73' 914 986 boxster engine conversion

[LittleBlue914]

hello there,
I have a 1973 Porsche 914 1.7,and a 74' 2.0 parts car. it is a great car, handles well, good mpg and a blast in the summer but i am getting a little tired of the lack of power and plus we all know how fun it is to start a new project, * the fresh un-touched metal and only your imaginaton to guide you. so here is my information i just need some of your knowledge to know weither to cut away or not.

1) i am 20 years old

2) i love my 914 very much but i also like to make things customized to fit me.

3) i bought my 914 almost 3 years ago with 92k, drove it for a little while to figure out what all i needed to do to it.

[LittleBlue914]

4) After about a month i parked it and began on the small stuff, reworking the brakes, full tune up, some random electrical work, (looked for an oil leak but couldn't determine the source at first

5) pulled the motor out around thanks giving 09' and gave it a 100% over haul,
while engine was out i did the ever popular hell hole and other rust repair

6) like i stated before i love the car especially the way it takes the windy highways. but i am looking for a project and it's either this or working on my older xj6 ( not nearly as fun)

7) after looking around the web at all the 350 Chevy v-8 conversions, Subaru, and Big Fours ) i decided to go with a nice 6 cyc. Porsche engine at least i think

8) i don't like the sounds of spending 10k on a 911 motor and trans so i did some local shopping and found a complete wrecked boxster for around 4-5k i think it was the 2.7, 5 speed manual with 75k But i could very well be wrong

9) if i do this swap i am also going to use the mono-block boxster brakes and get a suitable 911 suspension to do a full on 5 lug conversion at the same time

10) i know burning through a couple a hundred in a weekend isn't fun just to make your car drivable again but we all do it, but i would really like to keep this under 8k if possible



so here is the big question buy the boxster and put the water cooled flat 6 in my 914, look for something else to put in, or just drive it and save for something else. i see lots of 911 builds but i am unsure if i have ever seen a boxster to 914 conversion. here are few more things i would like to know about

i don't need or want anything with 300+ hp it would just ruin the car for me that's why i thought a boxster motor with around 150-175 would be perfect

1) will it work obviously

2) will the boxster trans work with my 914 axles or would i be able to use my 914 trans with the boxster motor.

3) any major pit falls anyone sees with this build ??

4) is that too much $$$ for the boxster

5) i do fairly well with metal (bend it or cut it into place) but i have not so good of a time with electronics so any information on integrating the motor electronics and the remaining 914 electronics would be helpful

6) i know it is a less than intelligent question but will my gauges work Tach, speed-o ect, again like i said no so good with the electronics


i know i sound a bit foolish and ambitious but builds like this are what my family and friends do, my father did a 944 with a 350 chevy turned out ok, not perfect but ok
i apologize for 2 posts but i thought i had a 1k character limit not 10k Reading ... it helps when you do it sometimes

[Dave at Pelican Parts]

I've heard a lot of people talking about this sort of conversion. I know of none that are running--zip, zero, nada. I know one that has been "about half-done" for the past five years or so... So you will get to break new ground if you do the swap.

The motor does not fit without relocating the inboard rear suspension mounts. So you get to redesign the suspension, which is cool if that's your thing, but certainly makes the conversion much more complicated.

Getting the engine management system to work will be an interesting exercise. Even more so if you wind up with the later motors that even open the throttle for you electronically. Lots of electrical work to be done there.

The existing gauges will not work, you will have to find later ones that will or have the guts of the later gauges swapped in to your housings.

The Boxster trans can work, but it will require modifying the rear trunk floor for clearance. I am not sure if you can hook up the Boxster motor to the 914's transmission or not.

I don't think you can get the job done within your $8K budget. Very definitely not if you're paying someone to do any of the major work (e.g., electrical) for you.

The SBC swap is very well understood and there are recipes to follow that will get you to your goal. Ditto the 911-engine swap. I personally would keep saving my pennies and do the 911 engine swap, but not everyone agrees with me.

--DD

[Matt Monson]

There's a new option that's just around the corner. I know of a company who is working on an adapter plate for mating the GM v8's to the Cayman S 6spd gearbox. Could be under the $8000 budget if you shop smart and can fabricate. The nice part is the v8 is a known entity. It's the Cayman gearbox that will be new territory, but it's cable shift, which is a step in the right direction.

[Rob Kalis]

My reccomendation is build a Jake Raby Type 4. You can use the engine you have (crankcase anyway), and you won't have to mess with the body, transmission, or anything else. You can easily get the 150 HP you are after, and better yet, loads of torque. That is the route I went with my 1975. My 1.8 liter is now a 2270. Be prepared to spend ~ 6K on the motor ,with you doing the work.

