DuPuis Family Cobra Build

[Hang 4]

I'd do the Wideband O2 for sure. Having an A/F gauge isn't all that interesting, but being able to download datalogs and tune with it is definitely worth it. There's a company called DIY Autotune that has both kit and prebuilt MS units as well as a lot of accessories and software. TunerStudio is awesome and can provide some of your "I only need it sometimes" gauges right on your laptop (Best to have someone else driving ).

 

[Ted]

Yeah, I'd go with Voltmeter, too. I have an ammeter in the boat (with single-wire alternator), but that's just how they did it back in 1976. Most people don't like having the power load running up to the dash for an ammeter vs a voltmeter, from a safety standpoint. The AFR is just one of those gauges that tends to swing back and forth a bit depending on operating conditions and such, which often makes it less useful unless fighting a detonation problem or trying to optimize the AFR for a particular operating range (like WOT or cruise RPM). I guess it just depends on if you want you gauge package to be a systems monitor, or a diagnostic/tuning center (not that those are always mutually exclusive).

Ultimately the data logging capabilities of MegaSquirt are more valuable than anything for diagnosing problems. The real benefit of the AFR gauge would be that, during WOT pulls, I could glance at the gauge to make sure it's not going lean, or at least not notably leaner than what I want it to do. But, the solution there is probably more monitoring the data from the MegaSquirt.

To the previous suggestion of a manifold pressure gauge, I've thought about that as well, but ultimately that's not something that's very useful. I'm not running a boosted application so I know what my max manifold pressure is (ambient). I suppose it could let me know if the air filters were clogged/clogging but I still don't think it's worth doing.

 

[charheep]

What no AOA gauge...

 

[Ted]

What no AOA gauge...

If I have an AOA on this car, I'm in trouble.

 

[jsstevens]

If I NEED an AOA on this car, I'm in trouble.

FTFY

 

[SoonerAviator]

Ultimately the data logging capabilities of MegaSquirt are more valuable than anything for diagnosing problems. The real benefit of the AFR gauge would be that, during WOT pulls, I could glance at the gauge to make sure it's not going lean, or at least not notably leaner than what I want it to do. But, the solution there is probably more monitoring the data from the MegaSquirt.

To the previous suggestion of a manifold pressure gauge, I've thought about that as well, but ultimately that's not something that's very useful. I'm not running a boosted application so I know what my max manifold pressure is (ambient). I suppose it could let me know if the air filters were clogged/clogging but I still don't think it's worth doing.

The manifold pressure gauge is useful as a diagnostic tool on NA engines for finding manifold/carb vacuum leaks and other anomalies. Engines at idle typically show around 18-20" of vacuum, and decreases with throttle plate opening (as one would expect). Mechanics that are well-versed in the gauge operation can identify sticking valves/spark plug gap issues/sub-optimal timing/etc. Again, it's more of a diagnostic tool than a quick-glance "is my engine running okay" instrument.

 

[Ted]

The manifold pressure gauge is useful as a diagnostic tool on NA engines for finding manifold/carb vacuum leaks and other anomalies. Engines at idle typically show around 18-20" of vacuum, and decreases with throttle plate opening (as one would expect). Mechanics that are well-versed in the gauge operation can identify sticking valves/spark plug gap issues/sub-optimal timing/etc. Again, it's more of a diagnostic tool than a quick-glance "is my engine running okay" instrument.

Agreed with your points there, but in that case it's definitely something that I wouldn't expect to use much. In my time as a mechanic, we never needed to use manifold pressure as a diagnostic operation. Then again it could have potentially been beneficial and we just didn't use it anyway.

 

[Ted]

Went to the auto parts store at lunch and picked up a new starter as well as some more Right Stuff, and then went by Tractor Supply for some nuts, bolts and a tap for one of the holes I need to tap. I went with a new CarQuest starter from Advanced Auto, figuring that should work well.

Interesting note on the starter that I hadn't noticed, but the guy at Advanced Auto saw while checking out the core. When the crankshaft snapped and the flywheel was moving around, it ended up damaging the nose of the starter. I hadn't noticed that (the starter was pretty dirty), but another good reason not to put that in and go with a new one.

