power block for JD 70

[Anonymous-0]

I know someone that has a 7-2 power block in his JD 70. He would like to know the bore diameter and any other information differing from the JD specs.

Thanks for any information you can provide.

Wes

 

[Mike Aylward]

Wes, the bore diameter is 6.5". When installed the compression was increased as well. I don't have my old catalogs where I can put my hands on them now to give the exact figures on compression. Perhaps Duane can give the exact figures. They will make a 70 pretty healthy. Mike

 

[Duane Larson]

The 70 power block was the last to be introduced, in 1962. The bore size was increased from 5 7/8 to 6 1/2", displacement was increased from 380 to 464 cu in, the compression ratio increased to 6.5 to 1, and if LP pistons were used the ratio went to 8.1 to 1. Between 12 and 20 Hp were added.

 

[Anonymous-0]

Thanks for the responses guys. That's exactly the information that I was after.

Wes