Piston Pin Clips

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
rayhall
New Member
New Member
Posts: 33
Joined: Sat Jan 02, 2016 6:48 pm
Location:

Piston Pin Clips

Post by rayhall »

I have a new set of pistons and that came with circular wire clips to hold the piston pins in place. I want to kill the person who came up with this idea. All most impossible to fit them. I have used spiral locks before and thought they were bad. They are a walk in the park compared to these.
Is there any reason why I cannot just use internal circlips.
Ray.
BCjohnny
Guru
Guru
Posts: 1772
Joined: Sun Feb 26, 2006 6:07 pm
Location: Black Country, England

Re: Piston Pin Clips

Post by BCjohnny »

Round section wire clips ?

I can't recall ever having a problem installing them, usually just roll them in

Maybe this might help if you're having issues
User avatar
modok
Guru
Guru
Posts: 3321
Joined: Sun Jun 06, 2010 1:50 am
Location:

Re: Piston Pin Clips

Post by modok »

The first one or two always seems impossible,
but once I find the right angle, and get the hang of it, they go in easy.
steve cowan
Guru
Guru
Posts: 2253
Joined: Wed Jul 27, 2011 5:22 am
Location: brisbane AUSTRALIA

Re: Piston Pin Clips

Post by steve cowan »

BCjohnny wrote: Mon Jan 04, 2021 1:18 am Round section wire clips ?

I can't recall ever having a problem installing them, usually just roll them in

Maybe this might help if you're having issues
Thanks for the link,some handy tools there,they can be hard on your thumbs :D
steve c
"Pretty don't make power"
hoodeng
HotPass
HotPass
Posts: 1092
Joined: Sat Mar 04, 2017 6:53 pm
Location: South Australia

Re: Piston Pin Clips

Post by hoodeng »

Look in the retainer clip groove, if it has a radius it uses round wire clips, if it is squared it uses circlips or spiralocks.
Also look at the end of the pin, if it has a radius on the end this goes with round wire clips, if it has a small radius or edge break on the end this goes with square finish retainers.

There are a number of wire diameters used for retention, two common ones are 1mm[.040"ø] and 1/16"[.062"ø] if you are not sure which your pistons have been supplied with get a piece of similar ø wire and form a checking tool, you can see quite easily if it seats proud or with side clearance in the root.

A similar method can be used to check the width of a square finished groove to determine whether it takes single internal rotor-clips or double wound, triple wound or two double wound spiraloc's, although they are quite dissimilar to look at.

One tool is .792"and the other .927" .

When i have found removal almost impossible i have drilled a 1/8" hole 45° to vertical of the bore under the side of the clip and popped it out that way
hoodeng
HotPass
HotPass
Posts: 1092
Joined: Sat Mar 04, 2017 6:53 pm
Location: South Australia

Re: Piston Pin Clips

Post by hoodeng »

i did try adding photos of two installation tools but my login keeps dropping out.
LSP
Pro
Pro
Posts: 362
Joined: Tue Mar 16, 2010 12:33 pm
Location: Charlotte

Re: Piston Pin Clips

Post by LSP »

rayhall wrote: Mon Jan 04, 2021 12:51 am I have a new set of pistons and that came with circular wire clips to hold the piston pins in place. I want to kill the person who came up with this idea. All most impossible to fit them. I have used spiral locks before and thought they were bad. They are a walk in the park compared to these.
Is there any reason why I cannot just use internal circlips.
Ray.
The pin retaining methods cannot be interchanged, the round wire locks must be used. Round wire locks are the preferred retaining method, as when the pin end chamfer contacts the lock, it tries to spread the lock rather than push it out.

Put a post the same size as the ID of your wrist pin on your work bench, that will hold you piston/rod assembly steady so it doesn't move.

Put a radiused cut/channel on the end of a screwdriver, it will help retain the lock as you gradually push the lock into the lock groove of the piston.
Nut124
Pro
Pro
Posts: 307
Joined: Wed May 06, 2020 10:44 pm
Location: Michigan, USA

Re: Piston Pin Clips

Post by Nut124 »

Rayhall, google it. There are some good videos on youtube. That's how I learned.

