Where do I check for a Cracked Block on a 248?

[Angelfish]

Edit December 29:  Got a call back, the car is sold.  Asking price was $7500 stored in a dry climate.

 

I'll be looking at what appears to be a very nice original 1937 Special 4 dr.   Hasn't run in many years.

 

Will I be able to see the common crack locations?  Worst case, how hard is it to source a replacement?

 

Anything else I should look at?  Price is reasonable so there's room for some expenses.   If I don't buy it I'll pass along the information.

 

 

Edited December 29, 2021 by Angelfish (see edit history)

[Bloo]

That is a good question. There is no good answer. There are many ways and many reasons a block can crack. The most common one is fairly easy to look for. In this scenario the car had no antifreeze in it and a cold snap came early, OR it did have antifreeze in it and it wasn't enough. Antifreeze was alcohol, and needed to be constantly replenished due to evaporation. The coolant froze. This breaks things all over the place, including some places you can't see, however a large portion of the damage is often on the outside where you can see it. Look all over the outside of the engine anywhere there is a water jacket. Not just on the block, but on the head too. If you are suspicious at all, and you have permission to, look under the pushrod cover. It hides the water jacket on one side. The damage comes because ice is physically bigger than water, so it pushes out with the force of nature and nothing can stop it. Cracks like this often show obvious signs of the outward push, leaving slight bulging spots in the iron, and making the cracks easier to see. If you find any core plugs pushed out of their holes, you should assume the block, head, radiator, heater core, and some other small parts are shot. If that turns out not to be true down the road, celebrate.

 

Another thing that can happen with a Buick Eight, some of them anyway, is that the rear drain plug on the side of the block is not low enough to get all the water out. Even if the owner pulled the plug, if the coolant was pure water there can be enough left in there to break the block. Look especially close around the water jacket at the back of the engine, just below the level of the plug.

 

Blocks can crack from overheating, or just from fatigue or casting defects. These cracks are less likely to be somewhere you can see. The truth is you probably wouldn't discover them until you had overheating or water in the oil or something. You may have to just gamble on that part.

 

Word to the wise: It's never ONE crack.

 

I'll bet Dave Tachney could find you an engine for that if you need one.

 

 

[pont35cpe]

Put some water in, and see where it runs out.

[Victor W]

To answer the other part of your question 248 blocks are not hard to find if this one is bad. Finding a '37 block specifically maybe a bit of a search but not impossible. 

 

Like suggested I'd look for obvious signs like bulging frost plugs or evidence of coolant seeping out. Check the oil and look for coolant or water.

 

Personally I'd be more concerned if the motor turns over if the car has sat not running for a long time.

 

Looks pretty complete and stored inside are two big things in its favor. 

[Angelfish]

2 hours ago, Victor W said:

 

... I'd be more concerned if the motor turns over if the car has sat not running for a long time.

 

Looks pretty complete and stored inside are two big things in its favor. 

Assuming the electrical is up to the task and has oil, is it safe to put a battery on it and give it a test spin?  

 

 

Edited December 29, 2021 by Angelfish (see edit history)

[kgreen]

Another location to check is just below the top of the block, about 1-inch down.  Check either side.

[Steve_bigD]

It might not be possible to get it to run after sitting for so long but if it can be done safely, I would recommend starting the engine and running it up to temperature. Observe the external block surfaces for signs of coolant leakage while it warms up and see if it stabilizes at 170-180 degrees or so. Also check that coolant is not rising in level at the filler and being pushed out.

 

What makes you think that the block may be cracked? Do you have any indication that the coolant may have frozen from the owner?  My 38 248 was badly overheating when I got it and coolant was being pushed out of the overflow tube on the radiator. When I tore the engine down the whole cooling system was loaded with sludge and the both the block and the head around the rear two cylinders were fully packed with rust and were receiving virtually no coolant.

 

As a result, the head was cracked around the exhaust valves of both rear cylinders, but the block was fine, just needing a thorough cleaning. It is much more likely to find a cracked head rather than the block unless as mentioned the block froze with water in it at some point.

[Angelfish]

1 hour ago, Steve_bigD said:

What makes you think that the block may be cracked?

It has relatively recent license plates so if I had to bet I'd say it's not cracked.  But a cracked block makes the car worth a lot less and early identification would save some headache.  Current temperature today is 0* F, every spring there's boats for sale with cracked blocks.   Managing expectations.

 

Edited December 29, 2021 by Angelfish (see edit history)

[pont35cpe]

1 hour ago, Angelfish said:

Assuming the electrical is up to the task and has oil, is it safe to put a battery on it and give it a test spin?  

 

 

Would be wise to drain or at least check existing oil/sludge, put in fresh oil, before attempting to start. If goo like drains out, may also have to remove pan to clean.  When pulling oil pan drain plug, look at what starts draining out like: some water, goo/sludge, dirty black oil, or clean oil. If clean, crank on.

[Jolly_John]

If you decide to see if the engine will turn over (not stuck), I would pull all the spark plugs first, shoot a little fogging oil down all eight holes to minimize any ring scrapping, keep the plugs out, and then try to turn this baby over. Of course, first be sure to check that the transmission is in neutral, or better yet jack the rear wheels up off the ground, in case the pressure plate or clutch disc is stuck to the flywheel. If you don't have a battery handy, you may be able to turn the crankshaft pulley by hand (with the spark plugs out). Good luck. John

[Str8-8-Dave]

Have you opened the drain cock on the radiator or removed the radiator cap and looked to see if the cooling system has coolant in it?  If yes and it has anti-freeze in it it may be ok...