DuPuis Family Cobra Build

TCABM said:
Invert the scheme; wheels will stand out better.
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That has been another consideration, and would match my wife’s Alfa. :)
 
It's now legally a car. :)

snek.jpeg

I hadn't done a fantastic job of keeping my receipts sorted for what the highway patrol was looking for, and it took me some time to get all of that sorted out. Registering a kit car first requires it to legally be made a car, which in Kansas requires a highway patrol inspection as well. It ended up being simple and pretty low-key, but the official statement is you must have all your receipts. That's not very practical (especially for a build like mine where so many parts come from so many places), but I brought enough to satisfy him and cover the major parts of the engine, transmission, and rear axle. Got my forms, thanked the officer, and was on my way.

The long part ended up being actually getting the titling and registration completed. While the one Kansas Highway Patrol guy does these inspections regularly, the county motor vehicle office doesn't. Not only had the woman helping me never done a kit car registration before, even the lead in the office hadn't done one in a long time.

Fortunately, this is a good office and everyone there is helpful and pleasant, but I was there for 2 hours to get everything completed. In the end, I walked out of there with a temporary tag for my personalized license plate: "SN3K". Short for "Snek", as in:

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(we call our son's pet snake "snek", and have also referred to the Cobra as such).

What would've made this even better is if I could've gotten this on the Gadsden flag plate:

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The irony is that if you have that plate, you can't personalize it - they just assign a number. So if you pick the "Don't tread on me" plate, they tread on you and assign a number.

I drove my daughter to school this morning, only to come home and then find a coolant leak. I have to figure out where exactly that's coming from, and I hope the answer isn't something that gets coolant into the oil system. I'm pretty sure it isn't as the leak is external, and I'm pretty sure it happened a few miles from home. The engine wasn't running hot.

It's been just under 5 years since the Cobra was delivered to our home, 5 years and about 2 months since I placed my order (it was right after I went to the FFR display at Oshkosh), and this thread started 5 years and a month and a half ago. The car isn't done, but it is at the point where the work to do is primarily body and various tuning and other tweaks and details. It's been a remarkably ride, and extremely satisfying to be able to now say "I built a car." With it now being titled and registered, that milestone is reached.

From here I think I need to start looking into some of these little details. Fix that coolant leak. I need to helicoil the threads for the valve cover bolts as a couple of them are stripped out, and that's been resulting in a seep from the valve covers.

I'm also going to make a change to the heater setup. Right now it has a push/pull choke cable to open and close the coolant flow to the heater. That doesn't work very well, and specifically it doesn't seem to shut off coolant fully. I'm going to replace that setup with a solenoid or electrically actuated ball valve. If I'm using the heater in this car I want full heat, I don't need partial heat. But the car also has air conditioning and I don't want the heat to be overpowering the AC and rendering that feature useless.

At this point I'm pretty confident in the wiring of the car going font to back, but I do want to get the air conditioning going and tested before I go ahead and put the transmission tunnel cover on. Maybe this weekend I'll get some time to work on that. With fall upon us and me now having a legal car, I'd like to drive it as much as possible (when I'm not riding my motorcycle).
 
Half Fast said:
Outstanding!

So what will you do for an encore? Build a plane, maybe?
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At this point my plan is to continue to try to "complete" some more projects. The Cobra's still got work to do - the thing doesn't even have a hood on it! The RX-7 needs to either have the carb rebuilt or else the 12A just swapped for an RX-8 engine (I really am liking this idea as I hate carbs and some more power would be nice) so that maybe I can finally run the thing in Lemons behind schedule. And there's the diesel swap for the Land Rover, something that I am planning on getting going more heavily on following getting the RX-7 fully race-ready.

And who knows what will happen bus wise. With us strongly considering an upgrade of some sort, and that upgrade having a lot of potential paths, the answer may be "Build a bus".

