Here's an article that took its sweet time before publishing... Anyway, things are going forward - slowly, but still forward!
I kept working on the case :
All edges are smoothed,
Casting marks are removed,
The ventilation holes between cylinders 1&2 / 3&4 are widened (the three fingers rule!) and smoothed,
the oil return hole at the bottom of the partition with the distribution gears is enlarged,
the ventilation above the central bearing is enlarged.
It may not look like much, but there's already quite a few hours of Dremel-ing to get there!
The global idea is twofold : first, enhance the air flow inside the crankcase to avoid over-pressure, second, ease the return of the oil to the bottom of the case, in order for it to go back in the oil circuit (the oil remaining on the inner faces of the case is useless!).
Smoothing the edges also helps preventing concentration of constraints in the material, and the cracks that could result from them. Well, to be honest, I'm not really too concerned about that on my little 1776!
As per the tools I use, it's first a pneumatic grinder with carbide bits to quickly remove material, then Dremel and its accessories (sanding cylinder, miscellaneous grinding stones...) to refine, and finally 120/180 grit sand paper for a final smoothing.
For the case's exterior finish, I used a fine rotary abrasive brush (on the pneumatic grinder, this baby gotta turn fast!). The objective was just to remove the oxidization and remaining muck after its previouss chemical cleansing...
I had my mind set onto using head washers an nuts around the case ("Gary Berg conversion") : the thick washers (4mm) and the 15mm nuts allow a tighter torquing of the case perimeter (2.7mkg instead of the origin 2mkg), leading to a more rigid crankcase.
But to do so, one needs first to spot face the case for the washers to lay flat on the material... As I did not really want to go ask pay a professional machinist to make that modification, and since I'm kinda stubborn (), I found a way to make it myself.
In order to do so, you would first need the right tool, a 22mm counterboring bit with a 8mm pilot tip (actually fellow enthousiast KY260, advised that Ø23mm is even better, as the washer may be a bit tight with 22mm). Not an easy to find tool, but I finally found it on eBay : a set of 23mm cutters, with two CM3 tool holders and 4 14.4mm pilot tips. At 44€, that was a steal!
As I don't have a mill, I want to use that tool with my drill press ; in order to do so, I lathed down one of the CM3 tool holders to give it a cylindrical end instead of the conical morse one. I also lathed one of the pilot tips down to 8.5mm (that hardened steel was very, very hard to lathe!).
Finally, I have the correct tooling, let's give it a shot!
Before I actually modify my crankcase, I did make a few tests on my former, out-of-tolerances case, just to validate the process first. Finally, I found a way to do it, by clamping my drill press down on the bench, turning the drill press head backwards to get enough height, and drilling slowly... I know my assembly will make any proper machinist shiver, but the resulting spot faced areas are really nice and flat and perpendicular : process validity checked!
So, here we go now, same procedure on my actual case. It's actually quite a quick process, except the ones below the case ; some Dremel work was required to free the way for the cutter.
Unpluging the oil galleries
In order to thoroughly clean the oil galleries, and by doing so avoid that some gunk would screw up all the nice work do so far upon engine's first start, you must un-plug the galleries. The operation isn't that difficult if you're careful : first center-punch the plug, then drill it with a 3mm drill bit ; then force-screw a sheet metal screw in that hole, and pull on it with an inertia hammer.
Since I did not have an actual inertia hammer, I thew one together with what was available around the workbench... I'm actually pretty happy of that recycling of an old rear-drum 36mm nut.
If you give this modification a shot, here are the plugs you'll need to pull (circled in blue) ; there are 10 of them, but I'll pug back only 9, the last one being the full-flow input.
The plug on the side of the case (right below and between the cylinders 3 and 4) is drilled to a 8.5mm diameter, all the way down (around 67mm, down to right behind the central camshaft bearing), to enhance the oil flow in the right half of the case. With a sharp drill bit, turning fast, going in slowly as to keep the bit from "screwing" into the material, that's quite an easy thing to do (back up often to get the shavings out).
