Alfa Romeo Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
148 Posts
Discussion Starter #1
I am mounting new pistons in my 1.6 engine, they dont have any arrow indication for mounting position, how can I check that i have mounted them rightly?
 

·
Super Moderator
Joined
·
11,210 Posts
If there is no wrist pin offset, and valve pockets are the same size, they can go either way.
 

·
Registered
Joined
·
148 Posts
Discussion Starter #3
I am not sure if Alfa pistons have or not any offset, but the shop manual talks about an arrow...
 

·
Moderator
Joined
·
9,923 Posts
I am not sure if Alfa pistons have or not any offset, but the shop manual talks about an arrow...
What Gordon is saying is that if the pistons have an offset or different valve pockets, then they will have an arrow. But if they don't have an arrow, then there's no offset/asymmetry, and you can install them either way.

I don't know what manual you have, but many Alfa manuals cover a lot of different models. I believe that back in the days of 1600 cc engines, wrist pin offsets hadn't been introduced yet.
 

·
Super Moderator
Joined
·
11,210 Posts
Actually the offset wrist pins were used on older engines (1300's) for better low speed torque.
It actually worked! My 101 1300 Veloce race car used offset wrist pins and pulled better from low speeds than othere cars with centered pins in forged pistons. I believe my 1300 Veloce pistons were cast Borgo, but as this was MANY years ago, I can't be sure.
 

·
Registered
Joined
·
148 Posts
Discussion Starter #6
These are my pistons:

But to remove any doubt, since the head is not mounted, i will take one piston out an check it...
 

·
Super Moderator
Joined
·
11,210 Posts
Check TWICE, assemble ONCE. Smart! If they are offset, and assembled backwards, the engine will run just fine, but generate unusual heat and feel "dead" (no power) in driving.
Don't ask how I know that.
 

·
Registered
Joined
·
148 Posts
Discussion Starter #8
Check TWICE, assemble ONCE. Smart! If they are offset, and assembled backwards, the engine will run just fine, but generate unusual heat and feel "dead" (no power) in driving.
Don't ask how I know that.
I am curious how do you understand the cause of why it unusual heat and feel "dead" (no power) in driving. :grin2:
 

·
Super Moderator
Joined
·
11,210 Posts
Because in a HURRY at a race track, I re-installed offset wristpin 1300 Veloce pistons backwards. My earlier WINNING race car then LOST, and I came in with heating issues. Tore it down again, noted my error, reassembled and went on the next day to three wins.
If it ran great, then does NOT run great after you did "something", you did "something" wrong. (usually.)
From my experience.
 

·
Registered
Joined
·
148 Posts
Discussion Starter #10
Experience is the hardest kind of teacher by Oscar Wilde

I checked my pistons, and they don't have any offset...
 

·
Super Moderator
Joined
·
11,210 Posts
Yes, but making MISTAKES is a learning experience, where accidentially getting the job right, without knowing "Why?" is the basis of future errors. (Gordon Raymond)
Life is a great learning experience to those that pay attention.
 
1 - 11 of 11 Posts
Top