Conrod lenght on 2,7 T4.

[T41303]

Im am now collecting parts for my 2666 cm T4 engine. The crank is a oettinger 80mm and I am planning to use a Mahle 103 kit with 22 wrist-pins.

So the question is.. Anyone that have any clue about rod-lenght that is usable for this setup?
Another question I am thinking of is if the 48 IDF will be to small , or will they work just fine on a 2666 with max rpm. 6000-6500 ?

[Wally]

Originally Posted by T41303

Im am now collecting parts for my 2666 cm T4 engine. The crank is a oettinger 80mm and I am planning to use a Mahle 103 kit with 22 wrist-pins.

Actually, most all rod lengths will work. I like a larger rod ratio, so I would suggest 5,5" or larger. I had an Oettinger 80mm crank and used 5,7". Just don't use the original rods, which will be tempting as the journal diameter of your Oettinger crank is 50mm, same as stock 2.0

Another question I am thinking of is if the 48 IDF will be to small , or will they work just fine on a 2666 with max rpm. 6000-6500 ?

Depends on your cam and heads. If you are going to make more than say 190 hp, then 48 IDF's will be restricting, even with 40 or so vents. I have seen it myself they restrict above 200-220 hp, and my guess is they leave hp on the table below that as well, hence the hp-guesstimate they will work up to.
Most engines work very well though with them and the only upgrade would be EFI with 45 or 48mm Throttle bodies, so your must really upgrade heavily or leave the 48IDF's be and see what they make.

Regards,
Walter

[T41303]

I think I will be using the 48 idf then, because this is not going to be a wild track-engine, but rather a reliable street-engine with a bit more focus on reability than wild rpm.
Another thing, do I have to take off some material innside the crank-case or cam for the 80mm stroke? What rod-lenght gives the least job?
Maybe I will go for the QSCUSA nickies and JE-pisons instead of the the Mahle, is there anyone that have any experience with the QSCUSA barrels and the JE-pistons?

I think the setup for the engine will be about like this :

80mm oettinger crank with 5,6 or 5,7 H-profile rods from CB, maybe there will be rods from Audi RS2, then the crank will be regrind to 48mm insted of 50mm.
JE 103mm pistons with 22mm wristpin and 103mm nickies from qscusa.
324 degree cam from german Schleicher with HD alu pushrods 1,7 std. rockers (8mm)and 911 swiwelfeet on Scat HD single springs.
Block machined for T1 lifters with Scat lube a lobe-lifters.
Heads will be CU -heads with 46 / 38 valves
The comp. I think I will have between 9,5 and 10.
Exhaust will be B.A.S complete system.
Carbs I think will be 48 IDF then.
And when it comes to the clutch I am a bit uncertain , will a 200mm cushlock with kennedy pressureplate be ok for this?

I am thinking that this setup should give a +/- reliable 200 hp street-power.

Would some of you have changed anything in this setup?