originally Posted by noelf View Post
I, and several others that run the Superior engines, have had front seal failures. We have all found that the front seal was installed with white silicone sealant. I am not sure what you mean by "the same color as lead" but white flakes is what we all had. New seals and plio bond adhesive were the answer.
it looks grey like lead but it could be dirty white silicon remnants.
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Steve Melton
Cincinnati, OH
RV-9A, Tip-up, Superior O-320, roller lifters, 160HP, WW 200RV, dual impulse slick mags, oil pressure = 65 psi, EGT = 1300F, flight hours = 800+ for all

Simplicity is the art in design.
My Artwork is freely given and published and cannot be patented.
www.rvplasticparts.com
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  #37  
Old 01-14-2017, 07:44 PM
cajunwings cajunwings is offline
 
Join Date: Jun 2007
Location: new iberia la
Posts: 768
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I believe the odds are good that the vent froze up and internal pressure pushed the seal out.

Over time all hollow cranks accumulate that sludge in the bore. 500 hrs is a good interval to have a look in there and clean it out.

Any chance the tail pipe is able to rise a little in flight and block off the end of the vent hose? By all means cut or drill a vent opening high up on the vent tube. Look at a couple certified planes to see how they do it.

I've had good results with aviation grade Hylomar as a sealant and I don't use oil any more as a lube when stretching the seal over the crank flange. A plastic grocery bag works great and the big bonus is no oil to clean off the rubber where you now need to put sealant.

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57 Pacer
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  #38  
Old 01-14-2017, 08:40 PM
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bruceh bruceh is offline
 
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Location: Ramona, CA
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My front crankshaft seal that was installed during the rebuild (prior to hanging the engine) leaked a lot. At the first annual, I decided to replace it. It came out way too easy. The seal was put in with some sort of contact cement (like pilobond). I bought the recommended Dow Corning 737 Neutral Cure silicon sealant and used this successfully on the second seal. That seal leaked still (but not as bad as the first one), so I replaced it again at the second annual. This time it was much harder to pull out the seal, so I can highly recommend using the silicon sealant! I guess the third time is the charm, since this last seal seams to be keeping the cowling on the inside from getting an oily spray around the starter ring. It still isn't completely clean in there, but MUCH better than the previous seals.
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  #39  
Old 01-14-2017, 08:56 PM
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Steve Melton Steve Melton is offline
 
Join Date: Apr 2011
Location: Cincinnati, OH
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Quote:
Originally Posted by bruceh View Post
My front crankshaft seal that was installed during the rebuild (prior to hanging the engine) leaked a lot. At the first annual, I decided to replace it. It came out way too easy. The seal was put in with some sort of contact cement (like pilobond). I bought the recommended Dow Corning 737 Neutral Cure silicon sealant and used this successfully on the second seal. That seal leaked still (but not as bad as the first one), so I replaced it again at the second annual. This time it was much harder to pull out the seal, so I can highly recommend using the silicon sealant! I guess the third time is the charm, since this last seal seams to be keeping the cowling on the inside from getting an oily spray around the starter ring. It still isn't completely clean in there, but MUCH better than the previous seals.
thx. it seems that I should learn how to do this job.
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Steve Melton
Cincinnati, OH
RV-9A, Tip-up, Superior O-320, roller lifters, 160HP, WW 200RV, dual impulse slick mags, oil pressure = 65 psi, EGT = 1300F, flight hours = 800+ for all

Simplicity is the art in design.
My Artwork is freely given and published and cannot be patented.
www.rvplasticparts.com
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  #40  
Old 01-15-2017, 03:01 AM
DwightFrye DwightFrye is offline
 
Join Date: Jun 2006
Location: North Carolina
Posts: 76
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There are now three people on our field who have had this problem, including Noel and myself. I built my engine down at their build school (when they were still doing that) and at that time, at least, were using that silicone sealant. It just didn't hold up.

As Noel said .... new seals and plio-bond was the answer.

Quote:
Originally Posted by noelf View Post
I, and several others that run the Superior engines, have had front seal failures. We have all found that the front seal was installed with white silicone sealant. I am not sure what you mean by "the same color as lead" but white flakes is what we all had. New seals and plio bond adhesive were the answer.
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