Author Topic: Alternate pistons for DT/SW models  (Read 2383 times)

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Offline Doug

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Alternate pistons for DT/SW models
« on: 20 Oct 2012 at 03:09 »
What are the current suggestions for alternate pistons for the 500 and the 600cc DT/SW models? I get asked time to time, but can not answer as I have been using reworked pistons of unknown origins for my SW5, and I cast my own for the 600cc models years ago.

I know some of the folk sprinting use (or were using) Arias Pistons. Considered good, but heavy (forged design) and expensive (made to order). Anyone come across a existing production piston that was found to suit the bill? One of the challenges is the short pin to crown distance of the Dougie OHV engine and the fact the valve pocket orientation is generally 90 degrees out from all other manufacturer's layouts.


Offline Alan Cun

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Re: Alternate pistons for DT/SW models
« Reply #1 on: 20 Oct 2012 at 10:42 »
Yes Doug,

 I have used Kawasaki pistons in my EW and E29 600. They require an 1/8 spacer under the barrels and the discarding of the small end bush and a pin that then fits tight in the rod and turns in the piston. I am pretty sure I also used these pistons in the 600 OHV models. I guess these Kawas may be obsolete now but I think they were Kawa fuel injected around 1000 or 1100 four cylinder maybe in the 90s.

regards Alan

Offline eddie

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Re: Alternate pistons for DT/SW models
« Reply #2 on: 20 Oct 2012 at 12:35 »
          In my 500? sprint motor I am using pistons from a Kawasaki Z400 twin. They are 64mm, so take the motor up to about 530cc (ideal for those who want to make use of worn out barrels), and the pin height is OK (just needs a new small end bush as the pin is 15mm dia). The top is domed but gives about the same compression ratio as the standard DT5 petrol pistons.
     Regarding the Arias pistons - from what Henry told me, the first batch they made for him were too heavy, so he sent them back to be modified. The second batch were fine and giving good results in his motors (12.18secs with 112mph terminal for the standing start 1/4 mile).
   Hope this is of some help,