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tips, technology, tools and techniques related to vehicle driveline components

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crashbash
david bash
st. charles
(215 posts)

Registered:
01/28/2008 10:53AM

Main British Car:
1979 MGB Rdst V8 project, 1968 MGC GT, 1969 MGB Rd olds 215

300 crank dampener
Posted by: crashbash
Date: April 05, 2011 01:46PM

Do any of you know some options for a dampener on my 300 crank in a 215 olds block? I may have the stock one laying around but I'm thinking there are better alternatives on the market. Would like engine to be internally balanced when I'm done.


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: 300 crank dampener
Posted by: roverman
Date: April 05, 2011 02:25PM

David, your new "bob weight", will determine how much Mallory/heavy metal,(expensive), you will need to internal balance. Stock 300's have quite a bit of ecentic weight on their dampener/flexplate.I believe, 4.0/4.6L engines are internal balanced,(better). Good Luck, roverman.


tr8todd
Todd Kishbach

(390 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: 300 crank dampener
Posted by: tr8todd
Date: April 05, 2011 07:34PM

You could internally balance then install a Rover balancer and flywheel. As Roverman said, the Rovers are internally balanced which makes the balancers and flywheels zero balanced and interchangeable. Shouldn't be too bad. You get into lots of Mallory with the offset grinding of the 4.6 cranks.


crashbash
david bash
st. charles
(215 posts)

Registered:
01/28/2008 10:53AM

Main British Car:
1979 MGB Rdst V8 project, 1968 MGC GT, 1969 MGB Rd olds 215

Re: 300 crank dampener
Posted by: crashbash
Date: April 06, 2011 11:23AM

Here's the story: I purchased 300 crank with mains already turned down for 215, forged pistons, forged rods, and aluminum flywheel. No dampener included. I understand this rotating assembly was intended for an aircraft engine ap. The crank appears to have already been balanced with what I assume to be Mallory. I am having a shop recheck this assembly to make sure it is in fact balanced. The shop tell me a dampener is something I need to come up with before he can do this. There seems to be a difference between internal and externally balance dampener according to the literature and they are not cheap. Dan J. suggested I have the stock one revulcanized, and I also have to consider pulley config.
So are the high tech dampener worth it? Has anyone done this exact build and what did you use. thanks


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: 300 crank dampener
Posted by: roverman
Date: April 06, 2011 02:04PM

David, If your crank already has heavy metal, for test purposes, perhaps start with a Rover dampener, as suggested. You didn't state "what" rods, but I suggest up-graded fasteners. For real serious Rovers, I use all steel, Fluid Dampeners from sbc's, bore/hone them to size and re-broach the key way. Good Luck, roverman.


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