ok after reading the recent post on sonic numbers im starting to get freaked out, is my motor a ticking timebomb? see attached

where it is marked THIN is a not as critical area , is the motor already built ? If so what HP level ?

But it's getting thin for the next overbore ?

The major thrust numbers on not horrible. In fact I would say they are fairly typical of many of the stock block race Mopars out there.

already built and been running, its 1/2 filled if that makes any difference, the other post had way thicker numbers and was talk about the block being junk, HP is high fives according to the ets/weight calcs

I wouldn't be afraid to use that block on a 600 or under HP motor with no power adders I built a stroker 418 C.I.340 block (made 525 HP on CA pump gas on a DTS engine dyno 6 or 7 yrs agao)with similar sonic numbers and the owner squeezes it with 250 HP NOS shot, he has ran 9.90 in a 3300 lb car with it that way for quiet a while now

thanks guys just got spooked and since im no wiz with motors just thought id check, i can sleep tonite, a R block is in the works for the next build though

Was that the finished bores or was it still waiting
to be bored... I see it said 4.030 and then it was
sonic checked... usually you sonic check it to find out
if it can be bored

All the thrust sides of the bore are decent enough considering its already bored to size. Sides of the bore (front and back as the engine sits in the car) don't take nearly as much abuse so you can get away with less.

Its together, run it!

What year is the block? Not that I think it matters, just for those who think it does. The thrust numbers are fairly equal and that's a good thing. Since you have plans for an R block, why don't you ramp up the power 'till she blows so we can all find out?

Remember a sleeve is just .125 thick and when put back in a damaged bore thats all you have--installed right they work so....... I have never seen a stock block that was not thin somewhere--run it don't worry IMO

IMO you're getting close, but you have a 1/2 fill. Just as important as minimums thickness is where that thickness is. A good sonic test should record numbers around an inch apart up each surface, plus the minimum thickness. You've got a 1/2 fill. If the minimum is above the fill but still near the center of the stroke you may only have lost power from wall deflection. If it's below the fill line you're fine. I use .150 as minimum for my engines but I dont hit your power range typically. If this was just going together I'd say get another block for near 600hp. You should be abel to see how good things stay by doing leakdowns periodically. If you see a trend of greater leakage, figure the bores may be flexing and look for the signs of friction or lost ring seal.

thanks guys i know it not the ideal block but we will see how long it lasts until the next build