Building a turbo 2.0 from a 914 GB engine

[ngobet]

Hi everyone,

So I have a project of turbocharging a 2 liters engine from a 914. Of course, I read everywhere that Wally did it with impressive results, but I actually couldn't find the pages about the build, so I decided to get a topic started here.

The specs will be as follow:

• Stock crank
• 228mm flywheel
• Stock rods
• Stock 94mm piston/ cylinders, with stock rings
• Stock 3 bold heads, they are not cracked but they require work
• Type 1 lifters
• Webcam camshaft
• Original cooling, since the engine will go in a type 34

The engine is already disassembled, and I am currently checking the parts. The case willl have to be aligne-bored and since I don't have the tooling I will send it to BAS in Germany.

I need your opinion about a few things:

• I am considering updating my heads to decrease the plug diameter and increase the valve seats at the exhaust to install 38mm valves, do you think that it will be useful? Does anyone have adresses in Europe for that?
• Can I keep the stock rods? mine have the 2 liters 50mm
• Should I change for some forged pistons, I have type 1 Wiseco on the shelf, will have to check if they are compatible
• Would you update the stock rings? I couldn't find something really exciting online

So I will really appreciate you input on this, and will keep you updated.

[wreck]

have a look on Face Book for "Get Back on Track " based in Denmark.Jakob can help you with what ever you want done with the heads ,from mild to wild . to add to your list , flywheel bolts from Thorsten Pieper ,he also has bushes for T1 lifters and ARP bolts for the rods .

I can't comment on the pistons as I don't have any experience with boosted engines , maybe ask the question on the forced induction forum .

[Wally]

If you are extremely carefull, read: have excellent knock control, intercooling and experience in tuning engine management systems, you can get away with stock pistons.
But...I wouldn't recommend it. Get the better pistons and ideally better rods as those are not expensive and you have a new set. Rebuilding the old set costs about the same-ish probably these days. The original rods are strong enough though if you don't get too crazy.

[ngobet]

Ok thank you Wally, I checked the Wiseco and of course they have the 22mm pin instead of the 24mm. Pin height is also slightly different at 35 instead of 35.9

I have never used knock control, were you able to find something reliable for flat-4 pushrod engines? I will run a megasquirt.

[ngobet]

have a look on Face Book for "Get Back on Track " based in Denmark.Jakob can help you with what ever you want done with the heads ,from mild to wild . to add to your list , flywheel bolts from Thorsten Pieper ,he also has bushes for T1 lifters and ARP bolts for the rods .

I checked that FB page and he looks quite competent.

However, I might do it myself, I want to weld the heads for 10mm plugs anyway.

[MegaRookie]

Ok thank you Wally, I checked the Wiseco and of course they have the 22mm pin instead of the 24mm. Pin height is also slightly different at 35 instead of 35.9

I have never used knock control, were you able to find something reliable for flat-4 pushrod engines? I will run a megasquirt.

You can have your rods easily rebushed for a 22mm pin, so if you want you can use the original ones. Or just buy chromoly instead.

Regarding the knock control. I used a megasquirt based one, but it didn't work for me. You can check J&S Safeguard as a separate knock controller, the Vampire for wasted spark with a Edis coil (if i remember correctly) and the Interceptor for coil on/near plug (I have that one)

Enjoy the build!

Mark

[wreck]

I've read that knock control is very hard to set up accurately , I'm in the early stages of going EFI and not sure to go with an Emu Ecumaster Classic with knock control or a Maxxecu street without . The Maxx has a dealer local to me , price wise at the end of the day is not a big difference .

[Wally]

I've read that knock control is very hard to set up accurately , ...

Yes indeed, thats why we use J&S Safeguard: there's nothing to 'set-up' besides one time the sensitivity and thats it. It works. Briljantly.

But its between $600-700,- iirc.
If you think rebuilding your engine is cheaper or if you feel you're an excellent tuner, then you won't need it

[ngobet]

I've read that knock control is very hard to set up accurately , ...

Yes indeed, thats why we use J&S Safeguard: there's nothing to 'set-up' besides one time the sensitivity and thats it. It works. Briljantly.

interesting, I checked and their "Interceptor" looks very easy to integrate. But there is no picture of the sensor, what does it look like and where did you place it? because location is crucial for the knock sensor.

[Wally]

because location is crucial for the knock sensor.

Actually, it isn't. Not to my experience with the Safguard though. It uses a regular Bosch sensor, used on many VW's like Golf 1,8 20V turbo and such. Very common.
I just mounted a sensor on the bell housing other side of the flywheel on one of the case parting bolts. No biggie

[wreck]

Thanks for the link Wally . the price coupled with the cheaper Maxxecu would be a lot cheaper than a blown engine

[ngobet]

I finally time over christmas to work on this engine.

I started by converting to type 1 lifters.

Started by turning a few bushings on my lathe in aluminium bronze.
https://youtu.be/L3Fch9u0_aQ

I will have to make a driver tu press them in the case, they are 0.05 oversized than the lifter bore.

Copied the length from a type 1 lifter


next, I milled the lifter bores in the case flat. right side on the pic still to be machined down


Looks nice


At the same time, I machined the case for the 98mm birals cylinders which I bought from AA.


I changed a few things, because I used the crank for another engine in the meantime. So I placed an order from BAS Ahnendorp to get one of their really nice 71mm stroke crank. In that way, I keep the short stroke.
The J&E pistons coming with my 98mm biral cylinders have a different pin height (30.3mm instead of 35.9mm), I will be able to order longer rods.

[ngobet]

I also started the work on the heads, to change the spark plugs from M14 to M12x1.25.

First I measured roughly the angle on the 914 2.0 liter heads. I machined a round rod with a thread to help measure the 2 angles.



then I mounted the heads on my milling machine and adjusted them until I was accurate.


angles ended up being 9° and 45°

I also referenced the center of the spark plug from the head stud hole inside.



to validate the measurements, I welded a spare head and drilled the new spark plug hole

Milling a flat surface


Drilling


machining the recess


It worked really well, spark plug location is perfect. Very impressive to see on the same head how different it is from original location. So next, I will well my 2.0 heads.

[ngobet]

With spark plug in

[Wally]

Wow! Great fabrication! Amazing what some folks just seem to make