So this is the story. In June of 2010 I purchased a beautifully restored 1974 914 from which the prior owner had removed the engine. At that time I decided to undertake the process of converting the car to a 914-6.



I have spent the last year and a half accumulating the knowledge and parts to perform the conversion as listed below. I spent a great deal of time researching which were the best parts for this process and accumulating each of the pieces. I ended up with a 3 liter engine which I retrofitted to Weber carbs, and it is probably good for an honest 200 hp.



Recently however I've seen a lot of discussion about people putting Subaru engines in their cars. There was one gentleman in Arizona who's doing some pretty spectacular things with his conversions with Porsche Boxsters that have also caught my attention. Additionally, I have a friend with a 2005 STI who claims that with minor modifications he has 340 crank horsepower and full reliability. We then spent some time discussing the merits of a 2000 pound car with 340 hp, which is easily upgraded, as compared to the same car with a 200 hp engine, for which upgrades are fairly expensive.

So this has got me thinking about the direction of my project. Everything I have accumulated (aside from the engine which is very fresh) is brand-new but nothing has been installed yet. I have not welded in the engine mount nor have I installed the oil tank, the front cooler or ran any oil lines. Therefore, although everything is ready to go in I am not actually committed to this route. Up front I have cut some additional cooling holes but that's about it. I assume that would only be helpful if a radiator is going to be there anyhow.



What I have been contemplating is the possibility of selling everything that I have accumulated and re-engineering the project to accept a mildly modified EJ engine and purchase all of the necessary conversion parts for such a project. I have the feeling that the cost will be about the same, or even less using the Subaru parts. However, I wanted to run this past the great minds on this board to get your input as to the propriety of this change of direction.

My 901 transmission has recently been gone through and is in great shape. My concern is that the 901 would not be up to the task of a 340 hp engine and that perhaps the transmission would need to be changed as well. However, if I need to buy a conversion adapter for a Subaru anyhow perhaps the change to a different transmission would not be a big issue? I don't know much about the shift linkage issues though.

I haven't done much research on the Subaru conversion issue simply because I was so focused on the 914 six conversion, however, I plan to start reading more about the nuances of Subaru conversions.

So my question is this: Am I completely crazy for thinking about changing gears at this late stage of the game?

What do you think it would cost for a relatively fresh STI engine including the computer/engine management system and harness, the conversion adapters and a good transmission.

Aside from a radiator and the appropriate plumbing, what other unforeseen costs would I be facing the situation?

I'm not really worried about the value of the car because I don't think the 914-6 would have any great value as it is simply a clone and does not have real provenance. Plus I'm really more concerned about the fun factor in the car than it's resell value.

Here's a list of the parts I've accumulated:

914-6 conversion parts

Engine:

1979 3.0 liter with large 39mm port heads, upgraded to Carrera tensioners

Powder coat fan, shroud, valve covers

Yellow cad plating on carb linkage and fan pulley

Turbo valve covers, fins trimmed to clear trailing arms, powder coated

914-6 Sheet metal (not fiberglass)

914-6 engine oil cooler with AN fittings

Weber 40 IDA/manifolds/linkage, completely rebuilt and bench tested by Paul at Performance Oriented, K&N Filters and rain hats



Intake manifolds are glass beaded, port matched to the heads, brand new gaskets and phenolic spacers

Jerry Woods complete distributor rebuild

Magnecor Spark Plug wires, new plugs

New high torque starter


Cooling system:

Mazda RX-7 front oil cooler with AN fittings, dual Spal electric fans with thermo switch



Patrick Motorsports 914-6 oil tank with AN fittings

Mocal external thermostat


Conversion parts:

Rich Johnson engine conversion mount

MSDS 1 5/8 inch headers for 914-6 with ceramic coating

6 cyl tach - early style with silver button on needle

Kennedy conversion flywheel with Stage 2 clutch, new throw out bearing

Holley HP 125 Fuel pump, filter, Holley regulator, -6 AN fittings



MSD 6-AL Ignition box, MSD Blaster high vibration coil


I figure I probably have about $10,000 tied up into all the above parts, not counting my research and labor time. I suppose I could try to sell everything as a package or, alternatively, sell the engine separately and then sell the conversion parts as a package.

Thanks in advance for all of your constructive input into this decision process.

It looks like a great start and I guarantee that if you finish your six conversion you won't regret it. You'll love the car.