Cleaning and plugging back the galleries
So, now that the galleries are un-plugged, it's time to clean them, and find a way to plug them back after!
Here's the tools of the trade for these two steps...
I ordered plugs from Torques.co.uk (great address I already got fuel fittings from). These are conical NPT 1/8"x27, 1/4"x18 and 3/8"x18.
They are anodized aluminium, really nice products ; to be installed with Loctite 577 pipe sealant ; make sure you have the imperial size Allen wrenches to tighten them in!
As for the cleaning of the galleries, any means are good. Myself, I'm first using the compressed air to get rid of as much shavings and dust as possible ; then bottle brushes, shotgun brushes and pipe-cleaning brushes... And lots of brake cleaning fluid ; some WD40 can be used too, to help removing any hardened oil sticking in the nooks and crannies.
To make it a bit easier, I like to mount the bottle/riffle brushes on my cordless electric drill, and then go back and forth in the galleries while turning full speed ; that's the way to go, galleries end up all nice and shiny! (sorry, no picture about it, I could not manage to get a proper picture inside the oil gallery)
Next, taping the plugs holes... This operation produces a lot of shavings and dust, so make sure you wait till you've finish this step before actually doing your final cleaning of the galleries!
Prior to taping, you first need to drill the holes : here are the drill bits sizes you'll need for that :
1/8" plug : 8,5mm drill bit (11/32"), going 15 mm deep
1/4" plug : 11mm drill bit (7/16" ), going 26 mm deep
3/8" plug : 14,5mm drill bit (37/64" or 9/16"), going 25 mm deep
Drilling depths are just given as an indication ; they totally depend on your taps and plugs, so don't take my word for it and make your own trials!
You need to be cautious while taping, as it's conical. As per the depth, you need to go little by little : tap a little, test fit the plug, tap a bit more, test fit the plug, et cætera until the plug sits flush with the case when tighten. To make it easier/faster, once the first plug of a given size is tapped, I make a mark on the tap for the next ones! (see previous picture, red marker stripe on the tap)
The gallery on the output side of the oil pump needs to be plugged as well. The pump itself is already tapped, but plugging the gallery too will prevent oil pressure from coming back in this gallery, causing leaks and/or oil going back in the case instead of the circuit. I put that plug deep into the gallery, that should help avoiding gunk and debris from stocking up in that dead-end part of the oil circuit.
So here we go gain, NPT 1/4"x18 tap, directly in the gallery without any prior drilling (inside diameter is correct). Half a turn ahead, quarter turn back to get shavings ou, and repeat... The plug will be tightened in the gallery with its dose of Loctite 577 pipe sealant again.
Out of the box, the cams edges are razor sharp, which may damage the lifters upon engine's first start. So I lightly smooth them down with my Dremel and a sanding drum. It doesn't need much, just smoothing down that angle a bit ; I finish it off with some 600 grit sandpaper with a drop of oil.
The journals are polished with some 2000 grit sand paper (a worn-out ScotchBrite pad would work too), to remove any imperfection and promote the oil film. If you use sand paper though, make sure you thoroughly clean the part after, as grit particles may get embedded in the material (well, that's more true about the soft material of bearings han the hard steel of the journals!).
Assembling the driving gear : the screws delivered with the camshaft have a ring protruding on top of them, which may interfere with the back of the oil pump. Since that ring does not bring anything in terms of resistance to the screws, I lathe it down (well, a file would have done the trick too!).
Finally, a thorough cleaning/degreasing of all the parts (brakes cleaning fluid, acetone), and assembly, torquing the screws at 25nm, with a drop of Loctite threadlock (the stronger, red one - you really don't want these to get loose!). The notch in the camshaft (that drives the oil pump) has to be aligned with the mark on the gear.
I give the whole thing a thin coat of WD40 to prevent any oxidization, and I put it aside, in a clean protective plastic bag.
The oil pump is a modified model, prepped by Feller Service (a french perf shop) : it's a Shadek 26mm base, machined to add a couple of O-rings around it (to prevent leaks and cavitation). The pump body and gears are rectified so that the gears are perfectly flush with the body (checked with my trustful rectified ruler).
