Anyway to confirm 2.7 punched out to 2.9L?

[ADDvanced]

I was told my 911 has a 2.9 liter, some sort of upgrade kit to the 2.7 liter. Is there anyway to confirm this without records, or taking the motor apart? Thanks!

[SandyI]

There's no such thing as a 2.9 upgrade kit. Which could be why there is no paperwork on the engine work.

[ADDvanced]

Erm..... I know I'm new here but:

2.7L to 2.9L Conversion From Andial

[SandyI]

I stand corrected. Sorry.

[HawgRyder]

Fastest and simplest way is what they use for Formula cars in racing.
Take out 1 spark plug....back off rocker arms for that cylinder...fill with alcohol (cylinder) when piston is all the way down...put graduated cylinder in spark hole...top up fluid to lower mark (you decide base line) and rotate crank slowly...when fluid gets to its highest point...measure the volume...multiply by 6...presto...engine capacity!
Bob

[afterburn 549]

Look at the bore for cyl jugs . a 2.9 is much larger and very too close to the studs. thats why is not done too much.
Or if you know the two different hole sizes...a 2.7 jug will be very loose in there...

[gregwils]

I would say not easily. This old thread suggests that they did not machine the case to accept bigger jugs, so you will either need to do what HawgRyder suggests or some how measure the bore and stroke.

2.9L Conversion

[Charles Freeborn]

Or just use logic. If it's been taken up to a 2.9 it will have a lot more poop than a stock 2.7. If it was a performane upgrade it's likely that there would have been conversion to carbs, cams, chain tensioners, etc. With all those changes you're really going to feel it in the seat of your pants.
-C

[afterburn 549]

AFAIK. they all used bigger cylinders.
To get .3 bigger that will leave thin to no cyl wall ?

[Matt Monson]

Originally Posted by Charles Freeborn

Or just use logic. If it's been taken up to a 2.9 it will have a lot more poop than a stock 2.7. If it was a performane upgrade it's likely that there would have been conversion to carbs, cams, chain tensioners, etc. With all those changes you're really going to feel it in the seat of your pants.
-C

That's really pretty subjective and given the strength or ill condition of various 2.7s out there, without a lot of seat time that's one that even the best butt dyno won't really be able to ascertain. And add in the fact that many times these engines got a compession bump and Euro P&Cs on standard rebuilds, trying to get a "baseline" feeling for how a 2.7 pulls is really difficult.

Ferg's '75 US Carrera pulls as hard or harder than many 911SCs I've ridden in.

[Charles Freeborn]

Well then you could ask someone more experienced. We're spoiled here in P'town. Steve Weiner or Jeff @ Rothsport could likely tell you without even driving it....
That aside, does it really matter what the exact specs are? How does the car drive? Are you lap times acceptable @ the track?

[Dodge Man]

Andial 2.7 to 2.9 parts & installation are not cheap so most people would have kept some paper trail. About the time the 3.2 came out in 84, some used SC 3.0 motors were available so spending big $$ on the 2.9 upgrade? Gotta measure volume or cylinder fit to be sure. If you have a certified stock 2.7 for a visual on the cylinder to stud clearance, that would be the simple way. If it runs good: drive it. Best of luck.

[afterburn 549]

Like i said earlier..I do not think you can bore a 2.7 set of jugs to 2.9