1973 VW race car, whiteblock powered

[Karl Buchka]

Figured it's time to break this thing out of Alex's showroom thread and give it a project thread of its own.

1973 VW Beetle rallycross car with a B5254F (2.5l 20v 5 cylinder) engine swap. The car was bought as a rolling chassis with the cage, 911 suspension, rear coilovers, and radiator already installed. It had previously been run in a rallycross class called Super Nationell with a pinto motor. Alex did all the brunt work on the engine and adapter plate before I moved out to Sweden, after which we double-teamed most of the work.

Fresh off the boat, almost two years ago:










Alex found a B5252F at the yard for 1000 SEK. Stock rated at about 170hp.


The engine is mated to a 4sp Vanagon transmission using a custom two-piece adapter plate.

Some pics of the adapter plate build. It made sense at the time, but in hindsight, this design is fairly idiotic. Something more along the lines of a KEP adapter would have been better.










Because of the adapter design, the trigger wheel had to be removed from the stock flywheel. We added a 60-2 pattern to the crank pulley at the front of the engine. In spite of the trigger wheel sitting on the damped part of the pulley, the car revs cleanly to redline.


Engine mounts with custom delrin bushings.


Machined a new alternator mount and an extension for the alt pulley.


The mount for the VR sensor. I am extremely happy with how this part came out. Done in 7075-T6 on a manual mill.




Custom 3" straight through muffler, all stainless and TIG welded.


Went for the cost-saving option with an MS1-V3 and a JAW O2 controller. The board is running the latest hires firmware and is mounted inside of a repurposed ECU case off some truck.




Looking pretty complete.


In the process of getting the car ready we ended up replacing the entire fuel system, including pump, filter, and lines. After that was finished we set our sights on the electrical system. Wiring clearly wasn't the previous owner's forte. The existing harness was an utter travesty, so we tore it all out and re-did it from scratch. Every wire and connection is soldered, heatshrinked, and covered in black nylon braid loom.

We also added this 39 pin bulkhead connector to the firewall. Disconnecting the engine from the electrical system is as simple as pulling this connector.


Example of the braid loom. This is the tuning cable for the MS. As you can see we opted to run it up to the dash through a locking connector. This ensures easy access from the passenger side of the car as well as easy removal for when a laptop hookup isn't needed.


The new dashboard. The buttons are grouped so that the critical systems are further from the driver's reach, minimizing the chance of inadvertantly shutting the car off while reaching for the e-fan or wiper toggle.


When the wiring and fuel systems were done, the engine was ready to be fired up. After tweaking the req_fuel a bit, the car started without issue. We initially ran it with a dry cooling system for the sake of simplicity. After adding water to the engine it suddenly refused to turn over. Troubleshooting revealed that the ports for three of the cylinders had holes in them. Turns out the guy who cleaned up the head accidentally poked holes in to the cooling jacket. Since the head was essentially junk at that point, we needed to tear down the engine and source a new one.

Putting the new head together.


While the engine was out we also patched and painted the firewall and the rear calipers were rebuilt.

Alex welded up a tank for the washer fluid. Still missing a sight tube on the side, but everything else is there.






The car in its current state:


And a short video of the first start:


Looking to have it driving in a couple of weeks. Clutch and brakes need bleeding, the catch can needs to be hooked up, and we need to build a seat mount. The cam sensor also needs to be replaced. When we first tried to start the engine we found the cam sensor to be faulty, so we changed the MS to run the engine in wasted spark. An oddity in the trigger layout means we were forced to switch to time based cranking, which makes the car somewhat hard to start and prone to backfiring. Sequential spark and trigger return cranking should solve both those problems.

[Tom Wiley]

Awesome. I doubt it weighs much.

[FunkyStankyChicken]

I was beginning to think you bros had quit cars

[doucheNozzle]

Damn.

[Tom Wiley]

I wonder if this thing will pull wheelies with slicks....

[gear whine]

thats some quick, nice work guys.
great job with the wiring. very clean and professional. similar to what i want to use for my harness...

keep it up!

[gdogg16]

Very cool guys!

[Karl Buchka]

Thanks for the kind words guys. It's always much appreciated.

Originally Posted by Tom Wiley

Awesome. I doubt it weighs much.

We haven't weighed the car yet, but we're hoping it comes in under 1800lbs wet. If we remove the ballast plates from the front end of the car it may very well wheelie.

Originally Posted by FunkyStankyChicken

I was beginning to think you bros had quit cars

Not yet. Sometimes the thought strikes me though...

Originally Posted by gear whine

thats some quick, nice work guys.
great job with the wiring. very clean and professional. similar to what i want to use for my harness...

keep it up!

Thanks. Not so sure on the quick part. We've been putting in hours on this project for the past two years.

Brought down the idle and started cleaning up the maps today. After some un-eventful tuning the car suddenly refused to fire. Diagnosed it as a no spark condition. Found this when I opened up the MS box:



So note to self: Don't ground all five ignition coils through one trace on a cheap stripboard. I guess I'd better hurry up and finish that accessory breakout board that I drew in Eagle the other day.

[Turbeam]

Nice work there!...... It looks so much better with a whiteblock hanging out the back than they do with a pinto, and no need for any messing with sumps etc in this case either.

Its bound to handle better with the lighter motor too, without any real negative effect on traction in the loose.


The only thing I'm still not very keen on is the alternator extension, I wonder how well those front bearings are going to hold out?


Most of the pinto powered ones I've seen leave the engine exposed with just a protective 'cage' around it, and I 've wondered how they were ever legal like that for road use with the cam belt exposed when the cover isn't fitted (which it usually isn't).

