I got a call last week from the machine shop rebuilding my engine. It seems the block is cracked and is no good. Today I got another 41 block ready to take to them to see if it is good. I spent about 2 hours prepping it and thought I should post what I did and suggest others consider doing the same if they are going through an engine rebuild. I blew out the coolant system of the block. It took me that long because I did not stop until chunks of corrosive material stopped coming out of the block. I used 120 PSI of air with two different wands that are shown in the pictures. About 90% of the work I did with the smaller wand. I assume that about 2 cups of debris blew out of the block. I do not know if machine shops normally do this for you but I hear a lot of guys complaining about engines over heating and this could be a reason for it?

If you haven't done it yet, you should remove the two soft plugs from the side of the engine, you will be able to clean a lot more rust from the block. Of course the engine rebuilder should remove the plugs when they clean the block.

Walt, Thanks. What is the best way to remove these plugs? Mike

Mike,
where did the stuff come out?

There are four large plugs, one in the front, one in the back and two on the side. They can be removed with a sharp punch. Sometimes if you apply the punch off to the side it will turn in the hole and it can be extracted with pliers. Also with the plug speared with a punch it can usually be pried out.

Usually an engine rebuilder will tank the block and boil everything out of it. Some use an oven that burns all the junk into an ash.

The stuff came out almost every single hole in the coolant system. The engine had sat for over 25 years so the first thing was fine dust then small chunks of scale. A month ago I had a head hot tanked and the same type of debris came out, so I would assume that hot tanking alone is not enough to clean out the coolant system? Thanks, Mike

The machine shop i use cleans the engine block, head and anything else that needs it by hot tank with proper chemicals. All clean out plugs are removed and new ones installed with the rebuild. I wouldn't use a shop that didn't clean the engine much better than I could.
Charlie

I used a local shop to clean my head, and am using a more reputable one for the engine rebuild. Have you ever checked to see how clean your block or head was after it was cleaned professionally? Good night , Mike

Mike
You will be surprised how much more gunk you will get after removing the freeze plugs. I would also use a high pressure water jet as well, most of them operate at a higher pressure than most air compressors and are a more concentrated stream.
Tony

And wear eye and skin protection while using them; can hurt yourself!

...I cringe every time I hear the term "freeze plugs"...

Hot tanking is intended for engines that have been run recently. It will remove any grease, oily deposits and some corrosion products but will not remove metal particles, rodent nests, casting sand, gasket remnants or other materials. If the engine has been stored for an extended period or has heating problems a passage may be blocked. In most cases hot tanking will not open it or thoroughly clean it. Same for some deposits on the bottom of the cooling passages. It is always best to probe with wires and tools to break up as much stuff as possible. Then blow out with air or water pressure. Only then take to rebuilder.

Mike,

i don't know if it would help, but I have a '48 216 engine complete that ran when I bought it. I'm down in Kalamazoo so not too far away. Am interested to hear how the cleaning and rebuild goes. What shop are you using? Is it one around Midland?

Mehl42 and others, I sure appreciate all your comments. This is my first experience with engine rebuilds. I took my cleaned up block in today. The shop is in Bay City, Michigan and is a large CarQuest machine shop. I have visited now three times and like the references I checked out am impressed. It seems to have about 6 to 8 shop employees. The guy working on my engine showed me a 12 inch crack on the side of the block at about 3 to 4 inches running parallel to the bottom of the block. Said else the engine did not appear to be in that bad of shape. He found the crack before plasti gauging it or hot tanking. If I had more knowledge I should have already seen it! I feel just a little foolish that I have been assuming the last 7 years that this would be the engine someday in my 41? Lucky for me I have another block that I think should work out? I also have a 47 block and a 49 in my car. I think before storing either I will have them hot tanked and plasti gauged. As Charlie says, "why store a boat anchor?" The machinist assured me he does blow out the engine and uses as strong as is legal chemical in their hot tanking process, so I should have one very clean coolant system? Thanks, again, Mike

P.S. Mehl42 my phone number is 989-832-7634

Was the crack along near where the expansion plugs are? I understand it isn't unusual to find cracks there as the block is thin and rots through from the inside.

A friend of mine had his 1940 216 rebuilt a couple of years ago. When they went to bore it out they ran into rust holes through from the water jacket. They had to install sleeves. Just thought I would mention it in case it happens with yours.

I have used a CarQuest shop near me and found the work was well done and reasonably priced.

What are "The expansion plugs"????.....So many folks are confused about what the "CORE PLUGS" are there for....Because so many "Old Guys" passed this information along to their kid's and grandkids (not knowing what the Hay they were talking about) that people don't know what they are anymore.I was told also that those plugs were to pop out in case your motor froze up to keep the block from cracking..SO HERE GO'S~~~~ THEY ARE THERE TO GET THE SAND {USED IN CASTING THE BLOCK}OUT OF THE BLOCK....AMEN....The car companies could care less if your car froze up because you were dumb enough to not read the owners manual (that they supplied with you car) and care for your car properly.
As a matter of fact it was to their interest if you did not read it!....Just like Some other poster said ...I could scream when I hear these "CORE PLUGS" referred to as "Freeze out Plug's"......ED

...I cringe every time I hear the term "expansion plugs"...

