Latest update for those who are interested - I finally heard back from the Australian company that does the Mazda conversion and I am quoting the email below:
[ QUOTE ]
Raymond,
Yes we do these conversions, however std E5(or E3) Mazda pistons are proving hard to get,
and you need 3 sets to do 2 x 6cyls, and they come from different piston makers, so we
have to match the sets for the best effect.
Basically we go from a pressed (Mazda)gudgeon to a floating one(Triumph), this requires a
pair of circlips and machined grooves together with custom made little ends, On my
Reckoning for the run of mill conversions, with a set of rods, resized and all assembled
would set you back about US$500 plus about US$50 in postage, Is this still attractive?
Some late news! ..... In speaking to our machinist today he says that the above are
good for road cars and a bit of club work, for racing you really need to use the pistons
for the turbo charged cars, much pricier, and with you being so far away I would prefer to
send you these, pricing on these will however take a little time, bear with us.
Other Bits,
You need special head gaskets with bigger cylinder area, these are US$100 each.
Early blocks have harder cast iron, and are preferable, late heads are best as they flow better.
(We have also done conversions using Mazda pistons at +.020ins and +.040ins as the stds
become hard to get, sometimes this leads to resleeving as the cylinder wall fails, over
here it is no problem as we have found a number of engines re-sleeved by the Factory!,
so if can you get this done over there, you can go even bigger)
Here we need to keep the compression ratio at around 9.5:1 to run on our 98RON fuel,
and while I don't know the fuel RON at your place, you need to consider it when rebuilding,
especially with the 1st mentioned piston set, as even intermittant knocking will
smash the lands off the pistons!
(I'm sending this now as I'm still waiting on our engine rebuilder to come back with
pricing, he is not known for his speed, however his work is top shelf, so we wait!)
regards,
Steve Rowland
[/ QUOTE ]
So, anyone got a wore-out 6 they'd be willing to donate for an experimental buildup? /ubbthreads/images/graemlins/devilgrin.gif