connecting rod length for a 2.5 16v

[dennisbots]

Hi,

I found a strange thing when i opened my engine.

Everybody is telling me and all information i have seen tells me that a connecting rod from a 2,5 16v has a length of 152mm from center to center.

Now i have taken 1 rod out of my engine and that is a 149mm rod.
So that's the same as an 2.3.

It is one of the first 2.5's. 1989 kat version.
The head is 100% sure of an 2.5.
And the rest of the engine to i think.
No sign of a swapped head to an 2.3 engine or something like that.
The piston is 1mm under the cylinder deck @ TDC

i checked on my engine and the number i found is;
102990 10000 702 ( AN UPSITE DOWN 3) 9,7
And the crank has 4 counter weights and has a stroke of 87,2mm
Piston is 95,5mm
So that should be an stock 2.5 to my knowledge.

So are there different rod lengths for the 2,5?
Or are the ruf and kat engine's maybe different?

Greetings Dennis Bots
(sorry i wright in English, my German is very bad but i can read it tho)

[JM Motorsport]

CC length on the 2.3 should be 145mm as far as i know. Piston should be aprox 1mm below deck surface at TDC on the 2.5, so it all seems ok.
.3mm, are you sure you messured correctly?

[Henger]

So are there different rod lengths for the 2,5?
Or are the ruf and kat engine's maybe different?

Greetings Dennis Bots

Hi Dennis,

there are no different rod lengths or any other mecanik parts inside the engine between the RÜF and KAT version.

Gruß Fränk

[Johan.c]

Dennis, Im sure that your piston should be 0,7mm below deck OEM.
1mm is also wrong.

When you messured your rods, did you messur from the midelpart wear the connecting rod splits part? (wear the bolts should be)

[dennisbots]

No i measure like this:
the big end (crank) is 48mm in side the bearing
the small end (piston fit) is 22mm.
The measure from the small end to the big end (not cc) but the smallest measure you can take is 114mm.
So 48mm / 2= 24mm
22 / 2 = 11mm
so its 114 + 24 + 11= 149mm
(I will try to make i picture to make it clear)

[dennisbots]

[Johan.c]

Dennis.... take away the bearing!

1. split the big end so you take away the bottom part
2. take away the bearing from the top part in the big-end
3. place the rod standing on the flatparts beside the boltholes
4. take your milimeter scale and place behind the rod
5. what dose the messurment in the center of the smal end say?

[Johan.c]

Better explaning: Vertical lines on big & smallend= CC = Center to center

[dennisbots]

still is 149mm
Also the engine looks like it is never opened before.
Every thing looks stock.

[dennisbots]

I forgot to look before but the part number on the rod is 102-08 and then on a 90degree turn a big 1 and a small 2.

on the bearing is written 102 4211

[dennisbots]

Turns out that more 2.5 16v's have the 149mm rod.
Joreto from Bulgaria has wrecked an rod because he went over his hp limit and has measured a rod that is also 149mm.

I think the first 2,5's have the 149mm rod and the later 152mm.
And they have different compression heights in the piston.