ALFAGTV6.COM

[matt]

Whats wrong with this picture?


This side of the con rod was facing the inlet side of the motor when removed. In the process of rebuilding i noticed the offset is the wrong way, it should be towards main bearing 4 right? and this being the case i read somewhere the electro etched numbers done by alfa originally are on the exhaust side too, proving this rod was offset the wrong way, so if this is the case this short block has been rebuilt twice(added punched markings) with #3 con rod the way! The other rods are ok

So is this rod suspect for futher use due fatigue, twisting moment etc

or am i splitting hairs and should install it the right way and get on with it?
Thanks Matt

[Mats]

If it was indeed fitted to cyl 3 the larger lump would have pointed towards #4 and the etchings is towards the exhaust. Or did you mean something else?

[ ] [ ] <- They should be like that.
1 2 3 4

[TS_turbo]

Hi
if rod offset is wrong rod small end will be not centered in the piston pin when instaled ... just put pistons(without rings is easier) and rod and bolt
rod to the crank and see is it wrong or not ... you can compare to other instaled rod pistons for centering on piston pin

[junglejustice]

The rod off-set on the Alfa V6 motors is ABSOLUTELY important and a common mistake that inexperienced engine builders make... (Not that I am experienced in this - just that I am fortunate enough to have someone with probably 500 or 1000 Alfa V6 rebuilds under his belt that taught me the important stuff from day#1 !)

I saw one come in where the motor actually started, ran for a short while and then within seconds on the dyno - BAM - it was all over...

The off-set pushes the piston up against the one side of the cylinder-wall...

Because this rod has seemingly been installed backwards once before AND since the rod-cap appears to have been flip-flopped as well (and now everything has been re-marked), I would be reluctant to re-use these rods!

NOS 12 valve rods are cheap. Heck, NOS 164 rods have slightly better metal-composition and the design on the later models is marginally improved... (Not that there was ANYTHING wrong with the older design or metal...) The main advantage to using NOS Milano/75/GTV6 rods, or even better - using some used or NOS 164 24 valve rods - is mainly that you would gain a less stress-fatigued rod....

Alfa Heaven has a set on there website for 20 bucks a rod...!

I have Pauter chrome molly forged steel for 220 a rod and Carrillos run about 300 a rod... New OEM rods run around 150 per...

While you have the stock rods - if so inclined - or some NOS rods in hand, have them shot peened and then nitrated/plasma heat-treated... Will help te cause down te road when you want to go SC or big-bore or higher compression...

[Mats]

So, is this for a V6 or a Nord?
I was assuming Nord

[junglejustice]

Funny... I was assuming V6... Don't know about the Nords but the V6s have this same off-set and it has come back to bite many guys...

[matt]

Its a nord, thanks for the advice, i was very careful removing everthing to ensure no mistakes and correct alignment etc etc, but in this case its been previously rebuilt/stamped with # 3 wrong! i only picked this up because when i looked up the bore from below the piston was over to one side not centred, and after checking the markings that had been stamped on the cap and rod i realised it was the wrong offset..........
So i've done at least 5000km since i've owned the car and who knows how many kms before i bought it with #3 rod wrong
So should i replace this one or use it, i assume little end/wrist pin and even the liner wear quickly if not fail! or are these rods strong enough to last just have to check little end bearings etc
When i attached piston and then holding the con rod side ways allowing the piston to "tilt" (not too quickly) and have no 'play' but maybe this check not good enough??? for little end - wrist pin

Thanks Matt

[Barry]

Matt,Simple
On the Nord-1+2 ofsets face one another and 3+4 face one another.
Dont hassle with numbers or etchings ..

easy..

[Barry]

On the v6-
cyl1-2-3 the ofsets are facing the rear
cyl4-5-6 the ofsets are facing the front.

[Barry]

To check a small end push to pin clearance..
Fit the pin to the rod ,one end pin and bush flush,other pin sticking out.
Take 2 fingers and knock down on the pin-now knock up on the pin-if you hear a tak,tak sound you have too much clearance..

[matt]

Ok thanks Barry i'll do that and post progress

thanks Matt