Hot Feet

[JohnK]

"I was thinking of an opening at the rear of the hood bulge... or a couple vents on the flat portions of the hood (to the sides/rear of bulge) to let the hot air out."

I can't convince myself that cutting any openings in the hood wouldn't weaken it, though I'd like to - once I did some work to ensure that where I wanted to cut was a low-pressure area. And then maybe figuring a way of reinforcing the area. I have slackened the side hood hold-downs so there's a bit of a gap between the hood and side panels, and cut some gaps in the wool felt I have where the hood and dash seat - but haven't seen much difference. The gap between the dash and the lower chassis tube dumps heat in my lap. (For those unfamiliar with the S2K, it has no scuttle/firewall - the instruments stick right into the engine bay and all of its heat.) I am seriously planning on finding a grill of some sort - like from a production car's AC system - that seals well and punching a hole in the dashboard. Since I've managed to get through life without acquiring a partner of any kind, blasting a passenger in the face with hot air isn't an issue :-) .

 

 

Don't know if there's enough space to do the thing shown in the Westfield, and while I think that this is a really nice solution, it doesn't address the exhausting of engine heat from the headers and block and all. See attached AirBox_spaceOccupied.JPG for a space reference re the Westfld solution vs the S2K. Myself, I'd be worried about compromising the integrity of the bonnet were I to add the Westfld/Caterham type vents there.

 

Radiator seal: look at i_Front_right_Low-angle in my set of pics - To either side of the radiator are panels that are mounted on the hood with tabs so the panels can be removed. And also see the attachment NACA_duct-NosePanels which shows the back of those panels and one sealing tab at the top of the radiator. If you want to tackle this job let me know and I'll take some more pictures. When the rad fan comes on, there's quite a bit of air that blows out of the NACA duct.

 

Footwell: Attachments Footwell* and HumpPositioning give an idea of how a person in need of a good 12-step program approaches sealing up the footwell. E.g. if you look you can see bits of a kind of heat-sealing gasket assy I made which traps some polyester felt where the secondary steering column goes through the footwell in order to seal that area up. Also, Lowe's or Home Despot GE plumbing Silicone is good for 400 degrees F and not that expensive - a real bargain. Other insulation came from Summit. They carry a good selection of different types and spell out appropriate uses well. What's not shown in the pic is some 1" thick urethane foam I got from MSC that I put underneath the polyester felt (white at base of hump) that's between the hump and the chassis, and I used a strap with D-rings to hold the hump down. This, especially the urethane, seals up the footwell quite effectively. Also, my wiring harness came with its master grommet intact and I was able to fit it to the hump for a good seal there too. Let me know if you want detail pics of this.

 

Every time I get bummed out trying to construct something that makes the car work like it should I step over an look at my 18 year-old Civic for inspiration. Amazing what you can do with visionary planners and a crew of well trained designers and engineers (and 20 or so years of development)!

[Mondo]

Don't mean to hijack thread (though we are talking about footwells too);

John, you have floor mounted pedals so it looks like your footwell black box just needs sealing around the bottom of it. What did you do for the throttle cable and are there any other wires/tubes penetrating the black box?

I do have a vent similar to yours on the driver's side but it's not nearly enough.

Perhaps you can start another thread for S2K heat abatement... I'd like to see pics around the radiator. I still don't see how it seals between the radiator and the hood itself. Plus the other side of the black footwell box.

 

Thanks

[JohnK]

Mondo,

I'll get you some pictures.

[MBEARDEN]

Took the Birkin out this evening...left the hood in the garage. 89 degrees with 45 % humidity. I could feel some heat in the footwell but not excessive. There appeared to be minimal heat from the console or firewall. Overall a very comfortable drive. Drivers footwell temp ( with a kitchen thermometer) was 89f degrees...just a little ventilation would have been great. Put the hood back on and took the same drive...noticeable footwell heat and a lot of console heat...footwell temp was 98f degrees. The heat radiates from the console and firewall...the Birkini top cuts down some cockpit ventilation. The second drive was not nearly as comfortable.

Passenger footwell was about 5 degrees cooler either way. The water temp was hotter by 10-15C with the hood on.

