Posté le 05/04/2017 at 21:50

Camwerks : DIY Camshaft measuring bench

DIY Camshaft measuring bench
Those of you who follow ShamWerks on Facebook already got a peek of this thing back in January 2015! Well, it was high time I finally write an article about it, right?

I stumbled upon a picture of a camshaft control bench on Vince/Panelvan's blog (here)...
As I had just bought the high-performance camshaft for my Ghia, the idea of being able to check its actual features (and verify what's given by the part's constructor) made its way ; I was pretty sure I could find a way to make it happen on a budget. And, let's put it mildly, I'm kinda stubborn. icone smiley laugh

Thinking about it, there must be a way to put together a stepper motor, a digital caliper (cheap chinese models have a serial output), and an Arduino to control all of the above and push measures to a PC through USB... Amarite? icone smiley wink

For those of you who don't like reading (aka "TL ; DR Team")

Long story short, after a couple of hours tinkering around, I got myself a functioning bench : here's the result in video : icone smiley laugh
(watch it in full screen HD 720p to be able to read the results)

Sorry for the less-than-average quality of the video, which in addition doesn't show the latest version of the software... I'll try to shoot another one with a better lighting! icone smiley wink
And now, for those who aren't afraid of reading ... Keep scrolling! icone smiley wink

Electronics

I use an arduino as an interface between the bench and the PC, but it can not control the stepper motor directly, it needs a driver ; I found a chinese one, based on a L298, for less than 5€ on dx.com (here).
Beware, if you use the same driver as I did, do not trust the allegedly regulated 5V output on it ; I wanted to use it, but it blew the very first time I tried to ; I ended up with a blown condenser on my arduino... icone smiley meh

Speaking of made-in-China, I also buy a 15€ digital caliper... Well, TBH, if I had to redo it all over again, I'd probably go with a slightly more expensive version : the electronics are identical between versions, but the "mechanical" part can be better. The entry-price ones tend to grip/jam a little bit, which can lead to measure inaccuracies.

Since I don't wanna have a battery that dies on me in the caliper, I use a LM317 to feed it 1.64V, generated from the 5V of the arduino (the original battery on those calipers is 1.5V).
I also add two transistors to step up the signals from the caliper (clock and data) to levels the arduino can read (2.5V minimum). That's kinda overkill, just feeding the caliper with a higher tension may have done the trick, but it didn't look nice to me...

I take appart the caliper in order to solder in the output cable (I use an old land-line phone cable, perfect for that use) ; you can find specific cables that will "plug" into your caliper, but they are more expensive than the caliper itself, to solder it is! I than tie-rap the cable to the caliper to avoid mechanical constraints that would for sure rip the solder apart.

After I validated the circuit on a breadboard (it worked like a charm on the first try, I would have never guessed so!), I transfer it onto a veroboard/strip board.
You'll find down here the schematics of my circuit. Mind you, I have no such pretension to say that this is the right/best way to do it, electronics is by no mean into my comfort zone... But it does work great, feel free to modify/enhance it as you like!
pied coulisse arduino electronique usbpied coulisse arduino electronique usbpied coulisse arduino electronique usb
pied coulisse arduino electronique usb
The Sketchup model is available here (4Mo).
Bill of materials :
  • Reg : LM317 Voltage Regulator
  • T1, T2 : Transistor NPN - BC547B - BC171
  • C1 : condenser 100 nF - 50 V
  • C2 : polarized tantale condenser - 1 µF - 35 V
  • R1: 240 Ω
  • R3: 75 Ω
  • R2, R4, R5, R6: 10 kΩ
Resistors are all 1/2W 5% metal film ones. For your information, R1 and R3 are the ones that "tune" the tension regulator (Reg) so that it outputs 1.64V...

The following web sites helped me a lot while designing my circuit :

Mechanical part

Now for the bench : I need something sturdy enough to get somewhat reliable measures.
I start with a Bosch Rexroth 45x45mm profil, bought on eBay, but in the future I'll buy from Motedis, they are much cheaper and have all the useful accessories...
The grooves let me easily move the mounts/brackets, and the caliper stand, making the whole bench adaptable to camshafts other that Aircooled VW ones.

