Elvira : Rebuilding the 36hp, episode 7 : intake manifold
episode 7 : intake manifold
Same issue as with the pushrods : the intake manifold is now too long to fit, since I've modified the cylinder heads... Gotta admit, I didn't see this one coming!
Since I did not want to modify my original 36hp manifold, I found a spare one on LeBonCoin...
There we go, I cut using a hacksaw, and I remove the dreadful 6.4mm! I take advantage of the accessibility opportunity to clean the inside of the heater tube, which was in dire need of some TLC. Definitely easier to do this while it's opened like that!
I MIG-weld the parts back together... Starting with the thinner, upper tube, the one that brings the air-fuel mixture to the heads.
To make sure to whole thing is air-tight (not easy to make air-tight MIG welds on the first try!), I close up the extremities using bit of a bike tire inner tub ; I use the valve from the same tube to put the whole thing under pressure (cue Queen's music). This gives me a way to pin point any remaining holes, which I grind, weld close, and file again (why on earth did I wait so long to buy myself an electric file??)... On the fifth try, it is air tight. I still have one or two micro asperities, that will be closed by the layers of paint. Plus, while running, the manifold is under depression, not under 5 bars of pressure... (the first one to talk about Jusdon gets a slap)
I then weld back the second tube, the heater one (the exhaust gaz go through this one to heat up the manifold and prevent freezing). This one is easier to weld as it's much thicker, there's less risk to "go through" with the MIG. Therefore I can grind nice chamfers before I actually weld..
But I don't have access to the cut other side of the tube, next to the first tube I welded. I hoped that a nice clean weld on each side would do the trick, but when I wput it under pressure, it was leaking all over the place. So I got the Dremel out, and cut a window to get to the inside of this cut and weld it from there. I welded the window back in place, and this time it was air tight on the first try!
Next step is as usual : sandblasting, 2 coats of rust-preventing primer, 3 coats of paint... And TADAAAAA!! Here's your 6.4mm shorter manifold! Yep, all of the above just for 6 f***ing millimeters! Dayum, you gotta love your compression ratio, right?!
It was then a complete redesign of the previous version, namely "Da Sham's Webpage", after 8 years online. I already had an online presence since '96, but it was only a single Geocities page, not an actual site...
Along the last 10 years, it's over 180 articles that I have published on ShamWerks. Quite a slow pace compared to other blogs, but I always give priority to actual content over a quick picture without context ; and that takes time!
Speaking of which, the average length of my articles keeps getting bigger, it's now have tripled since '08!
Recently, ShamWerks has evolved again to adapt to new medias : you can now browse the site from your mobile or tablet! The logo, too, got a bit of a dust-off... It was the perfect occasion to indulge myself to a small present to celebrate :
As usual, many thanks for your renewed fidelity, your messages, your help... Be safe on the road, see you soon!
Elvira : Rebuilding the 36hp, episode 6 : Rocker arm geometry
episode 6 : Rocker arm geometry
Milling the cylinder heads compression ratio might have seemed like a good idea, but now my rocker arm geometry is way off!
Since I've milled 3.2mm into each head, the whole engine is now 6.4mm less large...
So, I gotta shorten them pushrods! (and that's just the beginning...)
On 36HP engines, contrary to more recent T1, the lifter and the pushrod are one single part...
I start by making myself an adjustable pushrod to find out the right length : I grab an old pushrod, cut it in the middle, throw at it a length of threaded rod and a couple of nuts, and I'm ready to rumble.
Next, I install a dial gauge to measure the total lift ; I measure 7.76mm at the valve, which is relevant with what I obtained with my camshaft measuring bench (more on that later).
I then turn the crank until I'm at half-lift (that is 3.88mm) : while in this position, the pressure screw on the rocker hs to be perfectly aligned with the valve stem. Side note: some of you may argue that this shouldn't be measured at half-lift, but at the angle at which the valve has the maximum linear acceleration, as this is when you get the most mechanical constraints. From a mechanical stand point, that's right... But come on, this is just a 36HP, with chewing-gum valve spring, not a 2.4L with adamantium double valve springs running at 8000 RPM. The half-lift willl definitely but a good-enough approximation!
Anyway, I adjust the length of my pushrod, tryin to get the lifter in the correct position... Try, remove the lifters, adjust the rod, put back the lifters... After the 3rd try I had the correct length : 299.2mm, while the pushrods are initially 302.3mm long. That's 3.1mm I gotte take off of each pushrod ; it makes sense, since I got my heads lower by 3.2mm on one side, and 3.15mm on the other.
