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

[Mark Dubovick <mutant1@domain.elided>]

Russ,
    thanks for confirming my suspicions. The first two oil galleys were drilled
"free hand" something I've had a lot of practice at - while the subsequent two
galleys will  need to be done on the drill press. Drilling out the last three oil
plugs which exist in the block to clean out the internal parts is an excellent
idea. I thought about that as I looked at the block but was uncertain of
reclosing the openings. Down here in Tampa, Fla. I can't find a mechanic who will
recommend any shop for machine work although I may have stumbled accross one.
They turned the crank for me and it seems pretty consistent accross each journal
and from journal to journal. They have a reputation which generates a lot of race
engine work for them. If you have any recommendations I'd like to hear them.
    Thanks again for the thorough goings over of my engine bearing questions. I
hope to run into you at one of the Alfa events.
    Sincerely,
    Mark

AlfaNeely@domain.elided wrote:

> 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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