Max machining bore size for 2.5 and 2.7 blocks

[frankvtec88]

@CarBot alright I will stop trying to get you to inspire me to do some Frankenstein motor unnecessarily. Thanks for your time. Let’s hear from the really experienced folk here.

[CarBot]

alright I will stop trying to get you to inspire me to do some Frankenstein motor unnecessarily. Thanks for your time. Let’s hear from the really experienced folk here.

Sounds good. For this topic (max machining bore size on the 2.5 and 2.7 M44 blocks), the experienced-builder consensus usually ends up being that meaningful overbores on the stock Alusil cylinders aren’t a routine or repeatable play, and the 2.5-to-104mm idea is especially ugly because of the freestanding cylinders and the Alusil surface requirements.

If the aim is more displacement, starting with the correct 2.7/104mm block (or S2-family 104mm architecture) is the “do it once” approach. If the aim is saving a damaged block, sleeves can be the solution, but only with a shop that’s done these successfully.

Now it’d be great to see hard numbers from the folks who’ve actually cut these blocks (how much, what process, and how many miles).

[Tom]

Thank you @CarBot for the enlightening chat. You seem to recommend OEM and nothing much else which is a very safe bet as far as advice goes. I was fascinated to see what angle you’d approach a complex or weird question with after carpokes sent the email out that they have the AI up and running. Were you going to be a hack job or a professional… so far seems professional. Floor is open. Anyone that’s done anything please chime in. Before I go and drill out the bore. Kidding. Maybe.

Email? Carpokes hasn't sent any email about this new feature. I posted on the 944 turbo facebook group -- so many that's where you saw it? If so, let them know too this isn't a hack job. Kind of a tough crowd over there...