lighter wrist pins?

[KTL]

Originally Posted by 911pcars

Hmmm. Wonder why PAG went from 22mm to 23mm wrist pins? To add more weight?

Making a part lighter is all good to reduce static and/or reciprocating weight, except it's knowing how much to lighten and where to remove the "excess" weight. The consequences of going too far can be catastrophic unless budget isn't an issue on your build (or rebuild) list. Go for it, but with some knowledgeable direction.

Sherwood

Sherwood,

I think it was a "business decision" in that they simply pirated the 3.3L rods and crank from the 930 engine. So all they had to do is tweak the piston pin size and pin height in the SC 95mm pistons and there you have a 3.2L. In other words, I think I know what you're getting at- no compelling reason to use fatter 23mm pins in a 3.2L Carrera engine that makes not a whole lot more power than the 3.0L SC engine?

I recall looking on JE's site years ago for piston pin specs. Their tech info page was helpful in seeing the breakdown of their part number. With that breakdown you could see what the pin makeup was and go through their pin catalog via dropdown boxes to select your size, length, diameter, wall thickness, etc. and produce a list of pin offerings you may want to consider.

Their current site seems to be a watered-down version of the old site and doesn't have that feature anymore.

[Aircooled4evr]

Sigh...
It wasn't possible for me to get/find lighter 23mm wrist pins for the 3.6 pistons ...
So now i'm making them myself .... The originals are at 140g (WAY too heavy), I'll get them under 100g.

If you want something done, do it yourself!

[930cabman]

Originally Posted by Aircooled4evr

Sigh...
It wasn't possible for me to get/find lighter 23mm wrist pins for the 3.6 pistons ...
So now i'm making them myself .... The originals are at 140g (WAY too heavy), I'll get them under 100g.

If you want something done, do it yourself!

True. Lighter is better, but there is quite a bit of stress in the pin.

[Ollies930]

If you want quality wrist pins, try Trend Performance.

Wrist Pins

They can make anything you want in your choice of multiple materials and finishes. Best compromise for weight and value per dollar would be their tool steel wrist pin. Nearly twice as strong as standard wrist pins, if I remember correctly. But do not get carried away with making it too thin. A pin does not have to fracture to be bad, the problems start with a pin that flexes too much and starts galling/seizing in the piston pin bores.

[Aircooled4evr]

Originally Posted by Ollies930

If you want quality wrist pins, try Trend Performance.

Wrist Pins

They can make anything you want in your choice of multiple materials and finishes. Best compromise for weight and value per dollar would be their tool steel wrist pin. Nearly twice as strong as standard wrist pins, if I remember correctly. But do not get carried away with making it too thin. A pin does not have to fracture to be bad, the problems start with a pin that flexes too much and starts galling/seizing in the piston pin bores.

thanks.
Have tried them. But (at least not me) can't more than find their side. Nothing on the site actually works?!

[Aircooled4evr]

Further more. I HAVE started on the wrist pin's.
Bought the metal, designed/drew them in 3D. And thus determined their thickness, shape and weight.
Standing posing over the lathe to machine and polish them. Have talked to the companies that are going to harden them,
and plasma-nitrate them. Will do the lapping myself, and bring them to final tolerance.

[930cabman]

Originally Posted by Aircooled4evr

Further more. I HAVE started on the wrist pin's.
Bought the metal, designed/drew them in 3D. And thus determined their thickness, shape and weight.
Standing posing over the lathe to machine and polish them. Have talked to the companies that are going to harden them,
and plasma-nitrate them. Will do the lapping myself, and bring them to final tolerance.

Great news, keep us updated with your progress

[gorskined]

Grinding hardened wrist pins are not an easy task, they can’t be cut and needs to be ground and is super time consuming.( tape pin, set up grinder and vacuum, grind, remove tape, clean weigh repeat about 5 times per pin ) . not to mention guys with expensive metal lathes don't like to grind the super fine hardened dust partials gets everywhere and causes lathes to prematurely ware out and get sloppy . i balance my 6 pistons by grinding the id of the wrist pins in all i had 21. grams to remove from the 5 pins to make all my pistons and wrist pins equal in weight took about 7 hours ( tape pin, set up grinder and vacuum, grind, remove tape, clean weigh repeat )

[Aircooled4evr]

This is exactly the reason why you need to finish processing/treating your wrist pin's before you harden them! All I have to do after hardening is "lapping" them. Not quite sure about the finished surface treatment yet. (maybe DLC coating?) So I can't start the hardening process yet.

