ring gap posistion

[Captain Obvious]

12 hours ago, grannyknot said:

Me too, do you also have the scars from the razor sharp spring steel? The bag I store it in is covered in dried blood.

Haha!! Since I have two of these band styles, I may try modifying one (the one that isn't borrowed) to make it a little easier to use and work a little better.

And I thankfully found the sharp edge burr on that thing before it found me. So stupid. For the fifteen second quick wipe across a band sander is all it would take to dress that burr off. That kind of stuff drives me nuts.

So if you do spin one of those up in the winter, let me know if you want any input when the project comes around.

[Namerow]

10 minutes ago, Captain Obvious said:

So IMHO, the whole drawback to the tapered ring style is that it only works for one piston diameter. If you're only planning to do one or two sizes most of the time, it would be worth it, but if you have no idea what's coming in the door next week, you'd probably just get to be an expert with the spring steel band style.

So I wonder what the NHRA pro teams use?  Those folks build engines in the pits in between runs, so you would have to figure that they don't monkey around with low-buck tools from the local AutoZone (Canuck members read, 'Canadian Tire') store.  Any quarter-mile fans here?

Edited May 27, 2020 by Namerow

[Captain Obvious]

How it's made - NASCAR episode.

https://www.youtube.com/watch?v=P3_UQcnHB1E - At approx. 3:50, they use a tapered ring that looks just like mine. Might be the spark that made me make my tool...

 

 

[Namerow]

Maybe this pliers-style is the best option available to shade-tree mechanics like us.  It comes with a set of bands.  You choose the one that matches the diameter of your rings.  I believe that it eliminates the step that's problematic in the wrapped-sleeve types.  It looks like it also allows you to compress right down to the OD of the piston, without having to worry about free play in the tightening mechanism...

 

[Captain Obvious]

I agree. I've not actually used those, but knowing what I know now about the "overlapping band" style, I believe those pliers would be easier to use with a higher probability of success.

The modification I mentioned earlier about removing excess material from my overlapping band would essentially make them more like that pliers style. I think if I removed enough of the band such that there was no overlap, it would be a lot better. Limits the range it works for, but I'm not planning to do a whole bunch of this.

You certainly don't want to buy or make a tapered collar for every size piston in the world.

[siteunseen]

I've used this one one 2 rebuilds without any issues. Just got it as tight as possible and tapped the piston down with a hammer handle. 

 

[Dave WM]

for standard, maybe this?

https://www.summitracing.com/parts/wis-rcs08600

[siteunseen]

Don't forget to put rubber hose sections over the cap bolts to not scar the the crank.

[Captain Obvious]

6 hours ago, Dave WM said:

for standard, maybe this?

https://www.summitracing.com/parts/wis-rcs08600

Yup. That's the one I was going to buy before I decided I would try my hand at building a better mousetrap. Cheapest I found was on ebay for just under $40 shipped. So it may depend on how much Summit wants for shipping.

[Captain Obvious]

6 hours ago, siteunseen said:

Don't forget to put rubber hose sections over the cap bolts to not scar the the crank.

Got it. Hoover sent me some used condoms along with the other stuff in the care package. They look good, so I'll use them again.   

[ETI4K]

Another solution to the ring gap spacing issue would be to use Total Seal's Gapless Rings.  I ran these (perhaps an earlier version) after my initial engine build in '94.  I still staggered the gaps, though not necessary for compression leakage issues.

[Namerow]

16 hours ago, Dave WM said:

for standard, maybe this?

https://www.summitracing.com/parts/wis-rcs08600

When I checked this link, I encountered a name that I hadn't heard for 50 years: 'Wiseco'.  When I bought my first motorcycle as a teenager (a Yamaha two-stroke ), one of the performance mods I made was swapping in Wiseco pistons.  Glad to see they're still around and (apparently) thriving.  They have a huge catalog.