I have considered building a plane, especially as the kids get closer to the age of learning to fly (which we still intend to be something we do with them). But I just see that as too much of a delayed gratification project for them, and not something that aligns with their capabilities. However, they've all been thinking about their first cars. My one daughter wants a Jaguar convertible (an XK8/R, which is the spiritual and mechanical evolution from my first car - an XJ-S), my other daughter wants a Ford Thunderbird (the aughts era revamp of that car), and my son isn't certain yet, but he's got some good ideas ranging from Mercedes to various V8 manual transmission cars. All options that are #tedapproved

Ted's Garage has no shortage of work to do. :)
 
Not that it's an elegant solution, but a manual ball valve on the heater core line might be an easier solution for stopping flow to the heater core in the months when you know you won't need it. Then open it back up when the temps drop enough to justify using the heater.
 
Ted said:
Ted's Garage has no shortage of work to do. :)
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And you haven't even mentioned a motorcyle restoration yet. A cafe racer build (maybe build a Triton? :biggrin: ) might be just the thing for your son. Beats a car eight days a week!
 
SoonerAviator said:
Not that it's an elegant solution, but a manual ball valve on the heater core line might be an easier solution for stopping flow to the heater core in the months when you know you won't need it. Then open it back up when the temps drop enough to justify using the heater.
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I already have a place in the dash where a switch would work. And this is Kansas, it's possible to want the heater in the morning and the AC in the afternoon. :)

Half Fast said:
And you haven't even mentioned a motorcyle restoration yet. A cafe racer build (maybe build a Triton? :biggrin: ) might be just the thing for your son. Beats a car eight days a week!
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Are you forgetting about my Moto Morini? I think that's 10 or 15 pages back in the adventure bike thread. ;)

The boy wants the R1150GS for his motorcycle when he gets his license. Normally an 1150 would be too much, but that thing is fairly low on power and by that point he'll have been riding dirt bikes for... I suppose a solid 5-6 years. By then he'll probably be up to a 250 or something of the sort with an actual clutch. So, I think it'd be a just fine option for him. Certainly no worse than my Kawasaki KZ700 I had for my first bike.
 
Ted said:
…
Are you forgetting about my Moto Morini?
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I thought you sold (or tried to) sell it.

I’m keeping my eye open for Cagiva 906 Lucky Explorer in the rare Italian adventure bike category.
 
TCABM said:
I thought you sold (or tried to) sell it.

I’m keeping my eye open for Cagiva 906 Lucky Explorer in the rare Italian adventure bike category.
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I'm still planning to, I just haven't tried to at this point.
 
Ted said:
the 12A just swapped for an RX-8 engine
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Congratulations on the Cobra, fabulous.

Just putting my spelling police hat on for a moment I notice that you misspelled V8 in the above post.o_O
 
Nice! I remember seeing it as parts spread all over. Looked as if it had come from together, but it had never been together. And now it is.
 
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Spring Ford said:
Congratulations on the Cobra, fabulous.

Just putting my spelling police hat on for a moment I notice that you misspelled V8 in the above post.o_O
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While I've considered throwing the 4.0L V8 out of the Land Rover into the RX-7, I think ultimately if I'm going to do a swap it makes the most sense to stick with the rotary. Every car has a personality and a balance to it, deviating from that too much requires re-engineering the whole thing, and can upset the characteristics of how the car drives and handles. The rotaries are very lightweight, more about horsepower and revs than torque, and this car is geared for that with 4.88s in the stock rear end. Any V8 would increase the weight on the front end, which would upset the balance and handling this car has. The RX-8 engine adds about 100HP to the current ~130ish HP, has the same sort of rev range, weighs less, and adds fuel injection.

The only problem is generally finding one in good working order, and I might have to rebuild one to get there. But, I'm not afraid of rebuilding engines, in fact I rather enjoy it, and I love learning new things about new engines.
 
Ted said:
While I've considered throwing the 4.0L V8 out of the Land Rover into the RX-7, I think ultimately if I'm going to do a swap it makes the most sense to stick with the rotary. Every car has a personality and a balance to it, deviating from that too much requires re-engineering the whole thing, and can upset the characteristics of how the car drives and handles. The rotaries are very lightweight, more about horsepower and revs than torque, and this car is geared for that with 4.88s in the stock rear end. Any V8 would increase the weight on the front end, which would upset the balance and handling this car has. The RX-8 engine adds about 100HP to the current ~130ish HP, has the same sort of rev range, weighs less, and adds fuel injection.

