Cold air induction experiment

[Alspos]

My 308 VK has a cowl hood and a whopping hole in the bonnet courtesy of the previous owner. I figured I'd experiment and see if I could make a cold air induction system and utilise what I have.
1. Started with a bucket that's close to what I want.
2. Fibreglass (messily)
3. Modify the fibreglass to fit and miss plug leads and the bonnet
4. Tape to air cleaner base and cut to suit the hole. I extended the lip about 20mm above the bonnet
5. Rivet to the air cleaner and test if it works
6. Make pretty.

My thoughts - I figured air would be more likely to enter now via the top than via the engine bay and get heated on the way. The air cleaner is not directly open to the engine bay.

Observations - At 60, 70, 80 km/hr, I'm pretty sure it makes bugger all difference the way it's configured. The air temperature measured while driving was pretty much the same with or without the shroud. At idle, the temps were also similar.

Conclusion - I think the hoop scoop is letting in cold air regardless, but that may change when speeds get higher. I think to make a proper cold air induction you need to seal to the underside of the bonnet to completely isolate the air cleaner from the engine bay. I guess that's my next step.

 

[shane_3800]

Is that only forcing air through the top plate not the sides?

What you're making is how they actually are meant to operate.

 

[Alspos]

No, there is room between the side of the shroud and the air cleaner for airflow.

That's what I'm trying......

 

[shane_3800]

I would've just spaced the carb up.

 

[Alspos]

That won't prevent hot air from getting in from underneath.

 

[Ginger Beer]

My 308 VK has a cowl hood and a whopping hole in the bonnet courtesy of the previous owner. I figured I'd experiment and see if I could make a cold air induction system and utilise what I have.
1. Started with a bucket that's close to what I want.
2. Fibreglass (messily)
3. Modify the fibreglass to fit and miss plug leads and the bonnet
4. Tape to air cleaner base and cut to suit the hole. I extended the lip about 20mm above the bonnet
5. Rivet to the air cleaner and test if it works
6. Make pretty.

My thoughts - I figured air would be more likely to enter now via the top than via the engine bay and get heated on the way. The air cleaner is not directly open to the engine bay.

Observations - At 60, 70, 80 km/hr, I'm pretty sure it makes bugger all difference the way it's configured. The air temperature measured while driving was pretty much the same with or without the shroud. At idle, the temps were also similar.

Conclusion - I think the hoop scoop is letting in cold air regardless, but that may change when speeds get higher. I think to make a proper cold air induction you need to seal to the underside of the bonnet to completely isolate the air cleaner from the engine bay. I guess that's my next step.

Real nice

Maybe finish with some pinch weld, maybe????

 

[Alspos]

So when I read Ginger Beers comments I thought nah dude, there’s a pinch weld already around the bonnet hole, what’s that gunna do? Upon further investigation, pinch weld refers to more than one product. Der!
Anyway, after the new learning I bought a profile from Bunnings and chopped the top off my mold bucket. A few measurements, cuts and some pop rivets later, it’s done. Of course there was some scope creep, bonnet off to clean up the edges of the hole and paint the bare metal.