If your measurements are accurate (bore finished at .006" undersize), I would find a different block AND machinist.

tom

 

ANY shop with a Sunnen CK-10 or CV 616 and even a mediocre machinest, can straighten up the bores and remove the .006 material..

 

i guess you will have to take his word on it if you want to use it, good luck anyway

 

The low spot is about 4 " at the very bottom of the cylinder the pics make it look worse because of the glare,and there was actually more to be took off of the other cylinders,but even the cylinders that were bored and cleaned up good didn't measure a 4.185,he said they were just a little over 40,and he said he would bore it,and I told him I need to know that I am not going to put a piston through the wall a super chevy next month,but I trust this guy.When I brought the block in he measured every cylinder,and figured out what the other machine shop did.I will never take anything else back to that place,and I found out that is not the first time something like this has happen,but I learn from my mistakes,I hope it will be all right. thanks for everyone reply,this is the best sight on the internent.

 

ANY shop with a Sunnen CK-10 or CV 616 and even a mediocre machinest, can straighten up the bores and remove the .006 material..[/QUOTE
i sure hope so but it said he could make it back straight,how could they not take the right amount off,and why didn't they stop on the first one they found?The ones that didn't clean up are on the same side.I wish I new exactly what they were doing ,and why they didn't see that they didn't hardly take any off the block.

 

It would be a standard way to bore a block. Bore it to within a few thousands then rough hone then finish hone. I would have my doubts that the bore job is straight. You will know when you start to put it together. It should be nice a free if everything is straight and true. But will be hard to turn if it is not. Good luck with your build.

 

ANY shop with a Sunnen CK-10 or CV 616 and even a mediocre machinest, can straighten up the bores and remove the .006 material..

But honeing with either of these machines will not make the cylinders square to the crank. Only boring with a Rottler type machine that aligns off the mains can square the bores.

 

But honeing with either of these machines will not make the cylinders square to the crank. Only boring with a Rottler type machine that aligns off the mains can square the bores.

You aren't going to be able to index the bores with only .006" of stock removal. Only a hone will do the job. If he has .006" to get to final size, then just a honing operation will make the block quite functional if it cleans the bore up.


I've used Rottler airfloat bars, but I also used Kwik Way portable bars for years and just because you use a portable type bar or you use a power hone is not going to make an engine "sticky". If the bore is shifted slightly fore or aft or even a couple of thousands one way or the other, it's still going to turn over freely. The piston pins provide the necessary slack.


Brian

 

I believe he said he was going to bore the block,and I'm pretty sure he is going to hone it.If it does clean up,and it was bored crooked,how will i tell if it all cleans up?Will the piston wobble in the cylinder?If I take a dial bore gauge,and it reads true(4.185)It still really want tell me if the cylinder is straight will it,but I'm sure I'll find out that first pass.He said he was going to try his hardest to get it back straight I hope he can.

 

You aren't going to be able to index the bores with only .006" of stock removal. Only a hone will do the job. If he has .006" to get to final size, then just a honing operation will make the block quite functional if it cleans the bore up.


I've used Rottler airfloat bars, but I also used Kwik Way portable bars for years and just because you use a portable type bar or you use a power hone is not going to make an engine "sticky". If the bore is shifted slightly fore or aft or even a couple of thousands one way or the other, it's still going to turn over freely. The piston pins provide the necessary slack.


Brian

He said he was going to bore it with a rottler machine ,and he show me a bar that went from the front main to the rear main,and showed me the difference on the rear main on a 400,something about it was smaller

 

A stock 400 block has the same rear main seal size as a 350. However, the main bearings are larger. The block will rest on the bar crooked, and screw up your set up, this is what your machinist is talking about.

If your block is now 4.179, and your need to be at 4.185, then I definitely wouldn't be running a boring tool back in the cylinder, it's too risky, and even if you get it to clean the bore up, you don't have enough stock left to properly hone the block, which is necessary to removed the tooling marks left by the boring bar.


My advice is to have the block power honed to size. I would put some roughing stones in it and work at achieving a straight and round hole, then If I'm able to do that, I would finish it to size with the proper grit (280) for street stuff or 400 grit for race type rings.


Brian

 

He said he was going to bore it with a rottler machine ,and he show me a bar that went from the front main to the rear main,and showed me the difference on the rear main on a 400,something about it was smaller

If your bores are now 4.179, you are only taking out .006" to be to a finished .060" over bore.

.006" total is only .003" per side. .003" is about the thickness of a hair on some people's heads (not mine), my hairs are now fine shim stock.

What I'm trying to tell you that the only way to correct your block is to just hone it only.

 

If your new machinist wants to find out if its square have him make a zero pass or actually slightly less. He could keep bit oriented on opposite side of the shadow then feed it down, stop, manually turn spindle making sure cutter doesnt hit, keep doing that till at bottom. I doubt it will get very far down cylinder before it starts to hit on the side that didnt clean up.
The other guy bored it to .060 and it didnt clean on one side so the other side of cylinder got cut .060 or slightly more. Thats really crooked!
All the honing in the world isnt going make it straight again but it might be round. And if its that far off and you try to run it the rod bearings will be side loaded so bad it wont last one mile.

 

if you intend to use it do yourself a favor and have it sonic checked.

 

I'm a machinist (not automotive) and would have no problems boring an additional .006" diameter out of an existing hole. .0006" would be tougher, but doable. Anyway, this is beside the point.

Quote "I trust this guy".

That's the critical part. He sounds like he knows what he is talking about. He's analysed the problem, quantified it, identified a fix, and most importantly, says he can do it. You're understandably nervous because the first guy screwed it up, your knowledge and equipment isn't adequate to fix it yourself, and while the second machinist seems to know what he's talking about, there's still the possibility that he may not be able to save it and you'll lose your investment.

I suggest you tell him all this even though he probably already knows it, and get him to say, again, that he can fix it and get to the nitty gritty of how much it'll cost you if he CAN'T save it. Being very clear about all this is good for you and good for him, too. If the conversation goes well, hire him and give him a bonus when the job turns out well. A sixpack, a picture of the finished car, cash, whatever- anything that lets him know that you remember him and appreciate his saving your bacon. You'll have a friend and an excellent machinist for life.

Neil

 

I'm a machinist (not automotive) and would have no problems boring an additional .006" diameter out of an existing hole. .0006" would be tougher, but doable. Anyway, this is beside the point.

There is no doubt that you could set up and bore the hole. However, you have to leave enough material to hone the cylinder.

And yes, I would have it sonic checked.


I would make the guy that screwed this up get me another block. That is EXACTLY what I would do.

I would take it to court. He ruined a four hundred dollar core.


Brian

 

I called them today,and the guy who does the block had someone sick in the family,but they put it in the vat,and checked the block for any other damage.He will be there tomorrow,and he is suppose to finish first thing in the morning,and as soon as the block is complete I am going back to the first machine shop,and going to get the money back I paid him,and let him know that you guys and the new machinist let me know exactly what he did,and should make good on it,and If I wouldn't have posted this,and with everyones info the block would still be up there,and I would have never known the problem,and would have believed what he told me so everyone who posted I really appreciate it,and learned alot,This sight is very helpful.