Nickies and MAHLE Motorsport 2.7L to 2.9L Kit

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So, I disassembled my 2.7 a few months ago and sent parts off all over the country for machine work. While I've been waiting for parts to return, I ran across the press release for the "new" MAHLE Motorsport 2.7L to 2.9L pistons and LN Nickies cylinder kit. This kit seems interesting but pretty expensive at $6,659.05. Then today I get a 20% off code, which takes them down to $5,327.24. Hmmmm...

I figured I'd see what the forum thinks about this kit (I searched and didn't come up with anything).

Some questions I have are:
1. The Nickies don't come with a groove for a head gasket. What's the current thinking on this?
2. What modifications to the 2.7 heads need to be done if anything? Especially with no head gasket...
3. The compression ratio is listed at 10.3:1 at a 1mm deck clearance. Is this too high for California pump gas even with twin plugs?
4. The compression ratio is listed at 9.8:1 with a 1.4mm deck clearance. This seems better for CA gas with twin plugs, but is the 1.4mm deck clearance an issue? Some people say 1.0mm is optimal and others say up to 1.5 is fine.

Thoughts anyone? Thanks!

[twickes]

In every book I've read, 1mm is the optimal deck height. Race engine builders will go lower, but for the street, stick to 1mm.

[Jeff Alton]

Why not call or email LN? Charles and Stephen are very responsive and knowledgeable.....

Cheers

[75 911s]

If you do call, post the follow up as I’m interested in the kit too. Where’d you get the coupon? What about keeping some race gas to supplement the octane?

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I called yesterday but they couldn’t provide any guidance over the phone. I had to send in a support ticket…

Here is the code for the 20% off…

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Here's Stephen from LN's reply to my questions...

"For the 2.7, there isn’t enough room to put a sealing ring groove for the cylinder head sealing surface when you go past the 90mm bore size; the original Mahle 92s and 93s did not have them either.

The heads should be rebuilt and resurfaced. As the cylinders are freshly machined, there isn’t really a need to lap them into the heads, but some choose to do so anyways.

10.3:1 won’t be a problem with pump 91 and twin plug. If you want, you can increase the deck to 1.5mm to lower it a tad, but we do not think that is necessary as long as you twin plug it."

With this response, it looks like I'm going to pull the trigger on these!

[stownsen914]

Might be worth asking if sealing the cylinder to head is sufficient surface area to properly seal. I built an engine years ago using the Mahle 93mm motorsports cylinders, and was advised to use ni-resist flame rings to get them to seal properly. Involves cutting the heads and cylinders to accommodate.