The 2.7 arrives, build advice.
 

I purchased a 1975 911S two weeks ago in San Diego after looking for a California smog-exempt car in good condition for two years. She’s currently running a 3.0 motor which reliably transported my fiancee and I back to the Bay Area in style. What a fantastic coastal celebratory drive home; even the portions of the drive that were in 104 degree afternoon heat through the San Fernando Valley and the South Bay Area (San Jose) were enjoyable.

The sale included the matching numbers 2.7. I've spent the last year or so searching the internet for good information regarding hot rod builds on the 2.7 motor. I have both Bruce and Wayne's books.

http://forums.pelicanparts.com/uploa...1440694398.jpg

The only missing piece was the motor, but all of that changed yesterday when a large truck delivered a pallet to my driveway.

Mostly what I am looking for is some encouragement from Pelican members who have been through this journey and any recommendations of any shops in the Northern California area that are renowned for reliable air-cooled work (primary for time-certs if necessary, shuffle pinning).

This isn't my first rebuild ~ I've been deep in a 1972 Datsun project for the last few years which included a full build high compression motor ~ but it is my first journey into
air-cooled territory. Most of what I've found online is the hoards of people recommending folks like myself to ditch the 2.7 build and go for the 3.0. Since I have the 3.0 in the can and running, my energy is going into the matching-numbers 2.7 (well, until I short-stroke the 3.0 later). The story here is that the previous owner drove the car from it's offload off of the shipping truck to his house, felt something was wrong, and swapped in the 3.0 from his 1974 project 911.

My guess is pulled cylinder studs due to the thermal reactors but the motor hasn't actually been pulled apart as far as I can see. She'll be on the pallet until later this week when the air-cooled engine stand yoke arrives and I can get her onto the stand.

Thus far the project plan is Mahle pistons/cylinders, Carrera tensioners, PMOs, backdated exhaust. Would love to hear what you all have done and what has worked/is still working in your builds.

Many thanks,

~Cams

2.7
 

Hi, the motor in my car now has a 930 oil pump, machine work done at Ollies, 2.7 RS pistons, web cams, updated tensioners, 11 blade fan, backdated exchangers and exhaust, 930 valve covers, front fender oil cooler, weber 40 IDA carbs, MSD ignition, wevo shifter stock 2.7 heads and car runs nice.

You have to decide what you want to do with the car long term. Super nice all original? Show car? Or a hot rod. How far do you want to go?

IMO you will be wasting time and lots of money trying to hot rod the 2,7. Since it is matching numbers, it is worth more stock. You have the 3,0 installed. Keep the 2,7 in your garage, put Webers on your 3,0 and have fun.

I would save the 2.7 and run the 3.0

Just bought a 1975 CA 911s myself that has the original 2.7 165hp motor. Cannot wait to take all that smog crap off of it. Sort of wish I had your 3.0. I'm probably underestimating the value of midyear cars as far as number matching, but then again, the pool of air cooled continues to drop every day.

Saw you were looking for widened cookies too. Let's see a picture of this car... Update your engine rebuild here too so I can subscribe.

Mag case, don't forget to have case checked for possible line bore .

You may want to see what I did to mine - mostly stock but case savers/Raceware studs used

http://forums.pelicanparts.com/911-engine-rebuilding-forum/879894-2-7-engine-rebuild.html

I've owned plenty of both - due to the better reliability, longevity, and torque of a 3.0, I'd take the aluminum-case 3.0l all day long over a warmed-over 2.7. If I had both engines in front of me, and had thousands to spend on building/upgrading one of them, it'd be the 3.0 every time.

If you want to do a hot rod 2.7, I'd contact Henry Schmidt @ Supertec. He built the 2.7 we put in my 914-6 conversion, and we ended up with 199.5 hp at the wheels. A lot of fun in a light car!

The 3.0 certainly is a stronger case, but the original CIS pistons limit the HP you can get out of it.

Thank you all for such sober replies! I dropped by a shop this afternoon who seconded a few of your remarks and told me to "find a clean corner in your garage and forget about it". He also dropped a $11,000-$15,000 estimated bill for the costs (head work, heli-coil, case-savers, line bore, etc, etc, etc) I would accrue - knowing that I was planning on doing much of the work myself.

The 3.0 is great, but I have my own plans for that motor with PMOs, backdating exhaust, and eventually a better cam-grind ~ but really, putting the 2.7 in a corner? Someone is going to rebuild it, why not be apart of the learning?

If money is no problem then build it and find another car to put it in. 2 911's are better than one.

