Lock rings/spiroloks M.I.A

I pulled my engine apart and it has some old TRW's that SpeedPro now makes, part # L2443NF30 they have a 1.040 wrist pin and square groove. My engine had stock rods and were press fit so I have no retainers. Everything Speed Pro told me was obsolete, and I found some on summit made for a "1.040 wrist pin" but it does not state the O.D or I.D so how do I know it will work? Plus they are out of stock.

Speed Pro gave me the number LR169 for the new design but those are incorrect, those are for a different bore and round groove. I was also given the numbers for the old TRW design LR158 and LR179 but they apparently don't make them and I can't get ahold of a set.

All in all, I don't know the O.D of my piston groove, they told me 1.130. The only thing I can find to fit that has a larger I'D than my wrist pin so what good is it?   Does anyone have some old lock rings or know of a place to find some? I'm in a rush and waiting on balancing, we can guess on a few grams but I still can't put this S together!!!

I just ordered some lunati ones # LT043PL

They may be old stock they do not appear on lunati's site

I've also got them from Diamond pistons in the past and probe should be able to get the for you too.

I can only find them on Jegs, I just placed an order but I'll call tomorrow and make sure they do in fact still have them as the estimated ship date is the 3rd. I called Diamond previously but the tech guys were out to lunch. Do you know what the O.D needs to be for them? I'll call them tomorrow, they are 45 minutes from me so I could get them faster. My old boss may even have some if I know what exactly it is that I need.

Thank you!!!

Is that your Fairlane? I Likey  

bbf-falcon wrote:Is that your Fairlane? I Likey  

Yep that's it! That was the day I bought her, sitting in my old job's shop. Bought it just down the street from work, that's the engine I'm building because I found out the hard way it has 14.3:1 compression   now it's going to be faster, spin higher rpms, be able to handle nitrous, and look waaaay nicer   

Pistons are at my friend shop he's doing a balance for me. I'll measure them when I get them back but it will probably be to late for ya.

dfree383 wrote:Pistons are at my friend shop he's doing a balance for me. I'll measure them when I get them back but it will probably be to late for ya.

Hey, anything helps. And being that you already have them and it's being balanced, do you happen to know the weight? If I could trouble you for the weight of 4 of them I could tell my crank guy and he could get it balanced out while I'm waiting on parts.

i needed some snap rings for the same old trw's and napa had them.
dont have a p/n cause its been a few yrs but it was in one of theyre assorment drawers.
take a piston with you and a pr. of snap ring pliers.

bbfstanger wrote:i needed some snap rings for the same old trw's and napa had them.
dont have a p/n cause its been a few yrs but it was in one of theyre assorment drawers.
take a piston with you and a pr. of snap ring pliers.

No kidding? I'll try to find them at Napa tomorrow, we have an assortment at work and of course the size I picked snaps in but is loose in the bore and the next size up is too big   

I found an extra one that came from diamond

OD is 1.140 weight is 1.9 grams Ea

Watch using the snap rings they are ment fore different grooves.

dfree383 wrote:I found an extra one that came from diamond

OD is 1.140 weight is 1.9 grams Ea

Watch using the snap rings they are ment fore different grooves.

Thanks, that's what I needed! And what do you mean? Is it something to do with the thickness? The one's you have from Diamond are Spirolocks or snap rings?

.050 thick Spirolocks.

The groves in the piston are different. If they came with spirolocks use spirolocks.....

bb429power wrote:I pulled my engine apart and it has some old TRW's that SpeedPro now makes, part # L2443NF30 they have a 1.040 wrist pin and square groove. My engine had stock rods and were press fit so I have no retainers. Everything Speed Pro told me was obsolete, and I found some on summit made for a "1.040 wrist pin" but it does not state the O.D or I.D so how do I know it will work? Plus they are out of stock.

Speed Pro gave me the number LR169 for the new design but those are incorrect, those are for a different bore and round groove. I was also given the numbers for the old TRW design LR158 and LR179 but they apparently don't make them and I can't get ahold of a set.

All in all, I don't know the O.D of my piston groove, they told me 1.130. The only thing I can find to fit that has a larger I'D than my wrist pin so what good is it?   Does anyone have some old lock rings or know of a place to find some? I'm in a rush and waiting on balancing, we can guess on a few grams but I still can't put this S together!!!

The original L2443's with the square-cut clip grooves never came with Spirolox but were intended to be used with Tru-Arc snap rings, two snap rings per side, which is 4 snap rings per piston.

Sometime after the turn of the century, Federal Mogul (Speed Pro) changed the design of the square cut clip grooves to accept round wire piston clips, and those new clips should not be used in the older L2443 pistons with the square cut clip grooves. Federal Mogul stopped offering the snap rings when they switched to the round wire clips.

The snap ring size is a standard snap ring as available at your local hardware store; I have an incomplete set of original clips and could match to the correct size if need be. Incidentally, it is absolutely paramount that the snap rings be installed in a very specific manner, otherwise the risk of them getting "kicked out" of the pistons is increased dramatically (regular incorrect clip installation gave the snap rings a bad name and might be why Federal Mogul went to the round wire clips).

The nice thing about the original L2443's is that the original square cut clip groove dimensions coincide with a spirolox locking ring, usually the 0.042" thick locking ring, which again means two per side or 4 per piston.

Given the choice between the snap rings and the spiral wound locking rings, I'd recommend the locking rings.

Good info! I tried two spirolox today at a reputable engine shop I know and they were too thin. He is ordering snap rings for me and will get back with me tomorrow, what do I need to know about the installation other than putting the square side against the pin and radius side out? And then the opposite direction for the outside one.

bb429power wrote:Good info! I tried two spirolox today at a reputable engine shop I know and they were too thin. He is ordering snap rings for me and will get back with me tomorrow, what do I need to know about the installation other than putting the square side against the pin and radius side out? And then the opposite direction for the outside one.

Yes, when installing the snap rings:

• At each end of the wrist pin, install the two snap rings so that the "domed sides" face each other. In other words, when the snap rings are stamped out during their manufacture, the top-side is smooth and the backside is burred all the way around its edge from the punching process.  Always face the smooth, top sides together; the burred backsides face away from each other (one backside toward the wrist pin and the other backside toward the cylinder wall).  This way, the burred edges of each snap ring will not hang up on each other during installation.
  
• At each end of the wrist pin, install one snap ring so that the ears of one snap ring face 12 o'clock and the second ring's ears face 6 o'clock.
  

All that said, I stil feel the spirolox are the preferred way to go.

What is the size and thickness of the snap rings required?

dfree383 wrote:What is the size and thickness of the snap rings required?

I took an original snap ring (from an L2443 piston set) to the hardware store and it matches up perfectly to the snap ring intended for a 1-1/16" application. I measured them to be 0.048" thick but 0.050" is likely the intended thickness.

McMaster Car lists them here (part number 99142A470) at $8 for a bag of 25:

http://www.mcmaster.com/#99142a470/=slhnnn

The above link includes a print/drawing if you scroll down the page, and the dimensions for the clip in its free-standing state (lower right corner of drawing) are identical to the original clips provided with the pistons.