Sonic Testing a 440 Block

[Chatt69chgr]

I have a 77 440 block that I have discovered was bored 40 thousands over (stamped on the flat top pistons).  There was almost no ridge at the top of the cylinders.  I cleaned off what little carbon was there and easily removed the pistons with a light tap with a piece of wood.  The bores look good with no scoring, etc.  I would like to use this block for my slightly stronger than stock build (stock head--stock forged crank--CH4B intake--stock exhaust manifolds--forged pistons to give approx 9.5:1 compression ratio--Engle K56 cam).  I assume I would have to bore to 60 thousands.  From what I have read, I need to sonic check the wall thicknesses to see where I am as far as wall thickness is concerned (core shift).  My understanding is that I should be OK with a 60 overbore IF I have sufficient wall thickness (based on what I read on 440 source website).  I mentioned this to a friend of mine and he said that nobody here does that.  I have not called the shops to find out for myself.  And he said if they did, they would charge a lot of money.  Just out of curiosity, I looked up a sonic testing device and found that they run from $1200 to $3000 with a good one being available for $1600.  That didn't seem a lot to me for a shop to spend for a tool when you consider what all the other equipment costs that they typically use to perform the machine and balancing work to rebuild an engine.  Am I offbase here?  Assuming that the sonic testing should be done, what would I be looking for for minimum wall thickness?  Where in the bores should the thickness be measured.  Is there a place that would be critical?  What should this cost?  Thanks.

[Steve P.]

I am in the Tampa Bay area and ran into exactly the same thing. Every shop around here acted like I wanted to screw their daughters when asking about sonic testing.. WTF?? Wake up people.....   Some shops around here don't believe in dyno's.  It took me 2 months to find a shop that had mopar BB honing plates.... Again, WTF??

2 shops here told me they have heard of people putting their blocks on a Grey Hound Bus and sending it somewhere in North Florida just to be sonic checked.. I said to the owner of both places, (DOESN'T THAT SAY SOMETHING TO YOU)??   Hell, half of the shops down here don't have A/C and even more than that don't have CLEAN ROOMS for building motors..... 

If I had the money..............

[firefighter3931]

Chatt, the most critical dimension is the wall thickness on the major thrust side....which is the passemnger side of the bore on both banks of the engine...looking at it from the front. The thicker the better but it should be around .150 after boring, inmo. 


Ron

[375instroke]

I've seen them for around $1000.  I was thinking of getting one myself so I could check out a block before buying it.  Beyond the price of the device itself, the shops that use it charge per spot tested, so the more places they test, the higher the price they charge.  I think a good sample would be at 90 degree increments around the bore just below the deck, the middle, and just above where the water jacket starts on each cylinder.  If there is no ridge at the top of the cylinders, they may not need to be bored over, just honed, especially if it was set up with cast pistons and you are going to forged.  Another thing, even though the shops you found don't do sonic testing, and you may not need it, a shop that does do it regularly may reflect the quality of work they do and the demands of their clients.

[Chatt69chgr]

Thanks for the replies gentlemen.  I called what is considered the best shop in my area and turns out that they do sonic testing.  He said they charge $80 to do the whole engine.  I plan on taking the block down there and getting it done.  I will report back what I the results are.  Thanks.