To briefly recap: Ron bought a derelict 914 many years ago, only to discover that its engine was junk. He purchased a spare motor, and invited me to join in the festivities. We’re on equal ground, because neither of us has ever rebuilt an air-cooled VW or Porsche engine before. To quote Ron: “What could go wrong?”
The good news is, we are still in the disassembly phase, and as anyone who has attempted any kind of project can tell you, taking something apart is easy, compared to putting it all back together (and expecting it to operate).
During my 2nd visit, we were able to remove the rocker arm assemblies, pushrods, cylinder heads, and cylinders (jugs). Ron kept reminding me that he wasn’t too concerned about the condition of all these parts, as he has already purchased new replacements for all of them. However, one issue that is keeping me concerned is that we started with a 1.8L engine (I think), we are now working on a 1.7L engine (I think), yet the new parts are for a 1.8L, as that’s what Ron thought he’d be rebuilding until discovering that it had been stored in a pond. Hey, we’ll figure it out. (If you have any familiarity with the similarities and differences between the 1.7 and 1.8 914 engine, please drop me a line.)
During that same visit, we had intended to remove the flywheel, but we lacked the exact tools we needed (½” drive impact sockets). During my all-too-brief 3rd visit, I brought the required sockets with me, but, even with an air impact gun, the final flywheel bolt would not budge. We worked it so hard that its corners started to round off, so cooler heads prevailed, and we left it alone until a Plan B arises from the pond….
At my urging, Ron did buy a set of snap ring pliers, and they came in handy when removing the snap rings, two per cylinder, one on either side of each piston pin. With those out, the pins were easily knocked free with a drift and hammer, and all the pistons were removed.
I informed Ron that I had a busy August coming up, so in the interim, he had some decisions to make:
If the flywheel bolt can’t be removed, what is our next course of action? Just leave it be? He was leaning in that direction.
With pistons removed, the con rod bolts are accessible, and Ron was considering replacing the con rod bearings (but not the crank bearings). He was actively mulling that over.
While he had previously purchased a complete engine gasket kit, was he certain that it had everything we needed for reassembly? He was going to inventory that kit.
Since that 3rd visit, Ron emailed me with an update: he had purchased a set of bolt extractors, “guaranteed to remove the most stubborn rounded-off bolts”, so he was engaged in that exercise. I hope to get back to wrenching on this engine within the next week or two, but I’ve got the Alfa brakes to tackle, and that’s a project (and a story) that will take me through most of the remaining driving season.
For varying reasons, we (the “we” being my buddy George) and I are departing Friday morning. It’s about a 350-mile one-way trip, and while my 51-year-old Italian car is more than up for it, there’s still all that last-minute stuff to attend to. Since it got a full tune, valve adjustment, and oil change earlier this year, most of what I’ve put effort into these last few weeks has been cosmetic. After all, it will be on a show field with many of its siblings and cousins, and it needs to look it best!
Here are some of those recent efforts:
When I got the car in 2013, there were custom-fitted carpet floor mats in place. Pete, the previous owner, had had them made, and they fit well and looked good. But during my time with the car, the driver’s side mat had started to bunch up near the pedals. Looking at replacement mats online, the biggest challenge was finding a set that could properly deal with the “standing pedals” (hinged through the floor) on my Alfa. The set in the car had a rubber panel, cut to allow the clutch and brake pedals to pass through. I was looking for similar, and was not satisfied with what I was finding.
The good folks at Coco Mats (www.cocomats.com) offered to make a custom set for me, and went so far as to send me a template for a hanging pedal car, which I could customize. But during my email exchanges with them, they seemed reluctant to deal with a mat that would be slotted for the standing pedals. While I liked the idea of coco mats, I continued to search.
My usual UK supplier, Classic Alfa, didn’t carry floor mats at all, but Alfaholics did (www.alfaholics.com). While the mats appeared able to adapt to the pedals, the image on the screen was less assuring. The Alfa logo AND script were rendered in bright red, and took up a large chuck of real estate on the mat; perfect perhaps for a car with some red on the outside or inside, but my GT Junior has neither. I decided to keep looking.
