Driving a Solid Core Plug

[yorab]

As part of troubleshooting another problem, I need to drive a core plug (OMC referred to the part as a "cylinder plug"). This is not a cup-style plug or Welch plug; it is a solid slug about 7/16" in diameter and about 7/16" deep. Has anybody ever driven one of these into place? Any advice to get in in place properly without breaking things? Use sealer?

 

[boobie]

Get a 1/4 " drive socket a hair smaller than the plug and an extension and use that.

 

[jimmbo]

Place the plug in the freezer for a few hours, Place the casting in the oven and heat to 250, plug should drop in.

 

[yorab]

I can't put the block in an oven but I may have access to a heat gun. If not, I can use a hair dryer and that should get it up to about 160 degrees or so. I can also put the plug in the freezer. Thanks for the advice.

 

[yorab]

Also, I've got some Loctite and some 3M scotchweld 847. I'll probably use one of those but I'm not sure which. Any thoughts?

 

[interalian]

Place the plug in the freezer for a few hours, Place the casting in the oven and heat to 250, plug should drop in.

I'm not 100% sure, but if you have a hole in an aluminium casting and heat the casting, wouldn't the hole get smaller due to overall expansion of the material?

Chilling the plug is a good idea and you can cool it more by spraying it with freeze spray. You can 'make' freeze spray by inverting a can of dust-off blower spray that you would find at a computer store.

 

[jimmbo]

the hole gets bigger as the entire block expands too. When I was a teenager I asked a shop teacher about that. Something about the circumference of the hole had to lengthen... Next day he had a demonstration. Works for installing bearings/bearing races too.

 

[interalian]

Cool. Well, warm I guess. I've done the 'heat the ring gear and drop it on the carrier' on cars, as well as flywheel ring gears. Never tried to expand a hole in a casting.

 

[yorab]

I heated up the area with a hair dryer for a good ten minutes or so. I also had the plug in the freezer for about an hour prior. Slipped right in about 3/4 of the way. I used a ratchet extension and a socket to tap it in the rest of the way. I used medium strength loctite on the plug. I would have used high strength, but I didn't have it with me at the time. It seems to be solid.

 

[interalian]

Good stuff. Looking forward to a happy outcome.

 

[Joe Reeves]

Perhaps I've overlooked the mention.... where does that plug go? I've worked on may of those engines back then, rebuilt a few, but cannot visualize where that thing goes. For some unknown reason, I don't recognize the graphic either.

 

[interalian]

It's in the exhaust chest, one on each side, and appears to go into the main waterjacket.

 

[yorab]

That's correct, it leads from the water reservoir between the cylinder banks into the exhaust chamber. My guess is that this is probably the first time that one of these plugs has actually come out. I'll post more info about this problem in another thread as it relates to an overheating situation that I've been experiencing.