Options for a 2.2E rebuild

I'm doing a rebuild on a neglected 70 2.2E motor as a learning project. The motor is locked and had water in the jugs but the valve train and sump were clean and oily. I've been soaking the jugs with penetrants for a couple weeks and will soon strip the motor down the rest of the way to evaluate. My assumption is that the P's and C's will be toast and require replacement. Goal is to build a reliable, rev happy street motor keeping the MFI and run on street gas.

What are some options for this motor assuming P/C replacement? What size can I take it to, what cams, compression etc?

[Bobboloo]

Option #1. Least expensive route would be to bore your cylinders out to 85mm or more and install some JE's made to fit your cylinders.

Option #2. Find some servicable used 2.2S P+C's. Very, very hard to find though.

Option #3. This is a bit more expensive but is my favorite. Buy a set of used 2.7 (90mm) cylinders bore them out to 92mm and have them Nikasil plated and then install some JE's. This will give you a 2.6E shortstroke motor which should have a very usable torque band for the street. In this scenerio you leave the ports and induction just as they are.

I know the 2.2 case is not the best starting point when you need to bore the case spigots to 97mm for the larger P+Cs but if this is predominently a street motor and you use the E cams then the revs won't be too high which means a longer life for the case. Also keeping the oil temps down will insure longevity as well. (i.e. external front oil cooler)

You could always port and add S cams but then your cost goes way up because you would need to port the heads, buy the cams and the either buy S induction or port your induction which is not cheap. Plus the additional rev range of the S cam will put additional stress on the 2.2 case.

[Grady Clay]

Mark,

I think you don’t yet have enough information to make an informed decision. Wait until you split the case and measure everything.

In the interim, take the side covers off the MFI pump and inspect it for rust. Carefully turn it over and confirm that all of the fuel pistons move without sticking. Lubricate and operate everything. If everything appears OK, it would be useful to install your MFI on another known good 911E engine. For your purpose it could be a 2.0, 2.2 or 2.4. The goal is to get miles on it and confirm it is adjustable and stable.

Your decision to maintain the engine as original or modify it involves several considerations. Most important are your intended use and the condition and ability for the 911 to be refurbished as original. Some critical description of your 911E will help. Be brutal and realistic.

To maintain the possibility of originality, great care with your P&Cs may pay off. It is possible that you can recover them. In any event, Biral cylinders can be iron plated to fit given pistons. Even pistons can be repaired with wider rings or spacers. It is difficult and possibly expensive but possible.

I agree with Bobby (Pelican Boboloo, converting to a 90 or 92 mm bore P&C is great fun, reliable and not too expensive. I would prefer to use new Factory Mahle Nikasil “2.7RS” 90 mm P&Cs that are readily available and give 2519 cc but relatively low CR compared to your 2.2E. This will easily allow pump fuel. Twin plug will only modestly reduce the octane requirement to “regular” but will improve the drivability. The 92 mm RSR P&C will give reasonably high CR (~10.5:1) and 2632 cc. This is probably your most “rev-happy” option short of converting to “S” cams (expensive). At that CR, it will significantly benefit from twin plug to keep it on pump (premium) fuel.

My plug: A very high compression 2.8S MFI twin plug is probably the best appropriate engine - but is expensive. The biggest issue is it requires high octane race fuel.

I agree that JE pistons can be made to correctly fit. My understanding is that this may be a relatively short term (<<20K mi) solution. If you choose this route, there are more possible configurations.

Another possibility is to buy a core 2.4 or 2.7 (70.4 mm stroke compared to your 66 mm stroke). You can then build anything up to 2808 cc while using your MFI, cams and heads. I can tell you from first-hand experience that a 2.8E is a remarkable engine. I have one I built in ’73.

You will find some who recommend the (heavier) 3.0 and later. I am a proponent of keeping it at least stock appearing if not exactly stock.

Your engine looks great and very original. I don’t see anything that can’t be easily restored to original appearing You will want to do the normal case mods; installing piston squirters and the oil bypass. It would be unusual if the case didn’t need reconditioning.

Regardless of what you decide, you will greatly benefit from improved engine cooling. That can be changing to the 1.82:1 engine fan ratio and adding the ’74-’89 front oil cooler. Texas is known to have some hot weather. This will also reduce your octane requirements.

I appreciate your collecting the info on the engine resurrection. There is far more. I encourage you to do a diagnostic & maintenance transmission rebuild also. This is something you can easily do DIY. You need to consider all the systems in the car. As I said above; it is the condition of the 911 that is critical.

Best,
Grady

Edit for punctuation.

Bobby - thanks, I thought I'd read about using 2.7 jugs on a 2.2. A 2.6E, huh...That's something you don't see every day! BTW - loved your Irish targa - hope you get her back on the road soon.

Grady - good advice. Right now it's just an excercise. I'd never been inside a 911 motor and this one seemed like a good candidate. My first 911 was a 70 E and I have a real affection for the model. Unfortunately, the car that the motor/trans came out of was abandoned at a body shop several years ago and rusted beyond repair. I'm looking for a donor body to build around the lump. I'll probably build it as a stripped out street rod. Nothing perfect or concours, just a fun weekend car. I want to do as much of the work as possible to keep costs down. I do have my eye on a nice tangerine 70T with a bad motor - fingers crossed.

I hadn't thought about looking inside the MFI pump - will do that tomorrow. I had counted on having it rebuilt since it sat so long.

As I said, I've been soaking the jugs with Aero Kroil for a couple weeks and once the heads are off, I plan to tap the pistons in mid stroke to break it all loose. Question - If I do get the jugs off safely, can I clean the bores with a wire bore brush to evaluate? If not, what's the best method? If the gods are smiling and we do save the jugs, I'll go back as a stock engine. This one is very complete and I love the E motor.

Point taken on cooling.

The trans is next to come apart. I understand the 911 is a pretty easy rebuild and I'm looking forward to seeing it's guts as well.
Thanks for the help guys,
Mark

[Scott Clarke]

Mark-
I'm just finishing a very similar project. My 2.2E motor is now a short stroke 2.5. I took a little different route, but similar to Bobby's #2. I opted for a 7R case in the interest of economy and strength. I was able to purchase a late 7R that had the bypass modification made at the factory, and of course, the spigots were already the right size and it had piston squirters. It cost less that what modifying my 2R case would have run. The 2R case is sitting on a shelve in case anyone is concerned with matching numbers. I purchased reconditioned 90mm cylinders and new JE pistons. I went with 90mm due to concerns with failures I had seen posted that occurred between the cylinder walls and the CE ring groove. I did port the heads, as I couldn't get comfortable with the idea of restricted breathing in a short stroke motor, and I'd also like to keep open the option of S cams in the future. I'm using the E cams, however, for now. Let me know if you take this path, and I'd be happy to tell you more.

If you can get your pistons free, you might want to think about a 2.4 conversion. This would bump up the CR, and would only require a crank and rods. These are a dime dozen.
-Scott