Carbahn 4.6L Stroker build/long term review

[e90sanmarino]

Originally Posted by omgzirra_exe

Yeah, that noise is pretty much normal for "built" forged engines, and this is something I always mention. However, I'm curious as to what Carbahn will say, since VAC told me the noise was normal with forged components. I don't disagree with that, as I heard the same type of noise in my 2.3L stroker Evo 9, but didn't hear that noise in my stroked "F22C" from F20C (.2L stroked using OEM F22C crankshaft and OEM F20C pistons/rods), which only reinforces that it's limited to just the aftermarket forged parts from personal experience.

You can somewhat mitigate that with different oil, so you can test it out. Like I said, for me, I found Redline/300V 5W50 made things quieter, but I live in SoCal. Your mileage may vary in VN.

However, I still hear the noise if I'm putting my ear against my hood or fender on cold starts.

Thank you for your detailed response. I believe the fact that I am still using break-in oil may contribute to the noise. I will continue to monitor both the sound and the oil closely. As you mentioned earlier, during this stage, it's natural for a sense of heightened concern to set in

[Redd]

Curious due to the piston noise, is it necessary to warm up the car until the noise goes away before driving off?

[spammysammich]

Originally Posted by Redd

Curious due to the piston noise, is it necessary to warm up the car until the noise goes away before driving off?

Driving gently will warm up the oil faster than idling.

The cast pistons used in a lot of these modern high performance engines are often dismissed as being inferior for the application and yes, they are less resistant to knock than forged slugs. But they maintain PTW clearance and run much more quietly than forged. Pick your poison.

[amrazM]

Originally Posted by omgzirra_exe

Yeah, that noise is pretty much normal for "built" forged engines, and this is something I always mention. However, I'm curious as to what Carbahn will say, since VAC told me the noise was normal with forged components. I don't disagree with that, as I heard the same type of noise in my 2.3L stroker Evo 9, but didn't hear that noise in my stroked "F22C" from F20C (.2L stroked using OEM F22C crankshaft and OEM F20C pistons/rods), which only reinforces that it's limited to just the aftermarket forged parts from personal experience.

You can somewhat mitigate that with different oil, so you can test it out. Like I said, for me, I found Redline/300V 5W50 made things quieter, but I live in SoCal. Your mileage may vary in VN.

However, I still hear the noise if I'm putting my ear against my hood or fender on cold starts.

mostly any built engine with forged pistons there will be way more account for thermal expansion which is why we get these noises

[omgzirra_exe]

Originally Posted by amrazM

mostly any built engine with forged pistons there will be way more account for thermal expansion which is why we get these noises

yes sirrr not a pleasing noise every morning hahah

[e90sanmarino]

I have completed the oil change today at 160 kilometers (100 miles). I am pleased to report that there are no significant metal particles present. There are still gold flakes in the oil, which is to be expected.

Moving forward, I intend to raise the engine rpm to 5500 and limit throttle to no more than half until reaching 800 kilometers (500 miles).

Here are the clips of the break-in run (1/3 throttle) and the oil:

[charliev68]

Is the piston 2618 or 4032?

[e90sanmarino]

Originally Posted by charliev68

Is the piston 2618 or 4032?

I have no idea. Carbahn does not specify which pistons they use

[e90sanmarino]

I wanted to provide a quick update. Today, I received an email from Mr. Dinan himself, confirming that the cold start noise is completely normal.Here's screenshot of the email:

[e90sanmarino]

Please find attached a clip demonstrating light acceleration, shifting from 2nd to 5th gear. The combination of the Stroker with the Eventuri plenum is truly a match made in heaven. In this clip, I utilized 1/3 throttle and shifted at 5000rpm.

[spammysammich]

There is a rhythmic clicking sound for a good portion of the video that sounds like nothing I’ve ever heard before. Are you sure this is a BMW? /s

Sounds great.

[e90sanmarino]

Originally Posted by spammysammich

There is a rhythmic clicking sound for a good portion of the video that sounds like nothing I’ve ever heard before. Are you sure this is a BMW? /s

Sounds great.

Thanks man. Yeah it’s a secret mod, only non BMW drivers will appreciate