Hot rod 2.7
 

J&E PISTONS 9:5.1, 930 OIL PUMP, PORT AND POLISH HEADS 40MM INTAKE AND 32MM EXHAUST, 40 TIN ZENITH CARBS REBUILT WITH LARGER VENTURIS, 964 GRIND ON CAMS, FIDANZA ALUMINUM FLYWHEEL, SACHS ALUMINUM PRESSURE PLATE, MSD IGNITION AND BLASTER COIL, BACK DATED SSI STYLE HEADERS, 7:31 GEARS ON 915 TRANS. BEFORE AND AFTER SHOT.http://forums.pelicanparts.com/uploa...1441075636.jpg
http://forums.pelicanparts.com/uploa...1441075728.jpg

A nobel quest you are about to embark on...... :)

My engine program has extended into a 3rd year starting with the purchase of a core 2.7L engine (opportunity dictated timing) and progressing to a point where it is nearly ready to assemble. I went the opposite way though. My matching numbers 2.2T engine stays intact and stock, the 2.7 becomes the hotrod engine.

The cost estimate you received is not far off. Wayne's book is a great start in education but there is much more to learn and the costs in the book are rather dated. Those costs assume your core parts are in pretty darn good shape and you're refreshing rather than 'remanufacturing'. The engines are 40 years old now, remanufacturing is likely more appropriate.

I bought a core engine with 'challenges' somewhat unknown but sufficient for it to see a dark corner of a garage for many years. Turns out I only really used the case, cam carriers and a few bits and pieces. The crank/rods/pistons/cylinders/heads all became garage art and I sourced other quality used parts to remanufacture because of condition. The internals were flat worn out and junk. This expense should not be under-estimated.

It is an extensive list of work tasks but all depends on your scope. If an original spec type engine is the goal and things are in good shape inside, the costs may be radically less. If the goal is a reliable hotrod it will stretch into 5 figures doing a *lot* of the work by yourself and depending on spec.

You can learn a lot by a tear-down (carefully bag/label things as it may be a while before you get back to them) to understand what you may need to replace/rework significantly. Then you can decide what to do from there. Warning: a complete engine takes a small amount of space in your garage. A torn-down engine takes several times more space claim! I have both a complete engine on a roller dolly and a torn-down engine in pieces. The 2.7L pieces consume most of a shelving unit full of plastic bins to keep parts organized! Don't worry so much now about cleaning parts as the old grime keeps corrosion at bay in storage.

Have fun!

And don't forget to take photos of everything before you disassemble it. Several years later, when you begin reassembly, you will be grateful for the pictures.

This is a great warning that I do fully understand ~ a reason that the motor has made it from the pallets in the driveway to a small, rolling furniture dolly in the back of the garage in the last two days. I already have all of our belongings stacked on shelves just to fit the two vehicles that NEED to be inside. Looking for shop space to start tearing down or the right property with a large barn workspace.

Nothing like using a car project as leverage for a new home!

The camera has been at the ready for documentation: one of my favorite pastimes.

Looks great!

I hope you have just as much fun I did while rebuilding my 2.7 The hunt is on. good luck! Post plenty of pics.

Moving along.. slowly but surely.
 

So I finally bit the bullet and began renting space from a friend with 4 bays. We spent roughly 3 days installing two 2-post lifts because I'm sick and tired of crawling around on the ground (who knew I'd be doing it anyway while working on the 2.7...) It's been raining here so perfect excuse for spending all day inside, right?

http://forums.pelicanparts.com/uploa...1457664829.jpg

There's much more room for all of the vehicular hoarding I've been doing over the past three years.. including the orange Datsun and another one up on the lift out of shot which is currently getting some love for its future owner.

Anyway, to the point.. this additional space has allowed me the opportunity to finally dig into the 2.7. In an effort to prepare everything for the engine stand I spent a few hours looking for a local shop that carries the 12-point 12mm star hex for the flywheel bolts. After finally getting those loose I found some suspect areas of the case around the rear main seal. Take a look:

http://forums.pelicanparts.com/uploa...1457665160.jpg

Definitely looks as though someone did some previous repair to a cracked case. Don't know what this means as far as future rebuilding but I assume at this point there is no harm from continuing the teardown (and mental breakdown from specialty tools).

Was finally ready at day's end to mount the motor on the stand but will have to wait until our cherry picker isn't occupied with a 2JZ. Damn Japanese motors always getting in the way of real progress :D

http://forums.pelicanparts.com/uploa...1457665309.jpg

Next up: remove fuel injection, & flip motor to soak exhaust nuts with penetrating oil overnight in prep for heat exchanger removal... those things are RUSTY!

Making slow progress a few hours at a time:
 

http://forums.pelicanparts.com/uploa...1457821022.jpg

Success on CIS removal! Easy.

http://forums.pelicanparts.com/uploa...1457821096.jpg

Not too sure about this 'hack' job though..

http://forums.pelicanparts.com/uploa...1457821626.jpg

..or this melted goodness.. TRB: thermal reactor burn

3.12.16
 

Made some progress that felt very rewarding this morning. Removed all exhaust components without breaking one stud (although a few came out with their respective allen nuts). The tools for this job were a bit cobbled together:

http://forums.pelicanparts.com/uploa...1457827714.jpg

I had to use a cutoff tool to remove the tip off of my rounded 8mm allen T-handled tool to get proper purchase on the left-side of the motor's allen nuts. The previous a-hole who worked on this motor had managed to not get the studs far enough in to the motor and therefor limit the amount of useable hex. Finally with a torch and a wrench on the allen key I was able to torque them loose.

http://forums.pelicanparts.com/uploa...1457827627.jpg

End of day the bottom of the motor was exposed:

http://forums.pelicanparts.com/uploa...1457829798.jpg

Ready for the next few steps..

