Cracked heads

Attachments

  • IMG_1998.JPG
    IMG_1998.JPG
    43.1 KB · Views: 90
  • IMG_1997.JPG
    IMG_1997.JPG
    52.1 KB · Views: 87
  • IMG_1996.JPG
    IMG_1996.JPG
    50.5 KB · Views: 89
Being new to Model A's this is news to me, this is the stuff nightmares are made of.
My engine/heads seem fine...so far, but now I have this in the back of my mind.
How do I prevent this from happening?
 
Being new to Model A's this is news to me, this is the stuff nightmares are made of.
My engine/heads seem fine...so far, but now I have this in the back of my mind.
How do I prevent this from happening?

Biggest single thing is DON'T LET THEM FREEZE.

Putting down a head be sure to follow the torquing sequence, and divide the torque steps up to even smaller intervals. And go easy on the head afterwards while "touching up" torque.

Pulling up a head try to use methods that will pull the head "evenly" rather than wedging it up from the water pump or back end. I've not tried it but pressurizing the head (all four cylinders) with shop air might be a good methodology if one can connect to all four cylinders via the spark plugs (and find a spot where the valves are all closed). I have done the "turn over" with the starting motor, which works but is inherently uneven in application.

Joe K
 
If you mean the crack by the center water hole on the bottom side, then yes, that crack is very common and most times causes no problem
 
Being new to Model A's this is news to me, this is the stuff nightmares are made of.
My engine/heads seem fine...so far, but now I have this in the back of my mind.
How do I prevent this from happening?

To lessen more nightmares, I was told by a shop owner to make sure all your bearings are good, Iam not sure if Iam correct, but I think he said the car has over 30. This is an old car and every time I clean off more grease I find more hidden problems.
 
That's why Snyder's is selling hundreds of them every year! :rolleyes:

Must be. Buying a new head seems to be less of a gamble than a used one. I'm thinking I may end up with one of the new Winfield repro's that we've been seeing updates about. Out of four stock heads I've got, all of them are cracked. Only one (on a diamond block) has obvious freeze damage and is split up top. Of the other three, I was given one by a friend. Cleaned it up, and it's cracked. I bought one at a swap meet (looked it over REALLY well, I thought). Found cracks when I was cleaning it up, too. The one I took off my engine is cracked. None of those heads has the typical freeze damage...just tiny cracks from water jackets to studs, or from water jackets to outside edge. All of them look like they've cracked along casting flaws.
 
I agree and would never junk a repairable block. If there was a contest for the worse block, I could have won it about 6 years ago. I save the original engine number for show and tell, and cut out a section of the left side to use as a jig for making engine mounts for stands. The rest did go to scrap. I couldn't even remove the valves or cam due to such heavy rust.
 
That's why Snyder's is selling hundreds of them every year! :rolleyes:

I'm sure that an increase in compression ratio has NOTHING to do with it.

They're probably having trouble keeping 4.25s on the shelf.

Kidding - otherwise you may be in part correct. When a crack comes - why not upgrade?

Joe K
 
Some cracks have been in heads and blocks since the 1940's and were only detected recently, not sure they were a problem then and when you see some of the horrible repairs the freeze cracks have had and were used for the next 30 years as abused cars, not yet treasured antiques, i suspect the crack phobia is way overplayed.
Metal stitching exists now and brazing worked in the old days, as did nickle arc welding, so...
 
I'm sure that an increase in compression ratio has NOTHING to do with it.

They're probably having trouble keeping 4.25s on the shelf.

Kidding - otherwise you may be in part correct. When a crack comes - why not upgrade?

Joe K

Hey Joe, the other day I was looking around the web at some of the major suppliers and I noticed that it appears no one is selling a standard head. All I saw was high compression heads. I understand why, but it just seemed kind of odd that they didn't even offer them.
 
Back
Top