What was the original use for the large hole on the flywheel side of the right (passenger) engine case?

Looks like it could have been a good flywheel lock location.

To me it looks like very good spot for a crankshaft position sensor...

What was its original reason for being there?

There was an automatic transmission available in the VW 411 and 412. That hole was used to put in the bolts that connect the torque converter to the flex plate.

Years ago, I machined the proper slots in the back of the flywheel, and put a GM DIS ignition on a 2.0L engine. I used that hole with a machined insert to hold the crank sensor. The limp mode advance curve of the GM DIS was almost identical to the stock curve on the distributor. It ran great until the starter chewed up the flywheel ring gear. Then I put the distributor back in when I replaced the flywheel.

My plan at the time was to use a GM EFI from a 2.0L 4 cylinder to run the 914 engine. But with the death of the flywheel, the project never went any farther.

Wow, you did it the HARD way...

20 years ago, there was limited stand-alone equipment and I understand why you did it that way.

How many slots did you have to cut into that flywheel?
What a PIA!

I'm planning to use the holes for the clutch bolts (they are symmetrical at 60 degrees) to trigger a MS3x. The stock flywheel might give me trouble (because of the extra balancing holes) but an aftermarket conversion flywheel appears to have only the holes for the clutch plate. The MS3 can trigger on either the leading or trailing signal from the sensor and you can apply any offset you desire.

The distributor can be turned into a cam sensor and I have both sensors figured out now.

I'm buying one of the unilights in the for-sale forum as it should be gravy to make into a cam sensor set up.

I DO need to come visit you.

I wish "Vulcan Mind Meld" was a real thing...

Just to be the devils advocate. Why not just get a crank trigger wheel set-up?

Using the flywheel to be a makeshift 6 tooth trigger wheel just doesnt seem worth it. Not saying that it wont work, plenty of 4 cylinder engines use a 4-1 wheel, but if your going through the effort why not do it correctly?

A simple 12-1 trigger wheel will take full advantage of the MS3. Better resolution and if the cam sensor ever decides to fail you can use the missing tooth set-up and run Batch Fire mode and still have a working car.

https://thedubshop.com/crank-trigger-package-type-4-vw/

Thanks for other options guys.

The set up I have in mind would require nothing more than a fitted plug for the torque converter access hole, a magnetic sensor, and longer modified clutch plate bolts.

I'm a believer in "the simplest solution".

This also should be drop dead reliable with only the sensor as a possible failure point and should have easy sensor access.

I run an automotive AC specialist shop and have ideas for a much more modern compressor for this application. I want to leave as much room as possible between the crankshaft hub and the fan.

I'm going to attempt to install a modern variable displacement compressor and may need to make my own serpentine belt pully. The MS3X already has extra PWM outputs and should be able to control the compressor.

It looks like the Dub Shop may already have a serpentine pully available to work with his kit. I will ask them about this next week.

Thanks so much for the tips.

Rick

The early GM DIS ignition only had six slots to cut in the flywheel, plus one for the sync pulse at top dead center. I stuck a sharpie in the hole and spun the motor to get a center line for the slots. Then I chucked up the flywheel in a rotary table and machined a slot that was wider than the hole at 60 degree intervals, and one for they sync pulse.




I turned an adapter on the lathe, and mounted the pickup in the case. It was a fairly simple operation.

I had the throttle body and fuel injection system from an olds quad 4 to use. I just needed to machine an intake that would hook to the 914 runners and mount the throttle body.

It would have been unique.....

One of the real early uses of coil on plug!

We had shitloads of trouble out of those early all-in-one coil packs with the ignitors built into the base in the "normal" repair world.

The Cadillac Northstars used two of those and we had lots of trouble with those as well.

Both the Quad4 and the Northstar were wonderful designs that GMs quality control doomed from the start.

Right about the time they got them "de-bugged" they cancelled them!

What a waste...

So, only 6 slots +1 and you already had the angles indexed.

My hats off to you Sir!

That was a pretty good system to start with. The GM ECUs are way overbuilt, and they use 15% of their total computing power to run an engine.

Sounds a lot like how the human brain works...

The truck coils (01 and up) are the "budget" ticket for COP now. The junkyard used coils are better than what's available in the new aftermarket.

I will be using the IGN1A coils here.
https://www.diyautotune.com/product/ign-1a-race-coil/

These puppies can arc weld.

I really like the cam sensor set up that the dubshop has.

https://thedubshop.com/mini-cam-sync/

Too bad the're sold out right now.

I'm not sure if Original Customs still makes them or is still in business, but @McMark had made a nice little kit for crank trigger setup. I think they ran around $130.

