Mercury crankshaft

Hey Pete, so this was done to take weight from the " reciprocating weight " so would the " rotating weight " need to be lightened this much as well ?
Or do you think it took this much to get the reciprocating weight down low enough to balance the rotating assembly ?
I am finally building the blower engine you ground the cam for me for, do you think this crank would be a good candidate for this engine, ross pistons, scatt rods .. ?
Thanks ..
 
I will repeat my previous question : Has anyone seen a crankshaft removed from a running engine that looks like this? I know I haven't. I don't think this is a "factory" modification; it's too crude. Run it at your own risk.
 
elwood said:
Wow, I wonder what happened to this crankshaft ..
Ive had this Mercury crankshaft for a few years, and Id like to use it, but not sure if it would hold up, It is somehow cut close the rod journal, never seen this before.
Casting flaw ?
Click to expand...


elwood, Is there any chance you saved any bearing inserts from this engine?
If so, look at the backs. If original, there will a Ford logo or similar. If replacement inserts, there will most likely be a date code and brand insignia stamped on the back (along with any undersize). If original inserts, you will know that this crank lived a long and happy life, and will be good for more.
If replacements, the date code will give a good idea of how that crank lived after overhaul.
 
I seem to recall, years ago, reading an illustrated article by Barnie Navarro, where he showed how he radically lightened a crankshaft. Must have removed close to 30 % of the original mass. As I recall, the procedure would've used several cutting discs in a 7" grinder.
Much more radical than this 'small' piece removed from the throw on the crank pictured by elwood
 
We hot tank cranks to remove oil, etc, then remove plugs, if any, and flush the passages with air pressure. We check balance before and after grinding and polishing. Unless there has been some bad work, or other damage, rebalancing is usually not a problem.
 
I have personally removed at least 2 . From running engines , one had sucked a foreign piece down the carb ? Ruined one piston . Rehung a piston , new rings on it and sent it . Can't remember why the rebuild on the other but the boss said it lasted this long it'll last another 10,000 . Which was his shops warranty .
 
The judgement whether to use it or not should be based on balance results. Pure and simple


Alan - no on the oil
 
Hey 40 Deluxe, this crank was bought off ebay years ago buy a friend of mine, so theres no way to tell abought the brgs ..
 
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