 

[Ted]

I'm starting to think about the switches that I'll need. I think the cleanest option will be just drilling holes in the dash panel for the switches and mounting my toggle switches there. The reality is that I won't need many. The switches I expect to have will be:

- Tail/marker lights
- Headlights
- Ignition/EFI/fuel pump
- Blower motor for HVAC
- AC compressor (requires blower motor for HVAC to be on)

And, of course, an engine start switch or button

The heated seats come with their own switches which I will probably mount either to the seats themselves or on the transmission tunnel, normal spots for those to go. But alternately I could add switches for those. Also potential for adding manual switches for turning on the electric fan and the water pump, although I think the water pump should be tied to the master and the fan I expect to be tied to a thermostatic switch and the AC compressor. This is a simple car.

I want to go with high quality switches and covers that will feel good and feel like they have a good solid connection and feel to them. I'm debating what to go with on this. Mil spec switches I think would probably meet all the requirements there and also handle the exposed environment well. Of course they're also expensive, and I'd rather use spade connectors on the back (although screw-in would be fine as well). Definitely not solder.

I'm also debating whether I want to go with just a normal toggle switch for the "engine start" or else something more interesting. Since all I'll need to be able to power is the solenoid it's not going to need to be very high amperage. And somewhere in there is the master on/off switch. Again, with all of it I want something that has a good and solid, not cheap, feel. That's a hard thing to gather from just looking at something online, and I don't have much of an idea of brands for something like that.

 

[asicer]

I'm also debating whether I want to go with just a normal toggle switch for the "engine start" or else something more interesting.

Too cliche?

How about spacecraft style?

 

[FormerHangie]

I'm starting to think about the switches that I'll need. I think the cleanest option will be just drilling holes in the dash panel for the switches and mounting my toggle switches there. The reality is that I won't need many. The switches I expect to have will be:

- Tail/marker lights
- Headlights
- Ignition/EFI/fuel pump
- Blower motor for HVAC
- AC compressor (requires blower motor for HVAC to be on)

And, of course, an engine start switch or button

The heated seats come with their own switches which I will probably mount either to the seats themselves or on the transmission tunnel, normal spots for those to go. But alternately I could add switches for those. Also potential for adding manual switches for turning on the electric fan and the water pump, although I think the water pump should be tied to the master and the fan I expect to be tied to a thermostatic switch and the AC compressor. This is a simple car.

I want to go with high quality switches and covers that will feel good and feel like they have a good solid connection and feel to them. I'm debating what to go with on this. Mil spec switches I think would probably meet all the requirements there and also handle the exposed environment well. Of course they're also expensive, and I'd rather use spade connectors on the back (although screw-in would be fine as well). Definitely not solder.

I'm also debating whether I want to go with just a normal toggle switch for the "engine start" or else something more interesting. Since all I'll need to be able to power is the solenoid it's not going to need to be very high amperage. And somewhere in there is the master on/off switch. Again, with all of it I want something that has a good and solid, not cheap, feel. That's a hard thing to gather from just looking at something online, and I don't have much of an idea of brands for something like that.

Longacre makes good stuff: http://www.longacreracing.com/products.aspx?itemid=1732

 

[Ted]

Too cliche?

Those are really common, but the look is fairly classic and does work. I'm not opposed to that style at all and may go for it.

One thing that's important to me is the feel, though. So something that is well built and feels solid matters. I saw one idea that was very interesting on an episode of Jay Leno's garage. See here:

If you go through some of the details of the car, one thing the guy did was he overlaid a piece of leather over the pushbutton switches. There were two ideas behind it. First was having a very clean look since you then didn't see any switches anywhere, just the piece of leather. Second was that when you touched the switches, what you felt with your finger was a nice quality piece of leather rather than a piece of cold metal. I found that idea very appealing and I'd like to duplicate that if I could figure out how he did it.

Another thing I looked around for was a leather toggle switch covers. For obvious reasons that would be difficult to do, and I couldn't find them. But I would definitely like those if I could find them.

How about spacecraft style?

Also a cool idea.

Longacre makes good stuff: http://www.longacreracing.com/products.aspx?itemid=1732

I took a look there. So do their switches have a high quality feel when you flip them? One idea there I hadn't considered but really like was the single switch for ignition and starting with off-on-on/start. Removes one switch, and seems like a good idea.

 

[Ted]

I watched the above video from Jay Leno's garage again when the builder was talking about the switches. He said he used touch pad switches underneath the leather. I started looking at that and it would definitely be more work than I want to do.