Centerline, based in the states, possibly had a good-looking mat, as the screen shot showed the Alfa logo done up in proper colors. The issue for me was the entire mat wasn’t shown, and I wanted to see how they handled the pedals. So I called and asked if someone could perhaps take a photo or two and send that to me. The nice chap I spoke to said, “well, it’s Friday, but we could do that for you next week”, to which I replied, “great!”. When “next week” came and went, I called again, and got a different, somewhat less-nice chap. His first question was “who did you speak to?” and I replied “I have no idea”. When I again asked for pictures, he said “well, we’re kind of busy filling orders”. Hmm. Guess I’ll just look somewhere else then, shall I? (I never did receive photographs from them.)
Out of frustration, I Googled “Alfa Romeo mats made in Italy” (U.S.-made mats were for hanging pedal cars only). This brought me to the website of Mr. Fiat, where I saw good-looking mats for standing pedal cars. The Alfa logo was in all-red, but it was small and subtle. I called. Mrs. Fiat answered the phone, and verified that they had my mats in stock (the company is in Atlanta GA). She transferred me to Mr. Fiat, who took my order over the phone. I had the mats in 3 days.
The look is good; the fit is just so-so, but about what I would expect for aftermarket mats. Their main purpose, after all, is to protect the original rubber mat flooring, so these will get the job done!
I will admit that on 90-degree summer days, the vinyl upholstery in my car becomes a bit unbearable. So the idea of sheepskin covers, with their “cool in the summer, warm in the winter” advantages, appealed. I’m also lucky to work for a company which sells aftermarket car parts and accessories, and I bought my covers, through www.carid.com, from U.S. Sheepskin.
They are universal fit, and while the fit on the seat back is excellent, they are quite big on the seat cushions. The color is complementary at best, but that’s OK, because these are for travel only. Once I get to a show, the covers are coming off to expose the original upholstery. I’ve made some short local trips with the seat covers in place, and so far, pretty comfy.
Polish and wax
The Alfa has single-stage paint, meaning, no clear coat on top. Not sure that any 1967 cars had two-stage paint, probably not. I’m also guessing that its paint is lacquer, as it has that “soft” feel to it. Whenever I apply any kind of wax, the cloth quickly turns green, so I know I’m removing paint.
Since buying the car in 2013, I’ve put over 10,000 miles on it. When it goes on one of the New England 1000 rallies, it spends a full week outside, and that quickly takes its toll on the paint. In my garage, the car stays covered, but the paint still needs frequent attention.
Meguiars products have been my favorites for over 10 years now, and I’m 99% exclusive with them. For the Alfa, having tried several different combinations of products, I’ve settled on two: Show Car Glaze #7, and Liquid Yellow Wax #26.
The Show Car Glaze is a polish, designed to rejuvenate the paint by nourishing it and adding essential oils back into it. It has some compounding effect, but very little. I’ve read articles which refer to Meguiars #7 as “Queen For A Day”, meaning that it may be short-lived, but it will quickly bring back a deep shine.
Yellow Wax #26 is a blend of carnauba and other waxes. It’s easy to apply; there’s no rush to remove it; and it doesn’t dry white, so if you get a little in some nooks and crannies, it’s no big deal. It also seems to sit nicely on top of the #7 Glaze.
I started with the horizontal surfaces, which had the most hazing on them, and they cleaned up nicely. I was able to go lighter on the sides, and finished up with the front and rear. By the way, the #26 wax works beautifully on my stainless bumpers, frankly, better than the metal polishes I have. We’ll see how well the car does when it’s judged on Saturday!
The Alfa Convention in Montreal in 2017 was my first visit to an AROC event, and I was knocked out. I missed 2018 in Washington state, and am thrilled that the 2019 Convention is so close. Watch this space for updates and a full report!
Saturday was an almost-perfect weather day in NJ, sunny, warm, with low humidity. The sun was perhaps a bit too warm, as I pulled my ’67 GT 1300 Junior out of its stall so that we could work on the Spider in the cool shade of the garage.
