lighter wrist pins?

[Aircooled4evr]

Are there places you can buy lighter wrist pins separately?
I just bought a set of 92' 964 100mm cylinders & pistons, and was a little surprised the wrist pins weighed in at 139g. Found a old one from a 911 3.2. with exactly the same dimensions just thinner, at 120g!
Either you could buy such a set, and save 19g per piece.?
Or could one buy them even lighter, at original sizes?

Cheers.

[Flat6pac]

We would just order them from the shops that were known for machine work.
I would think whoever does your heads is capable
Bruce

http://forums.pelicanparts.com/uploads26/4ACBD157_96B1_4630_A9D4_FD21BB7C03C81601242051.jpg

[Dpmulvan]

Anyone with a lathe or mill can easily lighten your wrist pins.

[safe]

Is there an "ideal" wrist pin size?
Can you make a lighter stronger pin by using a larger diameter?
Porsche increased the size from 22 -> 23 on the 3.2.
The 924 has a 24 mm beast of a wrist pin, while most aftermarket pistons use a 22mm.

[stownsen914]

Perhaps JE or CP could provide ones like they include with their own pistons.

Personally, for a highly stressed part like a wrist pin, I’d prefer a proven off the shelf part than modifying.. I’d worry about what the ideal dimension/weight should be. Machining would need to be done carefully if you went that route, to avoid introducing a stress riser.

[Aircooled4evr]

Originally Posted by Flat6pac

We would just order them from the shops that were known for machine work.
I would think whoever does your heads is capable
Bruce

http://forums.pelicanparts.com/uploads26/4ACBD157_96B1_4630_A9D4_FD21BB7C03C81601242051.jpg

wow! That was light!
Is this from a post? I can only see this one picture ...
I do the heads myself, but haven't the gear to grind hardened steel.

[Aircooled4evr]

Originally Posted by safe

Is there an "ideal" wrist pin size?
Can you make a lighter stronger pin by using a larger diameter?
Porsche increased the size from 22 -> 23 on the 3.2.
The 924 has a 24 mm beast of a wrist pin, while most aftermarket pistons use a 22mm.

Yup. 23mm ... That's the dimension of my new pistons wrist pin ....
Joke aside, There is an ideal size-type wrist pin, relative to the engine type, NA, Turbo, weight of piston, 6 or 9000 rpm. etc.
I was just wondering why the "new" piston, which is lighter than my old 3.2, has a much thicker, and thus heavier, wrist pin.

[Aircooled4evr]

Originally Posted by stownsen914

Perhaps JE or CP could provide ones like they include with their own pistons.

Personally, for a highly stressed part like a wrist pin, I’d prefer a proven off the shelf part than modifying.. I’d worry about what the ideal dimension/weight should be. Machining would need to be done carefully if you went that route, to avoid introducing a stress riser.

This was also my hope, however can't find them seperate anywhere ... Sure I'm looking in the wrong places.
I know one can grind them conical on the inner diameter, out on the two contact surface of the piston, but would also prefer a tried and tested from a reputable company!

[Aircooled4evr]

Originally Posted by Dpmulvan

Anyone with a lathe or mill can easily lighten your wrist pins.

Depends on whether they also have the right tool for their lathe - mill.
You can't just cut in hardened steel. You have to grind instead.
And you have to be very careful with the surface finish!

[stownsen914]

I'd think that if you call JE or CP, they'll be able to help you

[brighton911]

I can confirm that the wrist pins CP supplied with the 98 mm pistons I used were considerably lighter than stock.

[Flat6pac]

That was the only picture I took for the for sale section
Bruce

[Neil Harvey]

Don't stop at the piston pins. Lighten everything. This is free performance you lose just turning that monster over.

63 grams is a really good weight. Our smaller diameter pins weigh this amount. Pistons are in the 370 gram range and the steel Rods around 460 with bolts.

Now, lose some of that valve spring pressure and you are on your way to a fun engine.

What does a stock 964 engine produce? 250 ft/lbs? Then each cylinder is producing 42 ft/lbs give or take.

Lose the weight!!!

[Aircooled4evr]

Originally Posted by Neil Harvey

Don't stop at the piston pins. Lighten everything. This is free performance you lose just turning that monster over.

63 grams is a really good weight. Our smaller diameter pins weigh this amount. Pistons are in the 370 gram range and the steel Rods around 460 with bolts.

Now, lose some of that valve spring pressure and you are on your way to a fun engine.

What does a stock 964 engine produce? 250 ft/lbs? Then each cylinder is producing 42 ft/lbs give or take.

Lose the weight!!!

I totally agree with this mindset! I'm lightening all the parts I can!
I'm willing to spend a lot of money on the project ... But I'm not MADE of money, so I have to do most of it myself, the old-fashioned way.
I drool over your super cool, and light parts !! But I don't even dare to ask about the prices..
P.S. unfortunately I don't have a clue regarding the American way with ft / lbs, oz, mpg, F and all that ..... I'm on the metric system.

[tx93086]

I am all for making parts light weight, but it does not add any power to the engine and the weights you are describing are not going to be a factor in the life of your rods unless you are Erving it so high that it is on the verge of distraction.

[tx93086]

Distruction, darn spell check.

[Aircooled4evr]

Originally Posted by brighton911

I can confirm that the wrist pins CP supplied with the 98 mm pistons I used were considerably lighter than stock.

Was that with 23 mm wrist pins? Do you remember their weight?

[motorracer]

I don't no the weight but they are light
they might be cmw from a 3.3 turbo

[BadToTheBown]

Have you considered Titanium? I have a pair in one of my Beemer boxers, they should be DLC'd and use bronze small end bushings (tribology in this combo will not gall)...best of luck...

[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