The International Cessna 170 Association

Since epoxy is a protective (as well as a sealing) material... if I were to overhaul/rebuild/repair my engine these days... even if the sump were in fine condition...I think I'd spend the $375 to have it treated anyway for preventive purposes.

I received my sump back from Okanagan, so I thought I would share the results. Total turn around time was about 2 weeks. Cost was $375.87 US ($500.00 Canadian) for the work, plus about $51.00 US to ship the sump to Okanagan via USPS, plus $37.50 US for them to ship it back to me via Canadian post, plus about $5.00 credit card currency conversion fees = $469.37 total cost/outlay. Not too bad.

Here's a "before" photo of the inside of the sump at the critical area where most corrosion occurs: And here are "after" photos showing the sump now, including the same area shown in the photo above: They did a nice job.

That does look nice.

Somewhere, someone suggested using a boro to look at the sump. I doubt it would work. The following is a sump as it was removed Problem is the sludge, it’s thick, which traps fluids against the case and causes the corrosion. How could it be removed to do a boro? A closer look, probably 1/8 to 1/4 thick at the base of the carb boss

Next the sludge was wiped away with cotton rag, doesn’t look too bad
Solvent used for a better look,
And Houston we have a problem That’s the forward plug. It’s buried underneath the engine by baffling when in the mount . Might be a good idea to take the time to get at it and clean out the sludge that will fill the drain plug core.

I’ll send it to Fred at Ok aero to see whether it can be saved, fingers crossed. In another post I found a three hole sump at Oshkosh. Unfortunately it has a small crack in it which may mean, I’ll be well stocked in briquette starter if they both turn out to be non repairable

Jim if Fred can’t repair your sump call or message me. I can help.

Jughead

Thks Jughead, I’m planning Arlington hopefully see you there!

I’ll be at the STOL competition in Independence OR.

c170b53 wrote:Next the sludge was wiped away with cotton rag, doesn’t look too bad

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Solvent used for a better look,
And Houston we have a problem

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That’s the forward plug. It’s buried underneath the engine by baffling when in the mount . Might be a good idea to take the time to get at it and clean out the sludge that will fill the drain plug core.

Jim,
Reviving an old thread here. It's interesting to see the variations in these sumps. I have a C-145-2 three-bolt sump that has the forward drain hole raised 3/16" to 1/4" as can be seen on the photo of the epoxied sump earlier in this thread. There's no way one could drain the last of the sludge out of the forward drain with this raised lip around the drain. Your picture on the other hand seems to show the inside of the drain hole flush with the sump floor. The other noticeable difference I found was the rear plug on some -- I'm guessing all three-hole sumps -- is 5/8"-18 rather than 1"-18. It's interesting to see how soon Cessna began finding corrosion in these sumps. Here's a Service Letter for tricycle gear Cessnas from 1964:The original baffling surrounding the forward sump area only has a small slot next to the forward drain. Airforms enlarges this so that it is possible to remove the forward drain valve without having to remove the baffle p/n 0550111-7.

I was surprised that the lip was missing, right up to the end of cleaning I thought I had found a unicorn.

Do you think the lip had been removed or is that the way it came from Continental?

There’s nothing “enlightening” that’s going to come from my post here... but Jim, I wonder if the corrosion around that drain isn’t more-likely attributable to electrolysis due to dissimilarity of the sump vs the cadmium-steel drain-plug?

The reason I’m wond’ring is that common-opinion says water/condensation ends up down in the sump and the taildragger tends to let that pool just forward of the carb/induction tunnel. But the last photo in your post shows that area without much indication in that place...but instead only forward of the drain plug itself.

(No edification likely to come from my postulations, just thinkin’.... (smell of rags-burning in the background...)

i haven't really thought too much about this sump as I believe its beyond help. Whats done is done, and the material left at the drain hole probably won’t be enough to withstand an errant tug from a wrench.
I took this engine apart to see whether there’s any life left in the remains. The sump drain hole looks much like the aft drain hole in the epoxied sump pictured earlier in this post. Looks like the boss would be an improvement and maybe thats a later style casting, just a guess. The more we know the more we question what we know I guess.

Well, my engine is getting a certified rebuild. The rebuilder said: “We are having a hold up on the oil sump. Had severe corrosion that had been repaired with a non approved method in the past. It is out at a vendor for repair and they are accessing it. If it isn’t repairable I’ll have to locate another one and they are almost impossible to find. ”.

Do you guys have a suggestion on repairs/replacement?