The output is already plugged, with the full-flow output on the anodized black, CNC aluminium cover (tastefully engraved with the name of my fav parts dealer! ).
More information about this pump on Feller's blog (in french only I'm afraid) ; actually if you give it a close look, my pump cover is somewhere on the last picture, on the right hand side...
Anyway, here's a really nice, highly recommended product, and made in France for once!
Still, I make a couple of modifications on it : first, the tear drop shaped input as recommended by Berg, so that the oil arrives nicely all along the gear. I also slightly grind down the rear protruding tenon, to make sure it won't interfere with the camshaft screws.
The oil inlet port is aligned with the gallery on the case (see this post by PanelVan) ; I was luck, I had less than half a millimeter gap, so a light Dremel sanding drum touch in the pump body was enough to align it perfectly.
And that's it, enough for the oil pump, it's ready to install!
"Small" upgrade of my workshop...
First, I managed to get myself a second garage, next to the first one. Well, not exactly next to, so I can't just remove the wall between'em, but close enough. Not a perfect situation, but better than nothing.
Next, I had an opportunity for bargain priced floor tiles (thanks a lot to my buddy Dangerous for this, and lending me his Type 2 to transport everything!), so here we go : let's tile them garages!
So, I have two garages, 17m² (183ft²) a piece, so a total of 34m² (366 ft²) ; I got myself 40m² (430ft²) worth of tiles, just to have some room to deal with cuts and broken ones.
These tiles are 50x50cm (20"x20"), solid porcelain stoneware, 9.5mm thick, anti-slip texture : 27 packs of them, 27.7kg each, so almost 750kg to move... Meh, I'll just get my spine replaced after this one.
Note : for you to imagine the 30km trip with the Bay Window Type 2, packed with 750kg of tiles, in winter, under heavy rain (orange weather forecast flood alert), without any heating (so windows wide open to get rid on the condensation, so in rained an much inside as it did outside!), with a fire extinguisher at my feet "jus in case because I have a leaky fuel pipe", and the obviously vintage braking system, I suggest you watch again the classic movie "The Wages of Fear" (1953).
Why tiles in a garage?
To answer shortly : way easier to clean, a quick sweep and it's clean.
I was rather happy about my floor paint, after 3 years of use : it resisted quite well, only a couple of compounds manage to dissolve the paint if let too long in contact (mainly braking fluid and aceton).
But my floor isn't perfectly flat : the concrete slab had originally been indented with a spiked roller to make it non-slip, and even though I had used a concrete grinder to smooth the surface (see this article), it's still full of small holes that keep gather dirt. Impossible to keep it actually clean.
And for those of you who think : "yeah, but if you drop a tool, your tiles gonna break!" : well, I know a tiled car body shop, they have tools falling everyday, and they even hammer form sheet metal on the floor tiles! So, no, I'm not too concerned about solidity!
And if I happened to break a tile, I have quite a few in advance, I'll just replace it with a new one...
OK, here we go!
First step : empty the whole garage to be able to tile : in itself, it's already a heavy project, fitting in one garage what usually fits in two... It's like playing a life-size Tetris.
Next, carefully preparing the floor : sweeping, vacuum, complete washing/rincing using "St. Marc" washing soda, and a coat of primer to make sure the tile adhesive sticks to the substrate. Then, tiling using "Parexlanko" tile adhesive (spread with a 9mm toothed applicator, using the double-gluing technique on the back of the tiles, important for solidity), and water-repellent sealing comound from the same brand. Nice products, I would use th same with no hesitation ; a total of almost 3 bags of 25kg of adhesive per garage were used, so it's another 150kg to transport... Plus 25kg of sealing compound for both garages...
As expected, the walls aren't straight, so I tile everything perpendicular to the garage entrance (if you ever so such a job, take your sweet time at the beginning to make sure you start square, Pythagoras is your friend here!). A world of thanks to my buddy Flo here for lending a hand!