Enzo had the correct oil with him, 75W-90 GL-5 gear oil, so we decided to start with the gearbox. Jacking up the front of the car under the front spring perches, sturdy jack stands were placed under the jacking points just behind each front wheel. For some reason only known to Alfa engineers, the transmission case drain and fill plugs are on the same side as the exhaust (the driver’s side), so I found it easier to slide under the car from the passenger side and avoid contact with the still-hot exhaust pipes.
Enzo read the printout he had with him from his electronic service manual: “Remove the drain plug; allow the oil to drain out until you see just a drip. Reinstall the drain plug. Remove the fill plug, and add the appropriate oil until it reaches the top of the fill plug; reinstall the fill plug”. It sounded too easy.
On my ’67, I knew that the fill and/or drain plugs required Allen wrenches, as I had done this job on my own car a few years back. I also knew that I had a rather good assortment of metric Allen sockets. I grabbed my drain bucket and positioned it under the tranny. At this point, I related a lesson I had learned a long time ago, and possibly had witnessed during my own repair travels.
While the instructions were clear enough, I said, they should not be taken so literally. What if the car owner removed the drain plug, drained all the oil, reinstalled it, and then found out that s/he could not remove the fill plug? ROOKIE MISTAKE!
An experienced mechanic would always remove the fill plug first, just to ensure that it could be unscrewed and reinstalled. Having done that, the repair person would have the assurance that fresh oil could be added after the old oil had been drained. So that is what we planned to do.
Peering at the side of the case, flashlight in hand, I saw that the drain (lower) plug required a regular socket, perhaps 19mm or 22mm. But the fill (upper plug) would need an Allen (hex) wrench. I asked Enzo to hand me an assortment of metric Allen sockets from my toolbox.
None of them fit. Most were too small; one was too large. (This too-large one was 14mm, and I’m certain that I purchased it specifically for my car.) So much for my presumption that my ’67 and his ’91 would use the same size tools. I slid out from under the car, and opened a drawer which consisted mainly of Allen keys, in both SAE and metric sizes. I grabbed a bunch, got back under the car, and tried them one by one. None fit. That’s it, I said. We are finished before we even begin.
With that, Enzo opened his car’s trunk and rummaged through the tool kit that came with the Alfa. He pulled out a hex wrench. “Try this one” he said. I did. It worked. Voila! His Craftsman 12mm Allen wrench he just happened to have with him was the “key”.
This wrench was about 5 inches long, and working on my back, I didn’t have a lot of leverage to crank counter-clockwise on this thing. “Get me a breaker bar” I shouted. “There are some black iron pipes in the same drawer as my hammers”. Enzo gave me a pipe about a foot long. STILL could not budge the upper plug. I’m not the strongest guy to have turned wrenches, which is why I keep an assortment of breaker bars on hand. But this fill plug was F.T.
Enzo said “I have an idea – you hold the wrench and the breaker bar, and I’m going to extend my foot under the car”. Before I could ask him exactly what he had in mind, Enzo pushed hard with his leg against the pipe, and we both heard that satisfying “crack” sound when something that’s uber-tight breaks free. We did it. With the upper plug out, the lower plug was quickly removed with a 22mm socket and ½” drive wrench, and the old, possibly original, gearbox oil was flowing out and into my catch can.
I had forgotten to mention to Enzo the need for fresh copper washers, but I just happened to have a few new ones on hand. I think that every drain plug on every ‘60s/’70s Alfa uses the same size copper washer! The magnetic drain plug had a bit of sludge on it, but it didn’t look like anything to worry about to me. I cleaned off the sludge, and gave the threads a quick gentle scrub with a brass brush.
The drain plug was reinstalled, and Enzo snaked a rubber hose from the engine compartment, down toward the transmission. I held the hose in place at the fill plug, while Enzo poured in about 2 quarts of the gear oil. Once it started flowing out of the top hole, indicating a full tranny, I reinstalled the fill plug. This transmission drain-and-fill, with the jacking, prying, and filling, took us over an hour and a half.
The rear axle, by comparison, was relatively easy. Besides, we were now experts. The jack stands were removed from the front. The floor jack was placed directly under the differential drain plug, and both sides of the car were lifted at the same time. With the jack stands in place at the rear, I noted that we needed the same two tools: a 12mm Allen for the upper fill plug, and a 22mm socket for the lower drain plug. We again needed Enzo’s muscular right leg (probably built up from years of playing soccer) to loosen both the fill plug AND the drain plug, but with that. the rear axle oil was flowing.
