So the machine shop called and said they had to bore my block for .060 oversize. they said they need the pistons and rings, the problem is I don't have them yet so I need to order some asap.

which ones would be recommended for a relatively mild build? will the stock connecting rods be ok?

yes, I realize I could buy a short/long block and not have to worry about any of this, but I still want to build the engine myself as much as possible.

thanks all

 

That is a very open ended question. But a general answer would be a set of Keith Black Hypereutectic pistons in a two valve relief slight dish or the standard four valve relief. You can reuse the connecting rods but have them checked for cracks. You can also balance them yourself if you have a bit of time and want to buy a cheapo rod balancing fixture. For mild naturally aspirated engines you do not need forged pistons, but at the same thought you shouldnt get cast either.

 

What overbore is it at now? If it's currently 30-over I'd check back and see if they can clean it up at only 40-over. Stock blocks and 60-overbores can get dicey sometimes. The cylinder walls just aren't all that thick in some blocks in some cases. Aftermarket blocks, no problem. But a factory block.... I pitch them once they need more than 40-over.

Not saying there will definitely be problems but the consequences are so bad if it does you'll wish you had never laid eyes on the thing.

 

60 overbore can get a bit touchy especially with cooling it. If you want to run a mild 500 lift 10 to 1 build, any hypereutectic piston will be fine. A .060 over street rod is rare to find, most .060 motors only run a 1/4 mile at a time. Not saying it cant be done, but its kinda unusual.

 

Why would you pitch them? Unless you have a vast supply of engine blocks at your disposal or its a 400 sbc you can just have liners/sleeves installed. For mild rebuilds a .060 overbore is not an issue in a 350 block. It would only be an issue if you were wanting to use a power adder or a high revving NA motor and it that's the case you shouldn't be using a factory block anyhow. Lots of members on these boards have 360s for a street engine and have no reported issues with overheating or cracking cylinders.

 

why not just let the machine shop order you some pistons? tell them you want a 2 valve relief flat top piston, and if it's under 500hp just get some trusty KB hypereutectics..

 

because not every "machine shop" is an "engine builder".

There is a difference.

if this shop is a "builder" he would be telling the customer what the choices are and those choices would based on what the customer plans to do with the engine & more important the builder's years of experience.

The fact OP is asking us versus asking his "builder" is very odd to me.

 

thanks for the input all, keep it coming. the machine shop it at isn't a engine building shop, just a machine shop. as far as who the builder is, that would be me. and before the debate gets started, yes I could just get a crate engine but there are two reasons I don't want to go that route; 1. I want to be able to say that "I" built the engine in my car and B. I can't afford to drop several thousand dollars all at once, I can however afford to buy bits and pieces at a time. the reason the block went out first is to see what I had to work with, since its useable now I can start acquiring other parts.

 

There are ALOT of .060" over 350s on the roads; more than most would care to even guess.

Most of the el cheeepo crank em out at the lowest possible cost kind of rebuilders do that; because that way, they don't have to check ANYTHING. If it bores, it builds.

Now, how long it lasts, is not their concern; as long as the check clears and it makes it through the 30-day warranty or whatever, then all's good. Also remember, those guys put those little telltales that melt, into one of the freeze plugs, to protect themselves against marginal cooling systems.

Frankly, if I had a junk 350 block and it needed to go 060" to clean up, I'd throw it in the trash and start over. In fact, odds are, your machine shop has just such a block already prepped and ready to go; prolly take your old block in as core and charge you MAYBE $25, if that, to swap with you. It'd be worth paying a coupla extra bux though, and get a roller-ready one instead, to replace it, if it's not that already.

 

Had a bore in a .060 over block crack after one time around the block. Atypical, but definitely possible. I'd throw it in the garbage too. Factory blocks aren't designed to be taken that far out. GM says their factory blocks are only good for .030 over, and that's their new blocks with better casting technology. Then you may say oh but the older blocks are "thicker" or whatever, "high nickel" and whatnots. The one that failed me was one of those "high nickel" blocks. You wont know if the cylinder wall is too thin unless you have them sonic test it or it fails you later. Might as well just save the money and get another block. Just get another 1 pc RMS roller block and you're good to go. All the machinework and pistons are going to cost the same (a lot), might as well get something that has better odds of surviving 100k+ miles.

 

As Tibo said, just put sleeves in it if you're uncomfortable with a .060 overbore. The only reason I would trash this block for another is if I was going from a 2 piece seal, non-roller block to a 1 piece seal, roller block. Also Keith Black pistons are a nice piece. Mine are for a .030 over and give me 10:1 compression. One thing that you shouldn't forget is that the rod bushing (the side that connects to the piston wrist pin) must be honed to size if youre getting new rods! They'll fit without the hone, but the clearences are so tight that you'll have excessive wear.

 

after having that suggestion on another forum also, I ordered them today.

 

That's a BAD idea. Not for any technical reason; purely for economic ones.

Sleeves are on the order of $50 a hole, installed. That's $400 to do the whole motor, PLUS whatever else the block needs. How is that "A Good Idea" when you can get a whole other block just like the one you've got except it DOESN'T need that, for $50? Or, a much newer one WITH the roller provisions, for maybe $100? Doesn't make sense spending $400 to fix something you can replace with something BETTER for $100.

The small end of the rod is a press-fit to the piston pin in most builds. AFAIK those pistons don't even support floating pins at all, and are always press-fit. Therefore no wear can possibly occur there.

 

There isn't any performance gained by free floating pins.98% of street rods should be press fit pins.The only logical reason for a free floating pin is in a race only use where piston swaps are sometimes common and limited use.

 

I have used KB hypereutectics 3 times and all 3 motors the pistons broke.
In my opinion, they are not a good choice for that reason.

 

A end user issue........................really didn't explain that one very well.

 

Exactly: which is why 99.999% of all typical street pistons, including most of the KB line, aren't set up for them. One of those things that for most people, is all maze and no cheeeeze.

But since press-fit pins are ..... press fit into the rod, the whole rod honing suggestion is pretty much a moot point.

 

I just used KBs for my 383 build this year. They are full floating and needed the hone. I cant say that for anything but the KBs tho, thats all ive used.

 

Some thought should be given to the bushing wearing out on floaters with street use....

 

I know, these came with the kit, werent chosen by me. I dont think ill have problems