Re: Spider engine in car rebuild-LONG

[Wille R Scandinavia <veloce@domain.elided>]

>Date: Wed, 7 Apr 1999 07:38:40 -0700 (PDT)
>From: "Dave M." <doc1590@domain.elided>
>Subject: Spider engine in car rebuild-LONG

Sorry about the long posting, but here is my 0,02

Step one is to certify that the pistons are the problem. Have the 
compression ratio checked when the engine is hot. The ratio should 
be the same on all four cylinders. 
Pour some engine oil in the spark plug hole and check the 
compression ratio again. If the ratio is increasing, the rings may 
be leaking. If the ratio is almost the same, the valves and the 
head need attention Remove the head and the sump. No need to 
remove the engine for this kind of operation. 
Place a hydraulic jack and use a piece of wood under the oil sump 
so you do not damage the alloy fins. 
Loosen the engine supports. 
Raise the entire engine as much as possible. Normally it's enough 
when the gearbox hits the body, so you may place something between 
the engine supports and the engine bay. 
 
Then raise the entire car and use supporting jacks for safety. 
Never ever work under the car if it's not secured by jacks. 
If you haven't already drained the engine oil, this is the time to 
do so. Otherwise you will need to wash your hair in kerosene. 
Undo the bolts and nuts securing the sump to the engine block. 
Gently draw the sump forward to get access to the crankshaft. 
>From underneath the engine, remove the bearing caps and mark them. 
They are already stamped with the number of the cylinder, but just 
to be sure ... 
Start with the bearing caps on the second and third cylinders. 
They are at their bottom dead point if you have done the right 
thing. 
Slowly turn the crankshaft 180 degrees until the first and fourth 
bearing cap is at their bottom dead point and remove these too. 
On the Alfetta and 75/Milano overhauling is even more easy. Just 
raise the car and remove the sump. 
 
Be careful so you do not damage the bearing surfaces of the 
crank-shaft and gently press the pistons upwards. Cover the 
crank-shaft bearings one by one while working. 
Mark the pistons so you know which is # one etc. 
Check if the pistons are of the offset kind. If so, there is an 
arrow on top of the piston. The arrow shows the direction from 
intake to exhaust, so be careful not to turn it the opposite way. 
If your engine is so old that it has the non offset pistons, I 
would replace them with newer ones. The Alfetta 1,8 pistons are 
excellent and easy to find. Both liners and pistons will fit your 
engine like new. The next photo shows the Milano engine with the 
liners removed, dots. As usual, the engine is still in the bay. 
Milano engine, liners removed 
 
Be careful not to damage the surface when you remove and change 
the rings. 
There are several tools for this purpose, but you own hands might 
be OK too. 
The rings are marked "TOP" etc. Have a look in a workshop manual 
if in doubt. 
Remember to keep the openings of the rings away from each other, 
i.e. 120 degrees. 
To remove the liners you may try just to press and draw them 
upwards. There are special tools for this purpose, however some 
are expensive. I use an old piston with the top ring on. Put it up 
side down in the liner until the top ring is expanding and then 
use a soft hammer and a piece of wood to remove them both. 
Remember to use an old piston, not the new one. The next photo 
might give you the idea. 
Liner in block 
 
Inspect the liners for scratches etc. Replace all if necessary. 
Use your fingertips to check them. 

Clean the bottom of the liners as well as the engine block, but 
remember the bearings! 
Replace the O-rings with new ones. Do not use more than one per 
liner though. 
There are steel shims available for diesel engines if your liners 
are too short. Once, I used a set from an IVECO diesel engine. 
That car is still running, BTW. 
The liners normally do not need any sealant, but since it is not 
that fun to open the engine again if it is leaking, I use a little 
bit of sealant. It is very important to keep the engine absolutely 
clean. 
Check that the liners are about 0,05 mm higher than the engine 
block, every one of them. This is what I have learned the hard 
way, believe me. Have a look in the Alfa Owners Bible or any 
workshop manual. 
I do the operation with the engine in the bay, it is not that 
tricky. 
Finally, have the head overhauled at the same time. Valves, guides 
etc. may need some attention too. 
Clean the pistons. Then take them to your local grocery shop and 
check their weight one by one. Unless you have a weighing-machine 
of your own.

There should not be any difference between them. If so, see your 
local Alfa Service station.

Saluti		Wille R
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