newbie engine question.

[Transporter]

Hello people, 

As my English is getting better every day, still there are some technical words in car's mechanic that I cant find in dictionaries or translators, I was looking on some Federal Mogul Engine Re-ring Kits and i notice that they have different kits for "in. Bore" so I was wondering what was this? and what it meant. I can assume it has to do with the size of something, could be the size of the hole where the piston moves? 


- Good thing this forum has spell check 

[firefighter3931]

Yes, that is correct the bore is the hole where the piston moves up and down and is measured in inches. 

[Transporter]

So in order to buy the right kit I guess I have to messure the bore itself before buying it (since this one expand with the combustion over the years) or I just buy a standar one for my 318?

[Nacho-RT74]

need to know what bore you actually have to get the right now. Lot of pistons have stamped the overbore on top, so you will now what rings will need to re-ring.

however IF YOU HAVE a NOTICEABLE step on top of cilinder, I think will need to measure the walls and get a new pistons and rings going to the next step on bore, according with the wall measure

New rings on a worn cilinder, will eat the cilinder walls fast and bad and will make you get two steps above the actual stance faster than expected.

thats at least my though

[Transporter]

need to know what bore you actually have to get the right now. Lot of pistons have stamped the overbore on top, so you will now what rings will need to re-ring.

however IF YOU HAVE a NOTICEABLE step on top of cilinder, I think will need to measure the walls and get a new pistons and rings going to the next step on bore, according with the wall measure

New rings on a worn cilinder, will eat the cilinder walls fast and bad and will make you get two steps above the actual stance faster than expected.

thats at least my though

I was just wondering since if I decide to open the engine I would like to do a good rebuild and since I'm gathering all the parts or at least the ones I would like to change, I saw that some of the pieces needed certain measures, now once I decide what to do I'll ask for some help to understand what to buy.

[Troy]

You probably don't want to buy pistons or rings until you get the engine apart and see how badly it is worn. I've heard of cheap builds where new rings were used with the right gap to expand them slightly to fit in the worn cylinder. For a cheap "rebuild" it makes sense. However, if the bores are very worn, tapered, our out-of-round the you will likely need to do some machine work to get them straightened back out. Typically, this involves increasing the bore slightly (.020-.030 inches). In that case, you need pistons and rings for the new diameter.

Troy