Piston / Cylinder Options for a 2.7L

[The Watson]

I'm trying to understand what the options are for new P&C's for my 2.7L. I see options for 90mm up through 93mm. Does going with a larger P&C combo require other changes to block, head, etc? If not, why not do it?

My initial intent was to go with 90mm LN Nickies with 9.5 compression JE pistons. But what about these larger P&C combos?

I'm replacing Mahle Alusil and want some extra umphhh

[Trackrash]

What are the 93s? Mahles? That would be a great option, if they are available and affordable.

[Flat6pac]

92s are bored out cylinders and JE pistons making a 2.8
Your cylinders are bored and nikisiled, JE makes pistons at say 9.5 and you have a 2.8
Bruce

[The Watson]

So is the base of the cylinder larger if over 90mm, requiring other mods ?

[The cap'n]

Boring your cylinders results in a larger bore, not a larger outer diameter. No alterations to the case will be required for this modification

The Cap'n

[dipso]

I thought that if you have 90 mm cylinders you have case spigots designed for a 90 mm bore.
If you wanted to go up in diameter, you would have to bore the case spigots. I'm no expert.

I also thought that boring cylinders to a larger bore lessens their heat displacement. Once again I am no expert, but I did do a lot of research before sticking with my 90mm. I don't remember why, but the two things above ring a bell.

[The cap'n]

Was I not clear? If you bore 90mm cylinders to 93mm, the outside diameter of the cylinders remains the same as if you had never bored them. If you choose to install cylinders larger than you can safely bore the 90mm cylinders, then you will have to enlarge the spigots in the case to accommodate the larger O.D. of the new cylinders.

Yes, one of the effects of reducing cylinder wall thickness by boring it out to a significantly larger inside diameter will be a decrease in the ability of that cylinder to transfer heat.

The Cap'n

[The Watson]

My original question was about purchasing larger bore cylinders rather than boring out existing cylinders. What issues, if any, does this create? For example, these:

Porsche 911 2.7 92mm Nickies inc. 9.5:1 JE Piston set - Porsche 911 1965-77 - Aircooled Nickies - Products LN Engineering

[The cap'n]

Perhaps a call to LN Engineering would be in order. I'm guessing they're gonna be a slip-fit, but I'm unfamiliar with their product line. I'm sure they'd be happy to answer your question. Because they're designed as a package, and heat issues are a known issue in enlarged bore piston/cylinder sets, I'm pretty sure they've taken the time to figure that in to their design. This is NOT some hack company, pushing products that aren't well thought out. For street use on commonly available pump gas, I'd be more concerned with the compression ratio than with the bore size.

The Cap'n