1967 912 Type 4 Turbo Build

[Cameron Henlin]

Hi everyone! This is my first post here. I have been lurking and planning out a build for a while. Finally have some plans coming into view that I was hoping I could get some feedback on.

I have a pretty beat up 1967 912 that I acquired over the summer. My plan is that I am going to turn it into a patina-ed out hot rod over this winter. Might do some bodywork next year:

IMG_2479.JPG

Anyways, the engine part of the hot rod plans:

I picked up a 2.0L 914 engine over the last few days. It's dirty but appears fairly complete:

Screenshot 2023-10-31 at 10.01.40 AM.png

Here is what I am doing with it, I think:

- I am going to yank the factory type 616 engine, clean it up, and either pickle and store it, or sell it on BaT. They're worth too much and can't reliably produce enough power (IMO) to bother with for a hot rod build.

- I am planning on doing a set of high performance valve springs/retainers or AA heads with "hi rev" springs (depends on if the heads are cracked or not, haven't checked yet) in the 914 engine.

- 912E cooling tins appear to be impossible to find so I was planning on making carbon fiber panels to fill the gaps between the 914 tins and the 912 body.

- I am going to build a set of mounts to attach the 914 mounting bar to the 912 body. Looks like a few people have used elongated bolts but it gives sloppy shift feel, I was thinking of building some boxed in pieces of aluminum to hold everything in place.

- I am converting to a megasquirt 2 that I already have on the shelf with wasted coil on plug using GM truck coils, trashing all the factory bosch stuff. I've done several megasquirt installs and am very comfortable here. I am going to tune it on e85 to help keep the engine cool and prevent detonation.

- For exhaust I am thinking of hacking up a Bursch exhaust https://sierramadrecollection.com/produ ... 12e-p55910, cutting off the muffler and welding on a T2 turbo flange in its place.

- Next I will be installing a g25-550 turbo with a .49 ar and and integral wastegate and then install a vibrant 3" muffler on a short downpipe

- For intercooler I am going to get a large 930 air to air unit and a duck tail deck lid, and cut the deck lid to fit around the intercooler

- I am trying to shoot for a pretty responsive 200whp or so. I think it's doable. it should be a little monster with this kind of power


Some questions for you turbo VW experts:

- I believe I can run a stock 914 215mm flyhweel with the 912 transmission, but I know the clutch/pressure plate won't put up with this engine. Has anyone used the spec stage 3 from pelican parts or does anyone have a different recommendation? I was looking at this one: https://www.pelicanparts.com/catalog/Su ... ch-kit.htm

- I mentioned I was going to make cooling tin spacers -- does that sound like a reasonable plan? Is there anything to be aware of while I am doing this?

- I notice a lot of turbo folks upgrading to DTM cooling, is it necessary? again I was hoping to mitigate cooling needs with e85

- anything else to be aware of as I get into the build? dumb idea to do a type 4 over a high output type 1?

[rubenski]

Cool but i can´t see the bottom half of your post

Verstuurd vanaf mijn SM-A528B met Tapatalk

[Cameron Henlin]

Cool but i can´t see the bottom half of your post

Verstuurd vanaf mijn SM-A528B met Tapatalk

I edited my original post. It looks like tapatalk doesn't support bulleted lists so I removed them and used some simpler formatting. Thanks for letting me know

[Wally]

Not sure about the rest of the motor, but the injection parts up top are not from a 914 2.0 unit.

Especially with E85, the stock cooling will do just fine.
And with the upgrades on heads and cam you mention, 300 hp comes VERY easy, probably at just 14 psi boost already.
I did a total stock 914 2.0 engine in the past on 1 bar boost and it made 200hp. 270hp with bolt on ratio rockers even haha!

The G25-550 unit suggests it maxxes out at 550(crank)hp right? If you really just after 200 whp, then you would be better of (more responsive) with a little smaller turbo.
215mm size has a very small range in pressure platse. There is much more to choose in 228mm (9" , a popular size) if that would fit the 912 Bell housing.
Be carefull with that glass transmission though as turbo engines can (and will) easily put out too much torque..

[Cameron Henlin]

Especially with E85, the stock cooling will do just fine.