This magnetic drain plug had the same amount of sludge, and it too was cleaned and fitted with a fresh copper washer. With the drain plug back in, we were ready to add new gear oil.
To route the fill hose, Enzo pulled the spare tire from its well, and unbolted a drain cap, which then provided excellent access to the fill hole. About 1.5 quarts of oil were added. We buttoned up, cleaned up, and started it up. A short test drive confirmed no untoward noises, and with that Enzo was safely on his way. Let’s hope there isn’t too much more to do between now and our mid-July departure for Pittsburgh.
SIDEBAR: THE ALLEN MANUFACTURING COMPANY
Most technicians are familiar with a tool that’s commonly called a “hex key” or “Allen key” or “Allen wrench”: it’s a six-sided hexagonal shape that’s inserted INTO a screw head or bolt head, as opposed to the more-common socket or wrench, also 6- (or 12-) sided that’s placed OVER the outside of a bolt head. The hex/Allen design offers the advantage of a smaller head that can fit in tighter places, and can even be designed to thread down and into a threaded hole or shaft.
“Hex” of course means “six”. But why is this tool also called an “Allen wrench/key”? You can thank Mr. William G. Allen, who, in 1909-1910, patented the design, and began manufacturing both the screws and the tools via the Allen Manufacturing Company of Hartford, CT.
My father worked around production machinery for much of his professional life, and set screws which required Allen wrenches were very common. My father’s extensive collection of Allen wrenches in both SAE and metric sizes are now in my possession, and even include some plastic carrying cases bearing the company’s name.
I’ve known Ron for over 20 years now – unlike the majority of my friends, whom I know either from school or work, I met Ron during my very first New England 1000 rally in 1998. He and his wife Carol drove an MGA that year, while Steve and I were in Steve’s Tiger. We hit it off because we liked similar cars, plus we were all from NJ.
Ron loves all kinds of cars and motorcycles, preferably those from merry ol’ England. He currently has a Triumph Spitfire, an Austin-Healey, and about a half-dozen British two-wheelers. Still, I would describe his tastes in motor vehicles as “varied”, as the fleet also includes a Ford Model A pickup, a pre-war Packard convertible, a ’56 T-Bird, and a Porsche 356.
About 10 years ago, Ron picked up a derelict Porsche 914, and after doing body repairs (he’s proficient at metal work), he finally peeked inside the engine to discover a disaster: water had sat inside the crankcase for so long that all the internals were frozen. Somehow, he found another 914 engine for sale for $200 and dragged that home. That’s when he called me.
Ron explained that he had rebuilt the engine in his MG Midget race car (numerous times) but was unfamiliar with this VW Type 4 air-cooled flat four. I told him in turn that I rebuilt the one-lunger in my BMW Isetta, and felt equally unfamiliar with the V-Dub motor. Somehow, he convinced me that I knew more than he did, and I agreed to give him a hand one day for a few hours.
I’ve turned wrenches for much of my adult life, and can even try to convince you that I earned a living at it for a year or two. My experience, though, does not extend to a lot of in-depth engine work. Perhaps my biggest contribution to Ron’s project would be as a disassociated 3rd party who could oversee the proceedings, maintain a slow and steady pace, and assist in keeping things organized.
Arriving at his house one day last week, Ron had the engine on top of a sturdy work table, and had cleaned off much of the grime. Even removed from the car, it’s difficult to look at this hulk and envision an engine in there. Frankly, I’ve never understood the appeal of these VW/Porsche boxers. If you popped the hood on my ’68 Mustang, you were greeted with 390 cubic inches of cast iron painted Ford blue. In a different vein, but equally impressive in my opinion, opening the hood on my ’67 Alfa reveals a 1.3 liter aluminum jewel, with the valve cover proudly perched above the dual overhead cams. Lift the engine cover on a Beetle, early 911, or 914 and you’ll see…. sheet metal shrouding.