To shorten the pushrods, I first remove the lifter part : it's pretty easy, you jut need to put the rod in a vise (in between two pieces of wood not to scratch it), and give a firm tap with a bronze piece on the lifter.
The rods are then lathed down, using a W20 8mm collet.
I also remove short of a 1/10th on the diameter over 12mm of length, unless you can't put back the rod into the lifter (trust me, I bent 5 of them trying). I suppose they had a machine at the VW factory that would hold the whole length of the rod to prevent bending.
To make sure the pushrod isn't bent afterwards, I just put it back into the engin case, and make it turn between my fingers : if it's still straight, it will remain centered into the tube! Obviously, don't push it all the way into the case, unless the flat side on the lifter will prevent you from making it turn.
Pour vérifier que la tige n'est pas pliée une fois le poussoir : on la remet dans le bloc et on la fait tourner du bout des doigts : si elle reste bien centrée dans le tube enveloppe, c'est qu'elle est droite! Evidemment, il ne faut pas la rentrer à fond, sinon le méplat sur le poussoir empêche de la faire tourner.
The pushrods on 36HP engines may contain a piece of wood inside (made out of beech wood) : actually that's known to be the only piece of wood in a beetle! (well, if you ignore the convertible tops obviously)
My pushrods didn't have that piece of wood inside ; but I had another one (gift from Eric SIMON) which did contain that rod. But the actual role of this rod has never been really established...
(Edit 20161103 : Oops, forgot to add pictures right here!)
I've read different theories on the subject :
To make oil go up to the rockers thanks to capillarity effect : I don't buy it. No pressure, no flow, and the oil would actually drip back into the rod. Nope, not happening.
Pumping effect due to the wooden rod going up and down into the pushrod... I don't believe it either, there's an actual oil pump pushing behind, I don't see how that would work.
To dampen the vibrations and limit distribution noise by absorbing some of the harmonics : well, why not, could be.
To limit the oil volume in the push rod. Thus limiting the weight of the pushrod, making the whole distribution lighter. Plus, upon starting the engine, you'd have less volume to fill up, meaning faster pressure build up. That could make sense ; the flow is anyway limited by the hole diameter on the lifter and on the rocker side : no actual need for the pushrod to be filled up with oil.
Anyway, as time goes by, these wooden rods tend to hit each side inside the pushrod, end up taking its shape, with the risk of plugging the holes. Therefore, I rather not having them...
My Golf is a 10 Millionth Edition (or "Champ" in France), and this limited edition had several very specific options at the time, one of them being the fabric used for the upholstery, a stripped blue that's on no other model (pictured below, from the period leaflet).
Well, actually, this was what I thought, for almost 20 years, until 2 years ago...
I then found out that in 1989, a limited edition of Jetta (the "GLI Helios" edition), of which only 1500 units were made, exclusively for the american market, had also received the very same fabric on their seats.
With a major difference though : it featured very desirable Recaro front seats!
Needless to say, I started hunting for a pair of those, but they're rare as hens teeth, and whenever an ad is published, it' always in the US, with prohibitive shipping costs.
Being my usual stubborn self, I kept looking, for almost 2 years...
Until march 2016, when an auction pops up on eBay UK, a stone's throw away from one of my in-laws! God Save the Queen!
I won't bother you with the details of the organisation set up to retrieve and ship the seats to southern France, but here they are, even nicer than I expected them to be! (yeah, OK, spending that much time and energy for a pair of bloody seats, I know I have a problem, leave me alone!)
Here's the difference between the original "Sport" seats and the Recaro version :
But how the Hell these parts, exclusively made for the US market, made their way to Europe?
Actually, around a decade ago, a US soldier dispatched to an american air base in the UK, decided to import his Jetta Helios... He ended up selling the car there, but unfortunately it got wrecked and sold for parts. The seats got bought and stored for the next 9 years, until their owner decided to part with them. They got attacked by rodents in the meantime, but were neatly fixed by an upholstery shop, with a leatherette matching perfectly the original one.
You know what happened next...
I still needed the railings to install them... I found'em in Poland (damn, eBay is a hard drug), a complete G60 set with electric adjusting (too much? ). Let's do it!
