MTFCA Forum

I need suggestions on these two crankshafts origin, etc. Are they cast iron, steel, who may have produced them?
Thanks!
RB

Randy,

Someone may know exactly what they are and who made them. Listen to them first and foremost...

I'm just shooting my quiver, being an exec with one of the foremost foundries in the world. (Present customer base includes Benz, Brembo, TRW, etc.)

To the best of my knowledge...the only 'currently active' foundry mark containing a TCS is for a Taiwanese company called Taiwan Cheng Shen. That doesn't mean it's theirs, just a clue. TCS was founded in 1988 so if your casting was made prior...zonk, on that clue. This clue may be a red herring...as its based on today.

Now, as to what it is...take a fairly sharp drill bit and a piece of extra sprue and touch the point with moderate pressure while turning...if it only dusts and fine powders and doesn't want to take a real bite initially, it is almost guaranteed to be cast iron. If it bites and immediately wants to make a strong chip...it is cast steel! (shhh....trade secret, left over and under the shade tree...lol)

Now...an interesting note...TCS Taiwan is noted for their ability to strictly control Meehanite pours! What the heck is Meehanite? It's a cast iron process where at the end of the day, the easiest answer is the grain structure because of all the extra control winds up being very close to that of tool steel even though iron. This imparts toughness, and, a very high degree of self-dampening.

Is that good enough for use as a T crank? Ahh...I'm not ready to say that, but also not ready to poo poo.

There was an Australian who offered cast 'something' and that apparently was a disaster but I don't know why. There was a guy named Ted D who did all of the work to get a cast iron 'formula' to be the most beneficial for the application, and on paper the absolute best solution...so much so that even the natural stiffness loss by going from Steel to Cast Iron, (while with all else the same dimensionally its a near 20% loss was apparently offset by other factors associated with his process). He went into production, and then was immediately undercut in price by the competition so he just gave up.

Let's hear from others...not much more I can add

George,
Thank you for the input! As you say, maybe more folks with offer some further input. I have no history to offer as these came from a stash of parts of a friend who died awhile back.
For now, these are just conversation pieces. It would be interesting to find out if they could machined to become decent crankshafts.
RB

ModelTSpeedster wrote: ↑

Sun Apr 28, 2024 8:28 am

George,
Thank you for the input! As you say, maybe more folks with offer some further input. I have no history to offer as these came from a stash of parts of a friend who died awhile back.
For now, these are just conversation pieces. It would be interesting to find out if they could machined to become decent crankshafts.
RB

They could be machined but as with any crankshaft of unknown origin, they would have to be crack inspected and checked for straightness prior to machining.
They don't have much radius on rods and mains ,which is interesting .
It's incredible the stuff that's found.

Cast crankshafts generally have large crankpins and main bearing journals, journal-pin overlap, and generally heavier sections throughout.
Modern cast crankshafts are often made of "nodular iron", whatever that is. Given the limited diameter of the T bearing journals, I'd think a forged crank would be much better in a T, especially for a higher output engine. However, proper counter-weighting greatly reduces certain stresses in crankshafts, so a quality cast shaft, properly counter-weighted, might do very well.
**The crankshaft pictured above looks to me like it is a foam core casting, which would indicate that it is of fairly recent manufacture.