Removing cleanout plugs-Merc Crank

Shoebox

Shoebox

Well-known member
I imagine this is one of those "Ya just gotta do what ya gotta do" things, but what might be the best approach to remove these plugs?


I will mention that I thought I could drill a hole, thread in a screw, and use my small slide hammer,... not so good.



Ready to hear what many of you guys have done. Thanks.
 
Hi Shoebox.. those cleanout plugs just screw in and out. They have a hex head for a spanner. I found there was nothing to be gained by taking them out. Just the experience.

Regards Kevin
 
All I ever did on the press in plugs is use a 1/4 inch dia lag bolt of suitable length and pry the plug out.
If necessary go to next bigger dia lag.
 
Fatheads4ever said:
Hi Shoebox.. those cleanout plugs just screw in and out. They have a hex head for a spanner. I found there was nothing to be gained by taking them out. Just the experience.

Regards Kevin
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Never seen a screw in plug. All the ones I’ve ever removed were press in. Lag screw and a slide hammer works well. If you do not remove them and clean all the old sludge and debris out of the journal’s your just asking for failure.
 
Fatheads4ever said:
Hi Shoebox.. those cleanout plugs just screw in and out. They have a hex head for a spanner. I found there was nothing to be gained by taking them out. Just the experience.

Regards Kevin
Click to expand...
Never heard of stock factory threaded plugs in a Mercury crank?
 
Fatheads4ever said:
Hi Shoebox.. those cleanout plugs just screw in and out. They have a hex head for a spanner. I found there was nothing to be gained by taking them out. Just the experience.

Regards Kevin
Click to expand...


Nope, not these. These are pressed in plugs, (Dorman makes replacements) I have read commentaries just tonight in the V8 Archives about this procedure, various approaches of how to do. I'd like to spare my machine shop this time if I can. Thanks.
 
I've only pulled the plugs out of my C59A crank. I wonder if the Canadian ones are different. It's possible that some previous owner may have installed the threaded bungs as the crank had been ground before.
 
Notice that the poster said he "found there was nothing to be gained by taking them out". I take that to mean the the crank was clean inside with no sludge. I also take it to mean that someone had been in there before.
 
All the 'chips' and debris from machining will also be in 'there'. Balance crank after cleaning and replacement. Newc
 
I believe the difference is Canadian Vs American.
The ones I've seen in Canada used screw in plugs.

As for there being no advantage to removing them, mine were plugged with sludge.

Kirk
 
This is what I found in a nice and outside clean crank from a french flatty running a filter system and having done around 900 hours since overhaul. So whenever you take an engine apart you should look into the crank, will save a lot of grief in the long run.
 

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I have only removed them once. I drilled a small hole, put a self tapper in and pulled them out. I reused them by gas welding the hole up, refitting and re-staking the edge of the hole.
As they are available and the part number is shown above it would make sense to get new ones.
I didn't know they were available when I did mine.
 
Tap the inside of the cup to 14mm. Use slide hammer with 14mm stud. Can even reuse old plugs if necessary.
 
I just use a slide hammer. Then (on my racing cranks) I have the machine shop tap them for screw-in plugs and away we go (obviously this is prior to a crank regrind and rebalance).
 
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Note, if you're using the stock soft plugs (noted up above), then make sure you "peen" a couple spots around the edges of the holes in the crank journals after installation - to keep them from potentially blowing out.

This is particularly true when you're running a late 49-53 oil-pump with its higher-pressure relief valve. If you blow a plug out, then you'll have no oil pressure and then you'll soon have no bearings.

I blew a soft plug out on my very first racing flathead - luckily, I shut the engine down to figure out what the heck caused the sudden major loss of pressure. I was 15 years old, glad I had enough sense to know something was majorly wrong and not just run it! Didn't hurt the bearings - thank God!
 
I just pulled a set today. Drilled and tapped 1/4"-20, used a longish bolt and a suitable socket as a spacer. Just wound the bolt in and it pulled the plugs out. It worked really well and guess what - I have it on video.
I have new ones ordered but if I was to weld up the holes I could reuse the originals.
FWIW I did pull some sludge out of the holes.
 
I'd be leary about reusing the plugs as they are bound to distort when initially installed. New ones are cheap.
 
Mart said:
I just pulled a set today. Drilled and tapped 1/4"-20, used a longish bolt and a suitable socket as a spacer. Just wound the bolt in and it pulled the plugs out. It worked really well and guess what - I have it on video.
I have new ones ordered but if I was to weld up the holes I could reuse the originals.
FWIW I did pull some sludge out of the holes.
Click to expand...


Mart,
Could you put up a link to the above video?


Thanks!
 
Shoebox said:
Mart,
Could you put up a link to the above video?


Thanks!
Click to expand...

It doesn't exist yet, all I have is raw footage. It will go out in order with the rest of the engine build series.

I can attach some snips here though, but will have to do it later as I have something else I need to do first.

Mart.
 
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