The best thing about this decision is the car will still look and mostly be original, and will still be the light, air cooled, nimble sports car it was designed to be, only a hellova lot more fun, when your back is pressed back into the seat by all the torque. The only thing I miss is fuel injection, which can also be added with some more $$. The sound of a 6 is also nice, but the 4 with 4 weber throats sitting about 18" from your head sounds pretty good too.

Good luck with the decision.
Keep us posted.
Rob in Overland Park, KS

[racer]

Sounds like a lengthly project.. I don't know all the dimensions, but I imaging a bit of fabrication for engine and trans mounts are an issue.. what about axles? Does the Boxster motor mate to anything but the newer trans? then running shift rods/cables.

As mentioned, lots of electrical work and perhaps even more-so for the 2.7 since its e-gas vs the 2.5s cable.

Then mounting radiator lines (i'm sure the SBC crowd has done this already though).. capping off powesteering pumps?

How does the Boxster motot compare in size to the 911/914 motors? how much HEAVIER will the car be with the new motors/radiators etc.

What about mufflers/exhaust? is there room for something modern emissions compliant under the 914?

No HP conversion/upgrade for the 914 is cheap. If you want something straightforward, then a big 4 is a the first choice.. then a 911 motor (but then you need oil tanks, engine motor mounts, etc etc.. all well documented.) plus the more hp, the more brakes, tires, (flares?) and suspension you will need. It becomes such a nasty slope!

[LittleBlue914]

well i appreciate all the good and amazingly fast responses

i am more than a little depressed to hear that the boxster isn't going to be an easy swap like i had hoped for.

i can do all the fabrication needed for the job but it is all the electronics that are really holding be back here. and i knew it would be.

i don't really want to put a v-8 in the car, just wouldn't be the same fun little puddle jumper,

so i am not really sure what to do i gave some thought to putting my 2.0 motor in and trying to conjure up a 6 speed boxster trans but if you look at it realistically another 15- 20 hp in my mind isn't going to be much more exciting than the 1.7 i have but the 6 speed would be nice

if anyone has suggestions or information please feel free to share, i am always interested in learning about something even if I'll never get use it

also yet another couple of my under cooked questions " if i where to find a 6 speed boxster trans would i need a boxster clutch kit, or my new 911 style Sachs 6-spring clutch kit i already bought and put in my 1.7"

"also if i where to re do my 2.0 regardless of weather or not i buy larger displacement pistons and cylinders witch FI system should i use, the completely re worked 1.7 or do i have to use the more than questionable 2.0 FI, they are both D-jet, i just don't want to waist $500 freshening up another fuel system i may not keep in the car"

and again i apologize i know there stupid questions but i searched the interweb and found very little on the subject

Thanks George
73' 1.7
74 2.0

[racer]

Why do you *need* a six speed?

imho, the 914 motors work great with the 5speed they already have (and heck, in 1970, not many cars had a five speed to begin with!) Between the 5spd, disk brakes and fuel injection, the 914 was extremely modern in its day.. its just that its day was 35+ years ago

I will say, I really LOVED my 2056cc 4cylinder 914. Mine was a 1970 and with a full tank of gas was 1990lbs. The 2056 put out approx 120hp. Easily kept up with my dads original 2.0l SIX. Great torque, good fuel mileage (mine had dual webbers).. reliable and in keeping with the spirit/lightness of the original car. No.. it wasn't a street racer, but it did have tremendous balance and at the track, many assumed it wasn't a 4 since it could keep up with 911s.

I say, take the spare 2.0 and make a nice 2056 out of it.. maybe even something bigger (2270?). They really waken the car up.. but they don't make you buy new transmissions, axles, engine mounts, oil tanks, radiators etc. They are true "plug and play".

[Nostril Cheese]

Swapping in a Boxster motor will neither be easy nor cheap. Have you seen what Boxster motors go for? Even the 2.5L base engine sells for $25,000 from Porsche (see for yourself.. 986-100-920-92).

If you are looking for cheap power, the best option is a Subaru swap. It's a flat engine, makes well over 200HP and there's plenty of support out there for it.

As far as keeping it air cooled, You will need to completely rebuild the engine with a good cam, lots of head work, additional oil cooling, and a way to deliever more fuel. Webers or aftermarket F.I. arent cheap.

Mega Squirt is a kit-based fuel injection system that may work, but it involves a fair amount of knowledge to make work correctly.


Don't feel so bad. I got my first 914 1.7 at 19.

What I did was find a 2.0L out of a wrecked 914, rebuilt it with slightly higher compression, a decent cam, read every piece of info I could on modifying VW cylinder heads and smoothed them out as best I could, then ran it on Weber 40's. I figure it made around 120HP.

That is all you will need in that car. Trust me.

