Freeze plug quick fix??

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flyfish

flyfish

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So, I was at the track on Saturday, warmed up the car and made a time run. Got back to the pit, grabbing a drink and noticed water dripping out from under my oil pan....long story short, I have a leaking freeze plug (and my racing was done).

I know the proper fix would be pull the motor and replace the plug(s), but has anyone tried the rubber compression plugs as a temp fix (see example pic below)? I think I can reach it well enough to knock the old plug out and insert the compression plug, but I don't think there is room to hammer in a new plug with the engine in the car. I was just trying to not pull the engine till the off season if I can help it.

I was also not sure how well these hold up. My water pump is a constant speed Moroso water pump drive, and I don't let the car go over 200°F, 16lbs radiator cap.

What do you think? Is this a dumb idea?
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I've used rubber plugs, had one in a Ford I used to own for over a year. It was in a bad spot to get to as well. DO NOT put slimy slick sealer on them such as RTV. Clean the hole, put them in dry, they will "stick" to the sides so to say
 
i did one years ago , also on a ford :rolleyes:, left it for about 2 years, no problem
 
These Dorman copper expansion plugs are quite a bit better and could be a more permanent fix. I've heard that some marine engine builders use these rather than press in plugs on new builds.

81oLAg44ZBL._AC_SL1500_.jpg
 
I have used them with no problem, just don't over tighten them, it will cut the rubber.
 
Also, does anyone know the size of the freeze plugs on the side of a 360 LA block?
 
They work well. Go for it!
 
flyfish said:
So, I was at the track on Saturday, warmed up the car and made a time run. Got back to the pit, grabbing a drink and noticed water dripping out from under my oil pan....long story short, I have a leaking freeze plug (and my racing was done).

I know the proper fix would be pull the motor and replace the plug(s), but has anyone tried the rubber compression plugs as a temp fix (see example pic below)? I think I can reach it well enough to knock the old plug out and insert the compression plug, but I don't think there is room to hammer in a new plug with the engine in the car. I was just trying to not pull the engine till the off season if I can help it.

I was also not sure how well these hold up. My water pump is a constant speed Moroso water pump drive, and I don't let the car go over 200°F, 16lbs radiator cap.

What do you think? Is this a dumb idea?
View attachment 1715778474
Click to expand...
They work on street engines, I’ve never had the few I’ve used over the years pop out but at the drag strip on a high 10 second car is it? No way in hell would I take the chance regardless of how many say otherwise, how many runs you planning?? envision being the guy that has one pop out, rpm’s at what? 6500+/-?? at a buck and a quarter at the top end at the track?
93C73006-9066-41E7-A928-257781BDD39F.jpeg

Street? Absolutely. Track? Yes, dumb.
 
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Big_John said:
These Dorman copper expansion plugs are quite a bit better and could be a more permanent fix. I've heard that some marine engine builders use these rather than press in plugs on new builds.

View attachment 1715778506
Click to expand...
Thanks for posting that, old book I have mentions Mr. Gasket making those back in the day, apparently not any more, these Dormans appear to be the same thing.
Dorman Products - 02483
Just ordered me a few:thumbsup:
 
kursplat said:
i did one years ago , also on a ford :rolleyes:, left it for about 2 years, no problem
Click to expand...
Me 3! Cleveland rear by the starter. Put it in in the Pep boys parking lot in Riverside on the way home from Palm Springs. Sold the car 5 years later and it was still in there.
 
didn't work for me, but i had some corrosion to deal with on my block

0714162013.jpg
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was that a rubber expansion plug failure? Maybe you didnt tighten it enough. They should barely fit in uncompressed and will seal up with only about 3 turns. I could not physically get a core plug in my app behind the starter. If its out, brass plugs are a whole lot cheaper and are an easy install.
 
My first 340 block had one freeze plug hole, that was to large. Probably look like that above from the factory casting and had to be bored out larger.
Can't remember the size plug i had to use but it was some odd ball size like 21/32 or some thing like that.
 
12many said:
They work on street engines, I’ve never had the few I’ve used over the years pop out but at the drag strip on a high 10 second car is it? No way in hell would I take the chance regardless of how many say otherwise, how many runs you planning?? envision being the guy that has one pop out, rpm’s at what? 6500+/-?? at a buck and a quarter at the top end at the track? View attachment 1715778737
Street? Absolutely. Track? Yes, dumb.
Click to expand...
I've been wrestling with that thought as well (leaking on track).....I don't think the pressure would get high enough to pop it out, because I don't have a water pump that spins at engine speed (it goes at a constant slow speed because it runs off an electric motor, and I don't let the car get too hot)...but I still have doubts.

Yeah, on second thought, on I'll probably just not race until I can pull it and fix it right....I might put in the rubber plug thing to drive around town for the next couple months.
 
Used those back when I was young, poor and had no tools or space to remove an engine.

Some outlasted my time with the car they were installed in.
 
flyfish said:
I've been wrestling with that thought as well (leaking on track).....I don't think the pressure would get high enough to pop it out, because I don't have a water pump that spins at engine speed (it goes at a constant slow speed because it runs off an electric motor, and I don't let the car get too hot)...but I still have doubts.

Yeah, on second thought, on I'll probably just not race until I can pull it and fix it right....I might put in the rubber plug thing to drive around town for the next couple months.
Click to expand...

Cooling system pressure is regulated by the cap. I doubt 16 pounds of pressure will blow out a correctly installed rubber soft plug. The cap will blow off first and release the pressure. I’d put one in and run it. They are better than most people think.
 
12many said:
They work on street engines, I’ve never had the few I’ve used over the years pop out but at the drag strip on a high 10 second car is it? No way in hell would I take the chance regardless of how many say otherwise, how many runs you planning?? envision being the guy that has one pop out, rpm’s at what? 6500+/-?? at a buck and a quarter at the top end at the track? View attachment 1715778737
Street? Absolutely. Track? Yes, dumb.
Click to expand...
This was a 8 second ride. Guy survived. Kim

FBDB7E4A-BDE9-43EE-9AD5-9033FB273EAB.jpeg
 
The only problem with temporary fixes is just like the problem with the old full sized spare tires.
People would put the spare on and then never got around to fixing the flat. They didn't remember until the next time that they got a flat and found a flat spare in the trunk.
Fix it properly at Your convenience, not wait until the next Crisis happens...
 
Buy the install tool and skip the temp fix. They have a ball end and an angled handle. Best $60 you'll spend.

513nBTdaULL._AC_SX355_.jpg
 
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