Don Terrill’s Speed-Talk

Why haven't more aftermarket piston manufacturers gone to round wire locks with chamfered wrist pins? Am i missing something here? They seem to hold as good as any set up and much easier to work with than some other set ups.

Works and easy to work with...well there's your answer...lol. Spirolock sounds fancier, like an upgrade on paper.

While the round wire locks have been around for about 25 yrs in some brands of pistons the use of other locks may require a complete re-engineering issue by the manufactures standards.

many current high quality forged piston manufactures do use wire locks and others use single and double spiro-locks just to be different but their is no real advantage with the exception of disassembly

Buy from CP - Wiseco and the others are stuck in the past.

Wire locks with a chamfered pin is stronger than spirolocks because forces acting on the pin force the locks into the piston rather than outwards towards the cylinder wall as with a square groove.

kramm-lox are easy to use. Buttons are the easiest.

MTENGINES wrote: ↑Thu Sep 06, 2018 3:19 pm kramm-lox are easy to use. Buttons are the easiest.

I love Kramm-lox....to bad some ignorant assemblers complained about them and now they're not standard with CP pistons anymore.

It all depends on what engine you work on , all the Wiseco pistons i use have come with round wire locks for years ,W5752 and CW20 being very common and easy to fit .
The Kramm-Lox locks that comes with CP is easier to flick in with a small screw driver than the installation tool due to a dip in the forging between the o/d and the pin bore groove that the lock wants to seat in first and is difficult to climb out of into the pin bore. Bearing in mind the piston is assembled onto the rod in its normal attitude ,crown up.

What happened to using snap rings? I hate those darn spiral locks...

Snap rings (or tru arcs) break the "eyelets" off often and destroy parts. Wire locks are the only way to go unless you are on a 45 minute turnaround.LOL





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Krooser wrote: ↑Fri Sep 07, 2018 12:02 pm What happened to using snap rings? I hate those darn spiral locks...

Spiral locks are easy. Not sure why everyone has such a problem with them. In or out, once you have the hang of it, it's like bing, bang, boom done. I use a small screw driver for installation, and a pick and the same screw driver for removal

I have seen people destroy Spirolox by overworking them into the groove ,same with the internal Rotorclips . The installation of two turn crimped Spirolox[the most common for me] is greatly facilitated by using a compression tool ,the one in the picture makes installation easy ,if i don't have a tool to suit uncommon ones i stretch them out a little and walk them into the groove .
As for Rotorclips ,if you compress them just enough to start in one side of the groove and then swing the other side in you don't stress the the thin section next to the eye,nearly every broken clip i have seen is fractured in the same place, i have seen guys compress those things till the eye lugs pass each other on the pliers,ouch!
The installation picture is from the Spirolox engineering specification manual.
Cheers.

Some customers like wire locks.

Some customers like spiral locks.

No manufacturers care one way or the other.

Krooser wrote: ↑Fri Sep 07, 2018 12:02 pm What happened to using snap rings? I hate those darn spiral locks...

If you want to use them, most will fit in the same grooves as the spiral locks. You can get them in tool steel if you're worried about breaking them.

needforspeed66gt wrote: ↑Thu Sep 06, 2018 3:23 pm

MTENGINES wrote: ↑Thu Sep 06, 2018 3:19 pm kramm-lox are easy to use. Buttons are the easiest.

I love Kramm-lox....to bad some ignorant assemblers complained about them and now they're not standard with CP pistons anymore.

Just installed a set of CP's, they have Kramer-Lox ... and the tool

The instructions for Spirolox say to stretch them out to 3/4" or so before putting them in. If you do that, you just stuff them in with a blunt screwdriver, no finicking needed. And to get them out, you lever one end up, it pops out, and then you can sometimes pull them out the rest of the way with your fingers.

I used to hate to see engines come in with Spirolox, because apparently whoever put them in *never* read the freakin' instructions... getting an unstretched Spiroloc out was always tedious.