Piston ring compressors........sizes?

[77Mini]

My mother in law asked me what I wanted for Christmas, so I told her Lisle ring pliars and 2 sizes of piston ring compressor. Once I got them I started looking at the sizes. Small one is 2 1/8"-5" and the bigger one is 3 1/2"-7". I might not have thought this out.

My question is.....is there any point in having the larger one. Like really, when am I going to do a piston over 5"?

Should I return it or is there a reason I would use the larger one? Do they work better in the middle of the range?

 

[four.cycle]

Something tells me you just answered your own question.

If I had to guess a number, I'd say that about 99% of our sales on piston ring compressors was the 2-1/8" - 5" model:

 

[77Mini]

I kind of think so as well. I don't have any plans to start rebuilding dump trucks in the near future. Just want to make sure I'm not missing something.

 

[four.cycle]

In my last gig, I saw a lot of engines go down the production line, and I do not recall very many of them having pistons larger than five inches in diameter.

 

[454ragtop]

If you're doing more than 1 or 2, better off with a pliers style ring compressor.

 

[BillK]

I have been in the machine shop business over 30 years and I think I have only seen a couple of engines with bores over 5" and I was not assembling them anyway

I have gotten away from any of those type of ring compressors and use the solid tapered ring type instead. The problem with that is you have to buy one for every bore size you do.

Some guys are saying to get the pliers type compressors but they do not work well at all on modern engines with the very small and very flexible rings. The type you have is second best to the solid type.

Be very careful using the ring expanding pliers. My opinion is they typically expand the ring too much no matter how hard you try. I pretty much put rings on by hand only. Again, on the new engine you almost have to.

 

[nelstomlinson]

It might be a little small for this piston ring. Image is safe for work.

 

[77Mini]

I have been in the machine shop business over 30 years and I think I have only seen a couple of engines with bores over 5" and I was not assembling them anyway

I have gotten away from any of those type of ring compressors and use the solid tapered ring type instead. The problem with that is you have to buy one for every bore size you do.

Some guys are saying to get the pliers type compressors but they do not work well at all on modern engines with the very small and very flexible rings. The type you have is second best to the solid type.

Be very careful using the ring expanding pliers. My opinion is they typically expand the ring too much no matter how hard you try. I pretty much put rings on by hand only. Again, on the new engine you almost have to.

I watched a video the other night comparing the type I have and the solid tapered style. Its pretty easy to see they are the better option. I like the flexability of this though. It might be worth picking up that style if there is a size I plan on doing more than once. 4.030" would be the likely candidate for that.

 

[tom-ky]

I always preferred this type:
https://www.amazon.com/dp/B0009OR93I/?tag=atomicindus08-20