Its a nice touch if that modified engine cover fits over the new motor......but it would also be nice to get a little sneaky glimpse of it through a mesh grille......

Had the original head's ports been opened out quite a lot then? Thats got me thinking, I haven't had water through my worked head yet either.......


Should be a lot of fun.

[Karl Buchka]

Thanks for the comments.

Both Alex and I freely admit that the alternator mount and extension are far from ideal. I'm sure the bearings are begging for mercy, but with the limited run time this car is likely to see, I'm hoping it will last long enough. In the mean time I won't waste my time thinking of a solution to a problem that doesn't exist (yet?).

This car did come with an engine cage just as you describe, which we plan on modifying to fit. The engine cover almost fits. It will need to have a small hole cut in it to accommodate the top of the cam cover. I'm not too worried about hiding the engine as the sound should attract enough attention.

[pwschuh]

Did you figure out what class you'll be able to run it in?

[Tamnakz]

Hot sex in a beetle!

[SteveMD]

Originally Posted by pwschuh

Did you figure out what class you'll be able to run it in?

Wild guess it must be some class that requires the motor be in the original location but motor itself is 'free'.

[volvorsport]

crikey , wish id been over to see this now .

you say its a vanagon box ? has it got the diff welded up ?

[500dollar744ti]

nice build! are you going to pin the crank pulley so it's solid? not that i've ever seen a whiteblock pulley slip, but you never know.

[Karl Buchka]

Paul, with the 20v head we can't run it and be competitive. If we swap in a 10v head we could probably hold our own in a slower class.

Dave, it'll be here when you come back. The box is from a Transporter, Vanagon, same ****. The diff is open.

Matt, not sure I follow. The pulley has the roll pin and two bolts locating it with respect to the timing belt pulley.

[FunkyStankyChicken]

Originally Posted by 500dollar744ti

nice build! are you going to pin the crank pulley so it's solid? not that i've ever seen a whiteblock pulley slip, but you never know.

Like pins through the rubber dampner?

[500dollar744ti]

^^^ yeah, or something similar

Originally Posted by Karl Buchka

Matt, not sure I follow. The pulley has the roll pin and two bolts locating it with respect to the timing belt pulley.

i mean put a couple of locating pins in the rubber so the outer part can't spin if the damper fails. you were saying something about it running fine even though the pickup teeth were on the outer part of the damper but i wasn't sure if you had done anything to make the pulley a solid mass so it won't slip.

[Turbeam]

The crankshaft damper is there to act on unwanted resonant frequencies along the length of the shaft, but there isn't any real movement as such that would have any effect on the accuracy of the pick up so that arrangement will be absolutely fine.


I'm not sure about whiteblock dampers, but these can and do fail on other motors, even if it is often on high mileage engines and where oil or other contaminants have got to the rubber. They sometimes also separate through corrosion of the metal parts of the pulley or show signs of 'tearing' or cracking of the rubber part long before they let go. The rubber in the photos looks to be in pretty sound condition, and the sensor mount is solid as well as neat..... I can't see any problems there at all.


Just as a precaution, I've seen dampers fitted with 3 or 4 pins that will locate the outer pulley section in case of failure. They bore a set of holes through the outer section and the rubber and a slightly smaller diameter hole inside each of these into the inner part which is then tapped and fitted with a pin or stud. This still lets the damper work as designed, but if the rubber fails the pins continue to locate the outer part and prevent it flying off.

tbh, the pulley is going to be so visible on this beetle that any sign of splitting should be easily noticeable at a passing glance anyway. No extra mass has been added to the damper either (in fact it has been reduced), so this just shouldn't even be an issue in this case.

[Johann]

Originally Posted by Turbeam

as well as neat.....

Yes it is.

Had a couple of high mileage engine's here, one with 512+K km's on it, and of all things the dampers seem to be in very good condition.

Nice project, to bad it isn't road legal.

[volvorsport]

if its 170 hp , it should be the GLT engine with big inlet ports and variable intake ?

[Karl Buchka]

Thanks again for the kind words.

Matt, we've considered making it solid, but then it won't function as a damper any more. This engine is going to be living at pretty high RPM. Anything we can do to mitigate the negative effects of that is ideal. That means leaving the damper as a damper imo.

Turbeam, that's a good idea with the pinning. The clearance between the outer holes and the pins can probably be quite small, as I don't see the outer ring misaligning all that much with the hub. The rubber on the damper is cracking in places. We'll be keeping a close eye on it.

Johann, we could probably register it for the road without major issue, but I don't think any one here is interested in putting in the work required. The local track is only 10 minutes away, so getting seat time shouldn't be a problem.

Dave, that's the one. We're looking at intake manifold options though, as the current one is big, heavy, and just a general pain in the ass.

Put the new circuit board for the ignition drivers together yesterday. Quick round in Eagle, quick round in the etch tank, and a quick round with the soldering iron:





The photoresist on the edges of the boards tends to fray. It makes the final product look like ****. I'll have to start cutting them much bigger from now on.

[Xovaan]

Loving the build so far. Put some steelies on it and do endless burnouts.

I'm actually curious as to where you would recommend buying custom connectors / plugs. That green one looks awesome! I'm trying to replace the worn-out and corroded gray engine bay harness with something a bit higher in quality.

[Tom Wiley]

Updates?

[Karl Buchka]

The throttle linkage was completely ****ed up, so we fixed it in a sort of roundabout way:



This was a real spur of the moment thing we hacked together over two evenings. There's no telling if it'll even work right. Hoping to have it fired up tomorrow though...