Unfortunately the term expansion plug or freeze plug is better known to a lot of folks than "core plug". I agree with the explanation of the purpose of the plugs, it is just that the correct term doesn't seem to be used as often.

The common term amongst the trade down here is "Welch plugs". The holes are there for casting purposes and these plugs are a cheap way of sealing the holes up but they do (on some occassions) save the block in a total freeze situation. Some blocks do crack between these holes as well and sometimes not caused by freezing.
Tony

Tony..It would be interesting to find out were the term "WELCH PLUG" came from.....Just curious......ED

The 12 inch crack was directly under the "core plugs." The next time I visit the machine shop I will take a picture. It should help us all evaluate a block before taking one in for rebuild.
Thanks, Mike

Back in the day, it seemed that most cracks occurred along the top left side of the block (I think that may have been a relative thin place in the casting) and along the valve seats in the head. The crack in my 1936-36 head that I recently had tested was along the valve seats, rendering it a boat anchor.

I remember that sometimes my father, who ran a garage back in the 40 and 50s, used "K&W Block Weld" when the crack was not severe (and merely on the block itself). As one would expect, the results varied owing to the cleanliness of the crack, the ability of the block weld to access the crack and the severity of the crack, etc. Of course, I don't recommend doing that nowadays but it may work if one wanted to save the block for whatever reason. Then too, recently the price of scrap metal has gone up so much that previously easy found good used blocks have pretty much dried up. Well, in some parts of the country, at least.

As to the term "freeze plugs", it doesn't bother me all that much. It's just a common term here where I am and its enough for me just to know their real intent. I'm trying to think of other terms that are common but technically incorrect but can't think of any right now. Maybe, "water pump?" but not sure of the definition of "pump." Oh, well... whatever. Anyone know of any?
Charlie

The term "Water PUMP",in referring to a automobile, is another misnomer. That thingy is not a "PUMP" at all but in reality a "IMPELLER". But again that term "Water PUMP" is so ingrained in the language that if you walked into a auto parts store and told the person waiting on you that you needed a new "impeller" for your car he/she would look at you like you had two heads. The definition of the word "pump", according to the dictionary, could include the action of a "Impeller" Because is moves water along but a pump is mainly used to raise liquid to a level higher then it could normally flow to on it's own.
This post all boils down to a guy like me who is retired and has allot of time on his hands to think of stupid stuff like this and uses his computer to speak of it without risking being called a nut cake if he talked about this stuff to his neighbors.......ED

Charlie,
Don't have any problem with water pump because that is exactly what it is doing moving water at a rate higher than without it.

Now "wheel base"? What exactly is that? To me the wheel base is the ground.

Ed, I do think you have a problem, and I bet a lot of folks wished they had it. For therapy have you ever thought of buying another old car or truck, and requesting that the boss give you about 6 hours of unsupervised time each day, with a garage and budget to match your whims!!! Best wishes, Mike

...I said I "cringe"...I didn't say I correct ( oh , brother , why bother )...While we're on that subject , how about "disc" and "rotor"...

Mike......That's the problem, I have no "Boss" and I have too much free time on my hands now....I have no more room for any more vehicles or I would have more. Budget is not a problem and I am too smart to ever get married again...So It looks like you guys are stuck with me, at least till spring when I can dust off my 38 coupe, hit the road and wave back at all the folks that apparently have nothing else to do but wave at folks who drive old cars.....Ed
BTW...Thanx for the suggested therapy that may be a little better than talking to myself.

Mike, what is all that white stuff, you live near the beach? Terry.

So long as you know what it is your are talking about and can explain its operation there are a lot of car parts that are known by several different names, like piston pin, gudgeon pin, wrist pin all refer to the pin the holds the piston to the connecting rod.
Tony

Ok, since we're a little off topic anyway, how about "hot water heater?" I mean, why in the world would you need to heat hot water?

It's all a matter of terminology. In a house, a "hot water heater" heats cold water to make it hot. In a car, a "hot water heater" uses existing hot water and "heats" the inside of the car.

I think it was George Carlin who had a routine about oxymorons. He said if the water is hot it doesn't need heated so it should be called a "cold water heater", jumbo shrimp, fire department (SB fire put out department), etc..

I guess it depends on where ya live. I've always just called them "water heaters", and I'm pretty sure that's what it says on the box.

As for "hot water heaters" in cars, I definitely prefer them to the gas fired ones they put in the older, air cooled VWs.

Must be...He's outside...working...weathers great , wish you were here ! lol