I finish it up ith a stripe of grey paint at the bottom of the wall, to keep it clean when I sweep the floor (and cover the stains made by the sealing compound). Another solution would have been to make "skirting boards" out of the remaining tiles, but the added thickness would have been in the way when I install my shelves.
So, first garage done ; this one will be mainly used for storage, so I install there all my shelves. And since I scored on LeBonCoin (the french equivalent of Craig's List - that was a steal!) a set of really sturdy boxes that neatly fit in the shelves, I'll finally be able to sort out my mess stock!!
One down, one to go. Heads up, we're only half way!...
This one begins with moving the 350kg of my lathe (which almost fell on me this time, thanks Xavier for your help!).
Next is exactly the same procedure as for the first garage, deep cleaning and priming the floor (primer is mandatory to install tiles on a painted floor), and finally tiling :
And two down! Done! PHEW! I had under estimated the amount for work tiling such a surface would be!
These small things that make your life easier...
In the first garage, I first install 4 two-by-threes below the glass roof I have at the back of the garage : that will be a tire rack, and that much room saved!
Build in 3 minutes with what was laying around : 2 angle brackets, 3 old roller ball bearings, a threaded rod and a handful of bolts... And here you go, a nice kitchen roll holder running on ball-bearings!
Here's something I should have done 20 years ago, I keep using it all day long!!
Now for the workbench : I paint the feet/supports to be able to clean them later, as the raw wood stains very quickly in a workshop environment (and for the looks, let's be honest!). I give it two coats of a nice vintage "Eucalyptus" green, with a light sanding between coats. Sanding is mandatory on wood, as the fibers tend to raise after the first coat.
The shade of green is shamelessly copied from inspired by Jack Olsen's garage, of which I'm very fond of... If you don't already know it, you must give it a look on 12-GaugeGarage.com, and check the build details on GarageJournal.com (be careful with this forum, it's addicting and you quickly end up spending hours there!)
Workbench again, that was a paint in the ass to make : a strip fitting nicely in between the workbench top and the rock stone wall behind. No more washers or nuts rolling all the way behind the bench! Looks like nothing, but the usage comfort is so much better now! On the down side, it took me almost half a day fitting that strip, using a rasp and a Dremel...
The strip is made of 10mm thick MDF, covered with the edgebanding material that came with the bench top. It's then screwed on top of a 1"x1", itself glued/screwed to the back of the bench top. Neat!
I found on LeBonCoin again (40€, a bargain!) a nice all steel tool cart... Probably originally a medical cart, with that stainless top...
A bit of elbow grease and some paint to match the workbench, and it's perfect!
There, that's it, end of this upgrade, with a sore back and knees (all my respect to the guys whose job is tiling!)... Just to compare, here is how it looked like before...
OK, enough, now that it's nice and clean, let's put some grease and rust all over it!
Back to cruising speed and altitude at the workshop... Over'n'out!
As I explained in my previous article, after my signature "distributor gears salad", I'm moving to plan B : I'm taking the spare engine case from the shelf it's been sitting on for years, make some thorough measurements and... it's like new, with perfect, stock-size bearing saddles!
Bearing saddle 1 : 64.98 / 65.00 / 64.99 / 65.00
Bearing saddle 2 : 64.98 / 64.99 / 64.99
Bearing saddle 3 : 64.99 / 64.98 / 64.98
Bearing saddle 4 : 50.01 / 50.00 / 50.00 / 49.99
Finally some good news! I have an engine case! Woohoo!
While I'm at it I measure the crank that's inside this case ; out-of-round is OK with 0.01mm, but the
rod and main journals have been ground to 2nd undersize. Serviceable, but well, not ideal.
I take a deep breath and give it a good thinking... Since I'mm rebuilding a complete engine, why remain with a stock 1600?
So, after a lot of reflection about the cost / reliability / performances ratio of my future engine, I decide to go for a 1776cc : stock 69mm crank stroke, and larger 90.5mm bore pistons/cylinders.
My objective is to build an engine capable of long drives on the highway, but still playful on the little mountain roads of my area - this will remain a "week end driver", so mileage is not my priority.
