NEW spin on an old topic ....

Is this old-school or what ? ... I have heard of many horror stories about clips and spiril-locks breaking-loose or going out and MESSING up the motor big-time.

If buttons are not the plan - WHAT is the up-to-date way to be safe?

I ran buttons in my old engine with no problems, but they are heavy compared to new stuff.
Brian

I use nothing but buttons and have for years. With the simplicity of a button, I fail to see why anybody would choose spiro-locks. The weight would only be an issue in a max effort comp style engine and even then, the difference is negligable.

Monte

M S .. are there diff materials used ? .. list of suppliers?

I think that the weight-issue is far OUTweighed by the possiblity of engine damage.

i was going to post this question the other day. Monte do you know any reason people don't use them more often? all the bike pistons we ran had them and afaik aircraft engines use them. there are a couple different types i'm aware of. solid teflon and aluminum with a teflon insert. as for assembly it doesn't get any easier. they might add a little weight but i doubt it could be much unless you're using very short pins. some of the ones i used fit in the piston and some fit in the pin.

I bought an engine, small block chevy , it was a late model dirt engine, I just needed the light crank and got the whole thing. Well It had poly buttons in it. They looked like almond colored gum drops, and they didnt weigh but a few ounces per handfull.

Kasey

I'm getting ready to order parts for a 511 and now wondering if I should get butons.

Buttons are the only way to fly, don't have to worry about a lock comeing out and kiling your whole engine. Especally for an N2o app.
Steve

Where can you get them? I haven't seen them listed for sale in a long time.

Dennis Jokela

ANY piston company will set you up with buttons, all you have to do is ask. As far as converting an existing engine, thats easy. Measure the diameter of the piston at the barrel where the pin is, subtract the length of the pin and divide the remainder by 2. That is the length button you need. Now if the pin is up into the oil ring, that is a little more difficult, but all you need is the job number from the piston sheet and they can still set you up with buttons. As far as materials, the exotic material I order mine made from is aluminum

Monte

having used them in the past and seeing how simple the setup is why haven't they seen more use? never really studied it just figured there was some good reason they don't get more use. is there an issue with the potential length needed if using a lite piston with narrow pin bosses? for years i have wondered why buttons weren't used more often. after using them on the bike engines and seeing how easy they made things plus i can't ever remember them causing any problems just figured they were a good idea all the way around. they would polish the bore where they rode but can't say i ever saw any negative impact. could it be a cost thing? doesn't seem like they would cost that much more considering it would be one less machine operation on the piston being you don't need a retainer groove. i just wonder about the potential length issue

Anyone have a pic of one?

The reason "buttons" dont get much attention, is the simple fact that most have no idea what they are, or how they work. I think buttons are 3.00 per piston from Diamond, or maybe 3.00 each, but regardless, they are cheap. They can't be used on a super lite "slipper skirt" style piston, but other than that, they are good for any combo with full skirted pistons, which most are.

Monte

after reading this thread, i can't believe i haven't been using 'em. we used them in model airplane engines- bulletproof.

Not what I meant by a "full skirted" piston. A slipper skirt looks like a circle with rectangle attached to the bottom for a pin skirt. A full skirted piston is exactly that, has a fully round skirt. Has nothing to do with pin location. If the oil ring is in the pin, the button simply has a notch cut in it to support the oil ring.

Monte

Venolia does a good job with wedge and hemi pistons, buttons are pretty normal with them.

Also, they can "cam grind" the skirts. Very few manufacturer's do this any more. It only matters if you make big power.

What is the failure rate of a double spirolock?