Re: overdrive question

[Chuck Arnold <chuck.arnold@oracle.com>]

Anybody know how you increase the pressure in an j Type?
Chuck

Larry Young wrote:

>I used to race with an overdrive and I'm planning to go back to it.  The 
>big difference between A and J types is that the A type uses an 
>accumulator which is held at high pressure by the pump.  The J type 
>pumps only during engagement.  I believe the A type is better because it 
>engages faster due to the use of the accumulator.  The J type will take 
>some time to pump up.  The pump in the A type will consume a few tenths 
>horsepower, but you also get oil forced to most of the bushings in the 
>transmission and overdrive.  The best A-types are the ones with the 
>large accumulator used in non-IRS cars.  A lot of TR4 overdrives have 
>ended up in big Healeys, since only the works Healeys had the large 
>accumulator. Most people modify it for higher accumulator pressure for 
>even faster engagement.  You get a nice little kick in the butt when 
>shifting into overdrive.