2.7 cis

[bud]

How's the reliability on these motor. Are they a good choice for a six conversion? I have had one offered to me of $3500. It sounds like it has all the mods ie. case studs,cis injec.It also has headers, fly wheel,all it need is sheet metal oil tank and lines.Is this a good price and motor choice. thanks Bud

[halbl]

Most of the comments I have read specifically mention this engine as one to AVOID. There is a fitting problem at the drain tray level, warped case horror stories and a host of other complaints. There is probably a good reason the engine for sale.

[Dave at Pelican Parts]

Some people really love them. Andrew Warren has a really built-up one in his 914-6 conversion. You can see it listed in the "cars for sale" section of the Pelican site.

Supposedly they *can* be built to be reliable, and they are lighter than the later engines. But it is very expensive to build them "right". Pick up Bruce Anderson's 911 Performance Handbook for more info on 911 engines. [Guess what comes next?] Pelican sells it. So do other places, come to think of it.

I wouldn't trust a 2.7 without receipts for the build, and some reasonable documentation for the mileage.

I personally don't trust the motors. I have a friend who bought a 75 911S. There was a receipt for engine work to the tune of $8000. About a year later, he overheated it and it self-destructed on him. End of engine. That has made me somewhat paranoid about those motors.

--DD

[jamesm]

There is are big differences between the '74 model and the '75-'76 models. The '74 model used a normal exhaust system (very similar to earlier exhausts), whereas the '75-'77 models used thermal reactors. These reactors make underhood temps soar, and cause a lot of the heat-related problems. Also, the '75 and '76 models used a 5-blade cooling fan in place of the 11-blade fan used earlier. The fact that the '77 and later engines went back to the 11-blade unit should tell you something. In general, a '74 2.7 will be much more reliable than a later engine. Later engines that have been rebuilt AND converted to earlier specs can also be very reliable. However, you can't ditch the thermal reactor in most states because of smog laws, so that problem remains. For a 914/6 conversion this won't be an issue as the thermal reactors can't be used with the required 914/6 exhaust systems, anyway. For a smog state, this makes using a post '74 engine illegal.

[Bobbitt]

A 2.7 can be very reliable. I know several people with 2.7's in both 911's and 914's. Built right, they will last. They probably take more care in rebuilding though. I am in the process of installing a built 2.7 in my 914 right now.

I bought the engine for $400 complete. I then spent many many times that rebuilding it. $3500 seems way too much, unless it has had a serious rebuild, and then, I would want the receipts.

Things to look for: Has the case been shuffle pinned? This keeps the two haves from shuffling back and forth relative to each other. Have the studs been Helicoiled? Are they Dilvar? What fan (# of blades)? CIS is also a pretty terrible system. I put Webers on mine, but I don't have to worry about CA smog laws.

[michael]

Lets see, 27 mpg on the highway with CIS versus, 15 mpg with carbs. Yeah, CIS is terrible...

[Wayne 962]

I've got a 2.7 in my six, and it's not running because of that. The 2.7s should be avoided, however there are some caveats.

You need to perform the upgrades in order to make the 2.7s reliable. They need time-serts in the case (my head studs have all pulled), carrera chain tensioners, the seven blade fan, a valve job with the newer type valve guides. When putting the time serts in, you should probably machine the case flat too (which requires a full rebuild). I don't think I'm going to do this, and I will let everyone know if the engine leaks oil (from warping cases).

Also, don't even bother with 75-77 motors. They aren't really worth anything because they have probably been damaged too much with heat (mine's a 74S). Also, get the 'S' model motor - used they are not that much more, and surely worth it!

If you go with a 3.0L, you will have trouble with the flywheel, and will need a special flywheel package. The 3.0L motors usually cost around $4500-$5000.

I've compared my '74S motor to some 2.4S motors, and it blows them away.

Just my opinion, for what it's worth!

-Wayne

[GeorgeRud]

Ditto on the 2.7. Mine works great and I love it, but we did all the tricks in Bruce Anderson's book to make it right. With 3.0 liters available, I think that would be my choice (unless someone has a great deal on a 3.6 - no valve adjustments).

[J P Stein]

What the hell,may as well get my .02 in here.
ANY used motor is a risk. ALL new/rebuilt motors are expensive.
The tough part of the conversion is not the motor, but all the crap that goes with it.
The 2.7 isn't a bad motor, it just wasn't set up right.(not enough cooling,as already
stated)
The down side of a 2.7L in a teener is the requirement of an external oil cooler. This makes the job even tougher.( & expensive).
Anything over 160/170 hp needs this incliuding the 3.0L.
BTW I agree, $3500 is too much for a CSI motor. Now one of them B. Anderson specials is another story. Wanna sell,George? I've got two spots for one of those. I could do some major surgery on my 911 and teener at the same time and have parts left over.

[Wayne 962]

Hmmm, my 74S motor runs pretty cool in my 914; I would recommend an external oil cooler, but I wouldn't think it absolutely required.

The key problem with the 2.7L motors is the magnesium case. This case is a pain in the butt, as it warps, lets studs pull out, and is generally not as durable as the earlier cases. If you were to make the best 2.7 motor that you could, I would ditch the mag case, and put the internals into an aluminum 2.2 or 2.0L case. This is what most racers do. This is, of course, only if you are rebuilding the entire motor, and good early cases can be difficult to find (although I hear that they are still available from Germany for the tune of about $2K).

The 3.0L engine has more lower end torque, but not a lot more HP than the 2.7S. Get a 3.0L if you can, or a 2.4. Otherwise, be prepared to rebuild the engine. Also, don't do a top-end rebuild without installing the time serts for the head studs - they will pull out...

-Wayne

[J P Stein]

Alright! A good solid debate. Let's get to it.
Wayne you say your 2.7 runs pretty cool and not at all. A conundrum.
The racers run early aluminum case,but B. Anderson says it's not as strong as the 7R case.
The 2.7 pulls studs but the 3.0 breaks them.
The 2.7 is easier to install in a teener,the 3.0 is better but heavier.
External oil coolers are/are not needed.
Smaller(2.4 & below) are more reliable but not as much fun.
3.6 would be great but cost as much as a solid 73 911T(trust me)
Missed the 3.2. Let's lump it in with the 3.0 but include it's proclivity for eating valve guides.
If I've missed I'm sure someone will point it out.
OK,where to start. At the begining. Is the 2.7 AFG.
I contend that nearly all its problems are heat related and can be dealt with or in the case of the original post, have been if done properly.
Mr Anderson says that Porsche added oil coolers to its 911 when the hp rose above 160(as I recall). Sixes run hotter in a 914. Go figure.Forgive the spelling I am in a hurry.
Next.
J P Stein