Broken Circlip on oil pan drain magnet
 

Car has been running great with no indication of a motor problem. Imagine my shock when I pulled the drain plug on my FE and see half of a circlip. Don’t know where it came from but my first thought is a piston wrist pin. Any other ideas such as something out of rock arm assemblies would be appreciated. I’m running stock Ford adjustable rocker assemblies with aftermarket end supports. I’m pulling the valve covers and will scope the pan and cylinders. Any ideas will be greatly appreciated.

This post is only post is only showing up on the FE forum and not the latest post page. Don’t know how to correct it if required.

I found this on a different forum. It looks a lot like your 1/2. They are talking about the new D-6 part number and how it looks like a u-joint clip. I see you post on the front page.

I can’t seem to add pics

I agree piston wrist pin retainer. These are some old ones from a stock 406 engine long ago. Very brittle.

Thanks FFR448 for your reply. You have confirmed my initial thought that it was a fragment from a wrist pin retaining clip. The interesting thing is that the motor has never exhibited any symptoms of a motor failure. I pulled the plugs today and don’t see anything out of the ordinary. Going to do a compression test and bore scope the cylinders and the oil pan.

I am not sure how that would get out of the cylinder to get into the pan. You could pull the pan and check the cylinder walls for damage.

Send an oil sample to Blackstone Labs and listen to what they say.

I have seen engines get pulled and disassembled for pieces of "stuff" found in the oil pan that were never traced back to a broken piece of something in the engine itself. OTOH, there are a lot engines out there still running strong where the owner found something in the oil pan and decided "well WTF it's been in there this long, what harm can it do?" If your Blackstone report comes back with an abundance of wear particles then it's hard not to pull the engine and take it apart. But if your oil comes back fine and you can't come up with a clever way to inspect all the interior circlips without pulling the engine and taking it apart then you're faced with a tough decision.:cool:

Looks like a wrist pin circlip. An internal circlip. Rocker shafts are likely to be outside circlips.
Wrist pin circlips can dislodged and fall easily into the oil pan, more easily on a non-full skirt piston.
I would pull all the spark plugs and borescope all cylinders with each cylinder at BDC.
A wrist pin walking out will start to mark up the bore. A compression test of the whole engine may reveal a difference large enough to inspect a low cylinder first.

Uhhh, couldn't you just run the engine really hard and see which bore seizes up first?:confused:

To add on to what Gary said. This happened to me a long time ago when I built a Z code 390, bored 0.080 over with a borrowed 406 tri-power setup for the top. The engine was going into a 1957 Ford short tail. During the build, when I was getting ready to put the pistons together, some friends came by with some beer to help (what could go wrong). The pistons were assembled, put into the block and the rest of the assembly seemed to go well, It ran really strong for about a month and a half, until I developed what seemed to be a miss. During a compression test, coolant came shooting out of one of the spark plug holes. After pulling the head on the problem side, I found a big gash in the cylinder wall. On disassembly, the problem was the wrist pin was hitting and eventually broke through the cylinder wall. I couldn’t find the internal snap ring or pieces of it anywhere. So either it was left out during the build, put in backwards or not installed all the way into the groove. When I read and saw your picture, it brought back some memories.
Hopefully you caught this in time before there is any visible damage. But you may have to pull this engine apart to be sure where that piece came from.
Best,

Results of borescope of cylinders
 

First of all, thanks to all that replied to my initial post regarding the broken Circlip in my FE oil pan. I was finally able to borescope the cylinders and unfortunately number 1 cylinder confirmed my concern. The cylinder wall is scored and the motor needs to be removed, rebuilt or replaced.

Well I'm sorry to hear that. There's a certain benefit to knowing for sure what it was, but that's poor solace when you have to rebuild an engine.:(

Every time I break an engine, its an excuse to make it even better the next time. I guess that's the silver lining.

Sorry to hear that Tex.

When you do the replacement engine, there are wire circlips available today that I used to shun years ago when they first came out. They have improved them by orders of magnitude. It is not uncommon to see them in 1000 RWHP cars today. They have an excellent service record and are relatively easy to install or remove. Your pistons need to be built to use them. They can not be swapped into older design pistons. Additionally, the wrist pin ends use a small chamfer on the OD to load the circlip into the pin lock groove on the piston.

If all this sounds a little too chancy for you, the gold standard is still double Spirolocs. They are a bit of a pain to work with, but I have seen engines where the pistons come out in pieces, and the Spirolocs are still in their receiver grooves!

Don't sleeve the block. Replace the block. You will be happier in the end.


p.s. When you replace the pistons, check out Gibtec. They make billet pistons. Each piston is absolutely identical to the others, and if you hurt one, they can make an exact duplicate of it for you down to the exact gram weight — even years later!! BTW they are extremely price competitive with conventional forged piston suppliers. If you want to use them PM me and I'll give you contact info to get ahold of them.

I am just down the road in River Oaks if you need a hand let me know.

Use spirolocks next time..

Major bummer!