Everything is shrouded: the top of the cylinders; the cooling fan; the bottom of the cylinders; and the alternator too. I get it: no radiator, no antifreeze, no hoses or hose clamps. It does simplify things. But you still need to control airflow over the crankcase, cylinders, and heads to dissipate heat.
So the first order of business was to remove all the shrouding, and just as importantly, photograph and label each piece as it was removed, for reassembly sometime in the hopefully not-too-distant future. (Actually, the first task was to remove the starter and its attendant wiring harness on top of the engine, so this we did.)
This engine had already been apart at some point in its past. We knew that because A) the shroud screws were a mixed bag of slotted screws and cap screws; B) blue Permatex sealer was evident in various spots; and C) a few shroud screws had broken off in the case, something for us to work on later.
RON POSES WITH SHROUDING FOR THE CAMERA:
With the thin sheet metal shrouding off, we tackled the fan housing, a large aluminum casing at the front of the engine, almost as large as the crankcase itself. Here we ran into a few screws that would not budge. Ron first tried the blue wrench, aka the torch. When THAT didn’t work, he resorted to a drill to remove the screw heads. This finally allowed the housing to be separated from the case.
We marked the spark plugs 1 through 4, and took a snapshot to keep track of cylinder numbers. Removing the spark plugs, we found that the engine easily turned by hand, with no untoward noises. This was a good sign, and maybe just maybe, things are OK at the crank.
The clutch came off without drama once the pressure plate bolts were out. The flywheel was rusty, but we saw no obvious score marks.
This was enough work for one day. Ron’s plan is to use new/reman cylinders, pistons, and heads, all of which he already owns. I reminded him that he needed to order a clutch, and I suggested that he look for a shroud fastener kit, so we could avoid dealing with chewed-up bolt heads.
Ron pointed out there was no blood, no broken bones, and no one’s clothes caught fire, so he declared the day a success. He managed to convince me to return, and I managed to croak out a “sure”. But we’re going to need to get this thing on an engine stand soon – AFTER that flywheel comes off.
When I bought my Alfa Romeo GT 1300 Junior in March of 2013, it was for the express purpose of using it to participate in automotive events. There’s no denying that I have piled on the miles. The four New England 1000 rallies of 2013, 2014, 2015, and 2018, the Alfa National (International) excursion to Montreal in 2017, and two trips to the Greenwich CT Concours have accounted for the bulk of the mileage. Add to that the innumerable local breakfast drives and car shows, and you can understand how in 6 years of ownership I’ve managed to spend 11,000 miles behind the wheel of this fine Italian automobile.
Alfas, and Italian cars in general get a bad rap as “unreliable”. That’s not been my experience. Except for a dead battery right after purchase, and a failed alternator on the ’18 NE1000, those 11,000 miles have been trouble-free. I’ve mentioned to those who ask that the more I drive the car, the better it seems to run. The other side of that coin is that, as a ‘60s European thoroughbred, the car’s mechanical state of tune must be strictly looked after; indeed, the Alfa maintenance schedule, which requires more frequent service than an American car of similar vintage, should be followed as closely as possible. This is where ability to work on your own vehicle becomes a significant advantage compared to needing to pay someone to do what is in essence straightforward service work.
After I finished the valve adjustment a few weeks ago, I noted that the idle was terrible, and in fact, it was difficult to get the engine to consistently respond to accelerator inputs. My first suspicion was the car’s ignition system, so an order was placed with Classic Alfa for the suite of tune-up parts. (And they spoiled me again, with the package on my front porch is less than 48 hours.)
The service books recommend removal of the distributor for service work, and it’s held in place by a single 10mm-headed bolt, so it’s easy to pop it out. Checking the usual suspects for wear, I didn’t see anything severely out of the ordinary, although the points were badly pitted, and the gap was too small.
I ended up replacing the spark plugs, plug wires, cap, rotor, points, condenser, and, for the first time under my ownership, the coil, which looked original. The car fired right up, and as I’ve noticed immediately after prior tunes, the tip-in is magnificent. I took the car for an all-too-brief run around the neighborhood, and felt infinitely better about all the driving I’ve got planned for the Alfa for this year, especially the Alfa Club Convention in Pittsburgh in July.