[Bill Verburg]

The tapered Mahle pins used in the 993 RSR are

23 x 13 (tapered) x 50mm R 98g 4394409

here are the other 23s they offer
23 x 13.5 x 55.6mm CH 119g 9299621
23 x 13.9 x 63.5mm CH 131g 9301712
23 x 13.5 x 57.404mm R 123g 9298392

[Aircooled4evr]

Originally Posted by Bill Verburg

The tapered Mahle pins used in the 993 RSR are

23 x 13 (tapered) x 50mm R 98g 4394409

here are the other 23s they offer
23 x 13.5 x 55.6mm CH 119g 9299621
23 x 13.9 x 63.5mm CH 131g 9301712
23 x 13.5 x 57.404mm R 123g 9298392

Hi Bill Verburg.
Can you guide me in the direction of the thickness of the:
23 x 13 (tapered) x 50mm R 98g 4394409 ?

My "problem" is the choice of 964 pistons.
Their wrist pins are 23 X 60 mm. So this is my path.
Mine are calculated. to 98g

[Bill Verburg]

Originally Posted by Aircooled4evr

Hi Bill Verburg.
Can you guide me in the direction of the thickness of the:
23 x 13 (tapered) x 50mm R 98g 4394409 ?

My "problem" is the choice of 964 pistons.
Their wrist pins are 23 X 60 mm. So this is my path.
Mine are calculated. to 98g

I never measured but here's a pic of mine

[Aircooled4evr]

Here is the "design" of the wristpin. I have chosen the depth of the "tapered" end
(? .. concave?) so that it does not intrude over the support points on the piston. (I am familiar with the directions of forces in different materials) They are of course 23 X 60 mm. the steel chosen is: "Dievar" from Uddeholm. The curing process is determined by their use, alloy type and thickness. (which is a bit of a secret until they are produced.)

[Aircooled4evr]

Wrong picture above…

[dannobee]

Diamond shows an off the shelf pin 23mm x 2.250" in H-13 tool steel (Rc-54) at 104gm for $28/ea.

I'm sure that any of the regular custom pin manufacturers can make you whatever you want with far less work than what you're doing. You just need to make some phone calls. Diamond, BWE, Precision Products Performance, and even Trick Titanium (not to mention some of my custom go-to guys) will all do lightweight pins and save you many headaches. Piston pins are not just something you whip up in your garage, even if it IS equipped with a lathe and a mill. Ask some of the experts.

And if the numbers on your rods and pistons are accurate, I'd be looking to shave some weight off of there way before the wrist pins. JMHO after racing for 3/4 of my life.

[Aircooled4evr]

My pin has to be 2,362 ".... I'm confident in my choice of a newer alloy, Dievar. It's better than H-13 tool steel.
I've been on the phone with the right companies. Either there is a language/information barrier, or they just don't bother with a little trade, out of the states?
Either way, they can't help me. Must also admit I am getting fed up with the trading conditions across the Atlantic! Once the wait is over, you end up paying an expensive freight .. AND tax, customs & VAT ... (of the freight also of course) they aren't quite that cheap by then!
So why not make them myself, when I actually can?
Anyway, I'll be driving around feeling pretty cool by then ...

[winders]

Until one of your wrist pin fails and you engine eats itself......

[Aircooled4evr]

Originally Posted by winders

Until one of your wrist pin fails and you engine eats itself......

With the latest in alloy steel, (Diavar.) The latest in curing processes, vacuum curing and vacuum tempering, surface nitriding. Lapping maybe CCDIA surface ...

P.S. I have access to the same quality assurance / process as the big players, ie: the auto industry.

I think you lose a pin before I do ....

[winders]

You know more about wrist pins than CP???

[Ollies930]

Do you have the specs for Diavar and how does it compare to a high quality tool steel?