Have a qulified shop check the line bore, most all need it .
The bearings for line bore are expensive and sometimes hard to find.
There are several updates that need to be done
I do stress need.
Once all done and installed these are great engines but do not make the mistake the factory made.
They ran them HOT.
Too HOT

You're referring to updates like...? Case savers, oil bypass?

Yes
I also recommend cam oil restrictors after break in .

Can anyone tell from the earlier photo if the exhaust is indeed 1975 thermal reactor exhaust?

What is the build date of the car? Also, the exhaust manifolds are date coded on the bottom and should be a few months before the build date of the car if they are the originals. And yes, they are not the TRs

Thermal have a very distinct look .
You have typical factory exhaust.

No thermals..
 

I'll check the manifolds for the date coded when I get back into the shop. Build date of the car is... I believe... 7/74?

I'm hoping the non-TR exhaust is good news for head studs.

The exhaust is pretty rusted, especially at the connecting points. I guess I'm wondering if it is worth salvaging since I was headed for SSI when I was under the impression I had TRs to dispose of ~ I'm guessing SSI's are still an improvement over the factory.

I'll update the thread tonight with photos after I finish pulling off the valve covers and timing covers.

Thank you to you both~

More progress:
 

http://forums.pelicanparts.com/uploa...1458015769.jpg

Today began with removing the oil cooler.

http://forums.pelicanparts.com/uploa...1458015700.jpg

Four nuts and it slid right out, but I was concerned about the integrity of the transmission bolts after the welded edge that was supporting the yoke disappeared. I grabbed the cherry-picker and remounted the engine, minus the spacers I had fabricated to make up the difference between the case surface and the oil cooler.

http://forums.pelicanparts.com/uploa...1458015821.jpg

The yoke was now able to be reattached to sit flush with the case.

http://forums.pelicanparts.com/uploa...1458015942.jpg

I began disassembling the right side of the motor's valve covers. When I had both covers off, I checked the torque of the head bolts. A few were loose, as you'll see in my later notes. Here's a shot of the right-side disassembled:

http://forums.pelicanparts.com/uploa...1458016154.jpg

I was more concerned with the side that had the melted-looking lower valve cover. I got both of the timing covers removed..

http://forums.pelicanparts.com/uploa...1458016375.jpg
Right.
http://forums.pelicanparts.com/uploa...1458016404.jpg
Left.

..and moved on to the worse looking side:

http://forums.pelicanparts.com/uploa...1458016451.jpg

And, naturally, found this:

http://forums.pelicanparts.com/uploa...1458016643.jpg

..on the middle head. Oh well.. finally, my notes to finish the night:

http://forums.pelicanparts.com/uploa...1458016729.jpg

Yup.
Looks like you have an unmolested 2.7 and have to do the updates.
and you need Hyd tensioners.
Turbo valve covers if not there already.
Save yourself the grief and use RSR "O" rings in the rocker shafts upon re assy.

looks like the tensioners have been molested with some sort of nut and bolt deviance

Dont be scared to replaced worn "Hooked" sprockets and the chains.

You are referring to this..?

http://forums.pelicanparts.com/uploa...1458068196.jpg

..definitely looks suspect.

The hydraulic tensioner is the Carrera tensioner, correct?

Turbo valve covers, new chain and sprockets, and RSR o-rings have been on the to-do list.

I'm really trying to cover all the bases here, so thank you so much for the continued feedback. My 'fear', if there is one at this point, is not replacing ENOUGH. It'd be a real shame to take the motor apart and not do it right (like whoever was in this engine before).

Now waiting on my crows foot and P202.

My next engine will have cotton thread between case halves along with proper sealer.

You will need guides and valve work.
New plastic chain ramps.
Shuffle pin case with the other updates.

Don't forget the Raceware head studs, washers, nuts. The studs are exposed and orig dilivar studs oxidize and break. With the case savers and new studs, you won't be afraid to torque the heads properly

I have always just called them Hyd tensioners and it is a common upgrade.
They may have originated with the Carrera, IDK

Any machine shop that specialize in Porsche will be familiar with the upgrades.
You can not skimp here.

AfterB - I am glad you said that - I always thought that was a good idea and is a common practice on vertically split cases of opposed aircraft engines such as Lycoming and Continental. Silk thread is also an option. The aircraft guys know what they are doing but this idea has been poo-poo'd by a number of P-mechanics when I asked. I never agreed with them, but I am no mechanic.
Rob

I am not sure but I think cotton swells better than silk?
It works in boats...
Next, Do not follow too many aircraft procures. They are very antiquated.
I have no idea why it is poo-pooed, but there is followers, leaders and get to hell out of my way people
I just do what i have to do.
Like i said, i can do two valves for ya and i am over next door.
I have no desire to work on valves all day every day.......I am close enough to crazy already