Alternate Method of mounting Heat Extractor on early Gen5 Hoods

[RichSS2006]

I had too much to write so I started a new thread for this alternate mounting of the Heat Extractor on an early Gen5 hood. I have a 2010.
I followed much of the original thread started by Jerry7297. Many thanks to him the have the nads to make the first cut! I was also inspired by JMT's wish to mount like the factory did. He shared many pictures over email to get me going. Thanks!

So, I've finished my install on the underside.. I'll try to start from the beginning. This was not an easy install. I spent many hours measuring and remeasuring. It requires removal of the hood. You cannot do this on the car working on the underside.
Materials used: GM Heat Extractor: 22828242
GM Water Deflector: 23213078
2014 Hood Insulation: 23152819
Radiator Baffle: 22828415 (THIS PART DOES NOT WORK on 2010's) I'll be selling it.
3003 Aluminum Sheet 24"x 24" X .060" (I also ordered a .080" Sheet, but this proved to be too thick)
Aluminum Sheet 24"x 24" X .020" for template.
Six 5/16-18 brass toilet flange bolts.
Eight 5/16-18 threaded nuts.
Several washers.
Silicone Sealant
Six 7/16" Plastic Rivets (Hillman p/n 881209 from Lowe's)
Several 1/8" Aluminum Rivets to attached the Aluminum Sheet to the underhood bracing.

I initially installed the heat extractor with the 3 aluminum bars like others had done. I liked this and it fit really well. I would recommend this method for anyone doing just the vent, not the rain tray. I was worried about eventually denting the hood from the underside. I had added rubber feet between the brace and the hood sheet metal.Attachment 771234

I then started thinking about creating a way to mount the rain tray like the factory does, but the underside of the early hoods are completely different. And besides, I just cut all of the supporting structure loose.
Attachment 771236
So I made a card stock paper template to include a cut out for the extractor & mounting holes. I then included holes for the rain train and insulation.
Once I was happy with this I transferred it to a .020" aluminum sheet (easy to cut and flexible). This sheet was too flimsy to be considered as a final mount.

Once everything mocked up good I started transferring the dimensions to the thicker sheet using scribe. I then used a drill and electric jig saw to cut out the mid section and various holes. Cuttting this was not easy. I cut it as close as I could and then used a file to clean it up to my scribe lines.

Now I have this flat sheet. But the hood is not flat. I lightly bent the sheet over my leg gradually to get the right curvature for the underside. Also I should mention here that the sheet is cut back to front to follow the remaining braces on the sides. Roughly 22 inches at the back and tapering as it comes forward.

I also had to cut slots in the rear of the mounting sheet to capture the tabs on the back of the rain tray. These are then bent downwards to allow the tabs to easily slide in for install.

After I was happy with fit and had all of my adjustments for retainers and bolts. I painted both sides. Then I ran a bead of silicone on top of the bracing that is covered by the plate. Place the sheet on top and using a 1/8 drill bit. drill several holes for the rivets. I place a rivet in each hole right after drilling to prevent movement.
I also used a piece of scrap aluminum to place under the brace to prevent denting the hood surface when the drill comes through the plate and brace. A piece of wood would work too. After all holes are drilled secure it using a rivet gun.

Tighten the six nuts on the extractor. On the front two I found that I had to use a nut and three washers to hold the front of the extractor at the right height. This is followed by a washer and nut on the other side of the mounting plate.

I then placed the new 2014 insulation on the hood and retained it using my old plastic retainers. Four on the outboard side and four on either side of the extractor.

Next the Rain tray needs to be trimmed on the ribs that run along the sides. I thought about cutting the ribs completely off, but realized they serve to center/align the tray to the mounting plate. These are rough cuts. I later used a file to clean them up a bit. Then I place the rain tray tabs into the rear slots and secured the tray using the six plastic rivets. The center hole at the front is not used at this point.. I'm still thinking about that one...
The tabs by the way are hidden under the hood insulation.

Installed the hood on car and smiled!

I decided to take a ride and have my son take a video with the Thermo Imaging Camera. Although it was a nice day here in New England, 50 Degrees F. The video shows heat escaping with and without the rain tray. I think it will show a greater temp differential in the summer months.
I'll post the video as soon as I figure how to get it downloaded.
Hope this helps someone.
Rich

[RichSS2006]

Here is the video. This one was taken with the Rain Tray removed. The white areas are the hottest. As I said above the differential in temps would be greater in the warmer months (i.e.: More removal of heat).

[Jerry7297]

Awesome result man. I wish I would had been that inventive. You really thought outside the box, good job. Looks really nice.

[Eddiefuzz]

That's amazing! I still recommend the 1 1/2 x 1/8 inch, slightly curved, aluminum strips running from front to back along the edges of the hole, for support. WTG!

[FunkedOut]

that's a good looking install. congrats.
if I followed the other thread correctly, this rain tray directs water towards the rad fans, and the early 5th gens don't have a rad fan rain tray or provisions for them.
did I get that right?

where's the rain going now on your car?

if there's a way to keep from raining in our electric fans, I might cut that hole.
I think it looks better than the hex vents or ACS.

[RichSS2006]

The 2012's have a deflector the mounts to protect the fans. I bought it not knowing at the time that it wouldn't fit. I'll play with it some more to see if I can make it work. But to answer your question the water is collected by the tray and routed towards the front and dumped out of the two large openings. It actually dumps well ahead of the fans in front and on top of the radiator. If you look you'll see a flat area right in front of the rad and the core support. Without the tray your engine is all kinds of wet, so all bets off.


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[olblue75]

How much you want for one of those plates I'm really digging that!!!

[FunkedOut]

ok. without the stuff in front of me it's hard to tell.
I was thinking Chevy intended the rain to flow from the vent tray, to the fan tray and down.

you're saying the vent tray dumps on the metal area on the sides to where the hood latch is?

[RichSS2006]

It took a lot of time. I actually spoke to a friend about cutting some on a waterjet or having them laser cut. It was a pain cutting with a jig saw. 3003 Aluminum is somewhat soft, but at .060" it's tough. That's partly why I chose it. I wanted rigidity to be added back to the hood and I needed the plastic push pins to be able to hold.


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[RichSS2006]

Originally Posted by Eddiefuzz

That's amazing! I still recommend the 1 1/2 x 1/8 inch, slightly curved, aluminum strips running from front to back along the edges of the hole, for support. WTG!

Easier for sure, but wouldn't mount the rain tray like the factory did. About half way through I had wished I did it your way. Can you say time consuming....?

[RichSS2006]

Originally Posted by FunkedOut

ok. without the stuff in front of me it's hard to tell.
I was thinking Chevy intended the rain to flow from the vent tray, to the fan tray and down.

you're saying the vent tray dumps on the metal area on the sides to where the hood latch is?

It dumps out behind and below the flat area around the hood latch. I have about a 1/4" clearance between the rubber seal on the core support and the rain train when the hood closes down.

[flyer08]

If your friend can cut a few id be interested in buying one

[chevy 3]

That came out great Rich. Very clean looking.

[RichSS2006]

Originally Posted by flyer08

If your friend can cut a few id be interested in buying one

I actually need to tweek the location of the various holes. I have to draw it up in my CAD system and let him program and cut a test piece. He's always busy restoring his 1st Gen and building dirt track engines, so I doubt it would happen.

I'm also considering using small plastic threaded knobs and well nuts to mount the rain tray.