Firewall Penetration & Dry Sump Requirements

[the337]

I'm in the process of performing an engine swap (Nissan VQ37) into my 2000 E46 BMW and have a couple of queries while I'm planning my next moves.

Firewall Penetration:
I'd like to create a new opening through the firewall to route the engine harness into the cabin where the ECU will be located. As you can see in the image, the intention is to go through the factory location where the left hand drive model would have the steering column (or brake booster ?). It looks to me like this is a single thickness of steel only. The opening would be approximately 60-70mm in diameter to get the required plugs through. Are there any do's / don'ts or guidelines around doing this ?

Dry Sump Plumbing:

As part of the swap I've had to covert to a dry sump setup to avoiding touching the factory cross member and steering rack. Is there any specific guidance around what is needed for certification when using a dry sump setup, particularly around crank case ventilation and the factory PCV system etc ? With the pump I expect to actually be pulling a slight vacuum on the crank case (naturally aspirated engine) and I'm hoping to simplify things as much as I can so will be looking to reduce all possible associated factory and dry sump plumbing.

[Chris]

Oct 21, 2021 19:55:21 GMT 12 the337 said:

I'm in the process of performing an engine swap (Nissan VQ37) into my 2000 E46 BMW and have a couple of queries while I'm planning my next moves.

Firewall Penetration:
I'd like to create a new opening through the firewall to route the engine harness into the cabin where the ECU will be located. As you can see in the image, the intention is to go through the factory location where the left hand drive model would have the steering column (or brake booster ?). It looks to me like this is a single thickness of steel only. The opening would be approximately 60-70mm in diameter to get the required plugs through. Are there any do's / don'ts or guidelines around doing this ?

Dry Sump Plumbing:

As part of the swap I've had to covert to a dry sump setup to avoiding touching the factory cross member and steering rack. Is there any specific guidance around what is needed for certification when using a dry sump setup, particularly around crank case ventilation and the factory PCV system etc ? With the pump I expect to actually be pulling a slight vacuum on the crank case (naturally aspirated engine) and I'm hoping to simplify things as much as I can so will be looking to reduce all possible associated factory and dry sump plumbing.

View Attachment

Hi there

Firewall question, providing the hole does not weaken the structure then the only requirement is that it must be suitably sealed to prevent exhaust gases, vapour, and liquids from entering the passenger compartment.

Dry sump question, your vehicle must be fitted with an operational positive crankcase ventilation system, which draws gases from the crankcase and directs them back into the engine. I'm not completely familiar with dry sump systems but my basic understanding of them is that relying on the dry sump system alone would not this requirement.

Cheers

Chris

[the337]

Thanks for the feedback Chris ... regarding the firewall penetration, how do I (or certifier) determine that the hole has not weakened the structure ? Is there anything to go by or is it down to a bit of common sense around the location, size, quality of the job etc ?

[Chris]

Nov 4, 2021 18:34:04 GMT 12 the337 said:

Thanks for the feedback Chris ... regarding the firewall penetration, how do I (or certifier) determine that the hole has not weakened the structure ? Is there anything to go by or is it down to a bit of common sense around the location, size, quality of the job etc ?

I believe the certifier would concentrate more on where the hole is cut, but something best discussed with your certifier before you start.