Replace freeze plugs with engine in place

[bernd_st]

It's not absolutely neccessary to pull out the engine as long as your rear core plugs are still good. We did it on a couple of engines in situ and believe me it's absolutely worthwhile to be done on any 1725cc block. The process goes as follows:
- Remove the carbs, intake as well as exhaust manifold
- Drain the coolant
- Drive out all of the core plugs visible on the block side
- Get a garden hose and flush the cooling passages - use a bent rod made out of a gut wire coat hanger to scrape out all the crud, rust and casting sand from the passages while still flushing. Put specific attention to remove the crud around the 4th cylinder
- Flush until the water gets clear
- Dry up everything and install new core plugs with a slight smear of clear Silikone
- Remount the Manifolds, carbs, etc.
- Refill the coolant

Ready to go. You'll be surprised how stable your engine temp will be afterwards...

 

[hartmandm]

All my plugs are currently good. I looked at doing the freeze plug closest to #4 cylinder, but my conclusion was there isn't enough space to drive in the new freeze plug. It looked to me that only the starter should need to be removed to do the freeze plug near #4. I'm interested in hearing how you installed the new plugs. This might be a good topic for a new thread.

Mike

 

[bernd_st]

Yes , perhaps the starter need to be removed too to get better access to #4 plug. Not a big deal though. Installation of the new plugs is easy. Just find the biggest ratchet nut which just fits inside the plug ( depending on plug size though) with an extension and hammer it carefully & straight in. Don't forget the light smear of silicone beforehand...

 

[hartmandm]

I have the OEM Tools master freeze plug set.



I considered buying a spare driver rod and shortening it to have a minimal depth tool to hammer on ... but in the end, my memory is that there is only 6 inches of space between the #4 freeze plug and the steering arm pivot (LHD). Either using a socket or the OEM Tools set, I think the space will be reduced to 4 to 4.5 inches. I don't see how I can swing a hammer with 4 to 4.5 inches of space. There is more space if I come in at an angle. But the angle required seems too high and I am concerned the plug won't be driven square. Hopefully I am missing something obvious.

Thanks,
Mike

 

[bernd_st]

Wow, looks professional Equipment. Didn't even know that something like this exists. However never needed that and wonder whether the angled rods really work to get the plugs in squarely. Anyway you may try. With the ratchet nut the big advantage is you can go with hammering on just the nut or use various length extensions. It worked for me with the engine in situ. What I forgot to mention is that the core plug openings in the engine block normally need a bit of clean up with sand paper / brake cleaner before Installation the new plugs...

 

[husky drvr]

I think the space will be reduced to 4 to 4.5 inches.

Mike,

I don't have an Alpine to check space and angles, so these are wild, off the wall thoughts.

Is there a possibility to improvise some type of "screw jack" to press the plug into location?

The other is something I've no experience with so no idea about size, power, or location ability for a non specified use, but maybe an air powered palm nail driver?

Just my opinion, but by the time you've gone to this much work to attempt this job in the car, you're already about half way to having the engine pulled. If the purpose is more an internal cleaning than just a preventative replacement, then I would want to pull the engine just to make access easier, AND to be able to pull, clean, and replace the plug behind the flywheel. Not a procedure I would enjoy laying under a car in a streaming puddle of flush water.

Just a few thoughts,

 

[Tim R]

I agree with Don, why not just pop the engine out and do it properly? I don't see the point of replacing most of the core plugs but not the crucial one behind the flywheel.
Tim R

 

[mxp01]

I just did my core plugs when rebuilding my 1725. Now I did a complete rebuild so I had the engine out on a stand making it easier to access every plug. Being able to fully get to and clean out all the water passages is well worth it. It is also much easier to get the plugs in straight with the engine out and on a stand and gives peace of mind knowing they are in straight and wont leak.

 

[bernd_st]

Indeed. We all know the advantages once you have the engine out with excellent accessibility to the core plugs. I would even call it a MUST to change' em with a good water channel clean up during every engine rebuild. By the way not only the water plugs, but also the oil gallery deserves plugs out/cleaning too. My advise goes to those who don't have or don't want to spend the time for a complete engine out. The bent coat hanger will do the trick to reach pretty well around the 4th cylinder from the rearmost side plug ;-)

 

[Knightowl61]

#4 cylinder always gets the least water flow and debris builds up there. The last 1724 rebuild I did on an engine stand, popped all plugs and had crud up to the bottom of #4 cylinders back plug. It took a lot of work chipping out all the hardened crud and I found a head water jet in the bottom of the block.

 

[hartmandm]

Is there a possibility to improvise some type of "screw jack" to press the plug into location?

I procured a used Starrett screw jack to attempt this job. I wasn't able to figure out how to create a flat surface for the jack to apply pressure against.

My engine has 27k miles. The freeze plugs look to be in excellent condition, so I don't need to replace them at this point. I know pulling the engine would be best. Then the one job will snowball into probably 5 other jobs once the engine is out. And buying expensive tools, like an engine lift. So changing a freeze plug becomes a year long process. Lol



Thanks,
Mike