What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Was my 350 block over bored incorrectly?

S

smier

1/2 ton status
Joined
Jan 15, 2009
Posts
734
Reaction score
0
Location
Eastern, Pa
Hey guys, I need some quick advice. I had a 350 block that I had taken to a highly recommended local machine shop and had it bored to .040 over and clearanced for a stroker crank, etc... I spent a lot of money to have the block done, and I expected it to be done right... Fast forward 5 years, I've sold all my project vehicles and no longer have any use for this block. I sell it on craigslist for half of what the machine work cost me, and only slightly more than what a core charge for a motor in need of a rebuild and machine work would cost.
Tonight I get a call from the buyer, he started measuring the bores getting ready to start working on this engine, and he's telling me that the bores are off... They are coming in between .045 to .047, and he is upset. Says he wouldn't have bought it if he had realized it. So, is this acceptable? Does It need redone? Did I sell this guy a dud? What should I do? I'm as upset as he is, and I'm not out to rip anyone off. Let me know what you guys think, and what I should do if anything. Thanks!
 
Last edited:
I'd like to see how he's measuring the bores.
Joe blow in his garage probably isn't going to be all that accurate even if you handed him a nice set of micrometers and an inside mic.

I'd like to be tough and say a deal's a deal but I too have a hard time when I sell stuff even to a stranger if it isn't perfect or they feel they were misled. I always try to give them everything I know about whatever I'm selling. That being said if he's already paid and took the block I'd say the deal is done and maybe he'll pull the heads and measure the bores before he buys an engine off craigslist next time.
 
I should add that it's just a bare block, no heads or rotating assembly. He was a cool older guy that seemed to know his stuff. I don't really think he's trying to con me, and hasn't asked for anything more than clarification of specifics on the block so far. I can't say I have any reason to doubt him, and unfortunately I never checked the cylinder bores myself to verify. I just went off of what the machine shop told me and what my receipt said...
 
The other problem is the buyer is almost 2 hours away from me, so it's not like we could meet up and check it out. It's just the bare block, it was never even assembled after the machine work was done.
 
So do you guys think its more likely he is measuring it incorrectly, or that the bore size is off? If it is off as much as he says, is it usable as is, or does it need to be bored out again to say .060 over? I appreciate the input, I'm just trying to have my ducks in a row if this goes where I think it's going.
 
Last edited:
smier said:
So do you guys think its more likely he is measuring it incorrectly, or that the bore size is off? If it is off as much as he says, is it usable as is, or does it need to be bored out again to say .60 over? I appreciate the input, I'm just trying to have my ducks in a row if this goes where I think it's going.
Click to expand...

It's .060", not .600" which again is why I'm thinking it's a measuring error. You can't measure this stuff with a tape measure. :D
 
First off your decimal designation is wrong...60 over would be .060 not .60
Ideally the bore shouldn't be finished to size until pistons are bought for the project.
With that, I would make him the offer of having it checked by a proficient machine shop that has a cylinder bore Mic. that is what the machinist should have used to bore it .040. If its not, I would say your selling a bad part, although unintentional, its still not what you said it was....if it measures .040 then you should both be happy.

UNLESS, it was overbored by .006 or .007 for the pistons the machinist used to base the overbore on to begin with....as mentioned piston size should be measured before final bore finish is completed, and that finish can depend on what type of ring is being used.
 
Sorry guys, heat of the moment typo, I'm pretty pissed that this thing might be that screwed up, because it means I was ripped off... I spoke with our fleet manager at work this morning, and he says if its that far off, then in his mind its junk. He said even though you can take it out to .060 over, he personally wouldn't. Let's assume the buyer is measuring it correctly. He paid me $300 for the block, a good quality engine stand, and my cam bearing puller. Part of me feels like I already took a huge loss, but that was my choice to unload everything.
I don't really want to get into a battle with the guy, I just don't have the time in life right now. He is almost two hours away from me, which makes it not worth my time to go out and investigate it further. I've moved since I had the machine work done, I know I have a receipt, but not sure where it would be anymore. It's been 4 or 5 years since the block was worked on, I'm not sure if there is anything I can do on that end, plus I'm probably beat unless I can come up with a receipt.
I guess I'll wait and see what he wants to do. I guess I could make him bring everything back to me if he wants his money back, then I could check it out for myself... and then scrap the damn thing if its wrong. You try and unload stuff cheap, and its still a headache. Thanks for your input guys, I'm just trying to do the right thing.
 
You have your original paperwork from the machine shop, then he will need to take it up with the machine shop. You have no responsibility for something, when you gave the specs that were given to you. In my eyes, it's on the machine shops shoulders.
 
1) Your average idiot is NOT to be trusted with motor measurements.
2) If you had NO prior knowledge of the block being 'wrong', it's not your fault.
3) "ALL sales are final!", learn it, live it, love it.
 
I second that his measurements are probably off...or he may be trying to beat you down knowing it isn't worth your hassle. Tell him to bring it back and you'll give him a 1/2 refund of fuel for the drive + the $$$ for the parts.
 
I'm still waiting for a confirmation from the machine shop, but the forged pistons we were going to use called for a minimum .005" clearance. So the buyer may be correctly measuring AND it may be correctly bored allowing for the proper piston to cylinder wall clearance! This certainly would seem to explain the issue.:woot:
 
exactly....as I mentioned, the pistons are critical to proper cylinder bore/honing....the rings are important to know for the proper cylinder finish to allow proper seating.
If the pistons are 4.040, then 4.045 would be proper cylinder final sizing after the last .005 is taken with the cylinder honing process.
A matter of .046-.047 could be a discrepancy in measuring technique or measuring equipment compared to the machinists' equipment.
 
you don't measure a cylinder bore with an inside mic, or calipers. Chances of him having the correct mic is slim. Just sayin.


bought as is, where is. No warrantee expressed or implied.
 
I agree with what has been said I bet ya he is using a snap gauge and calipers.

He really needs a bore gauge. If he doesn't have a bore gauge then there is no way I would trust his measurements.

Being an older guy I bet his response to that will be I been doing it this way for years, never failed me before
 
DEMON44 said:
you don't measure a cylinder bore with an inside mic.
Click to expand...

Since I'm the one that mentioned this I feel the need to say I agree, we don't use that setup when boring blocks but it can be done accurately that way if you know what you're doing.
I bore a lot of pulleys, sprockets and gears for bearings which generally need .0005" to .001" press and I do it all with an inside mic so measuring a cylinder bore accurately enough for this argument wouldn't be difficult using the same tools.
 
DEMON44 said:
you don't measure a cylinder bore with an inside mic, or calipers. Chances of him having the correct mic is slim. Just sayin.


bought as is, where is. No warrantee expressed or implied.
Click to expand...

Correct. It's the buyers responsibility to check and make sure the parts are what he wants and in good shape before he hands the money over. Not the sellers.
 
You must log in or register to reply here.

Latest Posts

Top Bottom