Long Term Project Needs a Go Box - Let's Talk Engine Options

[scootermcrad]

Hey Engine peoples!

I would like to have a realistic and open discussion about some drivetrain options for my project. I'll try not to be too wordy.

I have a 1970 911 RS/RSR tribute (hate that phrase) project that is a long term build and may be the death of me. It's a roller that came to me with no drivetrain. I plan to set the car up with coil-overs and notch for a G50 transmission since I need to do some work in that area anyway and want that option. When I do finally purchase a drivetrain I will be looking for a "running/driving" engine and trans that I can put in and run until I can refresh everything and get a feel for what I want/need out of the car. This will not be a race car of any kind, but am looking to build a nice driver that I can tune on a little bit. Looking for reliability and just a fun car to drive. I don't need something with tons of horsepower, but want the option to free up ponies when I rebuild the engine.

Up to this point, I've really been focusing on a 3.0/3.2L with a 915 trans backing it. Seems like rebuild costs and overall purchase prices are a good place to start, as apposed to a 2.7L and the extra work that has to be done to the cases that seem to heavily offset the costs. HOWEVER! It seems prices of 3.0/3.2 engines are really starting to go up and I'm afraid that I'm rapidly approaching the point of being priced out of a running-driving drive train in either of these categories. So I'm opening my mind, a bit.

The reason for the thread:
I would really like to get some experienced opinions keeping in mind the overall purchase price. COST is a factor, which of course sucks in a build like this. I just know what a slippery slope this can be.
1) Am I still better off focusing on 3.0/3.2L for overall buy-in from a running-driving standpoint?
2) Should I consider a running-driving 2.7L engine and gamble on the cases needing tons of work? There really seem to be quite a few available, but I'm scared it could be considerably more to rebuild and still be a smaller CI engine, relative to the 3.0/3.2
3) Should I simply go right for a complete rebuildable core motor and just build it right out of the gate and just plan on adding some time to the build.
4) Should I actually be looking at LATER engines? 3.6L with a G50. I was thinking as a package that would just really be more expensive at the end of the day by the time all the electronics and everything have been accounted for.
5) Should I also be looking at the plentiful supply of 2.4L engines (not sure of the differences between 2.2/2.4/2.7L engines) if I'm going to consider a mag case engine to build?

The plan was to run carburetors, single plug with a dizzy, but for the future may experiment with my own throttle body castings and fuel injection arrangement and run an aftermarket electronic ignition of some kind. Starting stock with a totally complete engine and trans that I can develop a baseline off of would be ideal, but I may not be in the cards if prices continue to rise like they are.

Just to reiterate, this is a long term build. The car needs a lot, but it's my dream and I want the build to be fun as well as the driving experience. I'm in no real rush. I just want to educate myself on the options so that if I come across a good deal on something I can snatch it up and build around it. Patience will be my friend, I have a feeling.

Thank you for any help! Hopefully the situation and questions at-hand make sense.

Cheers!
S

[Bigtoe32067]

You must’ve been sleeping for the last few years. Prices have dropped like a rock. Last year a running 3.0 was $12-14k. Now you cant give them away at $9900.
Rebuilt 3.0s were $16k now $10.5k

There’s some smoking deals in the for sale section right now. Fred (faapgar) has a nice one for a good price plus there are several others.

[mepstein]

I’d like to know where to buy the rebuilt 3.2’s for $10k. ???

[scootermcrad]

Originally Posted by Bigtoe32067

You must’ve been sleeping for the last few years. Prices have dropped like a rock. Last year a running 3.0 was $12-14k. Now you cant give them away at $9900.
Rebuilt 3.0s were $16k now $10.5k

There’s some smoking deals in the for sale section right now. Fred (faapgar) has a nice one for a good price plus there are several others.

Over the past couple years I've watched the sale of many 3.0/3.2's and have had the opportunity myself to buy them for cheap (one of them a running 3.0L at $5K!!), but most are not runners, or are questionable, and even semi-complete core engines seem to have generally gone up a couple grand for no particular reason. I've not seen any 3.0/3.2's rebuilt for $10.5K that didn't require a rebuildable core up front. I've admittedly missed out on some deals because the timing was all wrong (read: having kids) and I'm still not quite where I want to be to start building, but I've been at least trying to keep tabs on the market and adjusting my plan and education.

