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View Full Version : Why is Mallory metal so expensive?


Tim_K
09-15-2002, 10:28 PM
I've been wondering about this for a long time now. Does anyone know what the composition (alloy) is made up of? And how does that justify the price?

A few years ago, I saw a chart showing the weight of various diameters and lengths of Mallory, and the weight of what a drilled hole in a cast crank would be.

Metal drilled out + Mallory added = total weight change.


Also, I've heard of 3 naturally balanced engine configurations:

Straight 6
Horizontally opposed 6
60 degree V-12

Are there any others? Naturally balanced engines require no bobweights when balancing the crank, and as long as all the piston/ring/rod sets weigh the same, the engine will be balanced.

I had a Slant Six done about a year ago, and that's when I found this out. That information will come in handy when it eventually gets lower compression forged pistons and a turbocharger!

skankweirdall
09-15-2002, 11:08 PM
It's that expensive for the same reason Chevy's are so cheap. Because that is what someone will pay for it.

Luther
09-16-2002, 01:55 AM
Mallory metal is primarily a tungsten (W) alloy with a little copper (Cu) and nickel (Ni). Tungsten by itself is a very difficult, if not impossilble, to machine. Thus the reason for creating an alloy ("Mallory"). A very dense alloy; much more so than lead. The high cost is due to the tungsten content.

http://www.mallory.com/data/html/1300500.htm

About the only metal that I can think of that is more dense than Mallory metal (and only by a small margin) is depleted uranium. Doubt if they will let you stick that in your crankshaft.

72Challenger
09-16-2002, 02:58 AM
Another metal more dense than Mallory metal is gold, at 19.3 g/cm3. So maybe the Mallory metal isn't so expensive after all!

451Mopar
09-16-2002, 03:39 PM
Not only are you paying for the raw material, but alot of the machinest time to drill the crank, add the mallory metal, (often tack weld it in) and re-check the ballance of the crank.

pishta
09-17-2002, 01:13 AM
We all know what it does, but why do we use it? Wouldnt lightening the suspect part be easier? You add Mallory metal to the crank throw because the reciprocating mass is too heavy, why not lighten the piston/rod? I dont know, I never had to add Mallory. It just seems easier to simpelton me to lighten the heavy stuff to balance with the crank. Im sure there is a great explanation.

AndyF
09-17-2002, 01:56 AM
Typically it is used just to finish off a balance job that is close. In that case, a little slug of mallory is cheaper than taking weight off of 8 pistons or 8 rods.

Once in awhile an engine builder will get himself stuck in a corner and have to use a bunch of mallory to get things balanced. That is usually the sign of a bad combination of parts. I recently saw a 302 Ford stroker motor that this happened on. The customer got a "good deal" on a cheap stroker crank. But the cheap stroker crank required a $600 balance job to work with his trick pistons and rods. Had the customer known what he was doing he would have ordered a good crank from a good crankshop and would have been money ahead. Live and learn.

biggerhammer
09-17-2002, 03:57 AM
most balance jobs only make pistons, rods, (big end and little end are done seperate)rings, bearings, etc. all weigh the same, but to zero balance an engine(required on dry sump, recommended for supercharged or turbo-charged engines) it must completely balance the crank to a zero, meaning, as long as the other stuff all weighs the same, the crank is balanced, but is very expensive, and most cases unnecessary. dry sump engines generally use no harmonic balancer, but something different to dampen the harmonics.

Doug Wilson
09-17-2002, 04:01 AM
60 degree V6.

I have always balanced my pistons and rods myself, to the lightest one, and then had the machinist check my work. Never needed mallory metal.

Mercury is more dense/heavy, but is a toxic substance. I have about a pint of it, and it's damned near impossible for me to carry. Mercury can be used in many manufacturing environments, and is commonly found where precision balancing is required.

72Challenger
09-17-2002, 07:05 PM
Of course the problem with mercury is not the toxicity, but the fact that it's liquid at room temperature. Kinda hard for it to stay in the holes!

Doug Wilson
09-18-2002, 12:45 AM
Where there is a will, there is a way.

sanborn
09-18-2002, 01:15 PM
"Mallory" metal is expensive for several reasons. The primary metal is Tungsten, very difficult to process, and there is so little of it used, making the "setup" cost for manufacturing absorbed over a very small inventory.

It is expensive for balancing because of the base cost of the material; but, also because of the proper method of installation. Crossdrilling a counterweight, pressing in a piece of Mallory is very time consuming. The good jobs are only pressed in, when it is welded in, the machinist drilled(or bored) the hole slightly too large. Welding is then the only way to secure it.

It is very useful; for balancing a crank that has heavy components(rods/pistons,etc.), for internal balancing a crank that would otherwise have to be balanced externally(like a 360), for balancing a crank that have reduced diameter counterweights(less oil windage) or for balancing a very lightweight crank with reduced diameter counterweights and a very long stroke.

Tarrbabe
09-18-2002, 02:05 PM
Correct me if I'm wrong, but I thouht mallory metal was only used to balance the CRANK when it has been stroked, (adding weight on one side of the crank) thus the need to add weight to the other side to keep it in balance. Yes, with a lot of added weight from heavy pistons and rods, you will need to re-balance, but the main reason is to balance the crank it's self.
Jump in, please.

sanborn
09-18-2002, 08:22 PM
Tarrbabe, did my post confuse you? Let me know and I will try to explain again!

MOPARVANN
09-19-2002, 11:45 AM
Here is my little two cents worth. The 360 crankshaft must be externally balanced (weight added to the flywheel/converter and the front balancer) due to its design. This works great on a stock engine, one that normally operates under 6000 RPM, and is cost effecient. In our world ,of high performance and higher COST, it stands to reason that our crankshaft should be balanced on its own and not by adding weight on both ends. Mallory metal is costly but so is racing. I usually turn our 360 above 7000 with its cast crank and have never suffered a crank problem. I can only suggest that this success be contributed to the quality balance and machine work done by experts. Sponsor Plug-->REEVES PERFORMANCE AND MACHINE SHOP in Warner Robins, Georgia. They have extensive experience in MOPAR engines and have run them for several years. Precision work=RELIABILITY Mallory metal is like insurance for your 360 crank. Good Luck to all.

Tarrbabe
09-21-2002, 10:50 PM
sanborn,
No you did not confuse me. As usual, I didn't make myself clear. Usually mallory metal is only used to balance stroker cranks as weight is added to the throw side of the crank. If weight is added to the throw side, you must counter-balance it to return to balance. THE EXCEPTION TO THIS IS WHEN YOU WANT TO INTERNALLY BALANCE AN EXTERNALLY BALANCED ENGINE. Almost everyone knows that you must use different methods to balance externally balanced engines.
I often do not go into detail with my writings in an attempt to keep things breif. Sometimes this backfires as someone wants to jump on something they dis-agree with or they feel I didn't tell it right. I respect anyone's answer who is being constructive, as I try to be, except when I'm haveing fun sometimes, but fall short of my intended goals sometimes.
I also hope I'm not above someone poking fun at me sometimes.
I am on the road again and don't have much time now, but still enjoy the forum.

66Dart_GT
09-22-2002, 01:49 AM
My 340 crank has Mallory metal for balance as it was an externally balanced engine, itÂ’s now and has been for 5 years internally balanced and routinely twist it past 7000 with no problems,to date