I think that the best option will be the standard (albeit cliche'd) toggle switches with covers like noted above by @asicer

 

[Matthew]

Don't forget the ejection seat button:

 

[asicer]

I watched the above video from Jay Leno's garage again when the builder was talking about the switches. He said he used touch pad switches underneath the leather. I started looking at that and it would definitely be more work than I want to do.

So I had a chance to re-watch the video too (this time with sound). I thought it was a cool idea, but...

• He mentioned touch switches under the leather. There are two possibilities for that. The first is a capacitive sensor. You probably don't want that because it's too complicated and it probably wouldn't work with driving gloves. The second is piezo switches, which are less complicated. They act more like a conventional momentary push button with a very short throw but you'd still be on the hook for rigging up a latching circuit for the on/off functions.
• I get the "no labels" thing but that blank piece of leather seems a bit awkward to me. I think it would have looked better if there were at the very least circles engraved and/or embossed where you are supposed to touch (I have access to a laser cutter/engraver if you are willing to supply the material).
• As long as we're talking about cutting, engraving and embossing leather, it would also be cool if it could be engraved thin enough for status lights to shine through from behind. Either that or cut tiny perforations to let just enough light through.
• His switch bank sat a little too proud of the panel for my tastes. I would have preferred it to be closer, if not flush or even recessed.

Between the spacecraft switches and the missile cover, I have a slight preference for the spacecraft switches. It's both vintage and space age at the same time and the windowed door over the push button matches really well with the toggle switch guards. However, you can't go wrong with the missile cover no matter how cliche it may be.

 

[Ted]

Don't forget the ejection seat button:

Right now my plan is to use a Momo Anatomico shift knob:

This is the same shift knob that I had on both of my manual transmission converted Jaguar XJ-Ss, and I'm running the long version of the shift knob on my Ram. I really like it.

The steering wheel I'm going with is a wood wheel, though, so a wood shift knob, especially with a Cobra on it, could be a good option. A quick Google search doesn't find any good options for that, though.

 

[Ted]

So I had a chance to re-watch the video too (this time with sound). I thought it was a cool idea, but...

• He mentioned touch switches under the leather. There are two possibilities for that. The first is a capacitive sensor. You probably don't want that because it's too complicated and it probably wouldn't work with driving gloves. The second is piezo switches, which are less complicated. They act more like a conventional momentary push button with a very short throw but you'd still be on the hook for rigging up a latching circuit for the on/off functions.
• I get the "no labels" thing but that blank piece of leather seems a bit awkward to me. I think it would have looked better if there were at the very least circles engraved and/or embossed where you are supposed to touch (I have access to a laser cutter/engraver if you are willing to supply the material).
• As long as we're talking about cutting, engraving and embossing leather, it would also be cool if it could be engraved thin enough for status lights to shine through from behind. Either that or cut tiny perforations to let just enough light through.
• His switch bank sat a little too proud of the panel for my tastes. I would have preferred it to be closer, if not flush or even recessed.

Between the spacecraft switches and the missile cover, I have a slight preference for the spacecraft switches. It's both vintage and space age at the same time and the windowed door over the push button matches really well with the toggle switch guards. However, you can't go wrong with the missile cover no matter how cliche it may be.

I agree with everything you say there. I think I'm pretty much settled on good quality toggle switches. The other thing I was thinking about in this case was what sort of a feel/touch I am looking for in this car. Although this is a lightweight car, it's a very manual and direct car. Manual steering, manual brakes. So something like touch pad switches underneath leather would detract from that idea in this case.

I was thinking about the comparison driving the XKR yesterday. The steering on it in the parking lot is very light, and the speed sensitive steering does a great job of firming it up to a correct amount. But the overall point is low effort. The shifter for the transmission has a very light movement shifting between P R N D 4 3 2 (no 1, for some reason). It feels appropriate. The buttons are plastic, of course, but they have a light touch to them, which again, is appropriate for the car. The truck wouldn't feel right if its inputs were that light, and I think the Cobra wouldn't either.

So yeah, cliche'd toggle switches with covers.

 

[FormerHangie]

I took a look there. So do their switches have a high quality feel when you flip them? One idea there I hadn't considered but really like was the single switch for ignition and starting with off-on-on/start. Removes one switch, and seems like a good idea.

IIRC they had a nice feel, it's been a long time and toggle switch feel isn't the first priority when you're racing.