We use the DubShop units if the engine is out. We've been working with Lonnie at PermaTune to develop a drop in distributor(ish) unit for future kits.

The PermaTune unit would drop in the dizzy hole and have two outputs, one for cam sync (allowing sequential fire) and the other for crank. The engine can stay in the car making the EFI system a weekend install.

You may want to call Lonnie and ask about the new unit we've been working on. He's a fountain of knowledge.

Eric, thanks for the tips!

My first ideas for cam/crank triggers involved getting 2 4 cylinder mag pick up assemblies, fixing them into a distributor housing and chopping 3 of the teeth off of one of them. This would do it. You would have to delete the mechanical advance.

Most of the OEMs have moved to directly on whatever is rotating. Cam sensors are directly on the cam (usually the gear) and the crank sensor is directly on the crank.

The crank sensor looks super easy to me but there is limited access on the cam in a type 4 installation. It has to go on the distributor drive IMO.

I don't like sensors depending on a mechanical drive as any play in that drive may cause "jitter" and create problems where a directly sensing element would not.

I can easily see the simplicity of using a distributor as both, especially for the DIY crowd.

I am a fabricator/technician/designer and like to come up with my own way.

Separating the sensors also gives me a bit of adjustability regarding the "phase" between the two. This might or might not be important in the future.

One thing I will have to make that you might be interested it is a flange for the intake which places a modern injector exactly where the original ones are and then can be used for ITB or Plenum manifold. Plenum manifolds may well be the way I go.
Just look at the 964 motor in the classifieds or the Ferrari motor that is being installed in the forums for ideas. If I can get a plenum to work, I can easily control it with an ETB like this one.

https://www.summitracing.com/parts/bch-0280750151

That critter is cost effective and 60mm bodies can easily support a 200hp motor.
You add complete throttle control and electronic cruise control as well.
Most folks don't realize that the air pump has completely been replaced by the electronic throttle body and the decel valve (that so many have trouble with) is included in the Tbody. So, complete throttle mapping, electronic cruise, and a variety of emission controls can be utilized with ease.

The dubshops crank trigger looks very nice but it appears to be a PIA to get to with the engine in the car and I may need the room it occupies.

I spoke with my MS3 guru about my ideas and an MS3 Pro has the ability to run a PWM AC compressor in tandem with the engine.
A PWM compressor (especially if I use R12 which is legal in any 914) will have almost no drag on the engine at idle and is the path to sub 32 degree AC...
They made the compressors more efficient for fuel economy reasons but with the fine control this enables you can go sub-artic if you want.

My all-time record car for temps was a 12 BMX X5 that has an "intense" button on the AC control head. This was an R134 system that could hold 32.8 F on a 105 degree day.
It would do it at ANY speed including sitting still in direct sunlight.
Bad Assed!

I think you are over estimating the "jitter" that is caused and it is really a non-issue. Look at the OEMs in the 90s before they had all their tooling switched over to make those directly connected sensors.

Nissan, Toyota, Mitsubishi all had their CAS systems (getting their cam and crank positions) running off of the exhaust camshaft (directly connected or through a gear) driven by a rubber timing belt. This adds about all possibilities of error and they worked perfectly fine. The only time they would fail to keep accurate timing is when the motor made gobs of power and the torque would stretch the belt.

As for the phase relationship between the senors there is no need to adjust that ever mechanically. Only if the original design got it wrong, even then you just adjust it with software.

Im all for the do it yourself idea. There are plenty of projects I have made that cost me a lot more than just buying an off the shelf product. But it still doesn't stop me from poking holes in mine or someone elses idea. It all helps in the design process

Way too much thinking for a T4

once you put the motor together, the cam timing and crank timing have the same relationship....basically forever.

You are seeking a way to control when the spark event happens...crank timing can do that.
If you need input for the cam timing on the computer you are using, can't you just base that signal off the crank signal with whatever offset is required and call it a day?

Curious because I am going there on my next build...but I never figured I would need to deal with cam timing because its pretty much just fixed.

I would like to see pictures of the solution...to see how clean it can be.


Rich

The cost no object SBC builds all employ small Gilmer belts to reduce jitter that exists with an old-style chain drive. This jitter affected both cam timing and the distributor that was driven by the cam. The belts are a tiny little shock absorber in this application. Jesel is famous for their belt drives.

Torque will not stretch one of these belts very much at all before it breaks them.

Many of the CAS sensors used Mitsubishi sourced optical sensors (including the LT1 in the Chevy world). I like optical sensors; they worked really well.

