BlueBDA

I'm an idiot. Alternately, not being as hard on myself, I shouldn't make assumptions when I'm not with the car to look at things. I get it now. Cap provides the pressure valve for the overflow tube, thus a pressurized system. Makes perfect sense. So this weekend I will: - Cut a new overflow tube that reaches the bottom of the overflow tank, cut on an angle at the end. - Hose clamp that hose to the thermostat housing to allow the system to be able to suck overflown coolant back in. - Drill a couple of small holes in my new thermostat. - Install thermostat, fill with coolant, and try to get any air to burp out. If it then maintains proper temp I can then replace thermostat with a higher temp one. I just got the 160F as I wanted every chance of not running hot. I suspect/hope that the problem I've had is just the old thermostat failing. Which BTW was also a 160F one.

Picture showing the thermostat housing. You can see the vent tube that runs into the overflow bottle.

It's not pressurized. There is no valve or anything in the overflow tube - it's open to atmosphere, in the overflow bottle.

Why would pressure testing the cap matter if it's a non-pressurized system?

Thank everyone for responses so far. Of the list that Vlad gives above, I am relatively confident that my radiator is fine, I'm not running lean (probably a little rich, but I'm ok with that), and head gasket, water pump and fan are fine. I'm hoping it's just my thermostat, but we'll see. System is not pressurized. The radiator has no cap. There is a cap on the thermostat housing (of course), and an overflow tube that runs into an overflow bottle. The overflow bottle has no cap on it; the tube just goes into the open bottle. One thing I realized is that that tube is kind of short, i.e. it doesn't extend very far into the overflow bottle. So I'll put on a new tube that extends to the bottom of the bottle, so in theory the system could suck coolant back in when it cools. What size holes to drill in the thermostat? 1/8"? Any further thoughts on bleeding air from the system would be appreciated. I assume that I can run the warmed-up engine with the thermostat housing cap off, and add coolant as needed? I assume no RTV on the gasket? Lastly, does anyone have the thermostat housing bolts torque specs?

My 1700 BDA has been running very hot, and overheating and spitting up coolant on track days. I'm sure this has been covered before, but I never seem to be able to find what I'm looking for when I search the site. Temp climbs steadily until it hits maybe 110C per my gauge. I have replaced the fan switch and fan comes on reliably. So I bought a new 160F (71C) thermostat, which I was just going to install. My system is open to atmosphere, with a rubber hose draining into an open overflow bottle. I assume the thermostat and housing are the same as in a crossflow. Questions: - How do I fill the system with coolant? I never thought about it til now, but with the engine cold the thermostat is shut, so the coolant won't pass it to fill the block. - Should I drill a small hole in the thermostat to allow the block to fill, as some online have suggested? - How do I get all of the air out of the system? - Torque specs for the two housing bolts? - Should I use any RTV on the gasket? There wasn't any there before - the old gasket came off pretty easily, but again, some folks online say to use some RTV. - Could there be any other reasons why it overheats? Thanks in advance for any answers.

Critical to this discussion is the intended use of the car. A Tesla Model 3 Performance is great for the road, and from what I've read and watched it's just about there for HPDE track days. The ID-R is designed for one purpose - Pike's Peak. It's not meant for doing four twenty minute track sessions. What would you want to do with an electric seven? Street: Just a matter of balancing range vs weight. Guessing (maybe someone else can do the math) that an 80 mile e-seven might weight similar to a Cat, and perform similarly or better. Track: The math probably doesn't work here. Need range, which means weight, and aerodynamics, which means not a seven. Autocross: I think an e-seven could be built to excel at this. Aerodynamics don't play as big a role, and runs are short. I've thought about an e-seven with swappable batteries, built for autocross. EV West told me "people have tried swap-able batteries and it doesn't work out", but I think designed for autocross, with a trailer that is equipped to transport and swap the batteries, could be an amazing system. But - there's no SCCA Solo class for this, so after doing all of the work to design and build it, it couldn't compete. But it would be a ton of fun. It would be great if someone can chime in with some kWh/mass math.

I have a 6810 Aluma, non-tilting, with ramps I bought from Tractor Supply. Car fits perfectly, rides great, and total weight is right around the 1750 tow capacity of our Rav-4 Hybrid. Ramps fold in half and travel in the vehicle. I was concerned about how the tilt was going to work, and it would have put me over my tow weight limit. I did not have to make any modifications to the trailer.

Complicate, then add kWhr. Love it. I'd order my electric Cat now if they'd take my order.

Good luck with all of this. You're really making me appreciate my Dellortos more.