These guys have mil spec Honeywell switches: https://www.milspecwiring.com/Switches_c_323.html, should be better than what Home Depot stocks,

 

[SoonerAviator]

What about some type of billet switch panel?



Plenty of customizable switches that are backlit. Would be retro with the billet look, but modern for the functionality.

https://billetautomotivebuttons.com/

 

[Ted]

What about some type of billet switch panel?

View attachment 79725

Plenty of customizable switches that are backlit. Would be retro with the billet look, but modern for the functionality.

https://billetautomotivebuttons.com/

I've seen some people do those on their Cobras and they do look pretty nice. Two questions are 1) Do I want push-button switches vs. toggle and 2) Do I want switches labeled like that?

The more I think about it, the more I think that toggle switches that are either unlabeled or minimally labeled is what I want. With how few switches I have and nothing that would really be bad if in the on position, leaving things unlabeled I think is fine and also makes it harder for anyone to try to steal the car.

 

[tmyers]

My son's 68 Chevelle had a hidden momentary switch that had to be made or it wouldn't start. It was under the dash and not easily found if you didn't know where it was.

Sent from my SM-N970U using Tapatalk

 

[Ted]

Friday night we saw Ford v. Ferrari in an IMAX theater. I think the last time I saw a car on opening weekend would've been 15 or more years ago. No movie since has made me want to see it on opening weekend, and few have even been interesting enough to me to bother wanting to see them in theaters. I've been eagerly anticipating this movie since June 3rd, when the initial trailer was released.

Since the Cobra wasn't ready, we instead drove the XKR. Not a Ford or a Ferrari, but was built when Ford owned Jaguar, and still a performance car. Sadly, the local Cobra club didn't arrange a group drive-in like they'd originally said they would when the movie was announced. But Laurie and I used it as a date night, and the Cobra wasn't ready anyway, so just as well.

Without giving anything away, the movie did not disappoint at all. Obviously it's Hollywood so there were some inaccuracies, but I was frankly amazed at just how accurate it was on the whole. The driving scenes were fantastic with little for me to complain about as far as inaccuracies go. I am no expert on the history of the GT40, but from what I know, they did seem to try to keep things largely accurate. The story is incredible enough that it didn't need to be embellished or exaggerated much, although of course most (if not all) of the script was fabricated. The movie was very worth seeing, and one that makes me both excited and proud to be building a Cobra replica.

I'm at least somewhat disappointed that I didn't have the Cobra ready in time for the opening night. A movie of this magnitude does not come around often. However with Laurie and I have a date night and with the chilly temps, it wouldn't have been a particularly pleasant drive. To get the Cobra completed in time would've been doable, but ultimately stressful to have a deadline. As a friend of mine pointed out, for projects such as these, it is better not to have deadlines.

The movie does leave me more conflicted on whether to build a GT40 replica or an XJ13 replica as the next car. Something I like about the GT40 is that it's possible to build a replica that's correct (at least largely so) down to the engines used. The story of the GT40 is a fantastic one, and while the engines were racing engines (whether 289 or 427) they were also still Ford engines. The XJ13 ultimately is the racecar that never was, and the engine used in it was a Jaguar V12, but significantly different from what became the V12 used in the E-types, XJ-Ss, and XJ12s (along with others). For me engines are a big deal, and if building a replica of a car I like for there to be a level of authenticity to some extent.

Either way, the next car is a long ways off, I still have this car to work on. And while first start is something that I can see happening, it's not there... yet.

 

[Ted]

A little bit ago I had a good phone call with the production manager from Romac headquarters in Australia. They're willing to make me a balancer that meets what I want, and are going to work on building one. This looks like it will include the serpentine belt pulley, be 28 oz external balance, and include the 36-1 toothed trigger wheel. They're about a month out on production so they don't know if they'll get one before the end of the year between production and shipping, but that's fine. The reality is I'm more than a month away from running the engine anyway so that delay is fine. So we'll see how this works out, but I'm optimistic about having the balancer solution figured out.

