Wanted one 308 piston .030 new or used

squirrel

hi, looking for one .030 over piston for a 308 engine. Used is ok. Mine has a loose pin bore.

520 456 6428 or send a message. thanks

lostmind

Jim, check with Egge Machine , they make pistons and rings and valves.
https://www.google.com/search?source=hp&ei=yxsvXaLWAYe4tQat_48w&q=egge+machine&oq=egge+machine&gs_l=psy-ab.12..0j0i22i10i30.2967.7671..12291...0.0..0.184.1186.8j4......0....1..gws-wiz.....0..0i131j0i10.Axg-tm854xg

squirrel

I talked to them, they will make me a set of 6, but don't have a single, and won't make a single. I'm hoping someone has something left over....

29sptphaeton

Try Then & Now Automotive in Weymouth. MA  781-335-8860 ask for Tom or Lisa they have web site; www.then-now.com  You'll get quicker results with a phone call.

squirrel

thanks for the suggestion...but no help there, unfortunately. Still looking.

lostmind

Here's a thought. Can you use a bigger oversize and machine it down?
Maybe some one has .040 , .050 , or .060
You would have to cut the ring grooves also.
Never tried it.

squirrel

I expect it would be easier to find a .030 piston....but it would be challenging to machine a larger one to size. I do have a lathe, but I dont know if I'd want to try it.

still looking 

squirrel

Well, Dale did send me a piston....unfortunately it's .040 so I get to figure out what to do.

Courtesy Man

If you measure a new piston ( accurately)  the measurement is slightly bigger at one location than another - that is the piston is in the shape of an oval from being cam ground and not actually round - so a lathe cut down would destroy the desired shape.
That is my understanding -  Now this is very small difference needed for piston expansion as the engine heats up. Does this agree with more expert knowledge than mine ? Gert Kristiansen

squirrel

It agrees with my micrometer! I just measured the two pistons (old and new) and the new one is .010 bigger diameter in each direction than the other. They are both about .005" bigger diameter perpendicular to the pin, than along the pin.

I am considering taking the block to a machine shop, or borrowing a rigid hone, to open up the bore, rather than machining the piston. This bore has a healthy scratch in it, which it would be nice to get rid of.

trdrew

Along the lines of your last comment, maybe the piston pin bore could be machined to a larger diameter and then sleeved back to standard size?

squirrel

I want to just get the car back on the road, I don't want to take it all apart and do it right and spend $1500. I found a hone, I'll see how it goes. If I wanted to fix it right, I'd pull it all apart and bore the block 060 and buy a lot of new parts.

Ol racer

I can relate to your situation. You could consider taking the piston to a local Machine Shop to insert & hone a new bushing to fit W/Pin. (Actually, if the bushing is only lightly scratched but otherwise concentric, the scratch should fill with oil).

squirrel

The cylinder bore is what's scratched badly...the old piston also has a loose pin bore, which is one reason I wanted to replace the piston. I don't know if it would last too long.

Geoff

I understand that the cylinder bore is scored, not the piston pin bushing.  You should be able to hone this out, but you will have quite a job doing it, as you will need an adjustable hone, with coarse grit stones to remove metal and fine grit to finish.   A de-glazing hone will not remove that much.  And you will have to consider the  residue  of honing grit getting into the rest of the motor.   would be best to machine the piston I reckon.   
  

squirrel

yeah, it will be fun....we'll see how it goes.