Totally different type of vehicle, I know, but last year I worked the start line at a local autocross, and there was a guy there autocrossing his Tesla Model 3 Performance. It was really something to watch him take off from the start line. No revving, no drama (granted I know that lots of people like revving and drama), and it took off like a silent rocket. It was really cool to watch and (not) hear.

Have your neighbors come over yet to ask "What the hell is that?!"?

I love the idea. Really. Of course, owning a Caterham with a Cosworth BDA, I have an appreciation for the auditory pleasures of sporty cars (BDA, air-cooled Porsche flat-6, flat-plane crankshaft V-8...). But - we need to spit less CO2 into the atmosphere if we're going to keep this planet habitable for our great-grandkids, so I need to get my ears out of the 20th century and get with the program. I see wonderful opportunities for Caterham to design an electric, Se7en-esque sports car. Could have incredible performance, and aesthetically there's a lot that could be done to evoke the Se7en spirit in a more modern electric car. Keep it under $50k and I'll line up to buy one, once most tracks have sufficient charging infrastructure.

5th and 6th - 6-pt harness.

Makes sense Jim. I had to think about it for a while to understand why 2 plates, but I get it. Nice work. The screws that mount the belts look pretty tiny though?

Thanks guys. I think roll bar on driver's side of the car makes sense for me. One thing I've thought about is if there's a fire around the engine taking the bonnet off quickly and safely might be a challenge. Run around to undo all for latches, and then when I take it off I have to lean in towards the center of the car. Might be a pretty hazardous thing to do with flames under the bonnet...

I'd like to raise the rear view mirror that is mounted with my Brookland's screens. I've seen an extender for this on other cars. Is that an off-the-shelf part that I can buy, or do I just make one?

For this season I have bought a new helmet (Snell 2020) and this head and neck support: https://www.schroth.com/en/segments/racing/products/details/show/id-20-shr-evo-medium.html I just tried them out in the seven. I tightened the shoulder belts as tight as I could, and I was surprised at how easy it was to move the shoulder belts around on the HANS (ok - this one is an "SHR"), especially on my right side. I could shift the right belt further to the right, so it was no longer centered on the SHR. Then I realized that the belt mounts are not centered with the seat (see pics). Belt mounts and seat position are standard Caterham S3, so I am guessing that others have encountered this? Advice?

I bought one of these https://elementfire.com/collections/allproducts/products/element-e50 which I plan to mount in my seven. Trying to determine the best location to mount it. I'd rather not drill any holes. Best I've come up with is to cable tie the mounting bracket to one of the verticals or the diagonal on the roll bar, and then wrap with a velcro strap or two for extra security. Sound good? Any other ideas?

James, Nice to connect with you here. I am JeffreyC on BAT. Congrats again. Fun times ahead.

One option is to get inspected with the windscreen, then take a picture of the sticker to have that evidence with you when driving with the Brooklands.

Sounds like I should just go for the front R888Rs as you say, and see how it feels before spending for the new rears. My 91 Miata is supercharged, but still less HP than a new ND. I have Xida race suspension, and autocross it. Never had it on a track, since it's in awesome original condition and I've never wanted to cut it up to put a roll bar in. Also I drive it on the street, and I prefer to not have a rollbar on that car for street driving (I'm in the camp that believes a rollbar makes it less safe for street driving, in a rear-end collision. I never drive that car on the street in a way that it could flip over anyway.) For autocross I've done pretty well with it, and it's very fun, but it'll never be competitive as the supercharger puts it in SM class. It's a fun car, but a new ND would be better for both street and autocross. And have modern conveniences like power steering and air conditioning .

p.s. (I think I'm allowed to hijack my own thread ): Interesting that we have/had a similar collection of cars: Seven, hot hatch, Miata. How do you like your 2019 Miata? Been thinking of making the NA to ND move, thought the NA can't leave the family, as I've had it for 28 years.

Thanks Kitkat. Any concerns about going from 185-55 to 185-60 in the front? Still lower profile than the 215-55 in the rear, so I think it's ok?

So it's been a while and still no 185/55/13 ZZRs from Roger Kraus (or anywhere else). They are in a container in San Francisco Bay, which currently has lots of container ships backed up. No idea when the ship will dock, the tires get to Roger Kraus, they ship to me, and they arrive at my house. As it's May this weekend, and I want to get out on tracks, I'm now considering my other options. (My wheels are 6" and 7" widths): 1. Put new 185/60/13 Toyo R888Rs on the front, along with my slightly worn 215/55/13 ZZRs in the rear. 2. Put new 185/60/13 Toyo R888Rs on the front, and new 205/60/13 R888Rs on the rear. Opinions on these two options? I'm leaning towards option 2.