[Dave at Pelican Parts]

Originally Posted by LittleBlue914

"also if i where to re do my 2.0 regardless of weather or not i buy larger displacement pistons and cylinders witch FI system should i use, the completely re worked 1.7 or do i have to use the more than questionable 2.0 FI, they are both D-jet, i just don't want to waist $500 freshening up another fuel system i may not keep in the car"

If you build a stock 2.0 motor, use as much of the stock 2.0 injection as you can. Though a lot of the 1.7 parts will swap in and work OK but not "right". You can build a 2056cc (96mm P&C on the 2.0's 71mm crank) and still run it on D-jet, but you will have to tweak things to make it work really well.

The instant you go with a non-stock cam, the D-jet is just about useless. Either a set of dual carbs (single-carb setups are the absolute worst thing to get fuel into our motors!!) or aftermarket EFI. And if you dislike working on electronics, the aftermarket EFI is probably not for you.

120 HP is relatively easy with a hotted-up 2056, using carbs and a real header. Up to 200 HP(streetable, too!) is possible from Raby's 2270cc engines; he has the dyno charts to prove it! But his expertise does not come cheap.

--DD

[Nostril Cheese]

FYI, you CAN run a 2.0 with the stock 1.7 D-jet.

You have to use the 2.0L injectors and fiddle with the manifold pressure sensor. The hard part is figuring out how to make the runners match up with the heads.

[Jagshund]

This sounds sort of familiar . . . I'm putting an M96 engine in my '68 911 using all Boxster components (except the engine, of course). I think you might be best suited using all Boxster parts if you're going that way anyhow. I have a feeling that boxster hubs might be compatible with 914 axles but I haven't checked that yet, and can check on the compatibility of a 901 and an M96 block tomorrow. As for engine management, that wouldn't be an issue with access to the whole car.

Money issues- Assuming that the Boxster is in running condition, $4-5K would be about right if you can pull front and rear suspension and the drivetrain. The good news is that, if you know what the heck you're doing, it should work.

Edit: I also agree with the Subie swap. I'm in the middle of one now (into a '71 914) and purchased the engine, ECU and engine harness for $150.

[larrym]

a weber 73 works great with D-jet; wilder cams such as the hydraulic cam, don't provide the vacuum signal necessary for D-jet to work right - BTDT

aside from that - why not just weld your 914 shell over the boxster platform - I have a couple autobody friends in Salinas who can do that for you in jig time at, say, $120/hr

"if you got the money, honey... i've got the time"

[SirAndy]

Originally Posted by Nostril Cheese

Swapping in a Boxster motor will neither be easy nor cheap.

I agree!

The boxster engine is too wide for the 914.
You'll have to relocate the suspension pickup points in order to make room.

That is neither simple nor cheap ...
Andy

[cvwcr32]

We are nearly finnished doing a boxster drivetrain in a 72 914(2.5 5 speed) It bolts into the engine bay without any cutting but we made custom mounts to fit up to the existing mounting points.The only problem is that 2 coils wouldn't fit around the rear suspension but as we are using an Autronic ecu we fitted a Golf 3 vr6 coil pack and custom ignition leads. Wilwood pedals for hydraulic clutch and twin master cylinder for the brakes.Front brakes are modded 911 hubs,944 turbo rotors and Boxster S calipers.At the rear, redrilled hubs and Golf 5 calipers.The proportioning valve was deleted.
A custom made aluminium radiator was fitted to the front with air exiting through the hole left by the aftermarkt a/c in the floor.Plastic pies from a T3 van were cut to size and are very light and durable.
I will post some pics up when I get a chance.
Cheers Pete

[cvwcr32]

We have nearly finnished a Boxster 2.5 into a 72 914.The engine fits like it was made for it on custom mounts which pick up on the original body mounts.The only problem was 2 coils fouled on the rear suspension but since we are using an Autronic ecu a Golf 3 vr6 coil pack and custom leads there is plenty of room.Wilwood pedals are used for the hydraulic clutch and twin master cylinders for the brakes.Up front are modded 911 hubs,944 turbo rotors and Boxster S calipers, at the rear are redrilled hubs and rotors with Golf rear calipers( finally a proper handbrake).A custom radiator and plastic coolant pipes from a T3 VW were trimed to suit as they are light and durable.
I will post some pics up when I get some time.
Cheers Pete

[Matt Monson]

Pete,
Are you using the Boxster gearbox as well? I think this is really interesting...

[cvwcr32]

Yes , the complete drive train is used.The 914 drive shaft with a T2 100mm cv on the inner for the right side and a long drive shaft from an auto T2 for the left side.The shifter cables run under the engine into the tunnel and the shifter is mount on an aluminium base plate bolted to the floor in front of the handbrake lever(yes it has been converted to right hand drive and they put the h/b lever in the middle).Dansk extractors were fitted and 2 small cats with a single muffler and standard looking tail pipe for the stealth look.6 cylinder welmeister rear springs with coil over shocks make it easy to adjust ride height.
Keep you posted with more updates and pics soon.

[Dave at Pelican Parts]

I'd love to see the pics!

--DD

[Matt Monson]

Yes. Pictures please!!!