What cleanout plugs for Merc crank?
 

I just had my Merc crank turned and want to remove the old plugs to clean it out. What's the best thing to plug the holes back up with? Are they like small expansion plugs or is it best to drill and tap? Thanks.

Re: What cleanout plugs for Merc crank?
 

Randy: Drill and tap, I think 3/8 pipe and use allen plugs, makes it so much nicer next time, you refresh, balance and line bore the mains, too.... OLD....BILL

Re: What cleanout plugs for Merc crank?
 

I think Reds had some aluminum pipe plugs.

Re: What cleanout plugs for Merc crank?
 

I use Dorman plugs, 555-010... Press in... These are made for this. I use a tapered ream to clean off the old peen spots, locktite them, peen them in place...
Karl

Re: What cleanout plugs for Merc crank?
 

The Merc plugs are 5/8 the Ford 3-3/4 cranks have 3/8 plugs. I think Job Lot has the original plugs, there about 5/8" or so long. Walt

Re: What cleanout plugs for Merc crank?
 

Randy you dont need to drill them. Clean them out reall good and use a 1/4 pipe tap and put your allen plugs in with red locktite. You will sleep better.

Re: What cleanout plugs for Merc crank?
 

Originals were P/N 8CM-6307. They wer listed a 41/64" diameter at 11/16" long. Believe it or not, I found a set on e-pay one time.

Kerby

Re: What cleanout plugs for Merc crank?
 

Like Carl, I use the Dorman plug. Never had a problem.

Re: What cleanout plugs for Merc crank?
 

Say yes to the Dorman plugs. Don't even think about using 1/4" pipe plugs. The only thing they might plug would be the interior of a Dorman plug. WAYYY too small!. Depending on your level of precision any plugs, other than the original style Dorman, could send you to the balancing shop.

Re: What cleanout plugs for Merc crank?
 

I found the Dorman at my local Carquest Autoparts. they fit many makes & years. they are a tight fit. you can also get them from Red's Headers.

http://www.dormanproducts.com/da-32575-555-010.aspx

http://reds-headers.net/index.php?ma...ankshaft+plugs

Re: What cleanout plugs for Merc crank?
 

This is fairly straight-forward with the Merc cranks, no drilling is necessary, only tapping the existing holes for some 3/8" NPT plugs! Most OEM plugs come out with a "body-dent-puller" (as seen in the photo below)!

We do every one with this procedure, never went back to pressed pieces!

We also do the Ford shafts as well, but these need drilling! Definitely more labor intensive!

Thanks, Gary in N.Y.

P.S. Just be certain a fairly new tap is used, the crank material is reasonably "tough"!

http://thumb8.webshots.net/t/86/86/6...8gRheSw_th.jpg

Re: What cleanout plugs for Merc crank?
 

I get them at Napa, both the Ford and the Merc ones. I can get the Dormon part no. tomorrow. Walt

Re: What cleanout plugs for Merc crank?
 

As someone posted above... Dorman 555-010. However... Re-use the originals. Tap them (no drilling), slide-hammer them out. When you put them back in, stake. My engine-builder has been doing them this way for years.
(I've got a few of the Dorman plugs, for 'just-in-case'. I've had them for quite awhile, and have never had to use them.)

Re: What cleanout plugs for Merc crank?
 

what is the dorman number for the 3/8" plug?

Re: What cleanout plugs for Merc crank?
 

I haven't had any luck getting those small plugs....those I have been tapping 1/4 pipe if I recall correct

Re: What cleanout plugs for Merc crank?
 

Use Dorman plugs. 555-010. Available at CARQUEST and NAPA. If you use the drill and tap for a pipe plug, you better be sure you get every little chip out from that process or risk a scored bearing. JMO. John
http://i174.photobucket.com/albums/w...psaosgyyvb.jpg

Re: What cleanout plugs for Merc crank?
 

If you use the standard press-in plugs (as shown above) and then put in your nice high-pressure pump, and then run heavy oil . . . you should think about putting a little "pean" mark on the outer edge of them to hold them in (along with locktite).

I've had these blow out before . . . and there goes all your oil pressure . . . and then your bearings!

This is why I now have all the plugs replaced with a screw in plug - usually aluminum (so it doesn't throw the balance way off). I sleep better with screw in plugs . . . and they can easily be removed to clean out the rod throws.

Re: What cleanout plugs for Merc crank?
 

This is how its done. But steel plugs are fine they have no affect on changing the balance.

Harry