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#Post#: 71647--------------------------------------------------
Titanium wrist pin
By: Chainsawrepair Date: May 4, 2016, 12:00 pm
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I know folks have tried other wrist pin materials to save
weight. Is that the reason for the new Titanium wrist pins?
#Post#: 71652--------------------------------------------------
Re: Titanium wrist pin
By: Gatekeeper Date: May 4, 2016, 6:23 pm
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That's the only reason I can think of.
#Post#: 71656--------------------------------------------------
Re: Titanium wrist pin
By: Gatekeeper Date: May 4, 2016, 7:04 pm
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That guy has some cool stuff. Just not sure it's worth all of
the expense.
#Post#: 72484--------------------------------------------------
Re: Titanium wrist pin
By: Chainsawrepair Date: June 28, 2016, 7:32 pm
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Had some old saws checked the other day and one was over 14K in
the cut in 8x8 aspen or poplar and one set very rich on first
cuts was over 13K in the cut. I always wondered as things happen
to fast to watch on a handheld tach clamped on. Not bad for a
big saw.
HTML http://dominantsaw.com/collections/performance/products/hollowpoint-titanium-wrist-pin
What they say.
Reducing rotating weight is only one part of faster
acceleration. Trimming down reciprocating weight is the other.
An engine's reciprocating mass accelerates and comes to a stop
twice per revolution. You don't want a saw spinning north of
13,500 RPM to do any extra work. That piston is coming to a halt
27,000 times a minute! Dropping few grams from equation adds up
fast and has a direct impact on the performance of your saw.
The hard numbers: If you drop 7g by switching to Hollowpoint Ti
Wrist Pin, your saw does almost 450 lbs less work per minute in
the cut. Over the life of the saw, your internals will be way
less stressed.
These are racing parts with a shorter life than the OEM
equivalent, and therefore sold with no warranty. They are,
however, very high quality and will stress your saw less due to
lighter weight.
Should fit all 12mm wrist pin saws, even those not listed. Pin
is ~35.5mm long. Some shortening of the pin may be needed to
equal the length of your OEM wrist pin and fit your saw. Grind
from the outside edge in toward the center of the hollow, in a
rotary motion, and sand/smooth in a similar way as not to have
outward facing burrs.
#Post#: 72485--------------------------------------------------
Re: Titanium wrist pin
By: Gatekeeper Date: June 28, 2016, 9:14 pm
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It is very hard to watch a tach in a cut less than a second.
#Post#: 72490--------------------------------------------------
Re: Titanium wrist pin
By: NathanielVansickle Date: June 29, 2016, 12:12 pm
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lighter rotating mass has always been a priority in high rpm
engines, would think on saws that would be even more important
based on the rpms and limited size of bearings/journals.
#Post#: 74320--------------------------------------------------
Re: Titanium wrist pin
By: oldpro Date: November 7, 2016, 5:26 pm
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I started experimenting with titanium race saw parts over 25
years ago. Like all metals titanium is available in different
alloys and grades of strength. I used the highest strongest
grade of titanium available to experiment with.
I made some titanium wrist pins,and counterbored them for
minimum weight,the ti wrist pins weighed almost exactly half
that of a stock pin. Not knowing how strong they were I put 2
into a couple of our shops demo saws(virtually new),an 064 Stihl
and a 2095 Jonsered,then sent them both out with fallers who
ran them for 10 hours a day for a week,then brought them back.I
was happy none broke! But on teardown they were both severely
worn,more than any pin I've seen.
Titanium is about half the weight of steel and extremely
strong,BUT titanium is not nearly as hard as some steel
alloys,and quality wrist pins are made of tool steel,very hard
material. I looked into chrome plating them but it's not
possible with titanium.
Therefore I only consider ti wrist pins for racing,not for
modified work saws.
Among other racing parts I used it for, I designed and built 3
titanium race cranks with full circle counterwieghts(For high
high crankcase compression ratio) and longer stroke,in these the
titanium is ideal.
Reciprocating weight can be saved by lightening the piston or
running 1 piston ring,which many Pro competitors do...
#Post#: 82009--------------------------------------------------
Re: Titanium wrist pin
By: Chainsawrepair Date: March 28, 2018, 11:17 am
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Just read this on the Ti pins on their website. Nope not for me
at all.
How To Blow Up Your Saw With A Titanium Wrist Pin
Posted by Bill Lockwood at Feb 12, 2018
The short answer: Install One!
Dominant Titanium Wrist Pin
However, with careful observation, and a pledge to yourself and
your saw not to gamble, a Dominant Hollowpoint Wrist Pin will
"wow" your friends and impress your neighbors.
Here's what we send out with our wrist pins:
These are racing parts with a shorter life than the OEM
equivalent, and therefore sold with no warranty. Despite a
very-noticeable performance increase, they will fail after 35
(or less) tanks of fuel in a ported 372xp running our piston.
They are, however, very high quality and will stress your saw
less due to lighter weight.
#Post#: 82010--------------------------------------------------
Re: Titanium wrist pin
By: Chainsawrepair Date: March 28, 2018, 11:18 am
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more
Reducing rotating weight is only one part of faster
acceleration. Trimming down reciprocating weight is the other.
An engine's reciprocating mass accelerates and comes to a stop
twice per revolution. You don't want a saw spinning north of
13,500 RPM to do any extra work - that piston is coming to a
halt 27,000 times a minute! Dropping few grams from equation
adds up fast and has a direct impact on the performance of your
saw.
The hard numbers: If you drop 8g by switching to Hollowpoint Ti
Wrist Pin, your saw does almost 450 lbs less work per minute in
the cut. Over the life of the wrist pin, your chainsaw's
internals will be less stressed. Hollowpoint ti pins weigh about
9g, which is about half the weight of our Wiseco pins (about
17g). These run up to 0.0015" undersized for power gains, but we
have found differences of a thousandth of an inch in all the
manufacturers pins.
Failure. In our experience, the way these fail is the DLC
coating on the pin wears, losing dimension inside the wrist pin
bearing. This causes galling of the titanium, which eventually
overheats and destroys the wrist pin, sending the roller
bearings through the transfer ports, which, at 15,500rpm, will
then “pin” the piston to the cylinder. It’s a very destructive
failure. So, listen to your saw, set a limit to how much you run
it before checking the internals, and change out the wrist pin
early.
Fits 372 and some others with no modifications. Will fit all
12mm wrist pin saws, even those not listed. Pin is ~35.5mm long.
Some shortening of the pin may be needed to equal the length of
your OEM wrist pin and fit your saw. Grind from the outside edge
in toward the center of the hollow, in a rotary motion, and
sand/smooth in a similar way as not to have outward facing
burrs.
#Post#: 83977--------------------------------------------------
Re: Titanium wrist pin
By: trappermike Date: January 1, 2019, 12:44 pm
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I taperbore wrist pins and that's enough. I don't make claims of
15,000 rpm as this is meaningless,what counts is the rpm's the
saw turns in the cut under ideal conditions,my tests showed a
strong 100cc hotsaw under full load cutting at around 11,500. I
tach my hotsaws in testing. The pipes are designed for peak
power at the peak rpms they actually turn in the cut.
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