327 Block Drain Plugs

[Larry M.]

I've read the posts about the need to remove these water jacket drain plugs and the difficulty also...get the right socket... impact driver...PB Blaster...heat etc. But before I start I'd like to know: has anyone every broken the block or pulled the threads out trying to remove these plugs? If I assume they have never been out in 50 years what is the right approach? This is an un-rebuilt 38,000 mile engine with less than 100 miles many years.

[John F.]

Re: 327 Block Drain Plugs

Larry, mine came out with ease after sitting for 20 years. Just turned 49000 miles. Just get the socket on right and turn.

[Duke W.]

Re: 327 Block Drain Plugs

Six point socket, breaker bar, put some torque on it then jamb hard, and they will probably break loose. The plugs themselves are soft steel, which is why the hex can round off with a 12-pt. socket. The cast iron is pretty tough and I've never heard of the threads being pulled out.

Clean up the plugs and block threads, but if there is a lot of corrosion pitting, replace them. Install with the threads well coated with pipe joint compound. There is no torque spec for NPT - just tighten enough so they don't leak, which will be no more than 10 lb-ft.

Do the above and they will come out easy next time.

Duke

[Edward B.]

Re: 327 Block Drain Plugs

Go get yourself a set of spline sockets (Harbor Freight has them for around $10 a set). They work great on square head plugs.

Ed

[Joe L.]

Re: 327 Block Drain Plugs

I've read the posts about the need to remove these water jacket drain plugs and the difficulty also...get the right socket... impact driver...PB Blaster...heat etc. But before I start I'd like to know: has anyone every broken the block or pulled the threads out trying to remove these plugs? If I assume they have never been out in 50 years what is the right approach? This is an un-rebuilt 38,000 mile engine with less than 100 miles many years.

Larry-------


I've never damaged a block trying to remove these things. However, I never tried removing them with a 3 foot breaker bar, either. In some cases, after I applied what I regarded as the most torque I felt comfortable applying, I just gave up. I have heard of blocks being broken when too much torque was applied to these plugs but, as I say, it never happened to me personally. Thankfully.

[Terry M.]

Re: 327 Block Drain Plugs

I like an impact wrench for this application, but a proper socket is essential.

[Larry M.]

Re: 327 Block Drain Plugs

OK, I used the Duke Williams method and all went great....removed....flushed.....replaced with pipe dope....really only took "reasonable" force with a 1/2 breaker bar.....thanks Duke. On inspection I don't think they had ever been out before....no deformation to the wrench flats. Passenger side gushed when plug was out but driver did not......but one probe with a small punch and it gushed also. I strained the water and captured about 1/2 cubic inch of rust particles which is not much in my opinion. Now I'm ready to remove the radiator and replace it with a correct one. I'm going to use Zerex GO 5 and distilled water in my new DeWitts unit. I'm a happy camper.