NZ951

And what pistion options are there?

ftanguay

even with Darton sleeve they don't advise to go further than 104mm (2.7L) and technicly you can go to 108mm. I think you may go further with no sleeve... but I'm not shure about the non sleeve thing.

For the piston, the price of the Mahle with the coating for the alusil is very close to a sleeve job. I have paid 700$ for the sleeve job and 800$ for JE piston with ring and clip. But I'm shure there will be many other option.

ehall

NZ go to Clarks garage. Look in the shop manual section. Look under performance mods. There's a really good write up from Clark Fletcher on this subject, including actual cc calcs.

David Flloyds car is a 2.7+ , all bore engine. I believe he's at 106mm, and with sleeves. You can perhaps got to 106 safely in a 3.0 block, as they are much better supported at the upper end of the cylinders. That said, it's bopth cheaper, and more practical to sleeve, and re-piston, as a failure would allow you to replace iron/steel, rather than sleeve a torn up alusil block. Just my opinion. Mahle's are dumb assed expensive.

NZ951

I know about the sleeving options, I am curious about how much you can bore BEFORE you need sleeves.

ehall

I feel like what you read above, 104, unless you're talking about MID sleeves. They are a different animal altogether. GOD I WANT THOSE!

NZ951

Not talking about any sleeves, dont want to resleeve... want to not do that

fast951

With a NON sleeved engine, on the 951 I would stay 101 (maybe 102). This does not leave much in terms of cylinder walls thickness. On a sleeved engine, I think 108mm is doable (assuming you can find a HG for it).

There is a 951 with 106mm bore with nickasil plating. I'm supposed to tune it, we shall see how well it holds up.. I will not exceed 1bar while tuning it.