The one remaining item on the tune-up to-do list is the ignition timing. If I’m reading the books correctly, the best way to set the distributor timing for utmost performance is by checking it at 5,000 rpm. At that engine speed the “M” (for “massimo” or maximum) should line up with the timing pointer. The books also recommend NOT adjusting the distributor while at 5,000 rpm, and that’s good advice.
Note to self: every year, the ignition system needs to be checked, adjusted, and renewed as necessary at the start of every driving season.
As you read in “Alfa Romeo Valve Adjustment, Part 1” (or if you skipped your reading assignment, you can find it here), the valve gaps on my 1300 engine were out of whack, especially on the intake side. With cams temporarily removed, I measured all the existing shims, did the algebra to calculate the sizes of the needed shims, and placed my order with Classic Alfa in the UK. I was not the least bit surprised when the order I placed at 10 p.m. on a Saturday night landed on my front stoop before I got home from work on Tuesday. (I need to email them and enquire what happens after Brexit, presuming that Brexit happens.)
The following weekend, all the old shims came out, and the new shims went in, again following the “one cylinder at a time” rule I established so as not to cross-install the followers which must remain with their original cylinders. When reinstalling the cams, I could not get the timing marks between the cams and front bearing caps to line up. It made me nervous enough that I removed and reinstalled the cams a second time (remember that the timing chain remained attached to the sprockets). I finally convinced myself that once I released the bolt holding back the spring tension in the timing chain tensioner, all would return to sync, and that is exactly what happened. With the tensioner pressing against the chain, I rotated the crank and cams through two complete revolutions, and then tightened the bolt in the spring tensioner. The marks were still aligned, thankfully.
I double-checked and wrote down all the new valve clearances, and all seemed good (but read on). Since I had the spark plugs out, a new set of NGK B7ES plugs, which are in stock at my local Advance Auto Parts store, went in. With plug wires, intake plenum, and air filter hose back in place, it was time to attempt to start this baby, remembering that the engine had not been run since the car went to sleep the previous autumn. The engine started on the second try, however, there was an unhealthy miss at idle. I shut it down, and made plans for a complete tune-up, which was next on the Alfa’s to-do list anyway.
Postscript: I jotted down all the “new” valve clearances, and really didn’t give them a second glance, undoubtedly presuming that everything was done correctly. Today, while composing this blog post, I noticed that my spec for intake valve #3, .450mm, was unchanged from its original measurement, yet I have no doubt that the 2.15mm shim which had been in there was replaced with a 2.10mm shim, which means that the new measurement should have been .500mm. For now, I’m leaving this alone for several reasons: valve #3 was the closest to spec of all the intake valves during the original check; testing the thicknesses of the new shims revealed that how tightly I cranked on my micrometer made a difference in the measurement (including the effect of residual oil on the shim); and I’m not yanking that cam again for 0.05mm!
The owner’s manual for my 1967 Alfa Romeo GT 1300 Junior calls for the engine valve clearances to be checked every 18,000 kilometers. According to Google Calculator (before Google Calculator I would have used my slide rule), that’s every 11,185 miles. Coincidentally, I’ve put almost exactly 11,000 miles on the Alfa since purchasing it in March 2013. So in part to prepare for what is anticipated to be a very busy 2019 driving season, and in part because I really don’t know when this was last done, I decided to check all 8 valve clearances (4-cylinder engine, 2 valves per cylinder equals 8 valves).
Accessing the valves and followers is the simple part. This overhead-cam engine has its two camshafts at the very top. The valve cover can be removed once the spark plug leads, air hose, and the top of the intake plenum are out of the way, which is a 10-minute affair. The valve cover is held in place by 6 large Allen screws along the top, and two bolts at the front. I had never had the valve cover off this engine before, and my first reaction was one of pleasant surprise at how clean the engine looked.
My first task was to find the camshaft part numbers, to verify that these were Alfa Romeo cams and not some hot aftermarket replacements (in which case the clearance specs would be different). A prior conversation with Pete, the family friend who sold me the car, revealed that he wasn’t sure what cams were in it. The part numbers of both cams were readily visible, and verifying them against my technical literature confirmed that these are indeed the factory cams.
