Take the pan off and look at the front counterbalance.....machined or rounded from pounded.....nah. The cast crank has much more carbon than the forged. Forged has lots of alloys that the cast does not...Soooo, just take some fine paper, 1000 or so and polish the nose of the crank. Then apply just a taste of hydrochloric to etch it. The grain structure is the key.....the pounded forged has an aligned grain, and the cast has a random grain. After application of acid, use a good power loop and examine the end of the crank nose to look at grain structure. The results are obvious....and you dont have to take the pan off to figure out internal or external balance.....voila!
Cast crank, forged crank, whats the big deal.....
- Thread starter 66furys
- Start date
lemondana
Active Member
Lot of extra work, just look at the harmonic balancer.
volksworld
Well-Known Member
a pic to show the difference in grain structure would be great...
commando1
Old Man with a Hat
You're being facetious, right?
Actually, I thought it was interesting. I don't know as I would go through that exercise myself, but I found it interesting.
Not quite interesting enough to dig into it much deeper though.
We could talk about spark testing (something I have done a time or three), but I suppose taking a grinder to a good crank could be counter-productive. I think stock forged cranks are made of 1045 steel, so you'd want to look at the spark pattern/color for a medium carbon steel.
Interesting.....you need to be as old as dirt to remember such. This type of work went out with the visual look into the heat treat furnace to see color and temp. It also went the way of the German schools for engineers that would start the boys off with a file and hunk of steel.....that continued for weeks to get the feel of the stuff and how it behaved. Spark testing, who ever heard of such a thing!! I stood in a heat treat room in Germany where they removed a marine gear about ten feet in diameter from the oven that was more than dull red....and into the quench this monster went. I think if you ask todays young uns about this, they would ask about what semiconductor you were referring to.....this is why you will likely see a foreign company brought in to rebuild the bridge.
A lot of the talents of the trades are gone... Probably including spark testing.
I've heard the stories of the file and hunk of steel many times. They were handed a rough piece of steel and a file. The end product had to be square, flat and to size.
A couple years ago I took a one night blacksmithing course. It was a birthday present from my wife and it was a lot of fun. I got my bottle opener all forged and the teacher was talking about how to refine it with a file... So I grabbed a file... and the teacher is watching and saying "You've done this before I see". Next thing I know, I'm giving him a lesson in how to file something square into something round.
But speaking of heat treating. When I retired, I had a great offer to take over a one man business calibrating and repairing Rockwell hardness testers. The deal was really sweet and I did give it a lot of thought, but I was quite burnt out and needed to just stop.
I dont often talk in public about myself, but this reminds me of one of those lost opportunities. I had worked in navy shipbuilding for over a decade, and as I was exiting for other work, westinghouse electric comes up and says, we want you for the dc rep....a nice job. I could not even think about it since we had already begun the move elsewhere. Often wonder about that.
