Re: alfa-digest V7 #1213 - Alfa Main Bearings

[AlfaNeely@domain.elided]

In a message dated 12/13/1999 7:15:11 AM Central Standard Time, 
mutant1@domain.elided writes:

<< Subj:     Re: alfa-digest V7 #1213 - Alfa Main Bearings
 Date:  12/13/1999 7:15:11 AM Central Standard Time
 From:  mutant1@domain.elided (Mark Dubovick)
 Reply-to:  <A HREF="mailto:mutant1@domain.elided";>mutant1@domain.elided</A>
 To:    AlfaNeely@domain.elided, alfa-digest@domain.elided (alfa-digest@domain.elided)
 
 Russ,
     I have one more question for you. I've drilled the oil ways through the 
tops
 of the journals(#2 & 4). Do I also have to drill the lines through the 
casting
 perpendicular to the crank shaft. It looks as though the other three have 
drill
 spots which have been filed while these two do not. Also if this is to be 
done
 how do I fill the drilled areas on the side of the casting.
     On one other related issue, should i have the crank heat treated or 
nitrited?
 
     Thanks for your help,
     Mark >>

    The three factory oil passages are drilled all the way from one side of 
the block to the other.  The intake cam bearing oil passages come up from the 
intake side of the long holes across the block on 1, 3 & 5 mains.
    You do not want to drill all the way across the block by hand, which is 
why everyone drills from the exhaust side.  There is a small boss just under 
the top horizontal rib in line with number 4 main.  That is where you drill 
number 4 main.
     The number 2 main on the 1600 is drilled within the oil filter base 
mount.  I just looked and it appears you would drill just under the front 
stud that mounts the oil filter.  On the 2000 the hole is drilled right below 
the oil pressure sender, or through it if you have a steady hand.  You do 
have to put set screws in the outer end of the passages you drill.
    Some sets of main bearings have full oil grooves on all main bearings.  
Some sets have grooves only on the wider 1, 3 & 5 positions.  It your mains 
are fully grooved, all you have to do is drill the 2 and 4 mains.  If not, 
you may want to shop around.  Centerline did not have fully grooved mains for 
my 2000 and the parts guy really did not understand what I was asking when I 
wanted him to open a set of bearings on the phone.  I got a set from IAP.

      I also drill out the factory plugs in the three existing oil passages 
so I can clean them with engine cleaning brushes from Eastwood ( 
http://www.eastwoodco.com/index.html)  JC Whitney or others may have engine 
brushes or go to a gun shop and get rifle cleaning brushes.  I then tap the 
ends of the passages and Loctite set screws in the holes.  Get aluminum set 
screws if you can find them.  Just make sure all drill cuttings and such are 
washed out.

    I have done the above only on two 2000 engines, but the Alfa four 
cylinders are pretty much all the same, sort of.  I will do it to my 1600's 
when I get around to building my two 63 Giulia Spiders.

     On the crankshaft for my 84 spider race car I did have the crank ground 
0.010 / 0.010.  I did have it re nitrated afterward.  I also had the oil 
outlet holes chamfered to increase oil flow out of the crank.  The sharp edge 
of the oil hole impedes flow slightly, so the chamfer helps flow.  You could 
have the journals cross drilled to provide 4 outlets per journal rather than 
the stock two.
    As I recall, the 2000 cranks have a radius in the corners of some or all 
the crank journals.  The 1600 does not have these, which is why there are 
different bearing sets.  You could have your crank ground with a radius, 
which reduces the chance of a stress crack and use 2000 bearings.
    Make sure to replace the six aluminum plugs in the crank with set screws.
    I had my connecting rods magnafluxed, shot peened, the beams were 
polished, the big ends were resized and made round again and new bushings 
were put in the small ends.  My block was align honed to make all the bearing 
journals straight.  And of course, the whole rotating assembly was balanced.

    So what else can you do?  Heat treat?  Cryogenic treatment?  How many 
dollars you gots?  Check out Jack Beck's available services at 
http://www.orionmotorsports.com/  Or check around a large airport for a shop 
that does air plane engines.
    What part of the world do you call home?  I might be able to refer you to 
some experts closer to home.
Ciao,
Russ Neely
Oklahoma City

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