Mitsubishi stopped making these about a decade ago and now even the MSD billet distributor for LT1 is not worth buying. Only real solution for the LT1 crowd is an upgrade to the LS1 system with COP.

I have moved over to the current OEM style of doing things. Simple mag sensors directly on the item being sensed. The OEMs did this for cost savings first and accuracy second but the acuraccy is world class if the application is correct.

Thanks for your insight. sometimes another's views open up a world of possibilities...

I slowly coming to this realization. The cost of go-fast parts for these is ridiculous.
I will only build one stroked T4 in my life and am not interested in making parts for a niche audience.
The car I'm dreaming this up for cannot be modified IMO and has to stay VW T4 based.
Bolt ins are OK in my book and an entire motor is "bolt in" as long as you retain the original power plant in its original form.

I actually have 4 of these. Two which will be built, one of which "sky's the limit" and it will be water cooled something else...

I have two organ doners as well.

I have a few questions.
I get the install of the crank toothed wheel and why it needs to be there.
Is the wheel the same thickness of the washer that gets removed?
Is there a potential compromise of the fan hub mounting getting loose (like th other thread on here that bad things happened when it did get loose)

Second
Distributor drive gear stays in place, or does that get removed?
Seems like bouncy bouncy bad things could happen there?
Just did not see that in the video, and I did not RTFM.

Rich

Zims is building a drop in EFI kit for the 914. It is running on the first motor.

Took it from about 85 wheel horsepower to 120 wheel horsepower with no internal engine mods.

And it looks like a pair of downdraft carbs. Even uses the same throttle linkage. And no chassis mods. Installation would be about 4 hours if you already have stock fuel injection. Even the basic fuel map will be ready to run.

It is all plug and play. But for best performance, you need to get it dyno tuned for your engine after installation.

@partsguy22 - Got pictures?

SOT: As someone that has done a 6 conversion...I would absolutely do it again. Its a mount, oil tank, shift rod, exhaust that sets it apart from a 4. IMO cheap power when you think about it.

While other conversion like watercooled 6 or 8 will require a little more modification I don't think anyone will ever convince me it is cheaper/more reliable to get a t4 to the same power as the bigger engines.

And there it is...
That type of performance gain on a hot 2.0 or maybe a 2.2 is what I'm after.
I'd like to double the stock power of the original 1.8 L-Jetronic which I first have to restore to its original fuel injection which came with the car.
I will run it on a dyno in stock form first to get a base line.

On the big engine I will make internal engine mods and I'm planning on using E85 which could be worth some more power. 5-10% would be what I'd expect in a non-boosted E85 set up over 93 pump.

What is a normal WHP reading for a stock 75 1.8?
I would guess 60-65.

If you want to run e85, you are going to have to retune the EFI for it.

And the stock HP of a 74 1.8L was 76.

Yep, actually I'll use a GM flex fuel sensor and have two maps which the MS3 will blend automatically. Once it's set up it's transparent. 93 octane with have a much more conservative timing map and run 30-40% less fuel.
I will be employing a Bosch knock sensor as well.

My question regarding HP was what does a stock 914 1.8 register on a chassis dyno?
If you take 76 and multiply it by .85 you get 64.6.
This is using 15% as the calculated loss through the drive line.
15% is probably less loss than actually occurs.

Has anyone baselined a stock 1.8 on a chassis dyno?

The 1.8L has not been stock in so long I forgot what stock feels like. And for a couple of young people on a tight budget, a dyno run was out of the question.

When Betty and I first met, her car was a bone stock 1.8, and it was only running on 3 cylinders. So imagine how anemic that was....

My first 914 was a rusted out 70 1.7 with a 1911?? big bore kit in the early 80s.

I was 17 years old and did NOT know what I do now...

My dad bought it as a basket case, and I assembled the jugs and heads myself.

This was LONG before I started doing my own head work and something about them was wrong.

This car came to me with the crappy progressive two-barrel Weber (which the current car has as well).

When it ran it ran OK but...

There was so much messing with the carb that I removed the engine lid for quick access.

Occasionally it would throw fireballs into the air on start-up.

At one point I set my girlfriends family tree, in their front yard, on fire at three in the morning.

This is one of those memories you retain for LIFE!

Another interesting fact with me is that I swore I'd never mess with air-cooled VWs again in my life three decades back. My wife had a Super Bettle that gave us so much trouble I hated it. I was done with crappy low powered cars that required engine removal as much as that one did. I got really fast at drivetrain removal on that car.

Well in 2023 my dad again comes up with a 914, a stupid nice time capsule 914, and here I am dicking around with air-cooled VWs again.

Back then I was apprentice/journeyman level and knew little.

Today I'm not...