sports slipper Pistons + cheaper spares

[Ian Williams]

These are an extremely good and successful design, myself and friends here have run them for a number of years, no oil baffles and negligible oil consumption, good on you Tony for keeping them available. That said in regular road cars I also run standard Seven Workshop pistons with no baffles and minimal oil consumption, I think one of the key things is to have the reboring done by a reputable company. In my 35 years playing around with numerous sevens the only cars I have experience of with excessive oil consumption had either clapped out bores, the old wide ringed pistons, or those poor quality JP pistons that were around about 20 years back.

[Tony Betts]

Hi Tony

Many will likely be interested in the rings alone. What sort of oil ring?
Racers omit the oil baffles to reduce the power loss pumping air past the obstruction, but is reasonable road oil mileage then obtained?

hi bob,

sorry but i cant really give much away about the rings.

purly because of other so called cherrished suppliers have ripped us off in the recent past, from info we have freely given on this forum. to benifit you all

they spoil it for us all.

tony

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hi ian,

never had a problem with seven workshop pistons in the past, i used to us them when i was rebuilding peoples engine in the 1990s. 

i understand they are a copy of austins originals, so will be an expansion piston. jamie may have to answer any fitting details on these though. rather than me doing it.

i did read up on original austin pistons many years ago. but got a bit lost and surprised by the piston gap given for oversizes. i recall something like 2thou for every 20 thou over standard size piston?

also people will have to give there own opinions on expansion pistons in tuned engines, i was fine useing them in standard cars.

hope you understand all that, tony