Okay hear me out. I have been researching this for 2 days now. I ordered a new set of rings for my 460 original pistons. The rings are the right thickness and the right size for the bore but..... their width is smaller than the original rings. New ring width 1.53, old ring width 2.95. I can't seem to get a conclusive answer on if the width matters. I also am unable to find any parts that I can order with the width specified. I'm beginning to think it doesn't matter. Anyone with experience on this subject please help!!

 

The width of the rings matters a lot. Later 460 engines used a metric ring set and earlier engines used rings that were 5/64 5/64 3/16 widths. If your pistons are cut to use the wider rings then that's what you must use in the engine. The rings that you have now are not correct and won't work.

 

Yes, it matters. Ford made some changes to the 460 when they went to EFI on it. Make sure you are ordering, and getting, rings based on if the engine you are rebuilding is a carbed or EFI engine, or the pistons are from one of those anyway.

 

I am talking about the radial wall thickness. The 5/32 and 3/16 measurement is all right. The thickness I'm refering to is called radial wall thickness. I found a bunch of articles that say it doesn't matter.

 

Oh ok. I misread your post.

I ran into this same thing a number of years ago with a stock replacement Hastings ring set. The radial thickness(depth into the groove) of the top ring was reduced when compared to the old stock ring so I called their tech line just to find out why. I was told that it was done to make the ring more flexible and easier to conform to the bore. The old school of thought was to reduce the back clearance to very little so that there was less volume to pressurize when expanding the ring thus making it seal the cylinder better. Maybe it is all a compromise and having the ring be more flexible works better than a lower volume.

That engine(a 351 Windsor) sealed right up and ran well on the dyno.

The same sort of thing happened with ring end gap recommendations too. The recommendation used to be that the top ring had more gap than the 2nd. Now most manufacturers recommend running gaps that are equal or even greater on the 2nd ring. The reason being that it gives a larger leakage path at the 2nd to reduce the pressure that builds up between the rings. That pressure can keep the top ring from seating against the bottom of the groove which can cause blow by to increase at higher engine speeds.