BIG BORE ENGINE ADVICE

[Spike]

hi, have been looking into building an engine for the clio and have just come purchased a set of big bore pistons, with a view to using these as a basis for a complete engine build.
the pistons are forged by CP and i think they are in 2618 ally but not absolutely sure.
i have heard a few horror stories related to overbores on the v6 particularly siezure issues where the liner breaks at the top and gets dragged down giving catastrophic failure, any info or comments on this??
also a point that i find confusing is that the pistons are nominal at 93mm meaning the liner will have to be 93mm + the clearance. any advice on clearance noting they are probably 2618.
the other issue with 93mm nominal is that the rings are for a 93mm bore and will have excessive end gap at anything over 93mm, causing rediculous blowby.
has anyone had any experience of these pistons or even built a v6 reno engine to anywhere near this spec. if so what liners to use and mainly what sort, wet or dry?
my main choice for this route is that from the outside everything will be std, (no blower, nitrous etc visible).
total capacity will be just under 3.4 litre with a std crank and i would expect to see 10-15% increase in torque at this capacity, i have no idea on how much power this will make and quite frankly not interested, i am looking for the major increase to be between 4000 - 6000 rpm and be very streetable.
any valid info and comments, including guidance if poss, would be appreciated.

 

[Brett]

Based on what me and friends have used, Total Seal rings are the way forward for sure. This year we stripped down my mates 8.3 Pro Street motor before the season began and found the typical bore wear and piston slap a year of abuse would throw at it. We put it back together with a higher c/r, upgraded cam and different rings ie Total Seal ones. First good news this winter was that it ran strong all year long and the second was that on every rebuild through the year we realised the expensive soft forged pistons and bores were in much better condition than previous seasons.
Might be worth while getting a set for your build Spike. Seemed to work relly well considering the Pro Street drag motors run from cold to hot all weekend long.

 

[Spike]

i am looking at the total seal rings but still have an issue with the size, have contacted them in the states a i have an issue with the importer here.
are the rings you are using hard or a soft ring, and are they ring in ring or overlapping?
still need info relating directly to the clio though.

 

[Brett]

They are the overlap type and pretty sure they are soft as they are on cast iron and for lots of cold starts. If you have issues getting stuff from the states then let me know. Many of my mates have really good reliable importers that can get anything.