Spiroloxs
- Thread starter Sandy
- Start date
I will assume from your pleasant comments that the pin bore of your pistons doesnt have reliefs to allow easy removal. An old screwdriver with a 3/16"dia shank and a right angle bend about 5/8" from the tip sharpened like a scriber works for me. The 5/8" leg allows you to get some leverage to lift the tip of the spiroloc out of the groove by twisting the screwdriver handle, a spare fine blade screwdriver to stop the lock from flicking back into the groove helps as well.
Jac Mac
Jac Mac
Sandy,
I remember seeing this post on another forum. Spirolocks... grr... - Hardcore 5.0 - The Mustang Drag Racers Forum
Towards the end it mentions some suppliers of the tool, and some comments on it's (in)effectiveness!
HTH, cheers,
I remember seeing this post on another forum. Spirolocks... grr... - Hardcore 5.0 - The Mustang Drag Racers Forum
Towards the end it mentions some suppliers of the tool, and some comments on it's (in)effectiveness!
HTH, cheers,
Lynn Larsen
Lynn Larsen
Mr. Mac -
The pistons do have a notch in them in the pin bore. Just didn't have the right hacked tool. I'll will bend one up and see if that does the job. What ever happened to the user friendly Tru-arc's
I guess the tool didn't work and is why it can't be found anymore...
Sandy
The pistons do have a notch in them in the pin bore. Just didn't have the right hacked tool. I'll will bend one up and see if that does the job. What ever happened to the user friendly Tru-arc's
I guess the tool didn't work and is why it can't be found anymore...
Sandy
So since Sandy's talking about alternatives (Tru Arc), what are the pros and cons of teflon? buttons?
I only ask since I've experienced a breakage with the Spirolox. Fortunately the offending broken portion slipped harmlessly past the gudgeon boss and stayed in the bottom of the sump. The remaining portion of Spirolox was still sufficient to secure the pin. That was in a stroker Rover V8 with Chev pistons and rods.
Cheers
I only ask since I've experienced a breakage with the Spirolox. Fortunately the offending broken portion slipped harmlessly past the gudgeon boss and stayed in the bottom of the sump. The remaining portion of Spirolox was still sufficient to secure the pin. That was in a stroker Rover V8 with Chev pistons and rods.
Cheers
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They all have their place. The buttons are handy in an application subject to frequent teardowns. If your engine is going to be together for a while teflon buttons are not such a good idea as any debris that becomes imbedded will score the bore and definitely not in a piston with pin offset, same goes for alloy to a lesser degree. They use alloy in Lysaurus aircraft engines and it causes a bit of grief every time they start making metal in the filter only to find its the pin buttons.
With the spiro failure this can sometimes be traced back to a bend or kink created at fitting time which creats a stress riser. The pin moves back & forward in its bore under braking acceleration as well as being forced to do this by crank twist & flex particularly in stroker type applications. First thoughts with circlips were to hold pin endfloat to a minimum, but experience showed that around 0.005" was reqd to allow for the different expansion rates of the alloy piston steel pin with signs of circlip/ groove wear. I have seen some cases where the whole area outboard of the circlip groove has been broken or extruded away by the circlips. An incorrect crank balance job can also be a factor here.
Jac Mac
With the spiro failure this can sometimes be traced back to a bend or kink created at fitting time which creats a stress riser. The pin moves back & forward in its bore under braking acceleration as well as being forced to do this by crank twist & flex particularly in stroker type applications. First thoughts with circlips were to hold pin endfloat to a minimum, but experience showed that around 0.005" was reqd to allow for the different expansion rates of the alloy piston steel pin with signs of circlip/ groove wear. I have seen some cases where the whole area outboard of the circlip groove has been broken or extruded away by the circlips. An incorrect crank balance job can also be a factor here.
Jac Mac
<P>
. It is not easy to install but it is difficult to remove it! When you will remove one F@#$% you have to check if your piston pin groove is provided with a square section (for spirolock) or with a round section (for traditionnal pin clips). Check also your piston pin end that is provided with or without external chamfer (external chamfer is for traditional pin lock). It is not recommended to change the initial design.
About special tools, feel free to call Goodson that is a renowed tool specialist.
Request or download Goodson Catalog
If something is available, you will be informed.
Good luck
Sandy, be careful about this point. Usually, piston pin bore that are designed to fit spirolock are without notch (see picture). As you can see in the pin bore, these are several screw driver impactsMr. Mac -</P>
<P> </P>
<P>The pistons do have a notch in them in the pin bore. Just didn't have the right hacked tool. I'll will bend one up and see if that does the job. What ever happened to the user friendly Tru-arc's
<P> </P>
<P>I guess the tool didn't work and is why it can't be found anymore...</P>
<P> </P>
<P>Sandy
. It is not easy to install but it is difficult to remove it! When you will remove one F@#$% you have to check if your piston pin groove is provided with a square section (for spirolock) or with a round section (for traditionnal pin clips). Check also your piston pin end that is provided with or without external chamfer (external chamfer is for traditional pin lock). It is not recommended to change the initial design.About special tools, feel free to call Goodson that is a renowed tool specialist.
Request or download Goodson Catalog
If something is available, you will be informed.
Good luck
Attachments
Thanks for the pointers all!. The pistons are Ross that were a victim of a lost valve (all 8 were affected by valve and seat shrapnel) just trying to clean up a bit so I don't have so much junk sitting around. They do have a special spirolox notch but not sure it help since I was not too successful to get them out!
Mr. Mac - I thought that Smoky Yunik was a fan of the truearc's but I guess times are-a-changing on a better solution. I used to get the old TRW Forged pistons with the dual truearc's in the old days but never ran a motor as hard as the ones in the cars now.
Sandy
Mr. Mac - I thought that Smoky Yunik was a fan of the truearc's but I guess times are-a-changing on a better solution. I used to get the old TRW Forged pistons with the dual truearc's in the old days but never ran a motor as hard as the ones in the cars now.
Sandy
I'll take wire locks over spiro locks or TruArcs any day. Just be aware that the pins must have 45 degree X 0.040-in. chamfers at each end.
Pictures are better than my poor explanations. I have cutted 2 differents piston pin bore. You can see the square groove for spirolock and the rounded groove for wire lock (that is notched). Also 2 different piston pin. Wire lock must use chamfered pin 