Thanks for the info! I was thinking this should really help things cool on an air cooled engine. I couldn't find a whole lot of actual data on it, but it seems like the combustion temperatures would be lower and probably keep everything else lower too

And with the upgrades on heads and cam you mention, 300 hp comes VERY easy, probably at just 14 psi boost already.
I did a total stock 914 2.0 engine in the past on 1 bar boost and it made 200hp. 270hp with bolt on ratio rockers even haha!

That said, should I not bother with the head/valvepsring upgrades at this power goal? I was thinking the pressure from the turbo would potentially cause valve float early. I have experienced that messing around with other cars. I'd like to be able to rev to 6000 or 6500 without issue.

The G25-550 unit suggests it maxxes out at 550(crank)hp right? If you really just after 200 whp, then you would be better of (more responsive) with a little smaller turbo.

The G25-550 comes in several different sizes. I believe the .49 ar model is not really capable of 550 crank hp. I think this size is good for mid 300hp on a modern, highly efficient engine. Probably not that much on a type 4? These things are also tiny and spool incredibly quickly compared to older small frame turbos. I'm all ears if you've got a suggestion

215mm size has a very small range in pressure platse. There is much more to choose in 228mm (9" , a popular size) if that would fit the 912 Bell housing.

Great, so I guess pick up a 228mm flywheel, find a 6 puck clutch/pressure plate combo, and go? Any recommendations there? I am assuming that gives a big enough surface area to where grabbing at this power level shouldn't be a huge issue there?

Be carefull with that glass transmission though as turbo engines can (and will) easily put out too much torque..

I couldn't find any good enough on how much power people expect to hold with these transmissions. My plan at the moment is to just avoid powershifting and launching it until I come up with a better idea. It seems like if I find a rear shift 914 transmission I can flip it around and use that in the future and I think they can take a bit more of a beating. Haven't spent a lot of time looking into this yet however.

[my_medusa]

At First, nice Setup. How Walter told: Stock cooling +E85 is fine(redline Limit of Stock cooling about 6000-6500rpm??). I am Personaly Not a fan of big engines and small hot side Turbos, the g25 will Work but it is a huge turbo for 250-300hp goal. The 550 HP Limit ist garrett -sellspoint( Race Gas in a smaller Displacement super efficent testengines with high boost- thats what Garret said about the 550-660....). The map shows more 450+hp in an aircooled world which IS still way more than your goal, but it has a huge surge Potential so it's fine. get the Pulsar Version, now is black friday and you get the 0.49 as a v-band under 800dollar( If the Turbine housing is one day too small it's way cheaper to buy and Switch over to a 0.72/0.92 than having the garrett plus Pulsar has all 3 housings as Internat gated v-band). Save that Money and even save the Money from that expensive Header (you want to Cut/weld) and put it into the Transmission to make it stronger. If the Goal is to have it super responsive and also use it, than the trans/clutch will Not be your friends. And If you want a real responsive turbo get a holset he221w 7cm, it's a 350-450dollar new unit, proven on every engine it was Bolt on between 330-360crankHP (1.6-2.5l engines) with a even earlier surge Line and earlier spool plus lighter and way smaller . The g25 is Not that responsive than people think it is, the Wheels inside are way heavier than the he221 ones. Had both Turbos in my Hand and apart,would Not use the g25 if the Goal is under 350hp in a responsive street engine, but it's the better Match to a 2.0l and nicer to the Transmission because of the later spool. Early torque Kills Transmissions. So i would not care too much about the engine and think more about the Transmission.
Enjoy the build

And Not Junk the 616-sell it to the 912/356 people. They May can use Some stuff, those engines get rare

[Bruce.m]

The ‘67 came with a 901 type transmission. Internally it’s the same as the 914. Although the 901 usually has lower ratios than the 914 box. Less certain about 912 ratios. Came with either 4 or 5 spd

The transmission is not very strong. 1st gear is very weak in the 5sp version! As at hangs off the end and supported on one side.

