Elvira : Rebuilding the 36hp, part 2 : parts, parts, parts...
part 2 : parts, parts, parts
Step 2, bits and pieces :
The main issue when you start rebuilding a 36hp, is obviously the availability of parts...
Well, I must admit that the situation did evolve in a good way those past few years, you can finally get few parts directly from your usual dealer. But that's only reproduction, with only one reference available (i.e. you can't choose between Berg/CB/CSP/Scat/etc as you would on a type 1 engine), and I have doubts about the actual quality of these parts.
Anyway, it's been a long and bumpy road, but I finally found everything I needed to rebuilt my engine! One definitely needs to be patient with a 36hp... in the workshop as well as on the road!
What's next :
No old-speed preparation on this engine : parts prices are just way out of my league, for limited performances, and as soon as you modify anything on this block you must make other modifications to get a coherent, somehow reliable engine.
I hesitated a while about investing into a Wolfsburg West Okrasa Kit, but as long as they keep this ugly heads casting issue, I'll stick to the original heads. One day, maybe...
So, the only "perf" part will be the camshaft, the "Okrasa" camshaft from Joe Ruiz, even if I know Okrasa never produced camshafts for VW. It's actually a re-grinded shaft using the same admission diagrams as the early 356 (I've read somewhere Webcam takes care of the grinding). This will just help my engine make a better use of nowadays fuel evolution.
Then, I'll do my best to optimise the engine to make sure I don't loose any of the original 36hp :
Crankshaft, flywheel and clutch mechanism balanced.
Connecting rods and pistons weights balanced.
Cylinder heads : combustion chambers and exhaust duct polished, intake duct smoothed (probably overkill on a small 36p, but I can mabe grab a couple of free hp here and there), valve guide checked, valves lapped.
So here's the result of years (literally!) of parts hunting!
Well, actually, only part of it, I'll keep adding the rest along the way...
On the left, a used crankshaft, not NOS but double checked and within tolerances ; coming with it, a set of push rods used as well, but checked and fine. On the right, the Joe Ruiz Okrasa camshaft.
My flywheel was in a pretty bad shape, so I had to find a replacement : here it is, a bit rusty, it'll will need to be grinded. But the dowels holes are perfect. After a quick cleaning with steel wood, it looks better all of the sudden. I re-tap the clutch assembly threads : it was impossible to put in the screws because of the rust and threadlocker paste...
VW NOS connecting rods, NOS crank main bearings, NOS pistons shafts. Any real vintage enthusiast will have a boner looking at these pictures!
Yeah, this cost me a kidney, but at least I can reassemble the engine knowing that these parts are perfect... and come on, I had 2 kidneys anyway.
Pair of cylinder heads I found at the Valence 2012 swap-meet : 60€ for the pair, that was a bargain worth the 7 hours round trip driving by -14°C at 6AM! These are used, but in great shape, no crack between spark holes and valves ports, all the threads and studs are OK, they'll be just perfect once prepared. There's only one of the combustion chambers that has a naughty hit, but nothing my Dremel can't fix. It's getting tricky to find a set of 111.101.371A heads in good shape! I had found one NOS in Germany a few years back, but I never found a second NOS one, so I finally decided to sell the NOS head to get funds for the rest of the engine (contact me if interested!)...
Spring cleaning :
In order to work on a proper base, I've started with the inside-out cleaning of the carter.
Tray, brush, toothbrush, Scotch Brite pad, WD40 to begin, then liquid degreaser (the one from our local Home Depot equivalent used to be great, but the new formula is crap!), kerosene, hot water pressure washer (local car cleaning booth), and finally some brake cleaning spray to dry out the metal. All oil galleries are flushed with brake cleaning fluid, then blown with compressed air, several times to make sure they're clean.
A few bad news uncovered by the process : the carter is badly corroded on the underside. That will not affect the oil tightness, so it will remain this way. The last camshaft's bearing (which is the carter itself, there's no actual, separate camshaft bearings on 36hp engines) on the flywheel side has some corrosion spots. Nothing too serious, and the previous camshaft didn't have any marks, so I'll leave it as is.