You'd be surpised how easily someone who knows how could do it.
Walter R. Malik
Guru
Guru
Posts: 6353
Joined: Tue Jul 24, 2012 11:15 am
Location: Roseville, Michigan (just north of Detroit)
Contact:

Re: Piston Pin Clips

Post by Walter R. Malik »

rayhall wrote: Mon Jan 04, 2021 12:51 am I have a new set of pistons and that came with circular wire clips to hold the piston pins in place. I want to kill the person who came up with this idea. All most impossible to fit them. I have used spiral locks before and thought they were bad. They are a walk in the park compared to these.
Is there any reason why I cannot just use internal circlips.
Ray.
A lot of piston companies have gone to using them because they are a lot less expensive ... one may not be much but, thousands are.
Another reason is ...the chamfered pin end also tends to push them deeper into and not out of the groove

The groove in the piston would need to be cut the correct width with square edges and the pins would need to be the correct length with NO chamfer on the ends to use Spirolox or Tru-Arks.
I wouldn't but, Round wire internal circlips with "tangs" could be used in those pistons with square ended pins of the correct length.
http://www.rmcompetition.com
Specialty engine building at its finest.
User avatar
modok
Guru
Guru
Posts: 3321
Joined: Sun Jun 06, 2010 1:50 am
Location:

Re: Piston Pin Clips

Post by modok »

A square clip CAN work in a round groove. The VW and hoduh racers are doing it, and it is apparently working.
They are stupid enough to try things we would never think of and god bless them for it.

But I think.... the round wire clip is a fine design and you just need figure out how to work it.
Nut124
Pro
Pro
Posts: 307
Joined: Wed May 06, 2020 10:44 pm
Location: Michigan, USA

Re: Piston Pin Clips

Post by Nut124 »

rayhall, after you get the clips in, set the piston on it's side on a cloth and strike the pin hard with a mallet/dowel to check, seat the clip. Do this from both sides.

This will secure the clips in.
LSP
Pro
Pro
Posts: 362
Joined: Tue Mar 16, 2010 12:33 pm
Location: Charlotte

Re: Piston Pin Clips

Post by LSP »

Nut124 wrote: Mon Jan 04, 2021 10:30 pm set the piston on it's side on a cloth and strike the pin hard with a mallet/dowel
No
rebelrouser
Guru
Guru
Posts: 1938
Joined: Tue Sep 15, 2015 2:25 pm
Location:

Re: Piston Pin Clips

Post by rebelrouser »

modok wrote: Mon Jan 04, 2021 8:34 pm A square clip CAN work in a round groove. The VW and hoduh racers are doing it, and it is apparently working.
They are stupid enough to try things we would never think of and god bless them for it.

But I think.... the round wire clip is a fine design and you just need figure out how to work it.
WELL a few years back I tried it on a set of swap meet SBC pistons, one of the spirolocks came out warming it up on the dyno. Lucky I heard the little tap and shut it down, so very little damage was done. I won't try it anymore. I guess sometimes I am stupid enough to try things, sometimes I get burnt as well.
I have little trouble using either method of clip, I just had a whole drawer full of spare spirolocks at the time.
Nut124
Pro
Pro
Posts: 307
Joined: Wed May 06, 2020 10:44 pm
Location: Michigan, USA

Re: Piston Pin Clips

Post by Nut124 »

LSP wrote: Mon Jan 04, 2021 11:11 pm
Nut124 wrote: Mon Jan 04, 2021 10:30 pm set the piston on it's side on a cloth and strike the pin hard with a mallet/dowel
No
"Strike hard" could be a bit strong. How about "tap firmly" ?
LSP
Pro
Pro
Posts: 362
Joined: Tue Mar 16, 2010 12:33 pm
Location: Charlotte

Re: Piston Pin Clips

Post by LSP »

Nut124 wrote: Tue Jan 05, 2021 11:35 am
LSP wrote: Mon Jan 04, 2021 11:11 pm
Nut124 wrote: Mon Jan 04, 2021 10:30 pm set the piston on it's side on a cloth and strike the pin hard with a mallet/dowel
No
"Strike hard" could be a bit strong. How about "tap firmly" ?
I wouldn't let the piston touch anything, you could damage the ring land OD's, the ring groove itself, and possibly alter the skirt cam profile.....though some lesser piston companies will squeeze their pistons so their inconsistent skirt sizing "appears"
correct, yes it happens.

Another way to seat locks is to get a long 3/8" drive extension with a stepped socket attached that will just fit inside the ID of your wrist pin. Strike the end of the 3/8" extension to seat the locks after both are installed. Best position for the locks is 6 o'clock if possible.
Post Reply