[Cameron Henlin]

At First, nice Setup. How Walter told: Stock cooling +E85 is fine(redline Limit of Stock cooling about 6000-6500rpm??). I am Personaly Not a fan of big engines and small hot side Turbos, the g25 will Work but it is a huge turbo for 250-300hp goal. The 550 HP Limit ist garrett -sellspoint( Race Gas in a smaller Displacement super efficent testengines with high boost- thats what Garret said about the 550-660....). The map shows more 450+hp in an aircooled world which IS still way more than your goal, but it has a huge surge Potential so it's fine. get the Pulsar Version, now is black friday and you get the 0.49 as a v-band under 800dollar( If the Turbine housing is one day too small it's way cheaper to buy and Switch over to a 0.72/0.92 than having the garrett plus Pulsar has all 3 housings as Internat gated v-band). Save that Money and even save the Money from that expensive Header (you want to Cut/weld) and put it into the Transmission to make it stronger. If the Goal is to have it super responsive and also use it, than the trans/clutch will Not be your friends. And If you want a real responsive turbo get a holset he221w 7cm, it's a 350-450dollar new unit, proven on every engine it was Bolt on between 330-360crankHP (1.6-2.5l engines) with a even earlier surge Line and earlier spool plus lighter and way smaller . The g25 is Not that responsive than people think it is, the Wheels inside are way heavier than the he221 ones. Had both Turbos in my Hand and apart,would Not use the g25 if the Goal is under 350hp in a responsive street engine,

Appreciate the advice on the he221w, hadn't even considered non-Garrett turbos. Looking at these I think I can save quite a bit of money over the G25-550 also. Going to strongly consider the he221w, looks like it would actually be perfect for what I want.

but it's the better Match to a 2.0l and nicer to the Transmission because of the later spool. Early torque Kills Transmissions. So i would not care too much about the engine and think more about the Transmission.
Enjoy the build

Any advice on some things I could do to give the transmission some more strength? I'm not finding a ton of info online. I found one thread here https://forums.pelicanparts.com/porsche ... 356-a.html where some pelicanparts folks discussed putting a type 1 transmission in to a 356 (and one user mentioned a 65 911) chassis so maybe I should look at going to a build type 1 trans? This is somewhat attractive because I could give it some long legs. I think it's going to go back on the road with the current 901 transmission as is however and I'll deal with doing something else if it breaks. It's a 4 speed BTW -- sounds like people have a general opinion that these can take a bit more abuse than the 5

And Not Junk the 616-sell it to the 912/356 people. They May can use Some stuff, those engines get rare

Yeah definitely not going to junk it. It is very complete-looking and turns over freely, but hasn't been run in 20+ years. Probably a good candidate for a nice restoration build in the future. I have spare room at the moment so probably tossing it on a stand in the corner, pickling it, and vacuum bagging it.

[Cameron Henlin]

The ‘67 came with a 901 type transmission. Internally it’s the same as the 914. Although the 901 usually has lower ratios than the 914 box. Less certain about 912 ratios. Came with either 4 or 5 spd

The transmission is not very strong. 1st gear is very weak in the 5sp version! As at hangs off the end and supported on one side.

I wonder if there is some additional bracing that could be added inside of the transmission to help hold things together? Do you know of anyone modifying the 901 for strength? Mine is the 4 speed BTW

[Piledriver]

They make a billet intermediate plate for the 901 trans to help keep things together, as well as a billet diff side cover, but you still aren't doing full boost 1st gear drag launches. (boost is usually inherently limited i'm 1st gear at least)

I'm still trying to figure out how to do a flipped diff vw 090 automatic...
....but I have a 914. For a 912 it already spins in the right direction.
Would probably require custom axles, but those are things...

With a 300M input shaft it will deal with 300HP in nearly stock form.
(it might not even need the 300m input shaft for 300HP)
A variety of final drives and diffs also exist.

You could probably build a herd of them for the cost of a stock rebuild on a 901 trans, and rebuilding the automatic doesn't require any truly special tools.

[Cameron Henlin]

Got my dirty old Type 4 engine torn apart so I could clean it up over the weekend. I appear to have figured out a couple of things:

- confirmed beyond reasonable doubt that it is a 914 2.0 engine. I was pretty sure with the 3 bolt intake manifolds but confirmed by finding the serial number and noting that it starts with GA... I believe that means a 73/74 2.0 engine with 7.6:1 compression. Great for boost
- Ran a leakdown test and got back nearly 0% leakage across cylinders and no cracking around the spark plugs. I am going to go ahead and run it as is without buying new heads, doing head gaskets, etc

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IMG_2791.jpeg

Next, I am cleaning up the engine, painting the tins with some high temp paint, and wiring and looming my MegaSquirt wiring harness (which is on order)

I am curious if anyone has any valve spring recommendations for Type 4s. I am still thinking I probably need a set if I want to avoid valve float above 6000 RPM. I was looking at this kit https://scatvw.com/product/single-sprin ... retainers/ but am willing to do something else if someone has a better recommendation. I was just going to pump up the cylinders with my air compressor since the leakage is very low and do these with the heads on.

