Cracked 428 Cylinder

[cgmach1]

  Hi everyone, I'm new to the forum and looking for your opinion on my 428 block.  I use it for bracket racing only and have had problems with #1 cylinder cracking;twice now. The first crack happened after approx 85 runs and was sleeved with a 3/32 sleeve that didn't go through to water.  Got 25 more runs before it cracked again in the same spot; 7 oclock position about three inches long down the bore.  It is 4.165 bore, 4.125 stroke with probe pistons, Barry R's stage X heads with one of his solid rollers.  Is this block worth sleeving again with a .125 sleeve, filling the block to the water pump holes and cross bolting or is this block had enough?  Also would extra length on the piston skirt help with the side load on the cylinders?  The probes have a shorter length skirt then Diamonds pistons do.  Thanks for the help.

[jayb]

Are you saying that the replacement sleeve cracked?  I've never heard of that happening before; those sleeves are pretty tough.  The sleeves in my aluminum blocks are about 3/32" and I've never had that problem despite pretty high HP levels.

Also, for the original crack, it must have cracked through to the water jacket, correct?  So the sleeve has water on the backside in the original crack location?

[cgmach1]

Yes, the replacement sleeve cracked in the same location as the first one and yes it went through into the water jacket the first time.  That's how I found it. It was that goopy slime on the dip stick; still ran right on the number on the last run.  The first time I had this rebuilt after dropping a valve in a different cylinder (my fault) that shop had the balance so far off, 35 grams on the bob wieght and destroyed a new balancer, that I thought the bad harmonics could have caused this crack but now I'm lost.  I don't turn it that hard, 6500 and through the traps at 6700.  Maybe it's time to just start over with a stroked 390.

[RICK LAKE]

cgmach1 CG if this motor is for 1/4 racing only, then fill the block to start from the bottom to  1" below the water pump holes in the block. I would also have the block checked for trueness, and mag for other cracks. Do you have any pictures of the problem you can post. If the sleeved cracked again in the same spot, there is a problem with the boring that was done. I like Jay have never had a problem with sleeves in a block if they where machined right. Is the crack vertical or horizontal?? If the block was bored for the sleeves, I would be very surprise that the bores didn't go into a water jacket or cause a thin spot in the jacket and leak coolant or water into the block. I would start with another machinist to check out the block. We can sit here and guestamate possible problem and solutions. If you can find another FE block cheap, you are still looking at some machine work to get this one ready for racing. If you fill the block with block Crete, you do 1 side at a time. Use a sander for vibrating the Crete to remove air bubbles. give 24 hours to setup then do other side. I have seen and had problems trying to do both sides within a couple of hours of each other. Hoping for pictures. Rick L.

[jayb]

I think I'd be looking at a thicker sleeve from a different material.  Darton makes sleeves from different grades of iron, and some are stronger than others.  If you went with the .125" thick sleeve, you will have water all around the sleeve, and that may be better in your case.  I wonder if the single spot of water on your sleeve caused some kind of a thermal shock effect to cause the crack.

I think if it was me I'd try to save the block, go to the thicker sleeve and then fill it with hard block.  Also trying a different machinist as Rick suggests is probably a good idea, just in case there was a problem at the first shop.  Good luck with the repair, and let us know how it works out.

[cgmach1]

Rick, I don't have any pictures right now and the block is at the shop.  It is a vertical crack about 3/4 down from the deck and if I remember right it is about 1 1/2 " from the bottom of the bore.  I think I'll try what you and Jay suggest and install a.125 sleeve and fill the block to the pump holes.  Any particular brand of block fill work better then others?  I'll give this block one more chance if not I will have to see if I can get a 445 to run as good as this one.