Outside finish : I first wanted to bead blast the whole thing, but I've read numerous times this wasn't a good idea since the glass bead are then very difficult to remove from oil galleries and all the little corners inside the carter. And if these beads start wandering around in the oil circuit, it's a recipe for disaster, so I won't take the chance...
On the other hand, I've tried using a drill-mounted nylon rotating brush (blue ones from Home Depot, for soft polishing of wood), and I'm quite happy with the result! It sure ill tarnish a bit, but it's good enough to me.
Last news before I close this article... My crankshat/flywheel/clutch assembly just came back from balancing at Slide Performance. I recommend their service, great work, they've been very helpful and very nice contact on the phone. I've wok again with them in the future!
The flywheel has been resurfaced at the same time ; just compare the the previous "before" pictures, they're as different as chalk and cheese.
So! Finally I see the re-assembly time coming! Stay tuned!
Here's a project that was on hold for a long time... Way too long.
And, finally, it's gonna progress!
Some background explanations : the original little 36hp engine of my '59 beetle "Elvira", was totally breathless, barely any compression left. So, a dozen years ago (ouch! It hurts when you start counting years!) I replace the original engine with another one I bought from someone who told me it had been "rebuilt". I obviously preciously kept the original engine on the side, and started riding this new engine, which actually worked pretty well... for a few years.
But then, it started having troubles : oil pressure dropping down, a deep, loud noise at idle revs (sounded like "klong klong"), which disappeared as soon as I touched the throttle pedal... Well, it was difficult to trust that engine any longer.
So, I've decided to rebuild it, myself this time, in order to know exactly what's going on inside.
Step 1 : Opening the case.
All of this dates back to... 2008!! Four years!!
It's already been four years that I opened the engine, saw the damage, four years that the engine is waiting for some TLC, and Elvira is gathering dust! In the meantime, I moved, had no workshop, troubles to find 36hp parts, etc... Everything kept me from progressing on that project. But, finally, stars aligned, and Elvira should be back on the road soon! Woohoo!
So here we go, February 2008, with the help of my friend Laurent "Dangerous" (thank you for your help and advices buddy!), I opened and checked the lil' 1192cc...
This block had been indeed "rebuilt"... But most definitely not the way it should have been :
Regarding the noise I could hear when idling, it looks like it came from the flywheel : the dowells didn't have the correct size, and the whole thing started to move. Consequently, the bored holes in the flywheel are now slightly oval : direct to the bin!
A quick measurement of the crankshaft runout shows it is of limits. Barely, but still : to the bin.
The cylinder heads are totaled : cracks between spark plug holes and valves seats, broken fins, more helicoils than proper threads : with its buddies, to the bin.
The oil pressure regulator piston doesn't look great, it doesn't slide smoothly in its housing, but it is probably still salvageable. Not going to the bin, but needs TLC.
The dowells of the cranckshaft's bearings do not have the correct size, thus allegedly allowing the bearing to move... To be honnest, they look like they were poorly handmade with a hacksaw and a file, not even properly debured...
On the bright side : the engine case bearings housings roundness is OK ; a bit of corrosion underneath and around the oil sump, but nothing to be concerned about. The pistons and cylinders look like new, they definitely had been replaced - that, and the ugly fixes on the heads, is probably what the seller of this engine called "rebuilt"...
Anyway, it means I need to find a crankshaft, a flywheel, main bearings, a pair of heads... And all of the above for a 36hp, means one needs to be patient...
Yeaaaaah, I know, I'm not exactly what you woud call 'early' for my new year wishes, but hey, we're still on January, that's fair enough. Plus, com'on, this is me blog, I do whatever I wanna do. And since it's supposed to be the last one according to the Mayans, let me be, mmmmh-kay?
Anyway, Happy New Year 2012 to all of you, starting it with Audrey Hepburn should help making it a great year, dontcha think so? Hang around, there should be lots of new things on ShamWerks this year if everything goes as planned!
A sandblasting cabinet... Now that's a tool I've been looking for for quite a long time!
One can find different models for sale, but I find them pretty expensive, plus they never have the right dimensions (too large or too small)... So I decided to build my own, with ideal dimensions.