Other than that my goal is to bring the 912 itself into the shop early next month and begin work on getting its Type 616 engine out. It would be great to see the car move under its own power this year

[Cameron Henlin]

One other thing, I am abandoning my plan to do a Bursch exhaust. I am realizing to run that, I would need the factory 912E header/heat exchangers, or maybe something off of a bus? Regardless, I am looking at more complete exhaust options to hack on. I ordered a set of used factory bus headers without their heat exchangers to see about how they fit. If anyone has some particular exhaust options, I'm all ears. Otherwise probably going to weld up something very custom and ugly, then header wrap it. I don't care about having functioning heat or not at the moment

edit: I think this is the only fully bolt on exhaust system, which I'd have to hack on: https://tangerineracing.com/shop/ols/pr ... 10af342c98 pretty pricey!

that said almost certainly going to build something myself from the heat exchangers back it looks like

[Cameron Henlin]

Reading more about clutches today, I believe to run my type 4 with my 901 transmission and porsche starter without further modification, I need a factory-style 215mm flyhweel or a 200mm flywheel from an early vw 411. To avoid sourcing parts or needing to modify a bunch of stuff, looking around online, looks like my only option is the spec clutch I posted earlier: https://www.pelicanparts.com/catalog/Su ... ch-kit.htm

Also looks like a lot of the other performance clutch options are not sprung? Are you guys running solid discs in your stuff?

[Piledriver]

The 228mm setups work with zero clearancing in a 914/901. (BTDT) one does need the input shaft bearing added.
The ring gear is same size, and the 901 bell housing has plenty of room for the 228 pressure plates.

IIRC Wally(?) had a 215mm 914 flywheel remachined to be a 228, this was due to the 914 flywheel is a forged unit.
Later had one modded for a dual disc setup.

You are going to want 4032 aluminum forged pistons. Everyone makes them.
2000 series is too soft, Wiseco doesnt even recommend 2000 series alloy pistons for any endurance racing, just drag racing.
(the ring lands wear out with the buttery soft 2000 series alloys)

There is a 2KW permanent magnet factory gear reduction starter that also works with a little work with a rattail file.
application automatic mk4 TDI, there are 9 and 11 tooth versions, we need the 9 tooth.
New aftermarket units are available and seem to work fine.

[Cameron Henlin]

The 228mm setups work with zero clearancing in a 914/901. (BTDT) one does need the input shaft bearing added.
The ring gear is same size, and the 901 bell housing has plenty of room for the 228 pressure plates.

IIRC Wally(?) had a 215mm 914 flywheel remachined to be a 228, this was due to the 914 flywheel is a forged unit.
Later had one modded for a dual disc setup.

Do you have any specific recommendations for a 228mm 6 puck sprung clutch then? I prefer sprung for a street driven car. Seems like maybe spec is the only one out there offering pucked clutches with springs for our cars.

You are going to want 4032 aluminum forged pistons. Everyone makes them.
2000 series is too soft, Wiseco doesnt even recommend 2000 series alloy pistons for any endurance racing, just drag racing.
(the ring lands wear out with the buttery soft 2000 series alloys)

Interesting idea. I had planned on using factory pistons. In fact, with the leak down numbers being so good, I am planning on not even removing the heads, prior to putting it in the car. I am very experienced at EFI tuning so my plan here was to avoid knock and stay cool (again have E85 fuel coming in to play here )

There is a 2KW permanent magnet factory gear reduction starter that also works with a little work with a rattail file.
application automatic mk4 TDI, there are 9 and 11 tooth versions, we need the 9 tooth.
New aftermarket units are available and seem to work fine.

Thanks for the info, will keep an eye out here. My 67 porsche starter appears to be in good shape and engages/disengages/spins freely so was planning on running it for now. It appears to have been swapped at some point and is almost definitely not original to the car from what I see