The only problem is generally finding one in good working order, and I might have to rebuild one to get there. But, I'm not afraid of rebuilding engines, in fact I rather enjoy it, and I love learning new things about new engines.
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There was an LS-swapped RX-8 at the July Road Atlanta track night. It didn't perform very well, I passed it in the GTI. Engine swaps like that take a bunch of engineering and testing to get right.
 
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FormerHangie said:
There was an LS-swapped RX-8 at the July Road Atlanta track night. It didn't perform very well, I passed it in the GTI. Engine swaps like that take a bunch of engineering and testing to get right.
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That's also known as Tedgineering.
 
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FormerHangie said:
There was an LS-swapped RX-8 at the July Road Atlanta track night. It didn't perform very well, I passed it in the GTI. Engine swaps like that take a bunch of engineering and testing to get right.
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NealRomeoGolf said:
That's also known as Tedgineering.
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And (this is the fundamental basis of Tedgineering) these swaps cannot break the laws of physics. An LS is heavier than the rotary, it will impact the weight distribution (and just general aspects of having more weight period).

This is part of why I’d like to go with an RX-8 engine if I do anything. It’s lighter weight and only changes those characteristics for the better.
 
Ted: You need to swap a Deutz T-216 into the RX...run the start crank out the top of the hood like a toy car....
 
I've been driving the Cobra to take one of my kids to/from school when I get the opportunity (i.e. weather is good and everything else lines up). The car is pushing 400 miles on it now, and really it's a delight to drive - although of course I've got more items to do on it. But I've made a few bits of progress.

One thing I did was I re-plumbed the breather to be a full on PCV (yes I have a PCV valve in the valve cover). Negative crankcase pressure of some sort is better for the engine and so I thought I'd see how that impacted things. The engine does feel like it's running better with that.

I also went through and tried to address the valve covers not sealing. This was due to a few stripped valve cover bolt holes in the head, which I helicoiled. Those seem to be working and at the very least the oil leakage is substantially reduced, although maybe not quite eliminated. I need to look at it a bit more.

The headlight switch I'd put in failed quickly, although that one was not an OEM one. Silly me for buying an aftermarket one. I bought an ACDelco/GM Genuine Parts one and that should fix the issue, although I haven't installed that yet.

Really I need to spend a day and do some more clean-up on it, finish up the transmission tunnel and some other details. From there it's installing the windshield and roll bars, and then I can start on the body work. But you know I won't, because I'll be tinkering on other things.

One of the things I keep on thinking about tinkering on is something that lets me retain the individual throttle bodies, but lets me have a bigger/better air filter. RIght now, I have tiny K&Ns in each velocity stack - those are very restrictive (although also do a good job of protecting the engine) and I'm sure those are hurting my throttle response and horsepower significantly. Screens would be a more typical solution, but I really don't like those because they still let a lot in. I'd like to retain a standard air filter (K&N style) but one that is appropriately sized for a 400 HP engine.

A setup like what BMW did on the E39 M5 engine would work:

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But I'm not convinced I can fit something like that in the area provided. I've got some more thinking (and probably mocking up) to do there about what could be possible, but hood constraints also come into play. The engine makes sufficient torque (especially in such a light car) so the lack of long intake runners/velocity stacks seems to be fine. Actually it would be interesting to measure how long it really is currently from the top of the velocity stack (or even from the top of each throttle body housing) to the intake valve to get a true full runner length and see what that's optimized for.

I knew the filters would bog things down, but among other reasons I put them in because I wanted to protect the engine while the car sits.

Another thing I'm going to do is install an electric solenoid to control water flow to the heater core instead of the manual valve. I don't think it's opening or closing fully and so this will do a better job. Thinking about a couple of different options of how I'd like to wire that up.
 
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