For the stepper motor, since I've pulled appart my fair share of printers and photocopiers in the past, I've got a stash of spares... So I picked one ; a nice 200 steps motors, that comes with a 1/3 ratio gear/belt set, for a final 600 steps output ; that's 0.6° increments on a full 360° rotation... Not bad!

I lathe down an aluminium adapter for my stepper motor, and another one for the camshaft (with a nylon screw in order not to dent the camshaft), linked through a flexible coupler. This means I'll need a new camshaft adapter for each and every camshaft diameter... I can live with that, but I can imagine a system using a small chuck instead to avoid that.
Then with some aluminium angle scraps, and a few skateboard bearings, I make supports for the camshaft on one side, and for the motor adapter on the other.

Finally, the caliper is fixed on some aluminium angle ; I angle-grind a VW lift (with some finishing done on the lathe) to put it on the jaw of the caliper, in order to have the same kinematics as in the actual engine.
camwerks arbre cames banc mesure DIY métrologiecamwerks arbre cames banc mesure DIY métrologie
camwerks arbre cames banc mesure DIY métrologiecamwerks arbre cames banc mesure DIY métrologiecamwerks arbre cames banc mesure DIY métrologie
The stepper motor output is connected to the camshaft adapter through an aluminium flexible coupler (5€ in Chine, agian...), which forgives the alignment errors. It's a 10mm-10mm coupler, that I bored on the lathe up to 12mm to make it fit my already lathed parts.

Finally, to give the electronics some much needed protection, I fashion a box out of some perspex scrap ; I cut it with a jigsaw, then use a heat gun to bend it... The result might not be aesthetically perfect, but it does the job.
I lathe some plastic stands out of a bit of PVC round to attache the electronics... Yeah, I know, plastic screws would have been a better choice, but I did with what was available in my drawers, ok? icone smiley wink

There, the whole system runs now, even though some points will need attention.
camwerks arbre cames banc mesure DIY métrologiecamwerks arbre cames banc mesure DIY métrologiecamwerks arbre cames banc mesure DIY métrologiecamwerks arbre cames banc mesure DIY métrologie
camwerks arbre cames banc mesure DIY métrologiecamwerks arbre cames banc mesure DIY métrologie
On these pictures you can see the caliper movement return movement powered by rubber bands : it actually did not work that great, the caliper tends to jam, which creates mistakes in the measures.
In the video at the beginning of the article, you can see I now use a weight (a ratchet wrench extension, stuck on a neodyme magnet) ; it works much better like that!

Bench evolution

So, it works, but can be improved... As I was writing this article, a freidn o'mine gave me a good idea to make the caliper movement more user-friendly (thanks aSa!), so here's already a first evolution of the bench!

The idea is to use an eccentric cam clamping lever to lock the caliper in place ; you can find these levers in bike shops, as they are use to lock saddle seats(I got mine from "Decathlon" for 5€ : see here).

So, I order a few more pieces of the same 45x45mm Rexroth profile from Motedis : I ordered 10cm, 15cm and 25cm lengths (for an affordable 1.27€, 1.64€, and 2.38€), as I wasn't sure yet how I'd use it yet. I also ordered a few of those tapped blocks that go into the grooves ; at 0.30€ a piece, I wasn't going to go through the hassle of makin'em myself.

As I modify the caliper's brackets, I make it stronger by using two aluminium angles, to prevent it from bending from side to side.
Bosch Rexroth motedis aluminiumBosch Rexroth motedis aluminium
The result is perfect (see video) : moving the caliper is now done in a matter of seconds, no need to use a wrench to adjust it... Great!

