Rebuild 346 or not???

[LSUFAN]

I have a 38 7519 with a 346 engine.  The engine runs great, no smoke, noise, good oil pressure and has less than 5000 miles on it since it was rebuilt in the early 1970's.  The car has been in climate controlled storage for 30 years....not driven or run at all.  When I first ran the car about a year ago, the engine ran hot.  I discovered the coolant passages were clogged as was the radiator.  I flushed a lot of the crud out, but it is still very nasty and scaly, at least on the pump side of the block so I am sure the rest of coolant passages look the same. 

What can be done to clean the block without tearing it down to have it boiled and flushed?  I thought about pulling the heads and knocking out the freeze plugs to try and scrape at much of the junk out as I can.  I just really hate to take a part a good running engine that probably does not need to be rebuilt.

Any suggestions would be greatly appreciated!

Thanks!!! 

Trey

[Steve Passmore]

What you've already suggested is about the best you can do Trey without tearing it down completely, Remove the manifolds, heads, and block core plugs, use screw drivers, bent wire, anything you can to dig down into the rubbish through the water holes in the block and the core holes,  but you wont get at all of it, the only sure way even then is to pressure blast it out, but what a messy job your in for if its still in the engine bay   Don't envy you.

[Pat]

Trey,
I would give CLR a try before I took the engine apart. I read something on the internet about it working in a similar situation...and as you know, anything you read on the internet must be true
Google CLR and see what you think. For what it costs, it is worth a shot.
Cheers,Pat

[Steve Passmore]

In my past experience it doesn't mater what chemicals you put into a block your still left with the rust residue and this has to be manually removed. they are usually blocked at number 7 and 8 Trey so remove the two back plugs before anything else and see just how blocked it is before going further.

[LSUFAN]

Thanks Pat...I'm heading out to knock out the plugs now!  I am going to try to exhaust all efforts to clean this junk out before I tear it down and have it tanked.  Like I said, I just hate to take apart a good running engine.  And yes, it is out of the car at the moment.  I thought it would be easier to clean all the crud out if the engine was on a stand.  Beside, give me a good excuse to detail the engine compartment!!!

Thanks again!!!

[Otto Skorzeny]

If you can rig it up to run on a stand, you can cycle the cleaners through the block. I'd start with over the counter cooling system flush and work your way to the more caustic stuff.

I'd do that first before knocking all the plugs out.

[Jim Stamper]

     One of the things I use to clean in a block is a piece of 1/4" or a little larger wire rope (cable)  and 1' to 18" long, chucked up in an electric drill. I find it handy to thread it through a tube a bit larger than the cable. This tube becomes the handle and the means to hold the part of the cable stiff and guide it while feeding it into the block recesses through the freeze plug holes or anywhere else I can. Be sure to "fuzz up" the business end of the cable to so in effect you have a wire rotating wire brush up inside the block anywhere you can get it to. Lots of places I would think with the engine out of the car. I usually use the plastic sheathed kind. The tube should be 6-8" long. A cable can be fuzzed on the end to make an end brush or individual wires bent to 90 degrees to make a rotating brush. Try both. A variable speed drill is a good idea, keep the rpms down until it is inside, then brush the crap out of it. With care a good deal of the inside around the cylinders can be cleaned out.

     Good luck, and be careful.

     To do the heads, they would probably have to come off.

[Gergely Szentmartony 25603]

Trey,
I would give CLR a try before I took the engine apart. I read something on the internet about it working in a similar situation...and as you know, anything you read on the internet must be true
Google CLR and see what you think. For what it costs, it is worth a shot.
Cheers,Pat

Jelmar (maker of CLR) does not recommend it.
As they say here: http://www.jelmar.com/faq.htm
"Can I use CLR to clean out my radiator?
No, CLR should not be used on a car radiator for two reasons. First, CLR may not be compatible with the internal metals of the radiator. Second, it could have adverse effects if the CLR is not rinsed out completely."

[Pat]

Gergely,
I believe everything in moderation..LOL  When you look at that list they say you shouldn't use it on basically anything.  They say that others have recommended it for hot water heaters but they (Jelmar) don't. I am wondering if they are covering their backsides.
I have used it in the cooling system on my truck and it seemed to clean out a bunch of crap.I gave it a couple of good flushes afterwards.
Cheers,Pat

[LSUFAN]

Well, I'm getting a lot of great ideas here!  I did not get a chance to do anything yet due to other duties around the house!  Tough to restore a car with 4 kids and a wife! 

I think I'm going to plug off the waterpump this weekend and fill the coolant passages with some radiator solvent and let it sit a few days to get everything moist.  Then flush it with water with a few psi of air.  I'll see what it looks like after that. 

Keep coming with the suggestion...THANKS!!!

[LSUFAN]

Well,

    After exhausting all efforts to clean the junk out of the block without taking anything apart I decided to knock out the rear freeze plug on the left side of the block.  I found the rear corner of the block was toatlly caked and clogged.  I knocked out the rest of the plugs and found pretty much the same thing. 

    The only way I could see to get all the crud out of the block is to take it apart and have it tanked. 

     The engine is completely disassembled and ready to go to the machine shop.   The engine was very clean internally.  All the bearings had very minimal wear.  I was pleased to find that the cylinders are still standard bore and appear to be in very good condition.  There is no wear that I can seen to any of the cylinders.  I can see where the rings stopped at the end of the stroke, but with the exception of a ring line, I can't feel any wear.  Hopefully the machine shop can just put a light hone on all the cylinders and I can stay standard bore.  I don't have a inside mic so I can measure the cylinder wear...fingers are crossed!

      I have been cleaning out as much of the build up inside the coolant passages as possible before taking the block to the machine shop.  So far I have gotten out enough muck to fill a 1 gallon jug!  This thing was very clogged and very nasty!

      I'll update more after I get the block back.

Thanks, Trey


 

[Classic]

Don't forget the radiator.  You don't want to put a dirty radiator back on a clean engine.  Have it thoroughly flushed, boiled out, flow tested and pressure tested by a radiator shop that is highly recommended by fellow hobbyists.  If the flow test is slightly questionable, have the radiator rodded out or replace the core.

Water pump should also be rebuilt.  There are several schools of thought on how to rebuild these water pumps. Others on this forum are more knowledgeable than I am on rebuilding these water pumps, so I'll let them weigh in on this subject.

[Steve Passmore]

Well,

    After exhausting all efforts to clean the junk out of the block without taking anything apart I decided to knock out the rear freeze plug on the left side of the block.  I found the rear corner of the block was toatlly caked and clogged.  I knocked out the rest of the plugs and found pretty much the same thing. 

    The only way I could see to get all the crud out of the block is to take it apart and have it tanked. 

      I have been cleaning out as much of the build up inside the coolant passages as possible before taking the block to the machine shop.  So far I have gotten out enough muck to fill a 1 gallon jug!  This thing was very clogged and very nasty!

      I'll update more after I get the block back.

Thanks, Trey

As I said in my November reply Trey, what your doing is the only way. If you also take care of the radiator as Classic suggests you will have a car that runs cool even on a hot day in the thickest traffic, after all, when Cadillac sold them new they had to run cool in all situations  then didn't they? and you will have a warm feeling psychologically when you get that block back clean as a whistle.