If you could flush the underhood with outside air I think a lot of the heat issues would go away.

[JohnK]

"Don't mean to hijack thread (though we are talking about footwells too);"

 

Let me offer that this as information "of general interest": for those building a non-Caterham Se7en it provides some examples on what they might consider, and for those with ur-Se7ens to better understand better that Caterham's been doing some thinking as they updated their models over the years.

 

"John, you have floor mounted pedals so it looks like your footwell black box just needs sealing around the bottom of it."

 

The "hump", as I've heard it called, fits the hang-down pedal assy OK and I used it as-delivered. Fitting the pedal assy is separate from the issues of connecting electrics to the engine and the cable to the throttle.

In order to get a reasonable seal I had to add glass to the front of it and build up what it sits on just fwd of the dash. Even so, it was necessary to fill some space due to irregularities and flex, which was done well enough with the 1" urethane foam I found at MSC.

From the left, you can see the extension on the front and the strap used to secure it. http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/h1_Hump_in_place.JPG

 

http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/h1a_HumpFit_gaps.JPG

shows the size of one irregularity filled in and one gap I gave up on, which turned out to be not a problem (so far). Note at the far right I used treated wood to give the lip better support.

 

 

"What did you do for the throttle cable and are there any other wires/tubes penetrating the black box? . . . Plus the other side of the black footwell box."

 

http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/h2_Hump_in_place_RightSide.JPG

shows all the traffic that runs through the hump. The lowest is the wiring to the rear of the car (lights, fuel gauge sensor and fuel pump power inside Flexo sheathing), the grommet is the engine wiring harness, and the other thing is the throttle cable (Honda, re made from a piece from salvage yard). With some dremel work and a bit more glass I put an opening in that captures the stock grommet giving a perfect seal. The gap at the bottom I gave up on and just stuff with paper towel which seems to work fine beyond being tacky.

The single wiring harness connection: based to lots of bad past experiences with wiring and associated problems getting such systems to work without gremlins, I duplicated the Honda schematic exactly as per the Helms manual. The benefit of this is that when removing the engine, all the connections unplug making maintenance a lot simpler. See

http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/h3_UnderHump_ECU_Wiring.JPG

Oops! I now see that I routed dash the and the stock ignition switch connections through gaps I cut in the wood hump seat, avoiding extra ports in the hump.

 

"I'd like to see pics around the radiator.I still don't see how it seals between the radiator and the hood itself."

 

Work was inspired, as usual, by Carroll Smith. He gives a very nice explanation of what needs to be accomplished. Paul Snyder also helped pointing out the need for chin sheeting, which makes perfect sense because that's clearly a high pressure area. Smith talks about nozzle and augmenter.

The work at the nose was a bit tedious but came out well. Made cardboard pieces and fitted them through the front supported by the radiator since the sheeting, in order to seal properly, sits on the radiator tanks. Given this I could tape the cardboard in place and mark where it intersected with the hood. Then I could figure out how to put the supporting brackets on the hood to which I could attach the sheeting. Given the area between the brackets and the hood, and that GE 100% plumbing silicone is good for 4-500 degrees F this should live a long life and allow me to fix the sheeting if it gets hit by something. With respect to the radiator's top and bottom, I siliconed some tabs on the top of the radiator to seal that part off, and did the bottom with just the urethane foam on the hood.

 

http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/Ra1_Radiator_sealing.JPG

http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/Ra2_Radiator_sealing_Left.JPG

http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/Ra3_Radiator_sealing_right.JPG

 

Also related to getting flow through the radiator and only the radiator, I put sheeting on the chin so that the flow has to continue for some distance through this area before it dumps out the side port and below the engine.

 

The whole thing is secure because early on in the build I made proper mounts for the radiator. Reid supply handles some really nice and importantly strong shock absorbing mounts called Barry Bond mounts - they rely on rubber trapped in compression such that, even if the rubber is destroyed, the two pieces don't come apart. I welded stout tabs on the chassis and fabricated strong mounts to connect the radiator to these tabs. The time I spent on this paid off since it required me to position the radiator in the most optimal position with respect to the hood. So I not only gained a radiator secured by mounts that were designed to bear its mass but was also solidly positioned and placed with the greatest amount of clearance possible. Hence my sheeting won't be destroyed by a flopping-around radiator.

http://dl.dropbox.com/u/49212285/AnnouncementShots/Heat/Ra4_Radiator_mounting.JPG

 

"I do have a vent similar to yours on the driver's side but it's not nearly enough.

