Internal balance cast crank - Moparts Forums

Register Log In Moparts Forums Unlawfl's Race & Engine Tech Internal balance cast crank

Print Thread

Internal balance cast crank #2706641 10/14/19 10:10 AM 10/14/19 10:10 AM
Joined: Jan 2003 Posts: 6,388 Abilene, Texas F fastmark OP master
fastmark OP master F Joined: Jan 2003 Posts: 6,388 Abilene, Texas	Is it possible to balance a cast crank motor internally without heavy metal ?

Re: Internal balance cast crank [Re: fastmark] #2706662 10/14/19 11:25 AM 10/14/19 11:25 AM
Joined: Oct 2005 Posts: 8,861 Ontario, Canada S Stanton Don't question me!
Stanton Don't question me! S Joined: Oct 2005 Posts: 8,861 Ontario, Canada	Heavy metal is usually welded in. Cast is not easily welded so that may be one reason they're externally balanced. I imagine if all you needed to do is take weight OUT of the crank it could be internally balanced. You'd want to be drilling in the edges of the counterweights, not through them.

Re: Internal balance cast crank [Re: fastmark] #2706663 10/14/19 11:28 AM 10/14/19 11:28 AM
Joined: Jan 2003 Posts: 30,994 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 30,994 Oregon	If you use aftermarket pistons then you can usually end up with a bobweight that is low enough that the cast crank will internally balance. Depends on the combination that you're building.

Re: Internal balance cast crank [Re: Stanton] #2706825 10/14/19 08:32 PM 10/14/19 08:32 PM
Joined: Jan 2003 Posts: 6,388 Abilene, Texas F fastmark OP master
fastmark OP master F Joined: Jan 2003 Posts: 6,388 Abilene, Texas	I’m trying to fix a motor as cheap as possible just to drive until we get a good motor built. This is a cast crank 76 motor that someone just installed a neutral flywheel on the car and drive it. It vibrates. It runs fine. If we could balance it internally, that Would be the best. Not sure if you can drill the flywheel to externally balance for a cast crank. I guess you could but that would ruin the flywheel for the next motor.

Re: Internal balance cast crank [Re: fastmark] #2706829 10/14/19 08:48 PM 10/14/19 08:48 PM
Joined: Jan 2003 Posts: 3,680 South San Francisco, Ca 70sixpkrt master
70sixpkrt master Joined: Jan 2003 Posts: 3,680 South San Francisco, Ca	What about flywheel counter weights? [img]http://www.imgur.com/hxlGUJt.gif[/img] 4-speed 3:54 Dana 13.01 @107.93 with street tires (not hooking up)

Re: Internal balance cast crank [Re: fastmark] #2706836 10/14/19 09:25 PM 10/14/19 09:25 PM
Joined: Jan 2003 Posts: 30,994 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 30,994 Oregon	Yes you can drill the flywheel to balance it. The instructions are in one of the Mopar books. Any good machine shop should be able to do that if the engine is apart. If the engine is together then it is tougher since the shop will have to assume what the imbalance is. I'd think your best bet would be to buy the correct flywheel. Last edited by AndyF; 10/14/19 09:26 PM.

Re: Internal balance cast crank [Re: AndyF] #2706912 10/15/19 06:46 AM 10/15/19 06:46 AM
Joined: Jan 2003 Posts: 6,388 Abilene, Texas F fastmark OP master
fastmark OP master F Joined: Jan 2003 Posts: 6,388 Abilene, Texas	I was not aware you could buy the correct flywheel.

Re: Internal balance cast crank [Re: fastmark] #2706988 10/15/19 12:42 PM 10/15/19 12:42 PM
Joined: Aug 2003 Posts: 43,123 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,123 Bend,OR USA	Originally Posted by fastmark Is it possible to balance a cast crank motor internally without heavy metal ? Which type motor, SB or BB? I believe all the cast crank 318 motors where internally balanced Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1