Th passenger seat had that part ripped... That's pretty common on Recaro seats, resulting in the bottom of the seat caving in. Fortunately, you can find a replacement on eBay UK, under the name of "webbing" or "diaphragm"...!
Not that easy to replace though, as it's very tight! My solution finally was to grab each hook with vise-grips, then use a clamp to pull the grips towards the edge of the frame.
I still have to install a bit of wiring and a 20 amps fuse to use the electric adjustment thingy, but I can already enjoy the bloody things!
Dear Martin, thank you so much for your help securing the Glorious Seats!
Bonus : Gearbox linkage upgrade
Keeping on track with the improvement of both user experience and reliability, I decided to make a big update on the gear selector linkage.
The original bushings and links, made of plastic, end up wearing and breaking up (I think I changed mine at least 3 or 4 times). You then get a good 10cm end play on the gear stick, no matter if you've selected a gear or on neutral! You can still use the car if you're used to it, but forget about "race" driving. In the other hand, it's a pretty good anti-theft device!
Long story short, I ordered a "Smartshift 2" kit from USRallyTeam, which replaces all links with Unibal joints, and all bushings with Delrin-made ones (POM). No more end play!
I installed the kit on January 30th 2016, but it left a mark (literally) : as I was cutting off one of the joints with an angle grinder, I made a wrong move and sent the cutting disc into my left thumb. Cut down to the bone (got a nice gouge in it), tendon and nerves ripped... #ERsaturdayNight
Anyway, I spent a night at the hospital, but at least the kit is installed, no more end play in the stick, it feels great!
In the picture below, you can see the ugly original plastic joints and "ball", that usually wear off and break
Second picture is the kit form USRallyTeam :
now we're talking! I don't have a decent picture of the kit installed in my car, as it's not easily accessible to get a pic, but you can have a look on this page if you wanna know how it's installed.
I'll spare you the picture of my post-surgery, Frankenstein-like thumb...
As happy as I am with the result, and if I'd happily recommend that kit to others, it is not perfect either : the hardware is imperial threaded (doesn't make sense on a european car), I did not have the correct bolts (you need 2 left threaded, 2 right threaded,.. I only have 4 left threaded ones in the 2 kits I ordered), and the initial adjustment can be a bit tricky.
In short, not exactly a plug'n'play kit, but a great improvement nonetheless in the end.
Elvira : Rebuilding the 36hp, episode 5 : Fuel Pump
episode 5 : Fuel Pump
Let's continue with the "little things" ; well, "little", but essential! So, I giveth to you, ye Fuel Pump...
I've owned this car for 22 years now, and it has always run this very pump. It was long overdue for some TLC!
After thorough disassembling, I first give it a good cleaning with a brush and some brakes cleaning fluid, to get rid of most of the gunk. By the way, I can see that event though the pump's membrane is completely rigid, it's still in working order and not leaking! Pretty amazing quality part, I doubt the new one will last that long!
Next, just as for the carburetor earlier, I dump all the parts into the ultrasonic cleaning bath, filled up with lemon juice. It looks like new when it comes out after just 20 minutes at 80°C. I rince everything thoroughly with clean water to neutralize the acid action.
Before I put everything back together, I check that both pump halves are actually plane : 320 grit sand paper on my surface plate, a squirt of WD40, and I do 8 figures with each half. Right from the beginning, the sanding marks show it was far from being plane...
Ten minutes later, it looks much better! At least it should limit the risk of leaks right there...
I reassemble everything with a BBT rebuild kit. The membrane (main part) looks good, but on the other hand, I will not use the two small levers provided in the kit, they look cheap and flimsy, I'll stick to the original ones that still looks pretty good. The main spring is much longer and strong than my original one ; I don't know if it respect the factory measurements, but if so, my spring was in dire need of retirement!
In order to propermy install the membrane, you need to pre-load the pump ; this is supposed to be done using the VW328b tool (see it here on TheSamba), which I obviously do not own, so I make myself make-do one.
The 1958 workshop manual states that the pump's lever should be depressed by 35mm from the pump mounting plane ; so, a piece of laminated steel, three holes -one of which is tapped-, and there you go.
I finally just have to mount the membrane with a thin coat of grease, so that it slides smoothly in place, avoiding any "wrinkle" that may cause a leak...
And BAM, an as-new fuel pump ! The inside is packed with grease, and it goes back on the engine.