I have heard that some meticulous engine builders file-fit their rings with a torque plate installed. I am planning on building a 427 out of a Dart block. Due to the Dart block already being made of a stronger material I don't feel that the cores would deflect that much with a torque plate installed in the first place. Is it really necessary to install a torque plate to get an accurate end-gap? Which brand of rings are most widely used in street/strip app's and has anyone used those zero-gap ring packages from Childs & Albert? Also, how well do those bench mounted hand turned grinders specifically made for filing rings work? :confused:


[Modified by BlackRocket, 9:45 PM 1/24/2002]

 

I'm not a big believer in zero gap rings, and I don't know of any professional engine builders that use or recommend them. Leakdown under a staic test is alot different than in actual operating conditions. The leading edge thinkers are actually widening the gap of the second ring and finding less blow-by and more power, since the blowby isn't getting trapped between the two upper rings and lifting the top ring. I'd say stick with file-fit moly SpeedPro rings. You can be sure that if their was a real benefit to zero-gap rings, racers and the pro's would be using them.

File fitting rings with the torque plates installed is certainly meticulous, but in reality I doubt many actually do it. If you've got the time, go for it, but if you don't I doubt you'd see any detectable difference in any way. If you want to get really ****, why not heat the block up to normal operating temps and use a cylinder head rather than a torque plate. A solid iron or aluminum is certainly going to distort the bore differntly than a cylinder head that has coolant passages, bolt holes, varying material thicknesses, etc. Once you've taken the step to bore/hone with a torque plate, additional steps are a matter of diminishing returns.

 

Re: file fitting rings with a torque plate. It's a good idea and I would suggest it, but if you can't/haven't done it then I wouldn't fret over it.

On the rings themselves I would echo the sentiment above - stay away from the gapless rings. Just go with a good speed pro or C&A plasma moly ring.

 

I'm lazy I just called up and got fitted rings for my bore size - speed pro. I was also using a blue printed block and I knew the bore was as close to correct as possible.

My logic is 1/16th first and seconds rings are not made with high mileage in mind. The other thing is I have know idea what ever happened to my nice ring end filer. I also trust them to do a good job. I checked a couple out of the box and they were all right on.

 

push the ring 2-3" down in the cyl. with a piston; torque plate is not needed, except for honing.
I file mine with a $3 hand file and a vice; takes nearly 8 hours(most of the time spent checking to be sure)
the advantage comes from having the best gap for te application. since i use forged pistons and no power adder, i go with .012" top ring

 

BlackRocket

When you talk about file fitting rings, you're talking about a precission fit. My new engine had that very procedure done, and wether or not it's worth it? I figure it cant hurt.

The problem I have with it is this. There is a gap called out for Normally aspriated, another for Superchargers, and another for NOS. It seems to me that I'm stuck with the Normally aspriated gap :( no blower or NOS for me. Before you comitt to your end gap, be certain of what you want the engine to be. My ring set is made by JE.

KM


[Modified by 88-406, 7:23 PM 1/26/2002]

 

If you're going to all the trouble to build a custom motor it just makes sense to make sure something this critical is dead on.

I always buy .005 over and hand fit them. Since I do all the assy work at home I don't have a torque plate available. I guess it couldn't hurt, but not practical for the average guy. gapping them as described above is practical.

I've got one of the hand crank rotary filers but actually never liked it. I always just do it by hand with a small file. I've seen a power one that would be slick.

As was said above. I don't know of many serious builder using zero gap rings. The concept sounds good but doesn't seem to work in practice very well. With the emphasis on emissions you would think they would be OEM if they worked as claimed. I do know some blown alcohol guys that like them because the oil doesn't get dilluted/contaminated as quickly.

Follow the gap recommendations. Too tight is much worse than too loose!


Jim