ridge reamer?

[FlaBoy]

I will be pulling out a burned piston and honing/re-ringing that cylinder in the next few days.

I haven't done this job myself before (lent my dad a hand a few times over the years when I was younger). In talking to him, he mentioned that I would have to use a ridge reamer to clean up the top of the bore in order to get the piston out (so the rings don't catch). I had never heard mention of this before, and was wondering if this is something I will likely have to do, or if with more modern blocks/rings its not usually neccesary (his passion is older iron; 50/60's Mopars, to be precise).

The cylinder in question doesn't have much of a ridge to speak of (havent gotten out my mic/dial guages to try and measure it). It is noticeable with a finger tip, and you can feel it with a fingernail, but it doesn't really catch (if that makes any sense). Does it sound like I will need to ream the ridge? Since I'm going to be trashing the piston anyways, does it even matter if i damage the rings grooves during removal?

If this is something I should do, is this the kind of tool you can rent/borrow from the chair auto parts stores? If i need to buy one, what is a good place and what can I expect to pay? Any advice on its operation?

Thanks in advance guys!

 

[joe_schindler]

It really doesn’t matter about the piston that’s coming out. It might hang a bit; but should come out with out reaming. It might make it a little easier.

The problem is that the NEW ring on the NEW piston will probably contact this ridge when the piston cycles. That’s a problem if it does.

So; you ream the cylinder to keep this contact from happening. But; if you need to ream the cylinder to fix the top; that means you have taper. If you have taper; you may have some problem seating the rings.

You won’t really know what you have till you measure.


I worked at a place with a bunch of engineers. They had a sign they were very proud of. It said; “if you can’t measure it, we can’t talk about it.”

I hated that sign; but they were right.