Are file fit rings that much more important than rgular rings??

They give you the control to have the exact ring gaps you want. Rarely will a standard non file-fit ring come up with perfect gaps out of the box. Other than that there is no advantage assuming the rings are identical, one pre-gapped and one file-fit.

Jody

Depending on the pistons you have, its very important to check all the ring gaps. I would check them just to be sure they are the right fit according to the piston maufacturer.

If you're using KB pistons, no need for file fit. You'll be opening them up a bunch beyond what the pre-gapped are at.

I used file fit rings building my 427. That was the single most time consuming process in building the whole motor. I have one of those little bench based hand crank filers. I do have all my ring gaps right where i want them though. So that is nice.

Daniel

Don't waste your time with file fit rings unless you are a perfectionist or a sadist.
It won't make that much difference from the stock ring. HOWEVER, that does not mean you don't have to check ring gap with the fitted rings. You should check every one. Then use your handy ring filer if it is too close or small.

I wasted two days filing rings and came up with the exact same compression I started with.
Plus the fear that the gap may be too small and score a cyll if the motor got too hot. Save yourself the grief.

Dave

with the percise way that rings are made today, it is much more likley that your bore is out than a ring. I used the std. rings & checked all of them. If nothing else, its a good double check of your machinest's work.. graemlins/thumbsup.gif

cool, encouraging words