After looking at the fuel lines, I'm still conflicted about location and what exactly I want to do, so that means some more pondering. What I think I like the idea of the best is running the fuel lines towards the firewall and then utilizing the rear ports on the fuel rails for the supply/return, with the fuel pressure regulator bolted up to the firewall. This I think would result in the best setup. Some people have said I shouldn't run fuel lines right up against the firewall, or that I shouldn't bolt the fuel pressure regulator to the firewall. The alternative there would be running fuel lines either above or underneath the headers on the passenger side, which I'm not sure I'm a big fan of, either. No matter what those lines are fairly close to the headers and will require some amount of fuel lines within a few inches of the headers, but I definitely don't like the idea of fuel lines above the headers. Curious on thoughts others have, but I do need to spend some more time staring at it and figuring it out.

Laurie heads back to work tomorrow. I think my goals for this time will be putting in the last aluminum panel for the trunk area, figuring out the fuel lines, and then getting the starter and the oil pan installed. I may also buy a spool of wire and start running some of the wiring for the car, at least for the circuits that I know I want to rough areas.

 

[SoonerAviator]

I can't imagine what difference it makes if the fuel lines are on the firewall or above the headers. As long as they are secured properly, braided/heat shielded, and don't have connections/splices above the headers, I don't see why it's a problem. Once your get below the headers and onto the frame rail, you can run hard lines or whatever makes the most sense.

 

[Ted]

I can't imagine what difference it makes if the fuel lines are on the firewall or above the headers. As long as they are secured properly, braided/heat shielded, and don't have connections/splices above the headers, I don't see why it's a problem. Once your get below the headers and onto the frame rail, you can run hard lines or whatever makes the most sense.

I tend to agree. One thing with the Cobra builders is you have a lot of people who come up with ideas that aren't entirely based in reality.

No matter where you put the fuel lines even with a bit of clearance you shouldn't need to worry about the temperature. 495F is the temperature when gasoline self-ignites, and 395F is where it boils. Of course at higher pressure (the line will be running at figure 35-45 PSI) that temperature goes higher. So I'm not too worried there.

One friend of mine pointed out that what he'd want to make sure of would be the lines being in locations where I can easily check the connections for leaks. That is a fair point.

Last night I was looking at things in the engine bay a bit, and I could see either location (firewall or forward) working, but I think it will be a lot cleaner and neater looking done at the firewall. So that'll be my plan.

 

[SoonerAviator]

Only thing you might be concerned about is possible vapor lock issues if this was a carbureted application, but since it’s not, just route it whichever manner makes the most sense and has as little interference with hot parts as possible.

 

[Ted]

Only thing you might be concerned about is possible vapor lock issues if this was a carbureted application, but since it’s not, just route it whichever manner makes the most sense and has as little interference with hot parts as possible.

Agreed.

On the Jaguar V12s, they had a "fuel cooler" that routed the fuel through the low pressure side of the air conditioning. I think the theory had to do with some conditions where the fuel could boil or otherwise cause running issues. My first XJ-S had no air conditioning for quite a while, and once it did I still didn't run the fuel cooler, and I never noted any issues. That's the only car I've ever seen something like that on, too. It does make me wonder what conditions the factory had issues under since I never saw anything that indicated an issue with that in my time. It might've been one of those theoretical things or corner cases that never was seen in the field.

With my wife at work, it's time to start looking at the fuel lines and getting that worked out.

 

[Zeldman]

What will the fuel pump be, electric or manual.??

 

[Ted]

What will the fuel pump be, electric or manual.??

Fuel pump is a Walbro 255 LPH electric in-tank pump.

 

[Hang 4]

FWIW, I had my fuel regulator "inside and on the firewall" on my 911. It's air cooled(or Oil if you want to be specific) and it gets really hot in there. Never had any issues, including vapor lock on hot starts. This is post Megasquirt. The Porsche CIS OEM injection system had issues when heatsoaked, but MS with fuel rails and real injectors was no problem.

The irony of GM injectors working so much better in a Porsche product was worth a laugh.

 

[Ted]

FWIW, I had my fuel regulator "inside and on the firewall" on my 911. It's air cooled(or Oil if you want to be specific) and it gets really hot in there. Never had any issues, including vapor lock on hot starts. This is post Megasquirt. The Porsche CIS OEM injection system had issues when heatsoaked, but MS with fuel rails and real injectors was no problem.

The irony of GM injectors working so much better in a Porsche product was worth a laugh.

The CIS/K-jet setup when working properly is an ok system, but it seemed to me like it gunks up and starts to have problems faster than the earlier fully electronic EFI setups like D-jet. As I recall it also had a huge flapper valve for a MAF, which is a huge hindrance on performance. EFI really didn't hit "prime time" until about 1990.