I like the Subaru idea too, and either one would be a great car, but a six just looks, feels, and sounds right in a 914.

And yes, 340 is way too much HP for a 901 (IMO, others may say otherwise).

-Steve

I would like to know more about the guy in AZ that is doing the boxster conversions, as this is what I am looking at doing. But the idea for this conversion all started with the classic flat six conversion. So in mind it is all good!

Yes, I think you are crazy. You've got just about everything to go. In the long run, a 914-6 Conversion will be easier to sell than a Subie-Conversion & I would think would re-coup more $$$

However, if you do it, I look forward to your Garage sale

I think your /6 will give you everything you are looking for. The 3.0 powered a heavier 911 for 8 years and is a great engine. Plus you get the sounds, plus you keep it german, plus the value stays up.

I have to agree, subie power is enticing on the power to weight, boost, cost, etc...

My advice to you is simply this - know what the goal is, figure out what YOU want, and do it.

The beauty of most 914s are in the eyes of the owner.

Keep the Porsche engine. It belongs in that car!

Stick with the Porsche engine, you won't be disappointed!

Go for the Porsche transplant ...

...

I think both are great options- good luck with your decision.
If you do decide the Subi route, I’m in need of the Rich Johnson mount...or a -6 mount.

I think you should go Subie. I'll come over with a pickup truck to haul away all that ratty old German stuff for you, because I'm a nice guy.

I"m a subie guy and I say stick with the porsche 6... Your already 9 tenths done.. 200 hp 6 with torgue will be a blast,

It will be worth more
It will be fast
and its all Porsche!!

I went subie for alot of other reasons,, I had a -6 914..nothing like it!!

These are two completely different cars so it's not really a scope change but a new project entirely.

I've had both a strong 2.7L and, for about 13 years, a 3.6L engine in my "project" car. There is no substitute for power... ever. I've driven a bunch of four cylinder versions too and when their suspensions are right, they rock. That said there are a few details to figure out.

1. Driving: Both engines will please if the car is setup properly. Gobs of power is always good but the strength in this car is it's handling.

2. Sound: Porsche hands down. I'm tickled every time I start my car.

3. The build: Some folks like to build more than they like to drive. In that case both projects are excellent if they're executed well. Looks like this one is definitely that!

4. Cost: I don't know how much Suby projects cost but the car will likely be worth more as a 100% Porsche machine.

Good luck!

P.S. Shift the 914 transaxle very smoothly. Mine has done fine behind both engines since 1994 with one maintenance rebuild to seal it, and recently one broken pinion tooth.

Im a huge suby fan! Im going up today and gettinga svx engine and wire harness for future projects. BUT your there man. stuff the 6 in.

The 340 horse is probably a late sti/ drive by wire with forged pistons and cams and $$ and $$. the old story "want HP just bring money" rings true even with a suby. If you were just starting a 6, switch to suby makes sence put you there!

suby engine,wireharness core=2-3k
Sti engine built right= 2-3k (getadomtune.com)
Adapter/flywheel=500.00
wire harness build=600.0
audi4000 radiator/hoses=300.00
engine mount=?

or you could take it to renagade?

jcl

There are several different ways to look at this
Starting with the 3.0L. Money wise you're most of the way there and will have a
200ish HP car that will be a hoot....once you get the Webbers tuned. Gas mileage will suck and you'll have to learn the cold start drill to get it going each day. None of this is a big deal if you're a gearhead. The 3.0L is the most bullet proof motor Porsche ever made (IMO).

The Subie option is a good one with a few caveats.....the biggest of which is your 340HP dream. Without some serious cutting you can't get near enough tire under that thing to handle 340 turbo HP....I'm trying to be kind, but you have no idea what you're getting into. A stock WRX or STI motor would be a much better choice.
Even then you'd better have your shit together when the boost HITS. The subie guys have 4WD.....you have 1WD or 2WD with an LSD. Brits car had 10 inch slicks
and he went to 12s which made it drivable in a straight line when the boost HIT (only 10psi when I drove it). ... still you had to be ready to countersteer.

The Subie has modern EFI....all well & good from a mileage & starting standpoint....once you get it integrated into the 914 electrical system. That makes tuning Webers look like a walk in the park. The subie setup will add weight to the car. A big upside is cost. You can sell your Porsche conversion stuff, buy & install the Subie (if you DIY) and put $2k or so in the bank.....but you'd take it in the ass at resale time.