I really hope that what I'm seeing is simply a fluke, because I would still ideally like to run a 3.0/3.2, but I guess my point of this thread is to discuss other options, in the event that things elevate in price like Porsche parts have historically done.

So let me add a question to the pile of questions I've already asked... what makes a magnesium cased engine so much more expensive to work on than an aluminum cased engine? Is it the inherent tolerances of the cases themselves that require next-level machining? Is it components specific to that category/era of engine that makes them expensive?

I wouldn't mind a 2.7L as they're closer to the era of build I'm wanting to do, but following along with other posts, it just seems they are expensive to build and almost always have a pulled stud or just need a full rebuild right out of the gate.

One additional comment. I'm doing ALL the work on this car, with the exception of some processes that require expensive tools or special skills I simply don't have (like engine machine work), but for me the fun in all this is the build and then enjoying the fruits of my labor.

For me, carefully planning and education is the only way I'm going to accomplish this build. Dreams are often luxuries and this is one that I want to make come true with the cards stacked against me.

[mepstein]

The $3k worth of machining and shipping negates the lower cost of a mag engine. Not to say they aren’t good engines and not everyone wants a 3.0/3.2 but...
You take chances on any used engine. We’ve purchased 3.2 with “good” headstuds, only to have a stud break after a drive or 2. These air cooled engines are 20-55 years old and you never know what’s really going on until you open them up.

[scootermcrad]

Originally Posted by mepstein

The $3k worth of machining and shipping negates the lower cost of a mag engine. Not to say they aren’t good engines and not everyone wants a 3.0/3.2 but...
You take chances on any used engine. We’ve purchased 3.2 with “good” headstuds, only to have a stud break after a drive or 2. These air cooled engines are 20-55 years old and you never know what’s really going on until you open them up.

Thanks, and yeah, that seems to be the case I run into whenever I read about the comparison between the mag versus Al cases. This is the reason I shifted my focus to later engines with aluminum cases. For my build, which is far from being restorable nor is the goal to be numbers matching, it makes more sense for me to focus on what works versus historic preservation of the car, which started life as a 911T and underwent many changes before I saved it from certain death.

Anyway, it certainly seems it still holds true that mag cased motors are more expensive to rebuild. And you're right! These belong in certain cars and are still desired. Seems they are not the best bet for my project.

[scootermcrad]

Hey everyone,

I would like to revive this thread. Looks like the 911 Engine Rebuild forum has been cleaned up and a bunch has been removed, or something. Was looking for more build threads and technical info.

Since I first started this thread, the plan for the car has sort of changed, but mostly stayed the same. What hasn't changed about my build is that it still needs an engine and I'm about to liquidate some other projects that were ahead of it to try and make that happen before I can't afford to buy one at all. HA!

I took a deep dive into the market over the past couple weeks and it seems prices and availability of 3.0 and 3.2's (or later engines) have sky rocketed and availability is even worse. Even called around to a few places that usually have decent prices and one of them was even out of business. However... it seems the availability and cost of earlier mag case engines is still about the same. So let me bump this thread up with these questions.

My build is starting to look more like an "era correct" build plan for an early to mid-70's spec car. So the idea of a 2.4L or 2.7L mag case motor is starting to make more sense from that aspect. The build undoubtedly will span many years and I'll be doing most of the engine work myself, with exception of machining that I don't have the tools for. But, the up front cost and the timing and plans for the build pushes me towards building a mag case engine with the understanding the case could need more work than a later engine. I have not settled on a particular engine build spec, but it will be bumped up from stock for added fun, for sure. But I'm not looking to build a 2.8L RS or RSR spec'd motor, either.

All that being said, can we revisit this conversation about what is typically required with a mag case? Case savers? Line boring? What else about these engines do I need to look for when looking for a complete motor or even a long-block? I'm not sure I care if it's missing the stock intake since I'm planning on carburetors or even ITB's, but obviously the more complete the better when it comes time to purchase. A complete running motor being ideal until I'm ready to rebuild. And if something better comes along during "the wait", then I can always part ways with whatever I find and change directions. I just want to make sure that I get a good power plant before prices and availability completely kill this project.

Any information on mag case engines that could help guide my near future search would be helpful. Thanks everyone!