spiral or ring type piston pin retainers

[Tom Goldman]

I have engines with both dual spiral locks ,and the round wire rings.
Mahle has the round wire clips in their specialty performance line.
Since the wire ring engine has not been pressed into service yet ,I cant personally attest to their durability.
That being said , my finger tips were in much better shape after assembling the engine with the wire clips !!
Back in the 80's the machine shop that did my work was building some mighty successful Dirt Modified engines with the wire clips , I cant remember them having any failures. . ...Plus they had some Cosworth engines there which also had them.

[spike1]

I have been running round pin rings (CP) for over 2 years now (200 runs) in my 5.7 drag pak up to 8400 rpm and never had a problem with ring clips, pins or piston.

[rawhide]

Originally Posted by Tom Goldman

I have engines with both dual spiral locks ,and the round wire rings.
Mahle has the round wire clips in their specialty performance line.
Since the wire ring engine has not been pressed into service yet ,I cant personally attest to their durability.
That being said , my finger tips were in much better shape after assembling the engine with the wire clips !!
Back in the 80's the machine shop that did my work was building some mighty successful Dirt Modified engines with the wire clips , I cant remember them having any failures. . ...Plus they had some Cosworth engines there which also had them.

I have not seen a Cosworth piston that did not have round wire rings in them and they started business in 1959. The last V8 Ford Formula One engine they did ran at 19500 rpm without any failures that I can remember. Even flathead Fords had round wire locks.

[Rich Biebel]

I was in the engine machining and building world for many years and not once can I recall seeing round wire pin locks....from any of the major piston manufacturers.

Round snap ring type was common.....double per side and then spiral locks were the most common.

Yes they tear up your fingers and usually end up with some blood involved.

They made a tool for them but I developed a pretty easy method of getting them in and out.....no blood....usually...

I would guess the round wire lock does not pound out the groove like a flat lock does making it harder to disassemble pistons after some use...

I also assume the round wire lock groove is cut to fit the lock and if done wrong bad things happen...…

I usually Learn something new everyday...but I'm sticking with spiral locks.....LOL

[Tom Broome]

Originally Posted by Rich Biebel

I was in the engine machining and building world for many years and not once can I recall seeing round wire pin locks....from any of the major piston manufacturers.

Round snap ring type was common.....double per side and then spiral locks were the most common.

Yes they tear up your fingers and usually end up with some blood involved.

They made a tool for them but I developed a pretty easy method of getting them in and out.....no blood....usually...

I would guess the round wire lock does not pound out the groove like a flat lock does making it harder to disassemble pistons after some use...

I also assume the round wire lock groove is cut to fit the lock and if done wrong bad things happen...…

I usually Learn something new everyday...but I'm sticking with spiral locks.....LOL

I still prefer spiral locks also. But there were a few somewhat major piston manufacturers many years ago that utilized round wire locks. One you might have heard of....Cosworth. We used lots of them in the 80's on Buick R&D at the shop I worked at. Cosworth seemed to have it figured out, even the "on center bore" V6 Buicks still had rod offset issues and I can't recall a single Cosworth piston pin issue.

[Bob Mulry]

Originally Posted by Rich Biebel

I was in the engine machining and building world for many years and not once can I recall seeing round wire pin locks....from any of the major piston manufacturers.

Round snap ring type was common.....double per side and then spiral locks were the most common.

I'm not sure Rich, but I think that you might be referring to the doubled up Tru-Arc snap rings.

Bob

[Mark Yacavone]

Originally Posted by Bob Mulry

I'm not sure Rich, but I think that you might be referring to the doubled up Tru-Arc snap rings.

Bob

We used double Tru-Arcs a lot. Sharp side facing away from each other..to the outsides.
Again, no failures.
Also used single spiral locks too.

[Rich Biebel]

Originally Posted by Bob Mulry

I'm not sure Rich, but I think that you might be referring to the doubled up Tru-Arc snap rings.

Bob

No Bob.....What Mark said was spot on about Tru Arcs....exactly what we used and how we installed them..

I was thinking of some old engines and oddball stuff that we occasionally worked on....Round wire locks...

In my long working career I once worked in a pretty famous restoration shop here in NJ.....They did all old cars and specialized in Packards and other high end old cars....I worked on some real interesting cars for a while.....I worked in the mechanical end.....engines, drivelines,brakes, you name it.

Was to slow a pace for me and the pay was poor.....Rich guys spending a fortune and we got paid coolie wages....LOL

Like they say today.....He gone....that was me....

[gmonde]

thanks guys for responses ,, I did get some helpful information from the piston manufacture as well that puts my mind at ease
gmonde

[Rich Biebel]

The more I thought about it I do recall some old engines had round wire locks....maybe some foreign stuff......can't recall anymore exactly....its been to long....