[kidvid]

I just picked up my 302 Ford block from the machine shop where it was bored and honed to .040
over. It went in .032 over. On close insepection
I noticed the #1 piston bore had visible scratches going around the cylinder walls. I ran my finger nail over them and it would catch on them. There are some at the top and bottom of the cylinder. The rest of the cylinders are great.

I called the machinist and he told me that the cylinders were honed only because "you can't set up the boring machine to bore if it was already .032 over". And that it could be scrathches the hone was not able to get out. I have to load it back in my truck and take it back to him to see. I feel they should have mentioned something before I gave them my Visa card.

Am I having my chain yanked by thus guy? or is there some truth to what he says? Does he really expect me to put new pistons in a cylinder with scratches you can feel? What can be done if the scratches weren't able to honed out?

I know these are a lot of questions but I need some amunition when I go back tomorrow. Any advice would be greatly appreciated.

[johnnymopar]

did you fully inspect your motor before it went into the shop? If he was honest and reputable, he should have told you about the scratches immediately. Most places contact a customer right away if something unplanned arises. Since he didn't do this, i am led to believe that it is his fault. Also, i can't believe that he would just ignore this and want to go to the next step. Any good machinist would remedy this situation before going any further. I guess you could either try to get him to get you a new block, or you could rebore to .060 over. Of course i would insist that he pay for this. And don't give up until you're satisfied.

JB

[78 monte]

I once had a 350block bored .030 by a local shop.Looked nice measured .031 on the top of the cylinder and somthing like .026 at the bottom.Didn't find it till I measured it months later.
Anway on your motor did you notice these scratches befor you gave him the block.Maybe they were to deep to hone out????Which I think would require a sleeve or next size overbore.Don't really know what to tell ya.Have him look at it.I know at my machine shop they would call me if any problem or extra work arrose.

[ September 06, 2002: Message edited by: 78 monte ]</p>

[4 Jaw Chuck]

A boring machine can take as little as 0.005" of an inch out of a bore accurately, the reason he didn't bore it is because honing is just as fast or faster. I actually prefer to hone to size with coarse grit stones, I find that the time is the same if you factor in the setup and cleanup (you can't have little machining chips in the honing oil). Unless you bought the pistons already I can't see what the big deal is, hone/bore to 0.060". The shop should do this for free, inspection of your block during the procedure is part of their responsibility unless you told them 0.040" specifically. A scratched bore is not acceptable and they damn well know it, somebody dropped the ball over there.

[kidvid]

Thanks guys for your response. I thoroughly went over the block and micd the cylinders before to see what I had. The most noticeable marks ran verticle, up and down the cylinder walls. Those are all gone now. I don't remember seeing anything deep enough to be left over after a bore and hone. The scratches would have had to been over .008 deep to show up at .040 over. That seems like an awfully deep scratch for me not to notice.

[HotRodMan]

It sounds like it might be difficult to lay the blame on the machine shop. I would call the shop back and ask to speak to the manager in a calm tone of voice and see if he will do anything for you. If not I would go to another machine shop. They should have never given the block back to you in this condition without saying something to you about it. If you put your piston and rings in the engine the way it is now, I guarantee you will have problems with it, so have that fixed before you go any further. If the scratches are too deep to hone out, you will have to have another sleeve put in.

I learned a long time ago to take an engraver and mark everything you give the machine shop. Sometimes they will make an honest mistake and give you back somone elses parts, and sometimes they will tell you they installed new when they left your old parts in. I had this happen one time with valve springs. They told me they installed new valve springs, and I asked them if they were new how come each one had my initials engraved on the outside of the spring?

[kidvid]

I just finished going over the cylinder in question with a lght and magnifing glass. The scratches follow the pattern of the honing stones.
Its clear as day that the scratches were not from any previous condition but from the honing. I also spoke with someone who has had dealings with this machine shop and he says they are not very friendly when it comes to fixing mistakes, or if they will.

I'm also concerned that if I go to .060 over I'll encounter heating and other problems down the road. I have no experience with sleeves as far as pro and cons.

I appreciate everyones advice, thanks.

[4 Jaw Chuck]

Are the scratches at the bottom of the cylinder? If they are then the rings will never go over them and you don't need to worry. A quick going over with a ball hone can smooth them over and give you a nice plateaued finish which is a nice finishing procedure anyway. Sounds like they are the inevitable scratches that occur when the hone is withdrawn from the bore if the tension is not relieved on the stones sufficiently. They are probably not that deep if they were caused by the stones pulling out.

[78 monte]

If the block needs repair and the shop gives you attitude.Might I suggest discussing it with other PAYING customers infront of shop management.Worked for me at a local Music store that sold me gutted P.A. Horns.

[kidvid]

Unfortunitly there are scratches at the top and bottom. I've never heard of a ball hone. Would it get rid of the top scratches with out changing the bore size? They are honing marks that I feel were made by inexperience or being careless.

[4 Jaw Chuck]

Have a look at <a href="http://www.brushresearch.com/Index.cfm?FuseAction=TechnicalBooklets" target="_blank">this page.</a>

Download the PDF's and read what has been discovered about the use of flexhones (ball hone) to achieve a plateaued bore. Every japanese manufacturer has been doing this for years as part of their normal machining operations, we all know the reputation their engines have. These things are dirt cheap too, 30 bucks for one to fit your bore is typical.

[kidvid]

I returned the block to the machinist this morning. They admitted that it was their fault. That it must have been the first bore honed and somthing must have gotten caught on the stones. He said he would fix it by seeing if there was "a couple of thenths" he could pull out. I told him I didn't want to bore out any further and he agreed he did not want to go that route.

Now I'm wondering, these "tenths" he's talking about. Will they effect the piston clearence? What are the consequences of to much gap?

[ September 07, 2002: Message edited by: kidvid ]</p>

[4 Jaw Chuck]

He is going to oversize the bores to get the scratches out, machinist talk/BS. How much oversize do you think those scratches will take the bore? Anything more than a 0.001" would be too much in my opinion, do you have your pistons yet?

[woodz428]

The point your missing is that 040 in a 302 Ford is too much to begin with, unless you're running one of the high dollar FRRP(SVO) blocks. If not,I'd get another one and start over. 030 is about the maximum for a reliable small block Ford. If you got off the shelf pistons you should be able to get an exchange for the smaller one with a small re-stocking fee, then if the machinist is reputable you should be able to have the new block rebored for no charge. It sounds like sloppy work and if they won't make it good I'd look elsewhere.

[kidvid]

I appreciate everyones input very much.

Fortunitly I have not bought the repuild kit yet. I was waitung for all machine work to bo done first.

The machinist may be able to get the scratches out at .001" maybe .002". This whole situation has really messed things up with my plans to blue
print this engine. No matter which way I turn I'm screwed. If it wasn't for you guys helping me out I would totally be lost. Thanks.