Originally Posted by Frank C. Bowman

I was asked by a customer to leave information in this section of RCU Forums. I have been a machinest all my working life and making Custon Piston Rings for approx. 12+ years for Gas, Glow and diesel engines, some motorcycles too. With my custom rings, performance will improve over nearly all factory rings because of the material I use, machining method I use and Ring gap I recomend with my rings. I use fine grained cast iron machined from solid round bar stock rough cut on OD to .010 oversized and finished with a .002 finish cut on OD for accuracy. OD of ring is cylinder bore to assure ring fit is correct and round rather than making ring larger than bore and shinking oversized ring after saw cut into smaller bore. Rings are then hand lapped to .001 smaller than piston ring land. I don't saw cut ring, I have a special tool that snaps ring before heat treat at 850+ degrees F. After heat treating on mandrels I gap ring to .001 to .002 end gap. Rule of thumb in machinest world on cast iron rings is .001 to .0015 ring gap per 1" bore diameter. I make bore gage to .0001 of cylinder bore to gap rings & ship all over the world. I make over 300+ rings and to date made thousands with a lot of happy customers. There is a lot more involved in my manufacturing process along with a lot of tooling involved, too much to discuss here. If I don't currently have dimensions to make rings for certain engines a lot of customers send the piston & cylinder to me to measure for rings & I install rings for no extra charge. I make special rings for 30 CC Homelite & 31 CC Ryobi engines that require a slight mod. of cutting anti rotation pin in ring groove down 1/2 way so my custom rings will overlap pin for much improved performance. Most rings for Gase engines $10 ea. shipped to most countries & US at $14 for 1 & $24 for 2 shipped. Discounts of $1 off per ring on orders of 10 or more mixed sizes & Brands fine. I have been endorsed many times by engine builders like Clarence Lee, Joe Wagner in magazines, etc. Email me if you have additional questions and a list of custom rings that I currently have in stock. Thanks & God Bless all. Frank Bowman at Bowman Rings. Email: [email protected]