Engine Block Water Leak

[Labrauer]

I have used JB Weld on the gas line fitting going into the carburetor and it works just fine but now I have another situation on the engine block. My 218 engine block has been repaired (welded) before I got the car and since I am doing a rebuild when the motor is running there is a few leaks where the weld is. My guess is that when the block was cleaned at the machine shop some of the corrosion in the water jacket came loose causing it to leak. My question is do you think if I put JB Weld on the out side of the block it would stop the leak and if so how would I prepare the block so it will stick and last forever? If it will not last I guess I will have to find someone that has a good 218 block they want to sell or donate to a good cause of getting another 48 Plymouth Special Deluxe Coupe back on the road.

 

Larry

[Andydodge]

Larry, doesn't sound good..........have you any pics showing where its actually leaking from?...........andyd

[greg g]

I have seen epoxy fixes used on block leaks and bypass leaks to some good effect.  The one thing we have going is the non pressurized systems meaning the goop has less work to do and a better chance of doing the job.  Permanent  who can say even the weld was not permanent.  But for a stop gap to keep the car running down the road, it may be just the thing.  Maybe also consider some coolant system stop leak like Bars leak along with the External patch.  

Edited April 23, 2015 by greg g

[jeffsunzeri]

There are several block-sealing (also listed as head gasket sealing) compounds available such as KW, Steelseal, Kseal and others. Some are easier to use than others. READ THE INSTRUCTIONS!  They all work and make permanent seals if the crack is not too big. These are commonly used in sleeved engines.

[RobertKB]

Pesonally, I would either find a good welder to redo the crack or better yet, look for another block. If you are rebuilding anyway, I would sure want a reliable fix. Maybe more work than you are looking for but still the best option.

[casper50]

https://www.youtube.com/watch?v=vgnQmfiIo9k

 

 

https://www.youtube.com/watch?v=WrPugU3qFD8

[soth122003]

The problem with JB Weld for a block fix is flexability, JB Weld will crack when subjected to high heat and low cold. So when the block heats up then cools down it will stress the fix. I would not use JB as a permanent type fix.

 

Joe

Edited April 25, 2015 by soth122003

[James_Douglas]

This is my 2 cents worth.

 

1. Drain the block.

2. Refill with REAL high concentrations of powdered TSP and water.  Not the fake TSP hunt down the real thing.

3. Run engine for an hour driving it around.

4. Drain block.

5. Fill block and drive around.

6. Drain again.

7. Take a drummel and grind out the crack on the block a LITTLE bit.

8. Start engine for 3-5 minutes to warm up.  Shut down and let heat soak for 5 to 10 minutes.  This will open the crack a bit.

9. Mix and fill in with JB weld.  Let sit for 24 hours.

10. Pour in jug of Ceramic Seal (See photo).  Follow Instruction.  The pray a little and see what happens.

 

James

Edited April 25, 2015 by James_Douglas

[RobertKB]

If you gotta pray, not worth doing. Do it right with a professional welder (unless you are one) or find a new block.

[James_Douglas]

I was just joking on the pray part. What I was alluding to was a benefit-cost approach to such a problem.

 

A generally agree with the do it once do it right approach.  However, sometime a simple fix that does not preclude a later proper fix is sometimes worth the effort.

 

I have used the about system on blocks before and about 70% of the time it works.  Also, in some cars welding in place is not an option due to the access.  The above process is relatively cheap and if it works you are saving a lot of time and trouble.  One can always pull the block and weld-replace if it does not work.

 

We had a fresh rebuilt 413 in a letter series Chrysler years ago.  Passed the mag check and ran great.  About 1000 miles into using it, a slight crack developed in the block between two core plugs on the passenger side of the block.  I used the above process and it went 25K and no leak.  I sold the car many years ago and I never heard of a problem from the owner who I see from time to time.

 

James