Should piston gudgeon pin retainers be replaced at rebuild?

-
The O.P., 70 Hardtop, is what this post is about, and his stock 273 pistons are machined for stock round wire pin retainers-put spirolocks in there is wrong!
 
stock 340 pistons are machined for a single tru arc retainer, flat side facing out. some aftermarket pistons are machined for double tru arcs-inner retainer with flat facing in, outer retainer with flat facing out
 
Marcohotrod said:
stock 340 pistons are machined for a single tru arc retainer, flat side facing out. some aftermarket pistons are machined for double tru arcs-inner retainer with flat facing in, outer retainer with flat facing out
Click to expand...
Measure a spiral lock sometime.

We aren't talking about 340's and aftermarket pistols, right...
 
toolmanmike said:
View attachment 1715140589 I like the spiral locks over the snap rings myself. Don't the snap ring style locks require 2 with the flat faces against each other? I'm sure it makes a difference what the snap ring grooves were machined for.
Click to expand...

MOPAROFFICIAL said:
Measure a spiral lock sometime.

I mentioned 340s in reference to toolmans question. MOPARAFFICIAL-why do u insist that the O.P. use incorrect retainers in his pistons just because u love them. I have not had any coffee today, and u?
Click to expand...
 
toolmanmike said:
View attachment 1715140589 I like the spiral locks over the snap rings myself. Don't the snap ring style locks require 2 with the flat faces against each other?
(((((((((((((((((( I'm sure it makes a difference what the snap ring grooves were machined for.))))))))))))))))
Here's the bottom line.
Click to expand...
 
I just reused them in the in the one on the stand. Honestly if you were really concerned the pistons would have been replaced. Sometimes it's not worth overthinking when you're reusing critical parts. I would not replace anything with an entirely different style altogether. Ever. But that's me.
 
Thanks for all the replies guys, now that is a really good discussion and I have learnt heaps. I have had 3 x 340 engines but never noticed that the gudgeon pin retainers were different!

I think Marcohotrod and Moper have some good points. (former: thanks for remembering I was replacing the rods - as another member remarked, "...if I was not disassembling the pistons..."). Well it is not a performance engine rebuild as such. But still going to be way better than when it left the factory, even with used pistons, but they are in such good condition and as I said, pistons for the 273 are not as easy to come by anymore. I will not be giving the engine hell, but still the occasional blat up to redline. The wrist/gudgeon pin clips are not a stressed component as someone mentioned. I was more thinking of 30 years of heat cycles and after all, they are only wire. And I have no idea if the engine had been overheated or not, as I bought it after it had "done it's time". But the engine was as clean inside as if it had only done 50k miles.

One member's answer was, "use them until they break, then replace them" I'm not sure if this was a joke or being serious. But I will not take heed of that!

I did go ahead and buy some circlips, all of A$8.20, but thanks to many posts here, I will now critical inspect the machined groove to see how they fit compared to the original round spring wire clip. And if I use them, will install with the flat side out. I certainly won't be using a screwdriver and fingers are impossible (i'm not a cyborg). I have the special plier tool for circlips, with the different sized pins for the holes etc.

If the original wire clips seem to fit better I will reuse them and I think I will probably sleep ok

Thanks
 
You must log in or register to reply here.
-

Back
Top