The Ford Barn

Smitty · 03-16-2022, 09:00 PM

Hi All,
Looking to replace the sludge clean-out plugs in 49-50 Mercury crankshaft.
Anyone have a source for these replacement plugs?

Thanks, Steve

Ronnieroadster · 03-16-2022, 09:09 PM

Replacing the plugs with the original type press in plugs is not the best idea. Since they only press in the can actually leak.
The best thing to do it tap the hole for a tapered plug or a straight thread using a thread sealer. Which way is best depends on the hole diameter.
Ronnieroadster

flatjack9 · 03-16-2022, 10:46 PM

The plugs are Dorman 555-010.

transbytip · 03-16-2022, 10:52 PM

Summit racing sells a alum.pipe plug.1/2 in i think takes allen head, you dont have to drill the hole just run pipe tap down hole.Cliff.

GB SISSON · 03-18-2022, 10:36 AM

Quote:

Originally Posted by transbytip

Summit racing sells a alum.pipe plug.1/2 in i think takes allen head, you dont have to drill the hole just run pipe tap down hole.Cliff.

I'm right there with my merc crank, back from the machine shop. I like the aluminum pipe plugs because I don't want to get it balanced and of course the weight of plugs is a concern. Glad I saw this, thanks.

Ol' Ron · 03-19-2022, 11:28 AM

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At one time Reds Headers also made alum plugs fort this crank. Now the issue of balancing the crank. If you have a stock engine rebuilt with the original rods. Major wast of money!!! Now if you have the pistons replaced, which are lighter than the originals. No need to balance the engine as this is reciprocating weight. Now the flywheel and clutch assy is a different story. If this is not the originak unit have it reblanced..Now up to the early 70s Balancing these engines wasn't done because very few shhops provided it. Industrial engine builders of Patterson NJ. Produced several 100 rebuild engines of most types, and never balanced aaayn. I recently had my 258 crank assy balanced by a local shop that build many stoclcar engines, I've done buisness with them for years. My 91A crank came from my stash, the rods came form walt Dupont and the pistons from JWL. Chopped esrly flywheel with 9 1/2 pressure plate. Flywheel had the lip machined off This engine was the similar to my first Hydro engine and I wanted to have it balanced as it may reach 6000 RPM, I everything worked out as planned.
The crank ahd ONE hole 1/4" in dia on the front counterweight about 1/4" deep. The rear had the same. The flywheel had one 1/2 dia hole 1/4" deep. all this cost over 300 bucks and for a street engine, that might hit 4K once in a while, I just don't see the point. However, 300 dollars is not a large amt of money in this day and age, and many can afford it. Some of us can't. I have to save my money now th have the cylinders bored and pistons fitted.. Need a set of Qa1 14: shock s if anybody has any laying around.
Gramps

03-16-2022, 09:00 PM	#1
Smitty Senior Member Join Date: May 2010 Location: Boston North Shore Posts: 752	Mercury Crankshaft Plug Hi All, Looking to replace the sludge clean-out plugs in 49-50 Mercury crankshaft. Anyone have a source for these replacement plugs? Thanks, Steve

03-16-2022, 09:09 PM	#2
Ronnieroadster Senior Member Join Date: Dec 2010 Location: East Coast in CT Posts: 1,529	Re: Mercury Crankshaft Plug Replacing the plugs with the original type press in plugs is not the best idea. Since they only press in the can actually leak. The best thing to do it tap the hole for a tapered plug or a straight thread using a thread sealer. Which way is best depends on the hole diameter. Ronnieroadster __________________ I use the F word a lot no not that word these words Flathead , Focus and Finish. "Life Member of the Bonneville 200 MPH Club using a Ford Flathead block" Owner , Builder, Driver of the First Ford Flathead bodied roadster to run 200 MPH Record July 13, 2018 LTA timing association 200.921 in one and a half miles burning gasoline. First ever gas burning Ford flathead powered roadster to run 200 MPH at Bonneville Salt Flats setting the record August 7th 2021 at 205.744 MPH

03-16-2022, 10:46 PM	#3
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,527	Re: Mercury Crankshaft Plug The plugs are Dorman 555-010.

03-16-2022, 10:52 PM	#4
transbytip Senior Member Join Date: Dec 2011 Location: ottumwa Ia. Posts: 132	Re: Mercury Crankshaft Plug Summit racing sells a alum.pipe plug.1/2 in i think takes allen head, you dont have to drill the hole just run pipe tap down hole.Cliff.

03-19-2022, 11:28 AM	#6
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: Mercury Crankshaft Plug Sponsored Links (Register now to hide all advertisements) At one time Reds Headers also made alum plugs fort this crank. Now the issue of balancing the crank. If you have a stock engine rebuilt with the original rods. Major wast of money!!! Now if you have the pistons replaced, which are lighter than the originals. No need to balance the engine as this is reciprocating weight. Now the flywheel and clutch assy is a different story. If this is not the originak unit have it reblanced..Now up to the early 70s Balancing these engines wasn't done because very few shhops provided it. Industrial engine builders of Patterson NJ. Produced several 100 rebuild engines of most types, and never balanced aaayn. I recently had my 258 crank assy balanced by a local shop that build many stoclcar engines, I've done buisness with them for years. My 91A crank came from my stash, the rods came form walt Dupont and the pistons from JWL. Chopped esrly flywheel with 9 1/2 pressure plate. Flywheel had the lip machined off This engine was the similar to my first Hydro engine and I wanted to have it balanced as it may reach 6000 RPM, I everything worked out as planned. The crank ahd ONE hole 1/4" in dia on the front counterweight about 1/4" deep. The rear had the same. The flywheel had one 1/2 dia hole 1/4" deep. all this cost over 300 bucks and for a street engine, that might hit 4K once in a while, I just don't see the point. However, 300 dollars is not a large amt of money in this day and age, and many can afford it. Some of us can't. I have to save my money now th have the cylinders bored and pistons fitted.. Need a set of Qa1 14: shock s if anybody has any laying around. Gramps