Now it was onto the actual clearances. To rotate the engine, I first tried getting a socket on the crank pulley bolt, but the fan shroud blocked that. The next-easiest way to spin the engine was via the nut on the front of the alternator. Popping out the plugs provided less compression resistance, and some moderate thumb pressure on the alternator belt was all that was needed to get the crank and cams to spin.
Paper and pencil at the ready, the valve clearances were checked in firing-order order (1-3-4-2) and recorded. While my owner’s manual provides specs in both millimeters and inches, I decided to stick with the metric measurements – I have metric feeler gauges, and the needed shims are sold in metric sizes.
The spec for the intake valves is 0.475-0.500 mm, and the exhaust spec is 0.525-0.550 mm. Six of the eight valves were out of spec: all 4 intakes and 2 exhausts, and, all 6 showed too little clearance, meaning the valves were not seating completely, subjecting them to less cooling since they were not making full contact with the valve seats.
The worst measurement was #4 intake: 0.350 mm, meaning it was 0.150 mm too tight compared to a correct outer range of 0.500 mm. Yes, we’re talking fractions of a millimeter, but specs are specs, and I felt that the clearances should be corrected.
Here is where it got interesting. My Alfa engine was originally designed in the early 1950s. It’s a very sophisticated layout, with not only overhead cams, but all-aluminum block, wet cylinder liners, hemispherical combustion chambers, etc. However, like most other OHC engines of its time, adjusting the valves requires removing the cams to allow access to the followers (buckets) and shims which are under the buckets. Most friends to whom I mentioned this procedure looked at me with a combination of horror and pity. “It’s really easier than it sounds” I would retort, which did nothing to alleviate their sympathy for me.
(As a complete aside, the first OHC engine to incorporate a valve design which allowed for adjustments with cams in place was the Fiat twin-cam engine, introduced in 1966. My 1970 Fiat 124 Coupe used this design, although I never did adjust those valves!)
The official Alfa procedure calls for locating the timing chain’s master link, disconnecting it, and swinging the two chain ends out of the way. This method opens the possibility that the cam timing would need to be adjusted at reassembly. Of course, some very clever people have devised a work-around. One of the service books I own is the Alfa Romeo Owner’s Bible, written by the late Alfa expert Pat Braden. He describes a method that does not involve unhooking the chain. Instead, he suggests loosening the chain tensioner, pushing the tensioner all the way IN (making for a loose chain), locking the tensioner in this position, and then lifting the cams toward the center of the engine without disturbing the cam sprocket/chain connection. In this way, on reassembly, the cam timing does not change at all. Ideally, this is done with both cam timing marks lined up with the bearing cap marks.
This is exactly what I did. With the tension off the timing chain, I started on the intake side and removed the 3 cam bearing caps (Alfa thoughtfully numbers the caps 1 through 6, and I documented everything with photos before turning the first nut). The intake cam was lifted and placed over the spark plug holes (which were protected with clean rags). The chain remained on the cam sprocket.
The next trick was getting the buckets out, as they were oil-covered and lacking a way to grab them. I realized that a magnet might do the trick, and it did. The bucket came out, and under it was the shim, which was also removed.
Working on just one cylinder at a time so as not to mix up any of the locations, I measured each shim with a digital metric micrometer. The value was recorded on the same sheet of paper as the clearances. I started on the #1 intake valve, went down the line to the #4 intake valve, then did the same thing on the exhaust side. Once all these measurements were taken, the shims and buckets were back in place on the engine. I gently placed the valve cover on top of the engine, lowered the hood, and took my measurements inside so that the ‘new’ shim sizes could be calculated.
I knew that all the out-of-adjustment valves were tight, so I needed greater clearance, so all the new shims needed to be thinner than the current shims. I found an online “Alfa shim calculator” someone built in Excel, and I used it, but I also checked all my numbers two more times. I aimed for the higher end of the spec, figuring that if the valves are tightening up over time, I had best start by providing the maximum clearance while remaining in spec.
My go-to Alfa supplier, Classic Alfa in the UK, sells shims in increments of 0.125 mm, so it was a fairly easy task to calculate my needed shim sizes. The order was placed, and now I just needed to wait for the shims to show up. But it certainly felt like the hard work was behind me!