Packard Forum Index » Post-War (1946-54)

I have the 356 engine torn down for total rebuild. The shop had bored the cylinders 030 over, installed valve liners and in the process of grinding the valve seats found a hairline fracture stretching from #8 valve seat to cylinder wall adjacent. What are the options? (if any). I don't mind traveling to qualified shop if it is only a few states away from SC. Picture below shows the crack from about "11 o clock" on the valve seat to "3 o clock on the cylinder perimeter. Somehow (in my limited understanding)I can't picture this as freeze damage. Wonder if it is a casting flaw from the original manufacture. Maybe the water jacket does pass thru this area but seems awfully tight for a passage.

Attach file:

---

  (144.29 KB)

As these cars age and have gone through thousands of heating/cooling cycles this has become more common. My GUESS it's just happens, nothing lasts forever. Of interest is that it's in #8, most distant from water pump and perhaps the hottest. Yes there's water in the area to cool the valves via the water tube which has been covered in many posts.

Suggestion: Remove the rear most freeze plug and probe downwards 1" to the bottom of the water jacket. If it's full of rust , that may be your problem.

I have a '52 I'm working on, crack from a middle cylinder. Had it welded by a specialty welder experienced with cast iron, then bored and sleeved.

Good luck

Thanks Fred. I am looking for the fabled "specialty welder" which I am sure lurks out there somewhere within 500 miles. No return calls yet but will keep trying. The engine has been steamed out but will check with the engine shop to see if they can check inside that freeze plug.

Sorry to hear of your problem, The old time machinist in the other end of the building my toybox is in would tell you to pin the crack and then sleeve the cylinder. and cut in a new valve seat to finish the job. He has been doing it like that for close to 50 years. Good luck

I have never seen liners installed in valve guides before. Seems more work than just pressing in new guides.

In engines with no valve guides, just holes bores in the block, when worn there are two methods of repair.. First is to bore out and install cast iron valve guides such as we are familiar in our Packards. Second is bronze "valve liners" alao known as valve guides. They ahve rings machined into them to retain oil and work very well.


I've never heard of bronze liners used in cast iron guides but I'm not up on the latest. Sounds good.

Thanks. Spent all day yesterday looking for that shop that can pin the crack. Might be a dying art but looked over three states with no luck.

Is that another crack in the top of the cylinder wall at "9:30"?
You probably need to dye penetrant test or magnaflux the whole enchalada. (takes care about the ones you're not seeing.)
It's a crap shoot welding cast in an engine block in critical areas. Any "good" engine builder could tell if it's repairable or not. From your request, I'm assuming your guy has stopped work and given up, not a good sign.
I'd be looking in parallel for another low miles motor/block, just in case. You get into the cost of repair vs replace. And there's no guarantee cast repairs will hold. No telling if another vintage block will be any good either, if it's a common problem one.

looking closely at the picture appears th crack goes from cylinder bore to exhaust valve and continues to intake valve or it may be the picture. Need dye test for positive check I do not have much faith in welding cast iron on a wear part like a valve seat