Interesting parts: Blank 101 1300 block

It appears that I have an opportunity to buy an 00120 block with a number appropriate to by SS.  Exciting? Yes! Well, to help make it happen I am selling off some of the more interesting bits in my collection of spares. Among them is this block, a blank 101 1300 in fantastic condition.

Before I get into the details of this particular block I should address the subject of blank blocks in general. I have seen these, or cars with them under the hood for sale occasionally and the story often attached to them is that Alfa’s procedure for catastrophic failure (thrown rod, broken main support web etc) called for the replacement of the parts with new factory parts. If the block was damaged, you got a new one.  I don’t know if the replacements were short blocks, or blocks only to which any required parts were added to replace any unable to fulfill their role, but in any case, what came out the other side was an engine without an identity.  Like that seen here.  Why no number?  Something to do with accounting perhaps.  Maybe they were supposed to stamp the new block with the old blocks numbers, but the dealers never received the stamp set.  Anyone know more?

Starting from the part you see at the end of the build, the outside. You can see this is a pretty nice block.  In better shape than any of the blocks I’ve built up before.  I would paint the dipstick tube if I were building this.

And here is the boss that normally wears the number, 00102, 00120 or otherwise. I am not sure how the subject of forged (00120) versus cast (00102) main caps was addressed as they required being machined together, and for that matter the 00120 block is shorter, requiring a machined to match front cover.  My parts book lists different part numbers for Veloce and Normale blocks so perhaps they are not related at all.

Here’s the exhaust side.  On a 1300 there is not much room between the lower header flange and the oilway just below the head gasket sealing edge.  I was going to use an after market header on my Sprint 1300 but it wouldn’t fit.  Threaded hole in the upper right hand corner of the block in this picture is the coolant drain cock pass through.

On late model 1300’s the engine number is stamped on the face of the bell housing flange seen here between the middle and upper bell housing mount bolts.

This is the timing case side.  Note the part number of the engine casting: 10100-011000.   When building one of these it’s important to remember the oil seal that seals the opening just above and to the right of the crank opening on mating face.  Seal goes in a pocket on the front cover.

This is the mounting face that would be under the flywheel, inside the bell housing.  The opening is part of the oil galley.  I think this cover is there to provide access to clean the breather labyrinth area out and probably also allows for some machining efficiencies.  The studs are all m8 x 1.0 thread.  A spacer goes between the bell housing and engine block.

Block and mains are all marked 246, a matched set.  Normally the front cover is stamped with this number too, but the front cover from this engine was stamped 500.  Did the blank blocks come with matched covers?  I assume so…  Note presence of factory washers and nuts.

A little better view of the cap stampings.  Note the position numbers below the ‘set’ numbers.  These correspond to numbers stamped in the block in the same orientation -good idea to match these up. These castings represent 4 part numbers, 101100110700 for the end cap with the cigarette seals that’s visible here.

Here is the sides of the main caps you would see looking past the timing side from number one piston hole to the end cap.  Another part number, on the number 4 cap is visible as 101100110500.  This casting is the same as the number 2 cap, but once the set has been matched to the block it has a permanent position and orientation.  The number 3 with oil pick up mount ears and number 1 both have oil passage ways machined into them and have different part numbers as well.  Note the casting symbols on the caps -these probably indicate material and who made them.

You can see in this picture the main studs, the positioning collars at the base of the studs that assure the caps are aligned to the block, the oil passages for the odd numbered mains, the dip stick hole at the number 3 position, the thrust washer cut outs on the number 3 main support, the structure of the main webbing and more.  I liberated one of the oil pan studs, missing here from the lower right corner, for my 00121 build.

I’ve seen blocks with the webbing that supports the mains broken so it’s important to inspect this area on a block you are considering rebuilding.  Usually this failure accompanies a broken crank which happens when the radiusing on a regrind of the crank is not done properly. Dominos.

The top side.  There are a lot of things that can go wrong in the water jacket area.  Studs can corrode, the liner seal bevel where the base of the liner meets the block can be corroded -basically anything in contact with the coolant/water can corrode.  The three holes in the lower right corner are oil passages so it’s important to put sealer on both sides of the head gasket where it goes around these Alfa’s are known for failure associated with oil and water mixing to produce a not-very-effective lubricant.  That’s my recently assembled 00121 engine for my SS in the background.

Looking down and in at cylinders 1, 2, and most of 3.  The rusty film is residue from the coolant drying out of the engine 30 years ago, and looks strikingly orange because for some reason a camera flash  accentuates rust color.

The other end.  At the base of the upper left most stud is a little pocket which makes a low point and is opposite the coolant drain cock hole seen in the third picture above.  It occurs to me as I’m looking at this that those two blind holes between 3 and 4 (and in the previous picture between 1 and 2) are probably to allow cooling water to get nearer the main bearing there since they don’t have forced oil lubrication like 1, 3 and 5.

It’s hard to see how nice the studs and liner seal surfaces are in the above pictures so I took this one.  I also turned off the flash so the rusty powder residue wouldn’t be so strikingly displayed.  If you have built a few of these engines, you know how nice this one is looking at this.

Here you are at the end of the pictures and you are wondering why I went so much into this block.  Truth is, I’m going to put it on eBay before long and wanted to document it because it’s pretty interesting.  I wasn’t going to include the front cover with it but now that I have given it some thought I think I will. Maybe they were matched in the process that saw the building of this engine in the first place.  The head and oil pan gasket surfaces were very well matched and the timing gear turned freely but without any play, indicating a good fit.  Anyway, I’ll add pictures of the front cover and update this post with a link to the auction when I go for it.  In case you are wondering; the head was uncut, measuring 4.410 (reserved for the 00120 build) and the crank was main .010/rod .020.  I would enjoy feedback on all this as I am still figuring it all out.


5 thoughts on “Interesting parts: Blank 101 1300 block

  1. The story regarding the blank number blocks being replacements is correct. In the early 70’s my brother ordered and purchased a new 1600 block from the local Alfa Romeo agents, and when it arrived it had no number on it, and the agents had no idea what to do about it. To this day it is in his Giulia Sprint GT, and still without a number!

    Mike from sunny South Africa.

  2. I’m surprised the #3 main cap has the ears for a normal’s
    oil pump pickup. You’d think they would leave that off if veloce caps are forged and the ears not required for the veloce oil pump.

    San Antonio, TX

  3. I regularly look at your very informative web-site because I’m restoring a 1600 Sprint 101 here in England. Regarding the oil supply to the main bearings I believe the 2 and 4 get a presure feed via the crankshaft. Don’t know what the blind holes are for – could they be for some ingenious tool to pull the liners out or maybe something to do with the cores during casting. Keep up the good work!

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