As usual, I started by drawing accurate plans with SketchUp (if you're a frequent visitor on ShamWerks, this shouldn't be a surprise!)...
For the cabinet to work properly, the bottom funnel-shaped sand recycling tank needs to have enough angle for the media to slide down to the bottom. That made my design way taller, and since the cabinet is supposed to stand on my workbench (quite high itself at 95cm from the floor), it's too high for me to use it comfortably. Therefore, I want the funnel to work properly and the cabinet on my workbench, I'll need myself to stand on some sort of support (a rim for example) in order to have a correct working position.
In terms of size, I've adapted the dimensions of my cabinet so that a 15" rim can fit in it. I have an idea for a flexible extension if I need to blast bigger parts, but it'll have to wait..
My SketchUp plan is available for download here.
The cabinet is built out of white melamine 15mm thick chipboard. That's purely an economic choice, as I hate working with this material : but al the boards for €37, that's a bargain... Additionally, the white surface will add a welcomed brightness inside. All boards are glued and screwed on a 27x27mm pine wood frame.
The only difficulty in this process is th bottom funnel shaped part, in which the media is recycled : in order for the assembly to be accurate, I need to make very precise angle cuts with my circular saw... In order to make it easier, I've printed the angle directly from Sketchup (removing the perspective effect to have a parallel projection) on A4 paper (see picture) : then I could directly put my circular saw on the paper and finely adjust the angle by visually aligning the blade with the print. I've honestly been impressed by the accuracy of the method, as my assembly wasn't totally perfect but very close to!
My saw can cut up to a 45° angle ; unfortunately it wasn't enough for one of the angles, so I temporarily glued a strip of wood below the saw's base to reach the 55.7°. The method isn't really secure but it worked like a charm.
As for the lights, 2 spotlights (first price models; €4.95 here) with 60W bulbs.
The blasting gun comes from eBay, a €18.90 model using standard ceramic nozzles. Gloves as well come from eBay ; I could have build'em from scratch using an air chamber and glued rubber gloves, but it was cheap enough to avoid this additional hassle (€19.95).
The acrylic glass piece is cut from a reclaimed piece I had in the garage ; it is mandatory to stick a sacrificial transparent protective sheet in the inside, unless it turns opaque pretty quickly due to the blasting media sanding the glass.
At the end of the funnel is a screw-in PVC plug, epoxy glued. It allows me to drain the media and change it.
On the right side of the cabinet, a PVC 32mm bend allows the connection to the vacuum. A couple of hooks and a rubber band help securing the vacuum hose in place ; an additional rubber band is wrapped around the extremity of the hose, acting as a gasket to make it air tight. On the opposite (left) side of the cabinet, another screw-in plug acts as air intake. It creates a diagonal, bottom-up air flow keeping the airborne particles level low during operation.
Ok, that's a nice box, but it needs to be perfectly air tight as well to work properly. for that matter, all assemblies/joints have been caulked (silicon caulk for bathrooms). Using a metal saw blade tip is perfect to smooth out the caulk with a nice round finish.
The door articulates on 2 shutter hinges (€1.95 each). Airtightness is ensured by a double rubber foam gasket glued around the frame. Hinges are placed taking into account that additional gasket thickness.
Door is closed using 3 screws (with Bakelite knobs I "reclaimed" 20 years ago from the windows of my high-school. I knew that would come up handy someday). It's probably overkill though, 2 could have been enough. Screwing snug tight compresses the rubber foam gasket, that's perfect. I originally wanted to put lever-type metal thingies, but they were too fragile, and do not offer any adjustment levels, so I decided to make my own system...
So, now I have a nice cabinet but it's quite bulky and my garage is small...
Fortunately, I had planned that from the beginning, and reckoned the dimensions of the cabinet accordingly : it's made to fit right above my workbench! With the help of a couple of pulleys, as the beast weighs a good 20kg.
Since I could get my hand on any reclaimed metallic grill inside the cabinet, I just used a piece of plywood instead. Works fine too!