I want a strong, durable, optimized engine, with a wide range of usability, while keeping the Mex injection manifold for now, but keeping an upgrade as an option for later...
So, I roll up my sleeves, and here we go!
I make some modifications to the engine case, inspired by the "Bob Hoover's Sermons", what he used to call the "HVX modifications" (read about it on his blog here, and there).
A good reading (in french, sorry!) as well if you want to give it a shot, this post and this post by Vince/PanelVan, who demonstrates this procedure very well.
The idea behind this modification, is that the right side of the case is supplied with oil only through the grooves around the central camshaft bearing (see schema below). That's far from ideal, since the lifters/rockers/valves on the right side (cylinders #1 & #2) are less lubricated/cooled than on the left hand side of the case (cylinders #3 & #4).
The solution recommended by Bob Hoover was to extend the lifters oil gallery (bottom right on the schema), and feed it through a hole drilled below the gear-side camshaft bearing.
OK, here's a schema of the modification, that'll be easier to explain!
In practice, to make this modification, we first remove the oil gallery plug (green arrow on the schema) ; there's a method involving drilling and pulling with a screw, but we found out it was actually way easier just to push the plug in, with a punch and a hammer, until it drops into lifter bore!
Next is the extension of the lifters oil gallery, to bring it up to 225mm long. I've used for that a foot-long, Ø6mm drill bit, and used a small hand-held electric drill. The trick is to go in slowly with relatively high RPM (to avoid breaking the bit in the case), using some lubricant to avoid vibrations (WD40 will do), and back off often to get the shavings out. A piece of tape on the drill bit helps spotting when to stop.
For the hole under the camshaft bearing, I used a Ø7mm on a press drill.
It's actually quite an easy process ; I was a bit nervous the first time, but I drilled 4 cases in a row that day, I was pretty confident in the end! Beware : make sure there's enough material on your case before drilling anything, not all cases are identical, and on some of them your gallery extension would end up outside of the case... Which would surely end up in the trash bin for that.
Simultaneously the oil grooves on both the camshaft bearings (red arrows on the schema) are widen with a Dremel to increase the oil flow.
As next, I drill a hole below the alternator stand to enhance the air flow inside the case, thus avoiding pressure build-up by using the volume on the cam-gears side.
The first hole is drilled with a Ø9mm bit, and then widen it with a pneumatic die grinder and carbide bits. My brand new bits eat through magnesium like if it was butter!
Here again, I was a bit nervous at the beginning, but the handling of the die grinder comes with practice... Three cases in a row that day!
Security Hazard : all these modifications produce quite a lot of magnesium shavings and dust, which are highly flammable. Magnesium burns at very high temperatures, and its combustion is almost impossible to stop... So make sure you safely and often get rid of these shavings/dust!
Next step, the case is shipped for some machining, but not alone : since we are a small group of friends building engines at the same time, we're pooling the shipping costs, and it's a complete pallet that leaves the workshop!
My case will be bored to accommodate the bigger 90.5mm cylinders, get a full flow outlet (to install a proper oil filter), a shuffle pin of the central main bearing (to increase the rigidity of the block), new 8mm inserts installed, and finally a complete chemical cleaning, just to start on a clean base.
And after a couple of weeks of patience, here's the result!
There, it look better already!
Camshaft / Lifters :
The camshaft is a L&G V280 lobe 108°, to keep a street-oriented yet playful behavior to this engine... a compromise, we'll see in practice if it was the right choice!
It's running thanks to a couple of straight-cut cam gears, to limit the axial efforts on the camshaft, and gather a bit of power too... The gears are steel and aluminum to limit their nose : steel on the crank, aluminum on the camshaft.
The lifters are Tool Steel ones, mainly for me not to have to worry about the camshaft break in (the unknowns of injections when you're a newbie, you know...).
They're lighter than the stock ones : 57g each instead of 87g, nice! That's will help grabbing HPs at high revs!
At a hefty 350€ the set, these are quite expensive lifters, but at least I won't have to worry about'em.
Finally, the camshaft will run on a set of dual thrust bearing, to make sure it's axially guided on 360°...