8070 crankshaft

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   I'm working on an 8070 with a bad rod journal.New crank is extremely high and used are in short supply.Local salvage wants to sell a complete engine out of N series combine.This counterbalanced crank was only used in 7080,7580,8070,4W-220,and N5 N6 combine.Opinions -anyone. Grind it,keep looking for used[anyone have one],roll the dice on the combine engine.Also,would you be afraid of a standard crank like out of a 7060 at a few hundred higher R.P.M.  Thanks for any input.

	This site is not affiliated with AGCO Inc., Duluth GA., Allis-Chalmers Co., Milwaukee, WI., or any surviving or related corporate entity. All trademarks remain the property of their respective owners. All information presented herein should be considered the result of an un-moderated public forum with no responsibility for its accuracy or usability assumed by the users and sponsors of this site or any corporate entity.
	The Forum	Parts and Services	Unofficial Allis Store	Tractor Shows	Serial Numbers	History

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
Lynn Marshall Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 13 Sep 2009 Location: Dana, Iowa Points: 2315	Post Options Post Reply Quote Lynn Marshall Report Post Thanks(0) Quote Reply Topic: 8070 crankshaft Posted: 23 May 2010 at 2:09pm
	I'm working on an 8070 with a bad rod journal.New crank is extremely high and used are in short supply.Local salvage wants to sell a complete engine out of N series combine.This counterbalanced crank was only used in 7080,7580,8070,4W-220,and N5 N6 combine.Opinions -anyone. Grind it,keep looking for used[anyone have one],roll the dice on the combine engine.Also,would you be afraid of a standard crank like out of a 7060 at a few hundred higher R.P.M. Thanks for any input.

Sponsored Links

DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 20942	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 23 May 2010 at 7:25pm
	If it has discolored the journal (even tho it might not be cracked) it has taken out some of the hardness and will someday fail on that journal. Imagine taking a grade 8 bolt and heating it will a torch until almost red and letting it cool off.......it probably isn't gr 8 anymore.

Kcgrain Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 24 Sep 2009 Location: Wisconsin Points: 774	Post Options Post Reply Quote Kcgrain Report Post Thanks(0) Quote Reply Posted: 23 May 2010 at 7:40pm
	The standard crank, does not have the counter weights, other than that they are the same, Like the Dr said i wouldnt try to reuse yours if its blued or ground in to. You dont need RPM to make the 170 hp of a 8070, and in my opinion the only reason they were counter balanced was to make up for the poor fuel delivery of rotary style pumps at high HP applications. An inline pump evens out the balance between the cylinders, which doesnt require the counter balancing to keep the engine running smooth at Hi RPM and fuel delivery. There are used counter balanced cranks available at salvage yards, like all states ag $850, its only 50 bucks more than the standard crank, and thats already ground and or polished.Before Id buy a crank, and over haul that motor I would first determine why the rod spun, and take care of that issue, like was the radiator plugged and it was over heating, is the valves shot so you have uneven cylinder pressure, is the injectors any good and in corretly, is the pump operating correctly. A cheap over haul of a crank , piston and liners will not be cheap in the long run.