Bad machinist? (Proper piston-to-wall clearance)

[phunny]

Wow... I've been following this and hoping everything would work out. Looks like you're in good hands now and the fact that they are willing to document everything is golden. You'll easily get your money back and then some. Just keep us up to date man.

 

[laserspeeddemon]

This just in latest from the new machine shop.

Hey Sean sorry to say but the block the guy did can't be used with the pistons we will have to do the other block. 2 cylinders were 8.5 thousandths over and 2 cylinders were 9 thousandths over. Give me a call or email with any questions. I'm gonna take pics of each cylinder with the guage for proof for ya

So I told him NOT to bore the motor, he told me he bored it 0.040" over without asking me and the new machine shop told me that he actually bored it 0.090" over

In a few minutes he replies with this.

Hey I just took the pics and they are all more like 10 thousandths over. We are gonna strip the other block and bake it for a day to clean it off since it's got oxidation all over it

That's right he bored it 0.100" over. Since the biggest pistons sold are 0.060" (and are not recommended to be used with sonic testing the block) this block is a paper weight.

Sure, you could stuff 0.080" pistons in there from a 4G64, but that is VERY risky, either way. 0.095" and 0.100" make this block toast.

 

[JacksonAuto]

9 thousandths is .009 which is fine. Not .090".

But .009" over what? If it's .009" over standard you're fine. If it's .009 over .060 then you're screwed.

 

[4g63monstr]

Wow... that is seriously shoddy quality. Sorry to hear about your bad luck man. Hope everything eventually works out for you.

 

[laserspeeddemon]

9 thousandths is .009 which is fine. Not .090".

But .009" over what? If it's .009" over standard you're fine. If it's .009 over .060 then you're screwed.

Ah, I misunderstood.... stupid numbers.

The pistons are 0.040." He bored it 0.009 over that. The new machine shop has the pistons already, but they also have a spare block.

Regardless, I didn't want to bore my motor 0.060" When I gave it to the first machinist it was bored 0.020" there was no sense in boring it straight to 0.060" It's just sloppy work, any way you look at it. And like I mentioned before. I told him not to do ANYTHING without calling me first.

 

[laserspeeddemon]

You know I realized I updated a different thread and I started a new one, but never really updated this one. So I figured I'd throw up an update post in this thread.

All work you see has been done by CNC Engine Dynamics in Winchester Virginia.

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[laserspeeddemon]

And more:

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[phunny]

Looks awesome

 

[keltalon]

Look like you got yourself one heck of a machine job

 

[Tyeler18]

I see dirt in your freeze plugs!

 

[Tfitch90]

Very nice i see u stay in Fredericksburg, i used to live there. I get in my manly pistons tomorrow but i went with the eagle rods. I have to do machine work i should bring my block all the way down there.

 

[Boostinsideways]

Damn dude, your should take that first guy to court, at least get his business license revoked.

 

[BogusSVO]

Looks like CNC did a damn fine job for you.

The way I was taught to block work was simple... rough bore the block appox .003 Under the finished size you want, order the pistons, recive pistons, mic pistons, then hone the block to the finished size.

I will work with a 4 inch bore for easy math..... std bore 4.000 + .030 over bore = 4.030 finished bore

so the block should be bored to 4.027, now the .030 over pistons are ordered, then checked (most pistons come with the clearance machined into the pistons ) Now when the block is honed there is enough metal left to set the clearace (PTW) and the proper grit stones can be used to get the proper finish for the rings used.

the first machinist you used may be used to dealing with domestic blocks for street use, you can be fairly sloppy with them and still turn out ok, an extra .001-.002 over the proper finished size and cheap cast pistons and cast iron rings will still run halfway decent and be quite.

Also due to the specs come up with, I bet he is not used to dealing in a metric engine and got the convertion form metric to SAE and back screwed up.

some shops should just pass on jobs they do not know, just as some people should not own tools.....

 

[laserspeeddemon]

Very nice i see u stay in Fredericksburg, i used to live there. I get in my manly pistons tomorrow but i went with the eagle rods. I have to do machine work i should bring my block all the way down there.

I would strongly recommend it.

 

[Whitelightnin01]

What kinda $ did you shell out for your machine work, if you don't mind me asking that is.

 

[laserspeeddemon]

I think the finally bill came out to $1600.

 

[Boostinsideways]

Geez man. I just saw the pics of that head. My head is cleaner, and its the original 144k miles head. Only this I had done to it were New lifters and new valve seals.

 

[g4ebguy90]

$1600 Not bad at all. As for the head, He didn't even take a 3M pad and clean up the ports were the gaskets go . What a d-bag.