Cast crank 340 tourque convertor???

[swinger340]

Where they are externaly balanced do they take a weighted convertor? Havnt seen any externals advertised excepy for 360. I see TCI sells the weighted flex plates for 360s but nothing for 340s. This is a stock bottom end 73 340 duster. 727 was rebuilt ,No convertor. Dont want to put wrong one in and have vibrations. Thanks for any help, Kevin

 

[northeast mopar]

Kevin, I just answered your PM. To answer the question on the balance. The early 340 had steel cranks(forged) which means they were internally balanced.
The later ones and the 360 had cast cranks whichn means externally balanced. If you bought a converter from a place like ATI it would have the balance weight on it. ANY converter can be converted to external balance by using the Chrysler weight package or taking one off and old converter. We have done it many times, and no vibrations at all if done correctly.

Dom

 

[swinger340]

Kevin, I just answered your PM. To answer the question on the balance. The early 340 had steel cranks(forged) which means they were internally balanced.
The later ones and the 360 had cast cranks whichn means externally balanced. If you bought a converter from a place like ATI it would have the balance weight on it. ANY converter can be converted to external balance by using the Chrysler weight package or taking one off and old converter. We have done it many times, and no vibrations at all if done correctly.

Dom

So do the cast crank 340s take the same weighted convertor as a 360 or does the weight amount differ between the 2? All the convertors im finding are neutral balance or 360 external. Cant find any 340 external. Good to see you on here i have heard nothing but good things about your work. Thanks, Kevin

 

[waggin]

the aftermarket flrxplates for 360 and cast crank 340 are diffrent i think I have a new one up in the loft,will look for it and it is a spare I had bought but then got another one with an engine I had bought, will try to let ya know

 

[fishy68]

So do the cast crank 340s take the same weighted convertor as a 360 or does the weight amount differ between the 2? All the convertors im finding are neutral balance or 360 external. Cant find any 340 external. Good to see you on here i have heard nothing but good things about your work. Thanks, Kevin

They do not use the same amount of weight. 73 340's used 2 weights of 25 grams each and 73-76 360's used 2 weights of 60 grams each. LA 360's after that used 1 weight that weighed 120 grams. That's a huge difference. If you use 360 stuff on your 340 it'll vibrate and destroy itself.

Have you looked at B&M flexplates. I don't know if they still do but I know they used to sell them for cast crank 340's.

 

[swinger340]

They do not use the same amount of weight. 73 340's used 2 weights of 25 grams each and 73-76 360's used 2 weights of 60 grams each. LA 360's after that used 1 weight that weighed 120 grams. That's a huge difference. If you use 360 stuff on your 340 it'll vibrate and destroy itself.

Have you looked at B&M flexplates. I don't know if they still do but I know they used to sell them for cast crank 340's.

I have looked but cant seem to put my hands on one. All I see is ones for 360s. Id be interested in buying one if anyone out there has one. I dont need any vibrations. That would suck. Especialy since its a customers car. Or i could weld 2 25 gram weights on it.

 

[70aarcuda]

http://www.summitracing.com/search/...ear/1973/Engine-Balance/External/?Ns=Rank|Asc

 

[swinger340]

http://www.summitracing.com/search/...ear/1973/Engine-Balance/External/?Ns=Rank|Asc

Awesome!!! Thank you so much. I just bought 1.

 

[fishy68]

Tony to the rescue!:cheers:

 

[oldkimmer]

...............Ur harmonic balancer will say...............use with cast crank 340 only on the ecentric weight..............kim.............

 

[swinger340]

...............Ur harmonic balancer will say...............use with cast crank 340 only on the ecentric weight..............kim.............

Yes i checked it and it does. This is a virgin block so it is balanced how ever good the factory did. Low milage car w head and cam work. Just a cruiser but i dont want it vabrating on the guy and make myself look foolish. I knew the cast cranks were external balance but wasnt sure on the weight amount.