I go back to my lathe to make a new camshaft adapter : it wasn't perfectly fit on the camshaft, fit created a small cyclic error in the measures.
And since I got myself some POM (PolyOxyMethylene), stock, I make 2 adapters : one for Type 1 camshafts (ID 25 mm), and another for 36hp ones (ID 24 mm). Both have an identical 34mm OD, so I can swap'em without having to adjust the height of the bearing support below.

On the feeler side, the one lift I had modified to install on the caliper's sliding jaw broke on me : that's a very hard steel, without any elasticity ; I did tighten a bit too much and it broke like glass.
So I made a new one, and this time I added ttwo MIG welding spots to prevent any "opening" when tightening the screw. No mo'problems!

I also make another feeler with an old 36HP lift ; same method, angle grinder, MIG weld, drilling/tapping. With this one I'll be able to measure my "Okrasa" 36HP camshaft (Joe Ruiz) : the Type 1 lift would not work on a 36HP camshaft, the cam is too small and the lift ends up touching foundry high spots... Many thanks to Eric "Underdog" Simon who sent me a sacrificial 36HP lift to make this one!
And TADAAAAA!
I also added a length of profile with a "needle" to precisely align the camshafts on the pulley spot, this way the curves in the software will precisely align too, allowing me to accurately compare camshafts.

Software

Now on the computer side, I needed a bit of software to pilot the bench, receive the data back from it and smartly display the results...
So I dove in and wrote CamWerks.
If you're interested, here's the soft, GPL open source license, you can download it and use it for free. Limited support on the other hand... I like you guys, but I ain't got much spare time! icone smiley wink This is a Java application, you'll need at least Java 1.7 on your computer to run it.
Just unzip the archive, and launch "CamWerks.jar", it should run first try... icone smiley smile

If you just wanna have a look at the output from my tests :
The Zip archive will be enough : it contains the files I generated from the different camshafts I had at hand (".cam" files, in the folder "Cam Files") ; even if you don't have a bench connected, you'll still be able to visualize them in the application.

If you wan't to build a bench like mine :
It's a tiny bit more complex, you'll have to :
  1. Flash your arduino :
    1. install the Arduino Serial Command library on your IDE (download here - it's just a handy USB communication library)
    2. Flash your arduino with the "sketch_CamWerks.ino" file (in the Zip archive, in the "Arduino" folder)
  2. Install the RXTX parallel communication library to enable PC/arduino communication (download here).
For those of you who'd like to dive into the code itself, I've put the project on Github : spoiler alert, I wrote a pretty ugly code, just bits and pieces thrown together. Does the work though. icone smiley laugh
The project is available here : https://github.com/ShamWerks/camwerks

Measuring cycles :
Sometimes, there are inaccuracies when measuring : the caliper may seize up a little, or a grain of dust on the cam, whatever... The result being a notch into the curve ; usually not much, a few hundredth at most... But to avoid that I implemented a N-rotations measuring cycle : I do the full-rotation measurements N times, and then take the average of each measure point. It smooths inaccuracies, while making the whole measuring process N times longer. But hey, no hurry, I can wait longer for a better result!

Cams profile view, as seen from the camshaft's axis :
Deducing the profile shape from the measures was tricky, I've had to ask for help to a math researcher friend of mine! Thank you JB for the tea-biscuits-and-math afternoon! icone smiley wink
The result is not perfect, and can only be correct using a flat faced lifter ; it'd be incorrect with a round one (as they are on 36hp), or roller-type lifter.
I also added a curve smoothing algorithm (a simple sliding window average) so that the cams shape would look nice ; long story short, remember this view is provided "as is", don't look too much into it.

Results

Following are the resulting data out of the different camshafts I had laying around...

As you can see, the first tab presents a Detailed Report giving different informations : duration re. lift, maximum lift, valve lift re. rocker ratio, lobe center and overlap.
The second tab show the lift curves of each cam ; the third and last tab is an axis view of the cams profiles.

Last but not least, I've added an option in the software to compare two camshafts. It allows to surimpose the curves from two different camshafts in order to visualize their differences.

L&G R280 Lobe 108°

Here we go, let's put my brand new L&G R280 Lobe 108 camshaft to the bench, and compare the output with the datasheet provided with it! icone smiley smile
Here's what I measured with my bench :
camwerks banc DIY arbre cames mesure levée duréecamwerks banc DIY arbre cames mesure levée duréecamwerks banc DIY arbre cames mesure levée durée
And now, let's compare this with the camshaft datasheet provided by L&G (the intake durations are given by L&G for a 1.27mm lift). Here's how my measures compare with the datasheet :
Datasheet Value
from L&G
CamWerks measured value
Cylinder 1 Cylinder 2
Int. Exh. Int. Exh.
Cam lift 9.19 mm 9.23 mm 9.13 mm 9.17 mm 9.13 mm
1.25 rockers lift 11.49 mm 11.54 mm 11.41 mm 11.46 mm 11.41 mm
1.4 rockers lift 12.87 mm 12.92 mm 12.78 mm 12.84 mm 12.78 mm
Intake duration 242° 242.23° 241.42°
Exhaust duration 242° 239.09° 243.19°
Overlap duration 26° 25.68° 26.15°
Lobe Center 108° 108.6° 108.0°
Not that bad huh??

The biggest delta I found is about exhaust duration : -2.91° / +1.19°, that's a bit much... I'm gonna double check the way I reckon the angle of the "peak" on the cam. Sylvain from Classic-Store (whom did not hesitate spending 20 minutes on the phone with me, while I only sent them a quick technical question... Fantastic customer service, thanks!) told me that it's not uncommon to have 1 to 2 degrees of difference on a camshaft, due to the original pattern/jig wearing off. So, not such a bad result in the end.

I've not yet managed to calculate the opening advance and closing retard... This information depends on the position of the camshaft in relation to the crankshaft (well, actually, the TDC and BDC), and I've not yet managed to integrate this into my formulas! (for now!)
I also do not have the "commercial duration" : well, this value is of no real interest actually, the lift at which it is measured is arbitrarily chosen by manufacturers. Only the durations at 1mm and 1.27mm loft are relevant to compare camshafts to one another... On mine, the advertised 280° duration is reached around 0.48mm lift.

Stock 1600cc camshaft :

camwerks banc DIY arbre cames mesure levée durée 1600 vwcamwerks banc DIY arbre cames mesure levée durée 1600 vwcamwerks banc DIY arbre cames mesure levée durée 1600 vw
Below is a comparison of my measures against the stock VW camshaft specs.
By the way : the stock values shown here are from VW forums (Flat4Ever and TheSamba), I'm not absolutely sure of the source... If you have any better figures, I'd gladly update my table!
Stock VW value CamWerks measured value
Cylinder 1 Cylinder 2
Int. Exh. Int. Exh. Int. Exh.
Cam Lift 0.754 mm 0.724 mm 7.65 mm 7.16 mm 7.34 mm 7.18 mm
Intake duration @0.50 250° 257.04° 246.00°
Exhaust duration @0.50 250° 250.80° 252.80°
Intake duration @1.27 214-218° 216.16° 209.91°
Exhaust duration @1.27 214-218° 215.65° 216.93°
Lobe Center 108° 105.6° 107.4°
Anyway, I'm still within the stock specs! icone smiley wink
Please note that the measured camshat is a used one, therefore the result may somewhat vary.

Comparing stock 1600 with the LG R280 Lobe 108°

camwerks banc DIY arbre cames mesure levée durée 1600 vwcamwerks banc DIY arbre cames mesure levée durée 1600 vw

Stock 36hp

The cams views doesn't look great towaards the peaks... My original measures probably weren't clean.
camwerks banc DIY arbre cames mesure levée durée vw pied moulécamwerks banc DIY arbre cames mesure levée durée vw pied moulécamwerks banc DIY arbre cames mesure levée durée vw pied moulé

36 hp "Okrasa" / Joe Ruiz :

camwerks banc DIY arbre cames mesure levée durée vw pied moulé okrasacamwerks banc DIY arbre cames mesure levée durée vw pied moulé okrasacamwerks banc DIY arbre cames mesure levée durée vw pied moulé okrasa

Comparing stock 36hp and Okrasa version

camwerks banc DIY arbre cames mesure levée durée vw pied moulé okrasacamwerks banc DIY arbre cames mesure levée durée vw pied moulé okrasa

Conclusion and future evolutions...

I'm not completely satisfied with the lifters I modified to mount on the caliper... They're not exactly parallel to the camshaft (wel, the angle grinder isn't know to be an accurate tool, right?), so they do not rest perfectly flat on the cam... Gotta do somethin'bout it.
And on the software side, I'd like to add the durations on the cams view...

The results are consistent and can be reproduced (I gaet only up to 3 hundredth of a millimeter difference between to measures) : for a prototype I threw together on the side of my workbench, I'mm really happy with the result! Yet I've no way to know how accurate my measures are : for that I'd need the output of an actual, professional bench, and compare the output with wine... I may have a solution to do just that, I'll let you know. icone smiley laugh

Anyway : keep in mind you should see this bench as a prototype, a "proof of concept", not a finalized project... But it already does the job ; hopefully it will give ideas to some of you! icone smiley laugh
Posté dans : Workshop
Affiché 138452 fois.
icon permalink
Posté le 07/03/2017 at 21:18

Elvira : Rebuilding the 36hp, episode 8 : cooler, tinware and shroud

episode 8 : cooler, tinware and shroud

Oil Cooler

I start by sprucing up my oil cooler. I put it under pressure to ensure it is still air tight, using a bicycle tire valve (same method I recently used for my intake manifold). It holds at 5.5 bars : we're good here.
Thorough cleaning using brake cleaning fluid and compressed air, giving the whole damn thing a good shake to make sure I get rid of any muck sitting in all the nooks and crannies inside...
Then I give it a light sandblast to remove the flaking off original paint (I obviously first taped shut the oil in/out holes), and then a thin coat of high temperature spray paint, just to prevent rust. Just to make sure the sandblasting did not affect the oil cooler, I give it another pressure test ; still holds at 6bars, we're still good (#paranoid).
It then goes back on the engine with a couple of brand new gaskets. Next !
VW pied moulé radiateurVW pied moulé radiateurVW pied moulé radiateur

Fan shroud and tinware

Again, because of my modified cylinder heads, I gotta touch up the tinware to make it fit the new engine width.
Since I'd rather keep my original tinware untouched, I managed to get my hands on a new set of tinware and fan shroud to modify them. That new shroud is slightly different than my original one, it doesn't feature the top recess (which makes room for the oil bath air cleaner)... Prolly an older shroud ; well, since I wanna move later to a two carbs setup...
pied moulé VW tôles moteurpied moulé VW tôles moteur
For the two over-cylinder tins , it's pretty straight forward : I just Dremel-cut 3.2mm at their base. Done.
pied moulé VW tôles moteurpied moulé VW tôles moteurpied moulé VW tôles moteur
pied moulé VW tôles moteurpied moulé VW tôles moteur
For the shroud, well, it's a bit more tricky. I make two triangular relief cuts on each side, which I then bend inward and weld back shut... And there you go, a 6.4mm narrower shroud.
Well, it did take a few hours to weld/grind! icone smiley laugh
pied moulé VW tôles moteurpied moulé VW tôles moteurpied moulé VW tôles moteur
pied moulé VW tôles moteurpied moulé VW tôles moteur
pied moulé VW tôles moteur
The two tins get sandblasted ; the shroud is too big for my sandblasting cabinet, so I sand it down to bare metal with an electric file.
pied moulé VW tôles moteurpied moulé VW tôles moteurpied moulé VW tôles moteur
Then, the usual ; anti-rust primer, some bondo finition (the shroud looked like a mine field), filler primer, sanding, and then finally painting with a two-component polyurethane spray can.
I wanted to give a shot to this product for a while now, as a friend recommended it to me... Not exactly cheap (25€ the spray can at Vernicispray), but I gotta say, the result has NOTHING to do with that of a standard spray can! Shiny! Well, sure, as I used it in my dusty garage, it's not perfect by any means, but way good enough for engine tinware as far as I'm concerned.