Those CIS/K-jet cars were some of the first to really benefit from MegaSquirt, arguably even moreso than carbureted cars.

I'm still debating what I want to do as far as MegaSquirt and EDIS goes. For EDIS, I'm more wondering if I want to try to find a new Ford wiring harness that has the appropriate connectors. I'm also considering just trying to pick up a wrecked late 90s 5.0 Explorer. That would give me everything I need to get the EDIS together and running. The problem then is I have a bunch of used components, and I hate putting those onto a new car. I should get over that probably. But I'm seeing plenty of Explorers I could pick up for $500, take the parts off, and then probably sell the rest of it for $500.

 

[Hang 4]

I did the Ford thing for my 911. Coil pack, EDIS module, plug wires. I went to a U-Pull junkyard and got 3X what I needed, went to an O'Reilly's and got them all tested. Sold the leftovers on Ebay for a small profit. Easier that re-selling an entire car if you have that option.

MS was a huge improvement over CIS. Prior to that, the most common option was to backdate to carbs.

 

[SCCutler]

For those of you who have converted to a MegaSquirt setup, where did you start? What all components need you add?

 

[Ted]

For those of you who have converted to a MegaSquirt setup, where did you start? What all components need you add?

Spike, that's pretty variable depending on what you're starting with and what you're planning on going to, since the system is so versatile and can control essentially anything from a TBI setup to a full on multi-port with coil-on-plug ignition (depending on which model you get). It also depends on what exists for your application since some people have to go as far as fabricating or modifying an intake manifold to support fuel injectors.

I'm assuming you're talking about your Eldorado which, as I recall, has a very old multiport EFI system and probably an HEI distributor. Given that, you could probably just buy the Megasquirt of your choosing and install it in place of the original computer. Some people will even buy a spare/dead computer for an existing EFI setup, install the Megasquirt, and then put the wires to the appropriate pins within the spare/dead computer so they don't have to hack up the wiring harness at all.

That might not be a bad place to start if the ignition is working, and then you could go from there to adding in ignition or whatever else you want to do.

 

[Hang 4]

Everything Ted said + a few more details

This company has plug and play MS systems. https://www.diyautotune.com/ Their site is not a bad place to get ideas and learn. There a few forums as well that have good info. The world ranges from folks that build the "brain" themselves to getting a package that is plug and play for a specific car and everything in between. Software wise, there is a program called Tunerstudio http://www.tunerstudio.com/index.php/tuner-studio that allows you to map the fuel and spark to your specific car and what you want for performance. There's a fee for TS, but it's well worth it.

For my 911, I did fuel first, that required the MS brain, fuel rails, pressure regulator, fuel pressure gauge, fuel injectors and bungs to adapt GM injectors to the 911 ports. Adding ignition required a trigger wheel, removing the distributor, an EDIS unit and coil pack from a donor car, new wires and rewiring and reprogramming the MS unit. I did this 10 years ago, so not sure I'm remembering everything.

Back to the regularly scheduled program - need more Cobra pics

 

[Ted]

For my 911, I did fuel first, that required the MS brain, fuel rails, pressure regulator, fuel pressure gauge, fuel injectors and bungs to adapt GM injectors to the 911 ports. Adding ignition required a trigger wheel, removing the distributor, an EDIS unit and coil pack from a donor car, new wires and rewiring and reprogramming the MS unit. I did this 10 years ago, so not sure I'm remembering everything.

Funny thing there. Because of how the 302/351 are designed (the distributor driving the oil pump) you need to have something still in the distributor hole that will turn the camshaft spinning into spinning the driveshaft for the oil pump. On the EDIS Explorers with 302s, they addressed this by creating a "cam synchrophaser" which goes in the distributor hole and is completely useless other than to create a check engine light and drive the distributor.

The 351 uses a bigger oil pump driveshaft than the 302 (I think 3/8" vs 5/16"). Bigger is better there in my opinion, but what that also means is that the 302 cam synchrophaser, while a clean little unit that would do what I need, couldn't work without modification. The other option is a 351 distributor that I either just put in and leave alone or (since that would look silly) put something like that in and then have a blank cap machined that looks less silly.

