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Discussion Starter #1
Hi All,

I have a 102 cylinder head which, on first glance appears to be in good shape, except that it is missing the intake camshaft housing. The fact that this is missing does raise some suspicions about the condition of the head (Where did the original cover go, and why?).

In any case, I would like to experiment with a replacement camshaft cover. I do understand that these are matched to the head during manufacture and need to be exactly right, so some remachining would be needed, assuming this operation is even feasible. Does anyone have any experience with this?

Does anyone have one of these laying around collecting dust? It is AR part number 102.00.01.052.00. If it is ID stamped 539 it will save me a lot of trouble, as it is probably the missing housing. :D

Thanks,
Steve
 

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Steve,

Interestingly, I've got a spare head with missing upper camshaft bearing plate as well. I don't recall which side, but will check shortly. If I stumble onto one for the correct side, I plan to have the shop face the surfaces and line bore the assembly so it will work with my engine. Although I've never done this on an Alfa engine, it is a relatively well understood process. It will result in the cam(s) being slightly closer to the top of the valves, so thinner shims will be needed. Clearly, one wants to remove the very least possible from the engine side of the cam bearings, else you might run out of room to adjust the valves.

Let me know if you find a pair from a dead head. Maybe we're missing opposite sides?

Any more plans to pick up the hood and rotisserie stand?
 

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Discussion Starter #3
Hi Don,

This operation seems to me to be a bit more complicated than a standard align bore. Since the three caps are connected together, it adds another dimension of needed alignment accuracy. But I am most concerned with the side-side variability of manufacturing, rather than the vertical, as this would result in two offset semicircles whose alignment could not be rectified by simply removing a few thousands and reboring. Then, there is also the question of the thrust surface. However, I did try a test fit of the housing from another complete head, and everything looks very close. With some effort, the cam was rotatable after assembly, so I am confident it can be made to work. The biggest obstacle may by obtaining a substitute housing.

I will PM you regarding my trip.

Steve
 

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I'm happy that facing both surfaces and doing a line-bore would true everything up nicely. However, a cam is not taking the type of loads seen by connecting rods, so it is possible to have a bit more variation in clearances and have everything work out. We had to straighten my head for the FNM, which result in the cam bores being out of alignment. We were able to relieve the front and rear caps just a touch giving me good turning with an acceptably tight clearance. A better result would have come from line boring, but the FNM does not have the round entry point at the rear like the 102, thus requiring a very specific tool to do a true 3-bearing line bore.

I've seen cam caps for FNM's for sale in Brazil, and they will fit. I'm sure you'll find what you need with some perseverance.
 

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Not that critical!!

As must now seem obvious to members of the BB (Mr. Peterson suggested I seemed content merely in fixing my car so I could get to a job as greeter at Walmart), I have seemed over the course of years merely content in keeping my two liter cars running instead of making them beautiful.

I cannot deny that (except for the Walmart job). I used one as a daily driver from December 1964 to March 1990. That means I worried about keeping it running. Truth is, I always had more than one, and would fix one while I ran the other or others. They have very simple engines with cast iron blocks. The pistons "rock" and slap and wear out. The crankshafts are not nitrated and hardened. The valves (unless you fit stainless steel ones in a rebuild) run only 25,000 before need to redo a head, and 50,000 miles is about the limit on the crank for the bottom end. Fixing them is not rocket science, but without some way to harden the journals and fit better valves the engine has inherent limitations. The oil pan baffles will not prevent the oil from running to the sides and starving the bearings if run hard on the turns on a track. Don't see much financial sense in sweating the small stuff. Just get them running so you can enjoy them.

But concerning this problem of what I call "cam bridges" I confess that I ran a head with the wrong set of bridges for more than the expected head life of 25,000 miles. Later when I was redoing that head after replacing it with another I had sitting ready, I discovered that there were stamped numbers matching the block with the two bridges. So I carefully examined the wear on them and found nothing unusual. Then I checked around and found the right head and took the bridges off of it and put them on the other head that had the right ones for the head I was redoing. Luckily that was the extent of the mixup because I only had to redo the clearances on three different heads. Since then I have been more careful, but I've kept the right pieces together ever since. Still, I never noticed any resulting problems. It was certainly a greater improvement to start using stainless steel valves with other than 10mm value stems so I could fit stem seals Always used to frustrate me that even with a carefully redone head that the engine was burning oil sucked through the valves.

Face it, the journal surfaces of head and both bridges are aluminum, and the cam is steel and the oil is under pressure. It did not seem all that critical, then and still doesn't. It is not a race car, and it makes no sense to run the engine above the red line. But, now that these cars are of such great value (they once were available in the $500 to $600 range), perhaps I will have to figure out a way to see if I can spend more money on keeping them pretty so I don't offend everyones sensibilities.
 

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Jay,

Actually, I fear the Walmart greeter job is in my future. In fact, it is one of my goals. I hope to set the record for being fired the quickest without actually raising my voice or touching anyone. Only now do I realize that I must drive my still-running 2-litre to work that day. Imagine Arte Johnson circa mid to late 60's.

I've had Renault aircraft engines nitrided (not nitrated - that would produce some variant of salt), and it produced a pretty impressive result. The original engines used a lead-babbitt bearing, but newer babbitt material is high nickel with no lead, so is much harder. Thus we decided to bump up the hardness on the crank so it wouldn't become the sacrificial element. Time will tell. No problem to do a 102 crank. Not cheap, though.

So - you recommend intake valve stem seals? Hmmm. I've got two heads at the shop now. I'll see if they can organize that.

I'm headed to the northern tip of Idaho tomorrow to pick up the float plane. If the weather turns crap we'll head east and come to your place for a visit.
 
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