In order to use these spray cans, you first have to hit the bottom cartridge, that holds the hardening component, then shake the damn thing a couple of minutes. You than have 6 to 7 hours to use the product before it hardens... So you need a bit of organization if you want to spray more to one coat!

Just one drawback I experienced : it might be because the temperature in my garage was too low, but by the end of the can, it spitted droplets instead of a nice even spray (even though I did heat the can before use by putting it above a radiator, and made sure the nozzle remained clean)... Just be careful.

The oil filler, small tin below fuel pump, and front/back half-moon tins all get their lick of paint as well... I did not originally planned to do so, but they looked dull next to the other shiny parts... icone smiley wink
pied moulé VW tôles moteurpied moulé VW tôles moteur
pied moulé VW tôles moteurpied moulé VW tôles moteurbombe peinture epoxy deux composants
pied moulé VW tôles moteurpied moulé VW tôles moteur

Generator

About a dozen years ago, I converted my circuit to 12V, using a rare 90mm generator (ref. VW 113903031E, ref. Bosch 0101206116), and a fitting Bosch 14V 25A regulator (ref. Bosch 0190350049).
But that regulator only held by one single screw on top of the generator, and since it was a bit too long, it had to be set askew... And, well, you know my OCD.
So i took a deep breath, a drill press, and drilled a 4.2mm hole in the generator body (making sure I wouldn't drill into a coil inside, obviously), which I proceeded to tap at 5x80 like the other one. Done! I then gave a lick of paint to the regulator, cut 3mm from its back stand, and now it ssits aligned with the generator. Much better!

As usual, since nothing is ever simple, while putting back together the fan assembly, torquing the nut at 6mkg, the expansible washer broke on me... Argh. Ordered a new one from VW Classic Parts (ref. 111119135), yet another week to wait... Damn, restoring these machines requires infinite patience!
régulateur dynamo Bosch pied moulé 12VDynamo Bosch 90mm 12Vrondelle expansible turbine pied moule
Dynamo Bosch 90mm 12Vrégulateur dynamo Bosch pied moulé 12V

...and reassembly!

To put everything back together, I ordered a set of stainless steel tinware screws identical to the original ones (mine weren't looking good). The cardboard "seal" between the generator and its stand is glued in place using Gasgacinch.

I also give a coat of satin black on the coil (an actual, real blue Bosch one), the generator's pulley, and the oil pump plate (which I had forgotten, and already showed rust spots).
The coil also receives a sticker reproduction to make it look like an old 6V one... That'll make the trick! icone smiley laugh

After a bit more of fiddling... TADAAAAA!! icone smiley laugh
bobine bleue bosch vw pied moulébobine bleue bosch vw pied moulé
VW pied moulé moteur
It seriously starts to look like an actual engine, right?? icone smiley laugh
OK, almost there now... If the pain in my shoulder gives me some slack, this baby should run pretty soon!
Posté dans : 1959 Beetle
Affiché 102167 fois.
icon permalink
Posté le 15/02/2017 at 18:08

Good Bye Pierburg, Hello Weber!

Conversion Weber 32/34
My Golf came equipped as standard with a Pierburg 2E2 carburetor. When this one works fine, it's a great ride...

But in the other hand, when it starts acting, it's a PITA : it's full of vacuum modules, dilatation elements,wax component, in which the cooling liquid goes through... Kind of a Rube-Goldberg machine, next to impossible to fix.

And you guessed it, mine started acting weird, it did not like last April's engine swap (I did write about it at the time already).