Back to the regularly scheduled program - need more Cobra pics

Right now I haven't actually done anything worthy of a picture. However, someone made a point that I'm still thinking about. The intake I have has a plenum area for vacuum on the underside between all of the throttle bodies. That plenum has a flat metal plate held in by 10 screws. I took the plate off and used some Right Stuff to make sure that it stayed sealed. However when I put the screws back in I tightened them, but I didn't LocTite them. Someone made the point that they should be LocTited so they don't come loose and fall into the vee.

So that has me somewhat conflicted. The reality is I don't think they would come loose as they got a good torque down and they're fine threaded screws. If they did fall down, they would probably just fall into the vee and sit there. Technically they could end up sitting on a lifter or pushrod but I can't imagine them staying there for long or being able to get lodged between the lifter and pushrod.

Theoretically the last thing that could happen would be for the screw to then make its way through one of the drain holes further down where it could drop into the spinning crankshaft. The theoretical worst case there would be that it would get lodged between two connecting rods or between a connecting rod and the crank counterweights. Realistically these are weak screws and even if it ended up there, I think the worst that would occur would be that they'd nick the rotating assembly. Obviously undesirable but I don't think catastrophic, and would then end up in the oil pan.

I think I'm overthinking this and it's probably fine. But it does have me wondering if I should pull the intake back off (which I really don't want to do) to LocTite them.

 

[SCCutler]

Spike, that's pretty variable depending on what you're starting with and what you're planning on going to, since the system is so versatile and can control essentially anything from a TBI setup to a full on multi-port with coil-on-plug ignition (depending on which model you get). It also depends on what exists for your application since some people have to go as far as fabricating or modifying an intake manifold to support fuel injectors.

I'm assuming you're talking about your Eldorado which, as I recall, has a very old multiport EFI system and probably an HEI distributor. Given that, you could probably just buy the Megasquirt of your choosing and install it in place of the original computer. Some people will even buy a spare/dead computer for an existing EFI setup, install the Megasquirt, and then put the wires to the appropriate pins within the spare/dead computer so they don't have to hack up the wiring harness at all.

That might not be a bad place to start if the ignition is working, and then you could go from there to adding in ignition or whatever else you want to do.

Ted, that's exactly correct.

In fact, I think I have a PDF somewhere from a fellow who (many years ago) did a mega sport set up on a similarly-equipped El Dorado; if I found it, it will be attached to this posting, for your viewing pleasure.

I biggest confusion came from exactly how the Throttle Position Sensor interfaces, because the TPS on the El Dorado is not a potentiometer-type, but rather, it has (if I recall correctly) either three or four wires and a phase-shift depiction.

 

[Ted]

@SCCutler I think you’d simplify your system overall. You’d probably want to replace the TPS with a proper potentiometer type. The “fast idle” I’m assuming is basically an electric valve of some sort that opens the throttle or otherwise adds air. That you could either add a manual switch for, maybe a relay of some sort, eliminate entirely, or replace with a conventional idle air control valve.

One question I have would be whether the injectors are low or high impedance. Normally MPFI injectors are high impedance (that’s what you want) but that system is old enough you should check, and it wouldn’t be hard to check.

I don’t see a coolant temp or intake air temperature sensor. Your want to add those. But to be honest, in Texas, you could probably get by without it. But it’s not too bad to add one.

 

[Ted]

With Black Friday sales going on all week it seems, I made a couple of orders today for the Cobra and may make some more before the weekend is up.

First I ordered my gauges. I went with good old Autometer Sport Comp gauges that fit the technological period I’m going for. Going with 5” for the speedo and tach and 2 1/16” for oil pressure, oil temp, coolant temp, voltage, and fuel level. The temp/pressure gauges are mechanical and 270 degree sweep. Saved a couple hundred dollars there.

The MegaSquirt manufacturers had a 10% off sale so I ordered my MicroSquirt ECU. This will also control ignition.

I looked at ignition coils (waning genuine Ford for that) and no places I found had deals on those or the modules. I found one place on Amazon selling the coils a lot cheaper than other places, but it’s a bit sketchy so I’m going to see if Summit Racing will price match when they have people back in the office.

It’ll be nice to have those in house since I’m a ways away from needing them but not too far out. Mostly I need to actually do some work on the car!

 

[Matthew]

I saw one of these today and I though of the DuPuis Automotive and Wrecking Service.

I gotta think if any of your vehicles needs pulled out of a predicament, this ought to be able to handle the job.