I've ddone my first tests using glass beads (200-300 microns, bought online on Matthys) at 4.5 bars (65 psi), on an aluminium part (the Albatross' intake/exhaust manifold). It was just a 10 mn quick test, without degreasing the part first, which was a mistake since a rubbery/greasy compound on the part prevented me from getting a perfect result. But for a first test, I'm delighted with the result, the aluminium ends up with a smooth satin mat finish, looks just as new!
The cabinet is perfectly airtight, only a few glass beads manage to make it into the glove (as I had to "fold" a part of them to adjust them on the metal rings holding them). Good news!
I just need to remember blowing/brushing away the grit at the bottom of the door before opening it after a blasting session, since it accumulates there ; I'll try adding an inclined/angled piece of wood to fix this later.
Actually, it's almost too airtight : the depression created by the vacuum cleaner make the gloves inflate inside the cabinet, even with the air intake on the door opened. If I close it, the glove become totally inflated and rigid! I'll probably have to add another air intake to limit that effect.
However, just as expected, my 3HP/100L compressor turns out to be a bit small for blasting : it runs a lot, I'll need to take pauses to let it breathe... Or find a bigger one.
The air blow gun inside the cabinet : bad idea, the quick coupler gets jammed with the grit. So either I install a 3 way coupler to have the blow gun permanently fixed to its own hose, or I just pull the hose of the blast gun out of the grit to use it just as an air blower. Well, I'll go with that easier solution!
Here are a few links that inspired me while building my cabinet, for your consideration if you want to do so :
As next I'll try getting heavy rust off of metallic parts using aluminium oxyde grit instead of glass beads. I'll post the results here in that very same article.
I consider as well building a cyclone dust separator (like in the "Dyson" vacuums cleaners) just like this one (in French), this one, or that one here.
To be continued...
Edit 30-08-2012 : a stand for the cabinet :
I've managed to rent the garage right next to mine, therefore I have a bit more of elbow room, so I decided to go for a bit of reorganization. It will be way more practical if the cabinet remains in the second garage, where I'll be able to use it anytime, without having to hoist it down from its storing space (t'was great from the real estate optimization stand point, but not that much when you wanna beadblast a couple of bolts real quick).
In addition, I will keep the cabinet away from the lathe, which wouldn't have liked the abrasive dust that always hangs around the cabinet...
So after some reflexion, and some more Sketchup, I decided to build a stand for the cabinet. Only out of scrap wood that I have laying around the garage. It'll have to be heavy duty since the cabinet is pretty heavy.
The legs will be made out of 62x75mm lumber (the left overs of the workbench project), the rest will the out of 19mm thick melamine chipboard (some od shelves I scrapped). The legs will be chiseled out at the top for the cabinet to slide into them. (check the plan).
I got it right first time... Pretty proud of meself gotta admit.
So now, the cabinet is at the perfect height, no need to stand precariously on something!
The shelf right below allows me to put a bucket to pour the sand/beads into.
Next step, a cyclonic dust separator??
Edit 10-09-2012 : Corundum blasting test :
I've switched the beads for corundum to check if I can actually remove rust. My test piece is an engine support from the Albatross, with quite deep rust, and several layers of paint.
The complete process took me around 10 minutes (at 5 bars of pressure), I you can see the result by yourself, it works perfectly! I'made a short video for you to see how fast it goes.
The only drawback is my compressor : 100L/3HP is a bit low (I knew that before hand), so it tends to run non-stop, with a risk of over-heating. If I ever have to do long blasting sessions, I'll have to make regular pauses for it to cool down a bit.
I also discovered that the corundum media slides way less easily than the beads towardss the bottom of the cabinet ; on the video, you can see I have to push back the sand to the bottom from it to be catched by the intake tube. Well, it's not actually too much of a hassle, and it give a few seconds off to my compressor .
After sandblasting, the metal must be protected asap, unless rust will settle back in a matter of days (even hours depending on the conditions). Here, I use a couple of thick layers of black Hammerite (well, mostly because that's the only thing I had at the garage at that time!).
I'll still have to install a cyclonic separator on the exhaust, and a form of siphon on the intake (as some dust manages to get out that way), and it will be perfect!