2.7 rebuild - thoughts on newbie's plan?
 

Greetings,
Just found this board and have been familiarizing myself with the surroundings. I searched the archives and found helpful information, and am searching for more before deciding what to do. I recently purchased a '76 911S targa knowing it needed engine work (leakdown test showed ring problems). Having read Wayne Dempsey's book and researched several web sites, I have a plan to rebuild the 2.7L motor. See what you think. Any personal experiences/insight/warnings are welcome.

First, some background info -

Car:
87K original miles, two owner, well cared for
Carrera chain tensioner, airbox relief valve installed
thermactors removed and stored in the Museum of the Failed
heads rebuilt to stock spec by Glen Krynock here in Richmond @ 68K

Me:
DIYer with two engine rebuilding experiences (Ford V8 and Triumph 4)
garage and tool supply adequate with special Porsche ones to be obtained
(anyone have any left over from their engine rebuild they want to sell?)

my plan:
I drop engine & remove everything down to the case (CIS, wiring, heads, cylinders/pistons, etc.)

Engine/machine shop (thinking of using RPM in Newington - anyone have other suggestions?) does the following:
remove head studs
split case
remove rods, crank
inspect all parts including heads, determine machining needs
install case savers and steel studs
reassemble case
install my new pistons/cylinders (from EBS with CR bump to 9.5:1)
complete long block assembly (heads, time cams, etc.)

I finish the job by reinstalling CIS, wiring, and engine in the car.

I'd appreciate any feedback, especially on a shop that would be willing to work with me on this. Thanks in advance.

Welcome
 

Welcome James. You've come to the right place. One recommendation: get your wallet ready. :wink: Check with Charlie on the machining recommendations; he's just been through that.

- Bill W.

Any possibility of building a 2.7 hot rod engine (see Bruce Anderson's book)? Webbers, E cams, high-compression JE pistons, SSIs...should be fun!

Welcome to the Board.
Sounds like a plan, but you need two more lines:

Break-in to specs.

Drive it like I stole it.

Welcome James:

I second what Bill said about bringing the $ for the rebuild.

I too have a '76 Targa with 164,xxx and with a rebuilt (many many miles ago) 2.7. One of the previous owners rebuilt the 2.7. Smokes a little (like they all do on start up) but runs well enough to put on the track occasionally. If I were you, I'd sell the 2.7 to a 914 guy and buy a recently rebuilt 3.0 or used 3.2 before rebuilding my 2.7 (probably same $ in the end). If you plan on keeping the car for a long time I think you'll get more out of the added hp / torque.

Now... that is not to say that there is anything wrong with the ground-pounding, stump-pulling 165 hp I currently have but, somethimes more is better. :lol:

Jase

James,

Might want to consider putting a 3.2 or 3.6 liter in :twisted:

RPM did my rebuild and EBS did the heads and cams for my 2.2. I highly recommend both shops. Be prepared, RPM is not cheap but you get what you pay for.
RPM took care of the machine work locally I believe.

Overall I am very happy with the work they did.

-Dan

James,

I just went through this procedure with a 3.0, minus the bottom end. I sent all my machine work out to Competition Engineering in CA. Top notch work and Walt has been doing Porsche machining for the past 25 years. I'm not saying the local can't do the necessary machining, but I didnt invest too much time looking for local shops when the praises have already been sung about the 'well knowns' (Ollies, EBS, Rennsport Systems, CE)......too bad they are out on the west cosat.

One thing to remember about the 2.7 cases is they are made of magnesium and tend to need machining to make them true again. Also, the head stud threads have tendancy to strip out the case and these also need to be strenghtened. The 2.7 may or may not have the oil bypass modification, and is a worth while upgrade to do while you are in there. I'm sure Wayne goes through all this in his book, just make sure you ask the proper questions and know the machine shop you choose can do the nesessary work correctly.

BTW: I second Dan's suggestion, follow the proper break in procedures, then drive it like you stole it:) Actually, these are one in the same after the 20-min. cam/rocker break in:).

Welcome to the board.

-Charlie

Agree w/all the rest but would like to add that such a low mileage car w/a “19K” rebuild has probably sat for some time. Why not drive the heck out of it & see if the rings reseat? When next you adjust the valves check to see if any case bolts have pulled lose or broke. Many of the experts say that failing one leak down test does not a bad engine make. Try doing it your self. The spark plug/compressed air adapter is cheep. Listen for air sounds at: air filter = intake valves. muffler = exhaust valves, case breather on the side of the oil filler = rings.

I’ve heard that leak down tests accurately diagnose bad engines 10 out of 6 times! The odds are in your favor.


If you want to see what $$$ to expect, see the Motor Meister web page cost sheet.
& NO I’m not recommending you use them!!!

Thanks for the suggestions. I'm looking at all options and I have considered an upgrade to 3.0 or 3.2 engine. I've checked the web sites of a few wrecking yards in Ca. However, by now all of them are 20+ years old and will cost $4k and up, and with my luck the one I'd get would need a rebuild six months after I buy it. The economics of that choice didn't seem to add up when the 2.7 can be rebuilt to deliver 200 HP, which is all I'm after.

This 2.7 engine did not have any pulled studs at 68K when the heads were rebuilt. All exhaust studs were replaced with Dilavar (sp?) at that time, which now seem out of favor now but that was eight years ago. It runs cool, rarely exceeding 180. Most of the recommended mods have been made, and overall it runs well once warmed up.

But, the other evidence of needing rings is the amount of oil consumption (a quart every 300 miles or so). The leakdown test was performed twice on the two bad cylinders, and both times the results were >90% loss. You could hear the air escaping into the oil tank.

I hope my wife can stand the sight of blood, 'cuz I think my wallet is in for some serious hemorraging.