Cylinder wall thickness minimums

[Bruce J]

I've spent $700 on two blocks now and both are crap. One a 76 400, the other a 73 440. Both have spots less then .100. Is it impossible to find a good block? I found someone that has some 230 400 blocks, are they any better in wall consistency. I'm at a loss, I can't just keep throw money in the trash.

 

[Photon440]

How many thin spots were found? A single cylinder, or all over?

 

[theman440]

It's not impossible. I've got over $700 in two blocks myself. I got lucky and the second one has thick walls. The first one had less that .100 in a couple spots like yours. They are out there and aftermarket blocks are hard to come by also - good luck.

 

[66Satellite47]

Based on my experience with sonic checking, the wall thickness varies considerably from block to block, even within the same casting number, on both 400 & 440 blocks.

 

[PurpleBeeper]

Dang.... I'm building a new motor and the block hasn't been done/checked yet. I will probably sleeve a hole if I have to, maybe you should too? I think it's about $100/hole, but you save the block.

 

[IQ52]

I've got eight 440 blocks/engines here I've paid $200-$700 for, plus $100 each for sonic checking, that I cannot use for anything but a stock or mild performance build. It's called life.

 

[IQ52]

Dang.... I'm building a new motor and the block hasn't been done/checked yet. I will probably sleeve a hole if I have to, maybe you should too? I think it's about $100/hole, but you save the block.

I wish it actually worked that way.

 

[1967coronet440]

Went through 2 when building my 505, paid 650 for both another 200 sonic checking

 

[Photon440]

I wish it actually worked that way.

Is sleeving not a viable option? I haven't used it but others have, and I don't know the pros and cons of it all.

 

[Bruce J]

I'm glad not only one, I don't feel so bad at least. I have a 69 440 that had corrosion in one cly, maybe I could sleeve it if the rest checks out.

 

[moper]

If the testing was done properly, you can tell if the cores shifted, or it's a rust pit, etc. I've failed a couple blocks for the cores being shifted, and it was cheaper to find another block than sleeve all four on a side, or relocate the bores to offset them. If there are 2-3 that need them just have it sleeved. Done properly they will be stronger than any factory cast cylinder.

The myths about the early 230 blocks are just myths. As are most of the "thick wall" claims. Mopar's casting quality sucked, its just that simple.

Edit: if the thin areas are in the pin axis, I'd call them fine as long as the major and minor thrusts are over .150" and the power level is under 600hp. You'll crack the main webbing before the walls really show a problem.

 

[IQ52]

Is sleeving not a viable option? I haven't used it but others have, and I don't know the pros and cons of it all.

I personally would not use a sleeve to fix a thin cylinder wall. I use them to repair a damaged or oversize cylinder wall.

 

[Photon440]

I personally would not use a sleeve to fix a thin cylinder wall. I use them to repair a damaged or oversize cylinder wall.

What if the wall was thin BECAUSE it was oversize?

 

[not so famous bob]

What if the wall was thin BECAUSE it was oversize?

I `d use a sleeve in a heartbeat, unless the cyl is dam thin to start with. Sleeves are most of the time better quality than about any block ever made I had two in a hemi block one time because of pin circlips coming out, letting the pin drag the cyl wall. THAT WAS BEFORE SPIROLOCKS CAME ALONG.

 

[Cranky]

I've spent $700 on two blocks now and both are crap. One a 76 400, the other a 73 440. Both have spots less then .100. Is it impossible to find a good block? I found someone that has some 230 400 blocks, are they any better in wall consistency. I'm at a loss, I can't just keep throw money in the trash.

I have one 400 block left. If it doesn't test good, I'll split the cost of the test with ya. Now, do you know of a shop that's local that you trust for testing? The only guy that I trust and actually likes Mopars is City Machine and he's located in Rosenberg. I'll even do a quick hone to it to get some fresh metal showing so the test will actually be accurate.....

 

[not so famous bob]

I have one 400 block left. If it doesn't test good, I'll split the cost of the test with ya. Now, do you know of a shop that's local that you trust for testing? The only guy that I trust and actually likes Mopars is City Machine and he's located in Rosenberg. I'll even do a quick hone to it to get some fresh metal showing so the test will actually be accurate.....

I know u ain`t talkin to me, but we don`t have a machinist around here that even tests blocks, or bushes lifter bores that I know of !

 

[Challenger340]

Why not just go BUY an 'El cheapo offshore Sonic Thickness Tester ? I mean for crissakes they are only about $100 bucks.... and good enough as long as you have a "known" to calibrate against, and do so OFTEN even as you are measuring the Blocks.

I can't do THAT as a Shop obviously, I have to maintain a $1,500 Stresstel for reporting purposes....
but just saying...
I had a buddy show up with a cheapo chinese $100. deal.... we compared... be dammed if that cheap P.O.S. wasn't within a couple of thou pretty much everywhere.... but with one caveat !
He had to constantly go back on the calibration pill every few minutes, and the curvature of the probe was a little persnickity and took some continuity.
and,
use the manual function to "imput" a sound wave speed against a known thickness for the material !
Once that stuff is sorted out.... like I said, the China deal was close enough !

 

[IQ52]

What if the wall was thin BECAUSE it was oversize?

My son used to ask me 'what if' questions. One such question was, "Dad, what if we were walking along a railroad track and a rail car was upside down and there were 10,000 chipmunks all over it?"

See post #12. If it was thin because it was oversized, for me, it was too thin to begin with.

 

[Cranky]

I know u ain`t talkin to me, but we don`t have a machinist around here that even tests blocks, or bushes lifter bores that I know of !

All the local guys to me have moved or passed on. Most have passed with one being a well known Chevy drag racer that owned a shop. I only used him to do certain things and another guy to do things that he didn't like to do lol. One guy that was good with Mopars passed on and I never even heard about it until I went to his shop one one day and it was 'closed due to death in family'. Another guy that was a buddy of mine moved away but at 70 years old, he's still doing work. He loves it....but is 300 miles away now.