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Possible cracked block


Keith-wc42

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I've just been looking through some photos I've taken of my Dodge engine while I'm at work and I noticed something worrying.

The three photos attached here are cropped/zoomed in on the same area of the block.

The 1st one was taken when I was in the process of repainting the head a few months ago. I sanded down a scruffy patch on the block ready to touch up.

The 2nd photo is after I touched it up with some grey paint.

The 3rd photo was taken last Sunday.

This must be a crack in the block I suppose. I would appreciate some thoughts on this please at this worrying time๐Ÿ˜”

IMG_20210915_183047.jpg

IMG_20210915_183012.jpg

IMG_20210915_182904.jpg

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It could be a crack, or a small porous spot in the block.

One of the things most people don't realises just hollow pressure the cooling systems are on these engines. ย A new truck and radiator would have a 4psi radiator cap on it, and it would only reach that pressure when working really hard.

Clean it and paint it again, maybe with some sort of sealant, then turn your radiator cap back to the first click so it is locked in place but not pressurising the radiator, and just drive it

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8 hours ago, Keith-wc42 said:

Can cracks here be fixed these days without the engine coming out?

ย 

Yes but not easy. ย The big problem is finding the extent of any crack, and if it is porosity you are limited to sealer.

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It has a couple of little pores.

One of the is marked in the photo. The other one can't really be seen in the photo, but its to the right and up a bit from the marked one.

I don't think i want to risk using K-Seal after reading some reviews of it blocking water channels.

I've just ordered some JB-Weld Extreme Heat which will arrive tomorrow.

If you look below the sanded away red primer though above the ring marker, it looks like its had JB-Weld or something similar already put on it. So it looks like these may have been repaired before.

Although i know nothing about this repair, it must have been done by my Dad.

Ive attached a zoomed in photo of this engine on the floor in 1991 and there is no repair, but a possible rust area in the same spot.

IMG_20210916_024149.jpg

1991.jpg

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Pores rather than crack I think, it'll flex every time that head bolt is tightened. ย Clean and cover, but don't be too hard on it as it is eighty years old. 8-) ย  Running the cooling system unpressurised would be the thing.

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That looks like a casting fault to me it's not a stress crack they are more linear and run along the grain boundaries what you have is a small pit imperfection in the casting that has probably beenย  there since manufacture.

The first question I would ask is have you seen any water seeping out from there?ย  if not my advice would be to leave it alone, certainly don't go digging around inside the pit.ย 

Pete

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I remember a hydraulic moulding press made by Daniels where the hydraulic ram cylinder sprayed the machine shop with a mist of Shell Tellus.ย  A new cylinder was ordered and fitted. I then with a sledge smashed the original cylinder , the wall thickness was 2" +ย  & oil had tracked through the CI abt. 2 feet before escape to outside.ย ย 

On a thin water jacket like this , similar porosity problem - so I drilled to investigated , luck was in and I used the smallest taper plug (with threadlock) - it was only 1/8" BSP ,ย  I would probably have gone up as far as 3/8" BSP.ย ย  After a few years - I ground off the square head and painted over - invisible repair at ยฃ zilch cost.ย ย ย ย  Devcon on similar CIย  recip. pump crankcasesย  & engine casings - the norm if not extensive.

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Working on it in daylight it's clear it's had some sort of stitch repair or downward rods.ย 

Not sure if you can see them in the photo as I'm outside using my phone and can hardly see the screen in the sunlight.

The pores are at the bottom of these stitches.

This is sort of good news for me, as it means it's been like this for almost 30 years, it's not happened on my whilr I e been the owner.... which I was feeling guilty about and the holes are not areas where the block has rotted through and would get worse, but down to a repair.

Im feeling a lot more confident about this now.

IMG_20210916_133457.jpg

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I masked the area off and put a smooth coat of jb-weld over it.

I used the original jb-weld after reading some bad reviews on the extreme heat version.

I pulled the masking tape off while it was still wet, so just need to sand paper in the edges and paint the block now.

I went out on a big run in the Dodge yesterday and it's fine.

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