340 damage dilemma

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frozenfish

frozenfish

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I'm trying to rebuild my 340 for weekend cruiser but need to make a decision on whether to scrap the block or not. Hopefully somebody with more Mopar engine building experience can advise. The block was damaged from wrist pin so I had it bored .060 and sonic checked. Results were not good, particularly on #4 which was already sleeved. When asked if he would dump about $2K in parts into the block with the measurements taken, the machinist's answer was a quick "No". Also needs new crank, pistons, and heads.
I already have about $950 in machine work, cleaning, and inspections. He can sleeve the whole thing and bore it back to standard for an additional $800 and not charge for the first bore already done. I checked around and found an '82 360 short block with 103K miles for $325. To get that cleaned, inspected, and bored to .030 would be another $500 or so.
Financially, seems to make sense to just sleeve what I have because you never know what surprises may be in the short block.
Here are pics of the measurements from the machinist's report, left and right. Let me know what you think.

20191115_161351.jpg


20191115_160716.jpg
 
Normally a sonic tester will only measure sleeve thickness, not the block behind it. So you're probably in better shape than you think.
 
What I don't understand why the block went .060 for a wrist pin gouge?

That should have been a sleeve and run it. No need to go .060 over for that.
 
frozenfish said:
Block was already at .030. wrist pin damage was .009. Decided to bore to .060.
Click to expand...
Live n learn, sleeve only the bad cyl and bore as little as possible next time.
800 is the going rate for 8 sleeves.
My opinion is... only if you're in love with that 340, otherwise buy a crank and a 360 block that will go .020 over.
 
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RustyRatRod said:
Normally a sonic tester will only measure sleeve thickness, not the block behind it. So you're probably in better shape than you think.
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That is not correct, if the sleeve and the original bore are in very close contact with each other as they should be for a press fit, the sonic wave will penetrate both and report back the total thickness. The only way only the sleeve would be measured would be if there was a cast iron sleeve in an aluminum block, with the tester calibrated to iron the iron thickness would be reported.
 
my68barracuda said:
That is not correct, if the sleeve and the original bore are in very close contact with each other as they should be for a press fit, the sonic wave will penetrate both and report back the total thickness. The only way only the sleeve would be measured would be if there was a cast iron sleeve in an aluminum block, with the tester calibrated to iron the iron thickness would be reported.
Click to expand...

Well, I've seen it first hand on several sleeved blocks. I don't know what to tell you. I wouldn't have said it had I not experienced it. Two of the blocks were aluminum with factory iron sleeves, so they were done at the factory. I've even sonic tested two Ford 8N blocks for the heck of it. They have drop in sleeves.
 
RustyRatRod said:
Well, I've seen it first hand on several sleeved blocks. I don't know what to tell you. I wouldn't have said it had I not experienced it. Two of the blocks were aluminum with factory iron sleeves, so they were done at the factory. I've even sonic tested two Ford 8N blocks for the heck of it. They have drop in sleeves.
Click to expand...
Like I said in the post, if there is a different metal, iron sleeve in an aluminum block, and the tester was calibrated to iron, it would report the iron sleeve thickness.
If both the sleeve and the block were cast iron, there would need to be a gap between the sleeve and the block bore for the sonic testor to only see the sleeve. And if it was a drop in sleeve, there would be a gap, so yes I agree with you on that.
 
my68barracuda said:
Like I said in the post, if there is a different metal, iron sleeve in an aluminum block, and the tester was calibrated to iron, it would report the iron sleeve thickness.
If both the sleeve and the block were cast iron, there would need to be a gap between the sleeve and the block bore for the sonic testor to only see the sleeve.
Click to expand...

I understand what you're saying and I'm not arguing or disagreeing. I'm simply stating what I've seen. Both with cast iron and aluminum.
 
10-4, if I click on your location while using Google Chrome this is what come up in the sidebar.
AF1QipO3YuCO_x6zlQF0Lr_yam75mPUlQkqXZJm8v4sK=w408-h272-k-no.jpg
I apologize, I couldn't help myself. But I understand all too well about being on the fence with which direction to go if you have that much already in it. Too much invested to pull the plug but more left to go, too.
 
So I double checked my numbers and I was off. If I walk away from this block right now, I'm out about $615. If I press on with the repair, the short block will cost me $2975 and still end up with 340 cubes. If I take the 360 short block, have it cleaned, inspected, and bored to .020 or .030 over, it will cost about $1700, provided the crank is still usable. Comparing 340 short block to 360 short block, the 360 seems to make better sense. Maybe a better decision could have been made prior to this but it doesn't matter now. It is what it is, moving past why this or that wasn't done. Lesson learned.
 
Garrett Ellison said:
10-4, if I click on your location while using Google Chrome this is what come up in the sidebar.View attachment 1715423838 I apologize, I couldn't help myself. But I understand all too well about being on the fence with which direction to go if you have that much already in it. Too much invested to pull the plug but more left to go, too.
Click to expand...
Ha ha! I pass by Santa Claus house all the time! Lol!
 
Is it the matching # engine for your car? If not, post the VIN data from the block here. You could match someone up with the original block for their car. In which case they may not care if it cost more than usual.
 
harrisonm said:
Is it the matching # engine for your car? If not, post the VIN data from the block here. You could match someone up with the original block for their car. In which case they may not care if it cost more than usual.
Click to expand...
Good idea! Is there a specific location to post it or just right here? Will have to wait until Monday when I make it back to town.
 
The major thrust surfaces are all an eighth inch or better at the top except for number four. If nothing else, that block could be grouted to the bottom of the water inlets and used for a moderate power drag race engine if someone doesn't need it for a restoration. The cylinder doesn't have to be as thick if it's only got water around the first inch, and sleeves are often times closer to being cast steel than cast iron.
 
I would never sleeve all 8 cyls of a cast block and plan on making any power out of it.
 
This block already has a sleeved cylinder will need to go 60 over and the sonic test was not good..and your thinking of stroking it..good luck,I see..BOOM in the future!!!
 
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