Do the 3.0, you've got the parts. Less hacking. You could do the Subie swap when the 3.0 dies. Maybe collect the parts for the subie at your convenience when you find deals?

I'd stick with the 6, you have all the good parts and it'll be awesome when done!

I feel like being such a new guy here I shouldn't really comment, but I will anyway I think you would be crazy to have done all that work, get a really nice looking motor and then go to a Sub. Those engines are great, don't get me wrong, but if you have already put in the work, why not finish it the way you have it? I also believe that Subarus are very torquey motors which is really what you need to worry about with transmissions like the 901. If you drove it like a grandma and didn't drop the clutch you'd probably be fine. But then what would be the point of having the motor in there in the first place? That six that you have looks beautiful, complete with the carbs and oil cooler. I say finish her up! If you get tired of it, or need more HP, you could drop it and sell it. Then buy a sub and a 915 and get crazy.

-George

since you're already most of the way there, stick with the porsche motor. i've driven an '04 sti and while it had nice low end for a turbo 4, the porsche is just oh so tractable.

I love the suby setups. I would not change from the Porsche 6. You are there. I would finish it & drive it. Then see how you feel. All changing now will do is prolong your project. Finish it as the 6 & if you aren't satisfied after driving it a while. Then you have plenty of options to make a change. So stick with the six

On the suby note. If at some point you do the suby. Just use the suby tranny also. You can change it from a AWD to a FWD & it will handle the power.

Having owned both a purpose built 6 race car, as well as a built 4 cylinder, one develops opinions.

On the street there is nothing like a 6. It was made for the car, when installed they go like stink and the look, feel, sound and handling are right.

You finish a run through mountain roads in your 6 and then do the same in your 914 subi, the difference would be like a date with Sandra Bullock as compared to Madonna. You know it just depends what you like.

If you further qualified which one you'd take on the basis of where you drive it, if your answer is the street then the 6 is the best choice.

Now if your are just looking for the optimum power to weight ratio then put a subi in. Although I think it would take some time to get the basics right, i..e., transmission, cooling, balance, handling and so on.

One last comment. If your not happy with 200 rwhp, then throw in a 993 3.6 and make sure your car isn't painted red.

....Ya.....just like he said
(remember it's a P-car not a vw)

your nutz! i only went suby cause the budget would not support a good old aircooled flat six. subi shit is cool but nothing sounds like the porsche, and i don't know if i could second guess what to do with that motor if it was on my garage floor. sixes are so sexy!!

I don't see why the "6" is not already installed. Enough said!

Hi rob, you better come over and have a beer.... I know your a really smart guy, I think you just don't want this project to end and it's getting close, I can come over and help install along with some support... I'm sure you will love it...

thanks for all the input everyone. Your points are all well taken.

I'm still trying to figure out the difference between a date with Sandra Bullock and Madonna, since they both have basically the same hardware and are going to be expensive either way the date turns out...

The only reason the Porsche engine is not installed is that I have taken so much time to get all the components procured and learned exactly where and how to install them properly. The next step is the commitment to welding the engine mount, relocating the rear brake lines, installing the oil tank and thermostat and running oil lines to the front cooler.

However, this is why I raise this question – because I can still back out.

Since my car is so close to completion and it really will be a street driven car I will go with the conventional wisdom and use the Porsche motor. Again, I do want to thank you all for your comments.

I'll post some pictures of the installation progress as it occurs.

thanks for the vote of support Jeff. Actually, the thought of this project lasting another year is not a pleasant one as I am not a patient person and this project has definitely tested my limits.

I think I'm going to try to find someone local, who has a shop and a good track record on working on these conversions, but whom I can pay to get me over the hump. Maybe something simple like welding in the mount and stuffing the engine in the bay would be the incentive I need to 'get 'er done'.

I know you're a busy guy with a "real job" and a family, like me, so I don't want to tax you with my project's problems. Now if you had an empty hoist in your garage that may be a different story...

I'd go with the Subie. No sense in denying yourself any longer..........
Just do it!

Since you have all of the goodies for the /6 put it in.

When you've driven it for a while and want another project find a Boxster with a blown engine and do a Suby transplant. The Suby in a Boxster seems like a natural swap to me.

I'm currently doing a round of R&D on Suby heads. The flow #'s on bone stock heads are amazing.

Clean sheet car I'd go (and did go) Subaru, but you've already done the major part of the Porsche conversion, so don't stop now.

Which confirms data from my butt dyno.

.