Around a decade ago, I had found on eBay Germany a rebuilt 2E2 for a fair price, but unfortunately the vendor doesn't exist any longer. There's a specialist in the UK (Bromyard) that offers complete Pierburg 2E2 rebuilding services, but for a hefty 395 £ + S&H (that's over 500 €), I wasn't too keen on going again with that same Hell-of-a-carb (that being said, looks like that company does a great job).
I also had the option of buying a brand spanking new Chinese reproduction of the Pierburg 2E2 : you can find them on AliExpress, and they will set you back around 100 €. I have to admit, I'm a bit skeptical on the quality of these...

Long story short, I finally bought a Weber DMTL 32/34 conversion kit from EuroCarb via eBay. It's cheaper this way than from national french re-sellers, 324.50 £ w/ S&H (which is 380 €, would have been 455 € w/o S&H at local stores).
Golf Pierburg 2E2 Weber DMTL 32 34 conversion kit
It's a beautiful kit, very well engineered. Installation instructions are clear, it's almost plug'n'play... Even thought the french traduction is a bit sketchy (and the fuel line clamps are a bit small, but I'm nit-picking). icone smiley wink
So now, no more faulty automatic choke, which functioning is a matter of voodoo sorcery, back to basics with a good'ol manual choke!

Installation note : the small bit at the end of the throttle cable cameinto contact with the vaccum element at the back of the carb, preventing the throttle from coming back to idle. I snapped it with a pair of pliers : fixed (on the middle picture below, you can still see the contact point before the modification).
Golf Pierburg 2E2 Weber DMTL 32 34 conversion kitGolf Pierburg 2E2 Weber DMTL 32 34 conversion kitGolf Pierburg 2E2 Weber DMTL 32 34 conversion kit
I installed the bloody thing on 01/29/2017 and since then : pure HAPPINESS! Starts neatly, acceleration is linear, the engine doesn't die on me any more when cold, more torque at low revs... I definitely should have done this a long time ago! icone smiley laugh
Posté dans : 1988 Golf MkII
Affiché 113374 fois.
icon permalink
Posté le 01/01/2017 at 08:15

Happy New Year 2017

Happy New Year
* 2017 *
Bonne Année
* 2017 *
Feliz Año Nuevo
* 2017 *
Buon Ano
* 2017 *
Gutes Neues Jahr
* 2017 *
OK, simply put, I for one will not miss 2016 a bit, it's been a tough year for many reasons. Good riddance!
In the other hand, 2017 will be a great year, full of changes, at least for me! (edit 20170720 : told ya! icone smiley laugh)

I wish you all a very Happy New Year, Health-Money-Happiness-Oh-But-You-Know-As-Long-As-You're-Healthy blah blah blah.

Be safe on the road!
Posté dans : News
Affiché 94397 fois.
icon permalink
Posté le 06/11/2016 at 12:59

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! icone smiley laugh
Since I did not want to modify my original 36hp manifold, I found a spare one on LeBonCoin...
vw pipe admission pied moulevw pipe admission pied moule
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! icone smiley wink
vw pipe admission pied moulevw pipe admission pied moulevw pipe admission pied moule
vw pipe admission pied moulevw pipe admission pied moulevw pipe admission pied moule
I MIG-weld the parts back together... Starting with the thinner, upper tube, the one that brings the air-fuel mixture to the heads.
vw pipe admission pied moulevw pipe admission pied moulevw pipe admission pied moule
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... icone smiley wink (the first one to talk about Jusdon gets a slap)
vw pipe admission pied moulevw pipe admission pied moule
vw pipe admission pied moulevw pipe admission pied moulevw pipe admission pied moule
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!
vw pipe admission pied moulevw pipe admission pied moule
vw pipe admission pied moulevw pipe admission pied moulevw pipe admission pied moule
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?! icone smiley laugh
vw pipe admission pied moulevw pipe admission pied moulevw pipe admission pied moule
vw pipe admission pied moule
Oh, and what about that fan shroud?......
Posté dans : 1959 Beetle
Affiché 84254 fois.
icon permalink
© Sham 1996-2019