Perhaps you can start another thread for S2K heat abatement..."

Planning on a NACA duct tucked behind the headers. Will post it when I get to it, and hopefully will find another solution or two to go along with it. If I get my nerve up I'll measure the underhood temp just behind the dash to have a reference value.

 

I find that going through an explanation of all this is valuable - it allows me to rethink the work and verify that my design actually makes sense in retrospect (and, of course, expose my thinking and work to anyone who cares to point out how badly I've managed to screw things up! ;-) ).

[Mondo]

Thanks John!

Boy you have a lot of stuff under that "hump". You have given me an idea of adding a buldge, similar to the bottom half of a litre bottle at the front of mine to handle the electric peddle assembly rod. Still have to figure something out for my brake & clutch hoses and throttle cable that come into the right side of hump.

 

I think your radiator is at a different angle and position than mine. I have a lot more room between radiator and bonnet. Since I don't have an overheating problem, more air moving around in there is probably better for now.

 

Thanks again for the pics

[sequential7]

I fitted air scoops on the side skins to direct air into the footwells, and fitted rotary slides on the inside so that they can be closed/opened by foot.

[twobone]

My S3 chassis does not have a pedal box cover. It just has a piece of aluminized heat shield foam that covers the hole where the pedals poke up thru the chassis.

 

I'm thinking of running hose from the front nose cone behind the mesh screen using these Hose and intake ducts:

 

https://www.pegasusautoracing.com/productselection.asp?Product=3620

 

https://www.pegasusautoracing.com/productselection.asp?Product=3626

 

I just then have to see if there is a way to SAFELY run the output end of the hose down into the footwell. I'm envisioning a mishmash of plumbing type PVC elbows that would point the stream of cool air down thru a hole I cut in the heat shield foam onto my feet.

 

Right now I have a large block style heater that even with the heater control switched off, still creates too much ambient footwell heat.

 

Of course the down side is that my interior would look like a mad science experiment, but my feet would be happy. I would just have to keep the hood on!

[MBEARDEN]

I fitted air scoops on the side skins to direct air into the footwells, and fitted rotary slides on the inside so that they can be closed/opened by foot.

 

I couldn't figure out how to run a hose from the front of my Birkin to the footwell, if I did it be running through a very hot area... I think the best option is the boat vent into the footwell. I had also thought about some sort of vent on the cowl in front of the window. My car has clamshells which makes positioning the side vent more difficult...one vent for each footwell and one maybe above the fender into the side of the hood to push some more outside air under the hood. Most of the heat we have is trapped under the hood...when I drove my car with the hood off the interior was noticably more comfortable.

[locost7018]

What about the side vents they used to have on panel trucks. The flush kind that pop out to bring in fresh air. I looked on the net to find an example but could not find any. Russ

[DavidL]

What I do on hot days is to run the heater fan but not turn on the heater. This does help, although footwells still get warm. This was a recommendation from the previous owner. Of course only works if you have a heater.

 

---David

[MBEARDEN]

What about the side vents they used to have on panel trucks. The flush kind that pop out to bring in fresh air. I looked on the net to find an example but could not find any. Russ

 

 

I looked for a pop open vent too...something like the pop up cowl vent on older pickup trucks...no luck either. Surely someone makes something like this...I have gone through marine part catalogs with no luck.

[locost7018]

MBEARDEN, try this link. I finally found something. http://www.rustrepair.com/stepvan_parts/onlinecat.htm?r=wi&p=wi-vents Click on the "side vents" in the Select a Part Page

Russ

Edited August 2, 2012 by locost7018
added info

[MHKflyer52]

MBEARDEN, try this link. I finally found something. http://www.rustrepair.com/stepvan_parts/onlinecat.htm?r=wi&p=wi-vents Click on the "side vents" in the Select a Part Page

Russ

 

Good source for a popup vent. :cooldude: