DuPuis Family Cobra Build

[SoonerAviator]

We have QuikTrips here, also RaceTracs, they're pretty similar. As you go up the Atlantic seaboard, you start seeing Sheetz and Wawa. IMO, they're all interchangeable. Some of them have soft serve FroYo, some have beer caves, some serve fresh food, some don't.

There's a QuikTrip at Clemson, SC along I-85 that sells so much gasoline I think they must have their own pipeline spur.

I've been to several Sheetz (including the HQ in Altoona, PA; and RaceTracs, but never the Wawa. We musn't leave out Buc-ee's, either, but they're more of a competitor to Luvs and the big truck stops. I'll still give a slight edge to QT in most cases, mostly just based off of employee service than the store itself.

Edit: I've only ever been through Kansas once, and that was on the way back on a long motorcycle trip. The part I was in just seemed flat and featureless, plus very hot. I started the day in Las Animas, CO, and ended it in Blackwell, OK.

Not an exciting leg of your jouney, lol. Blackwell isn't exactly a mecca of beautiful geography, either, but about the first stop inside OK when coming in on I-35.

 

[Bill]

Qu(KW)ikTrips are top tier certified, so it's good gas as well. I only fuel with top tier.

https://toptiergas.com/licensed-brands/

 

[Ted]

We have QuikTrips here, also RaceTracs, they're pretty similar. As you go up the Atlantic seaboard, you start seeing Sheetz and Wawa. IMO, they're all interchangeable. Some of them have soft serve FroYo, some have beer caves, some serve fresh food, some don't.

There's a QuikTrip at Clemson, SC along I-85 that sells so much gasoline I think they must have their own pipeline spur.

Edit: I've only ever been through Kansas once, and that was on the way back on a long motorcycle trip. The part I was in just seemed flat and featureless, plus very hot. I started the day in Las Animas, CO, and ended it in Blackwell, OK.

Coming from Cincinnati (where everything is bad), QuikTrip gives you an instant positive feeling when landing in Kansas.

- Consistently clean
- Top tier gasoline
- Friendly staff
- Very good selection of food and drinks, much better than most other gas stations

I don't eat much for fast food, but I'll get a hot dog or brat from QT sometimes.

Clutch plate in backwards....or the center of the plate spun out..?? Or could be a broken pressure plate.

Clutches are simple. Throw everything away and put in new stuff with better pressure.

I had a hot rod 283 that around 6800 RPM the stock pressure plate would just quit. It would lose pressure and just smoke the clutch plate. It would look like the engine blew until the RPMs came down and the clutch would slam together again chirping the rear tires....

It's pretty much irrelevant since I'm not planning on using the drivetrain myself, it's more that I want to be able to sell it as a running drivetrain "some work required." Makes it easier to sell. I'm still thinking a TKO for the Cobra.

You have tornados too in Kansas, just ask Dorothy.

Meh, just ask @Ted DuPuis .

 

[EppyGA]

QT has been in Atlanta for many years now but recently expanded into SC and NC making our trips up to Concord, NC much better.

 

[Ted]

Drilled and cleco’d the first two panels with the help of my girls this evening. Then removed the panels to paint them and rivet them on.

 

[Ted]

The kids are getting into the building thing, at least somewhat. This evening Genevieve (my little gasoline girl) said "We need to go build the Cobra!" We worked on it for about the length of one attention span (15 minutes), during which my son took some acetone to clean off the aluminum panels that are ready for paint. Tomorrow I'll let him paint the panels. I found the box with front suspension components in it, which will be the next step after putting these panels on.

Per the manual, after that comes the rear suspension. I may start to go out of order a little bit depending on timing and being able to pull the rear suspension out of the donor car. There are some other parts (aluminum panels, etc.) I can start to go out of order on without messing things up, and I may do that. I suppose I should also find the rivets since that will be a shortly upcoming necessity.

I picked up an air/hydraulic rivet gun from Harbor Freight today (the heavier duty one) for pulling the pop rivets. That'll make it all go quite a bit easier given the number of rivets to be pulled.

 

[Craig]

There's a QuikTrip at Clemson, SC along I-85 that sells so much gasoline I think they must have their own pipeline spur.

That’s like the Buc-ees near our place. I think they get a tanker drop every 2 hours or so. It’s one of the mid sized ones...only 96 pumps.

 

[SoonerAviator]

That’s like the Buc-ees near our place. I think they get a tanker drop every 2 hours or so. It’s one of the mid sized ones...only 96 pumps.

Lol they're almost comically big. I've only stopped at the one by Texas Motor Speedway.

 

[Craig]

Sooner: That's the one by me. The one being built over on 35E in Denton is 126 pumps I think.

 

[SoonerAviator]

Sooner: That's the one by me. The one being built over on 35E in Denton is 126 pumps I think.

I run past both of them on my trips from Tulsa to Ft Worth, since I usually cut over from US-75 to I-35 at Gainesville. Its been 2 months since I made that run, so I didn't know if the Denton was finished with construction and open yet. I still stop at the QT in Gainesville just to send some revenue back North of the border, lol.

 

[Craig]

Denton isn't open yet...probably a couple more weeks and it should be.

 

[Ted]

So here's my latest question: carburetors

This engine will be carb'd. One of the reason is I want something that is simple from an electrical perspective, without all the extra complexities of EFI. Not that I can't do it, I've been working on EFI for nearly 20 years, it's just that I don't want to.

I really, really want Webers. The look, the sound. But the reality is that for 44 IDAs (which seem to make more sense than the 48s for the horsepower range I'm aiming for) it'll add a solid $2k to the cost vs. a new Edelbrock 4-bbl carb and a standard intake. I've only driven a car with Webers once about 12 years ago, it was a Triumph TR3 with DCOEs on a back road where it was all at full throttle. I really enjoyed the carbs, and for any car guy there is an allure to Webers. Otherwise my multi-carb experience has always been SUs or Strombergs (not at all applicable to this engine) and otherwise I had a few 4-bbl Quadrajets that worked fine despite their reputation for being junk. Yes, Webers are also notorious for being challenging to tune.

For those who have more experience with Webers (and carbs in general), I'd be curious as to thoughts on Webers on a street car. While I intend on racing this some, ultimately this is a street car and it will live on the street. I don't care about fuel economy, but I do care about having decent part throttle and mid RPM performance since this engine won't spend all of its time up at high RPM.

 

[FormerHangie]

So here's my latest question: carburetors

This engine will be carb'd. One of the reason is I want something that is simple from an electrical perspective, without all the extra complexities of EFI. Not that I can't do it, I've been working on EFI for nearly 20 years, it's just that I don't want to.

I really, really want Webers. The look, the sound. But the reality is that for 44 IDAs (which seem to make more sense than the 48s for the horsepower range I'm aiming for) it'll add a solid $2k to the cost vs. a new Edelbrock 4-bbl carb and a standard intake. I've only driven a car with Webers once about 12 years ago, it was a Triumph TR3 with DCOEs on a back road where it was all at full throttle. I really enjoyed the carbs, and for any car guy there is an allure to Webers. Otherwise my multi-carb experience has always been SUs or Strombergs (not at all applicable to this engine) and otherwise I had a few 4-bbl Quadrajets that worked fine despite their reputation for being junk. Yes, Webers are also notorious for being challenging to tune.

For those who have more experience with Webers (and carbs in general), I'd be curious as to thoughts on Webers on a street car. While I intend on racing this some, ultimately this is a street car and it will live on the street. I don't care about fuel economy, but I do care about having decent part throttle and mid RPM performance since this engine won't spend all of its time up at high RPM.

I dealt with Webers of the one throat per cylinder variety in two different race cars. The biggest takeaway I have from that experience was that if they were programmed correctly, they worked very well. You may question my use of the word "programmed", but let's face it, a carburetor is a mechanical computer, and you program it by changing jets, emulsion tubes, and needles. However, developing the proper programming was not a skill that very many people possessed back then, and to make things worse, many more people thought they had that skill than actually did. If you can find a Weber setup that is made specifically for your engine, you should be fine, if you can't, you'll have to become that programmer, and to make things more challenging you'll be developing that program on a running car rather than a dynamometer.

You mentioned something about potentially racing this car. If you're racing and fuel injection is allowed, get it.

I came into the car scene in the early 1970's when cars were carbureted. I didn't know all that many guys that hotrodded their cars, and none of those that did went the multi Weber route. Once cars started coming with fuel injection, it was a bit of a mystery to all of us as the manufacturers were very closed mouthed about their systems. When some of the aftermarket guys started coming out with programmable fuel injection kits, the only people who used carburetors were we racers whose rules told us we had to.

If it were me in your situation, I'd go for a complete engine that included the intake. When you've got your car roadworthy, you're going to want to drive it, not jack around with carburetors. After you've had the car on the road for a year or so, if you really want those Webers, I bet you can sell your four barrel carb and intake for something, and then go to your Weber installation.

Actually, if it were me in your situation I'd want fuel injection. I lived through the carburetor years once, I have no desire to do so a second time.

 

[Bill]

I lived through the carburetor years once, I have no desire to do so a second time.

A-men! I lived through the carb years on bikes, FI is SO much better. Glad I'll never have to pull a rack of carbs and de-grunge again.

 

[-KLB-]

If you want your memories of this car to be many many dives into each carb to change the tuning, and many drives that just don't quite run right, and that nagging off corner hesitation that you can't quite tune out without making something else not quite work right, and this is all your idea of fun, then go for the webbers. Even 30 years ago, people who could balance and idle tune factory webbers that theoretically had the right jets and needles from the factory was few and far between.

I would suggest that if you think you really want to go this way, there may be some merit to starting with a 4 barrel set up. Get the suggested info for jets and other configuration, but put it away and don't look at it. Put in something that should be somewhat close. Figure out what the drivability symptoms are telling you, and what you should change, and go do it as many times as you need to.

Once you have that, consider if each time you had to do the process on 8 carbs. Would you still enjoy it? Consider if one carb gets an obsructed jet, you confident you can sort out which one it is? Or would you be rebuilding them all?

While I see a certain appeal to a stack of webbers, I also see a lot more appeal to enjoying a car like this, and I would want to get off on the right foot. And know what I was missing if it didn't go well, so I could evaluate when to pull the plug and go back.

The other thing to note, is that there are a lot of videos of setting up a carburetor and making a dyno run that make it look fairly simple, and they may even be somewhat acccurate, for engines that only run wide open for peak power. Accelerator pump configuration and mid range are more challenging from what I understand.

Whichever way you go, I look forward to watching.

 

[Ted]

I agree with the benefits of EFI. Having done product development and testing for EFIs for an OEM for a number of years, I certainly am capable of designing and tuning a system from scratch. Also if I wanted the velocity stacks of Webers, there are EFI setups for the 302 that use those, so that's a potential option if I wanted to go that route and get the look and the sound with the benefits of EFI.

On the whole, though, I just don't want to do EFI. I want a simple engine bay, don't care about emissions or mileage. But I do care about driveability, which was the point of the question, and a lot of driveability comes down to the skill of the tuner. I have no doubt that I can learn how to tune carbs well, including Webers, and frankly the carbs I've had I haven't ever had to mess with. Jumping from that straight into 4 Webers is a very Ted thing to do but the multi-carb aspect is a question.

The purpose of the car is to be a driver, sure, but if I just wanted to drive I would've bought a Viper (which I considered). Part of my other goal is learning, so messing with Webers would fall under that category.

The idea of starting off with a standard 4-bbl and potentially converting to Webers at a later point if I wanted to is worth consideration, though. Part of what I want from the Webers is the intake sound that you get (not to mention the impressive look when you open the hood), but I'm going to be happy with the sound no matter what I think. And, easy enough to tinker around more.

 

[Zeldman]

Actually, if it were me in your situation I'd want fuel injection. I lived through the carburetor years once, I have no desire to do so a second time.

I did carburetors ever since I could remember. The Quadrajets had bad reputations but done correctly they were better than Holley ever could be.

Seems in the race world we could buy a Holley for 150, then spend 700 on it to make it almost work, or we could go to the junk yard and look for a certain part number quadrajet, spend 50 bucks on it and out perform any Holley. So says the dyno. And it sure surprised people at the race track to see a "quadrajunk" out running in front.

Last carburetor I did for myself was an Edelbrock, which is just a remake of the Carter AFB. Basically I just smoothed a few surfaces to make a smoother air and fuel flow than what the mass production can do, changed the secondary's a little to match the engine size and away we went. The same engine with one of my carburetors would produce more HP and a little more gas mileage than a basic EFI setup. However there is after market EFI stuff that will beat me on power but it cost wheelbarrow fulls of cash to buy.

And yes, being able to build a carb is a dying art. There is nothing worse than having a vehicle with a worn out engine and a worn out carburetor. EFI makes it so much easier for the ''gas goes here, key goes here'' people.

Multi carb setups on cars are just too simple. I am contemplating building a 305 CID straight 6 with a three deuce set up for my old pickup.

The biggest problem I saw in the hot rod world was someone buying a used carburetor that was worn out and too big for their engine. They would come by our shop to get it fixed and to their disappointment we would show them why they got it for 20 bucks.

 

[Ted]

The used/worn out/wrong carb is exactly what I would not do. New. Period.

 

[sferguson524]

Lol they're almost comically big. I've only stopped at the one by Texas Motor Speedway.

We've got the world's largest chevron here outside of vegas..

https://lasvegassun.com/news/2018/jul/10/terribles-road-house-jean-touted-worlds-largest/

 

[jaybee]

Did the cylinder head bolts have sealant on them ?

 

[Ted]

Did the cylinder head bolts have sealant on them ?

I don’t recall.

 

[Ted]

Little progress today. The kids painted and riveted the first two aluminum panels on and then I put the upper control arms on. I think the next step will be pulling the rear end from the parts car.

 

[3393RP]

Ted, I would choose a Holley product over the Edelbrock AFB derivative. Tuning the AFB involves changing both the metering rods and jets, while the Holley metering circuit is simpler and changing the jets is easier. Making those changes on the AFB requires the removal of the fuel inlet and carb top. On the Holley, removing the bowls to get access to the metering blocks and jets just requires removing the fuel inlet fitting and the four screws that attach the float body to the carb.

A properly tuned AFB is a good carb. But unless you are going to spend the money for multiple dyno pulls, the Holley is easier to live with and is more readily adjusted.

But you probably know already know all of this.

One of the big disadvantages the AFB has is that if you slip up, the part disappears into the intake manifold.

Anyway, I would choose a Holley Model 4150 or 4160 between 650 and 850 CFM with an electric choke, dual fuel inlets, and vacuum secondaries. You know how to figure out the proper size. Mechanical secondaries might be more desirable if you so choose, but vacuum secondaries have always provided a better result for me on vehicles that are driven for fun and see the track occasionally.

 

[SoonerAviator]

Ted, I would choose a Holley product over the Edelbrock AFB derivative. Tuning the AFB involves changing both the metering rods and jets, while the Holley metering circuit is simpler and changing the jets is easier. Making those changes on the AFB requires the removal of the fuel inlet and carb top. On the Holley, removing the bowls to get access to the metering blocks and jets just requires removing the fuel inlet fitting and the four screws that attach the float body to the carb.

A properly tuned AFB is a good carb. But unless you are going to spend the money for multiple dyno pulls, the Holley is easier to live with and is more readily adjusted.

But you probably know already know all of this.

One of the big disadvantages the AFB has is that if you slip up, the part disappears into the intake manifold.

Anyway, I would choose a Holley Model 4150 or 4160 between 650 and 850 CFM with an electric choke, dual fuel inlets, and vacuum secondaries. You know how to figure out the proper size. Mechanical secondaries might be more desirable if you so choose, but vacuum secondaries have always provided a better result for me on vehicles that are driven for fun and see the track occasionally.

The Edelbrock is just about fool proof. It comes with color-coded springs/metering rods and swapping them out is a 30-second affair. Stuffing a shop rag in the throat of the carb eliminates any problem of dropping them in the carb. 500-600 cfm will be perfect for a 302-351w project when no forced induction is involved. The Edelbrock is easier to tune than a Holly, that’s mostly why it exists. Can you eek out a few more HP with a Holly? Usually, but it’s not as easy as dealing with the Carter/AFB designs for getting 95% of available HP right out of the box.

An Edelbrock Performer series 600cfm carb w/electric choke is going to be the easiest “out of the box” carb to get, imo. They’re also pretty much a set-it and forget-it carb, where I’ve had to tinker with Holly’s on occasion to keep them in tune.


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[455 Bravo Uniform]

We have an advantage the older mechanics didn’t have- data acquisition. I have Carter, Rochester, Holley, and Demon experience, zero Weber. But give the Webers a shot, and use EGT per cylinder or O2 logging to help you tune, then pull all the electronics off after you have it dialed in. Your brain is the ECU.

My kids remember tiny parts of all the stuff they helped me with when they were tiny. Enjoy it! They are having fun, and spending time with daddy, but probably won’t remember a lot of it. Doesn’t matter. Just an interesting footnote from a guy whose kids are in high school now.

 

[jaybee]

Finally got through all 8 pages. For what its worth in a prior life time I've busted plenty'o knuckles for a living including spending all day building and dyno testing Cajun sprint car engines as well as many other automotive specialty areas and car building.

At the end of the day, IMHO, unless you just have to say "I built it" you will always be money/time ahead to just buy a long block, rearend, etc, built by a specialist. Secondly, I totally get the idea of wanting the simplicity of the carburetor but you are really just trading the simplicity of installation for the complexity of use. When EFI systems came out initially costing $2000 and up it was worth the loss of time to spend tinkering with the carb as it doesn't really need all that much but with these new systems out there like the Holley SNIPER EFI for example that literally only has four wires to hook up carburetors just ain't worth the squeeze. In other words you'll trade a little bit of build simplicity to have something you can turn key on and have fun immediately and not have to tinker with.

Meh, two cents...

 

[jaybee]

PS - if you want a high quality ignition I'd recommend http://performancedistributors.com/

 

[3393RP]

The Edelbrock is just about fool proof. It comes with color-coded springs/metering rods and swapping them out is a 30-second affair. Stuffing a shop rag in the throat of the carb eliminates any problem of dropping them in the carb. 500-600 cfm will be perfect for a 302-351w project when no forced induction is involved. The Edelbrock is easier to tune than a Holly, that’s mostly why it exists. Can you eek out a few more HP with a Holly? Usually, but it’s not as easy as dealing with the Carter/AFB designs for getting 95% of available HP right out of the box.

An Edelbrock Performer series 600cfm carb w/electric choke is going to be the easiest “out of the box” carb to get, imo. They’re also pretty much a set-it and forget-it carb, where I’ve had to tinker with Holly’s on occasion to keep them in tune.


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I was thinking a 650 CFM would offer a little more margin. You sound like me, I would rather have a properly sized carb favoring the least CFM for the job, and the formula for determining that isn't rocket science. I think Ted said he was going with 370 or so CI.

Over the years I've seen people put Holley 850 double pumpers with mechanical secondaries on 5500 RPM street car engines with less than 400 CI and couldn't figure out why the engine ran like crap.

I've used both, I guess my preference is the Holley but I don't disagree the Edelbrock is a good carb. I've used the marine version on a couple of boats, and for years Mercrusier put Weber AFB clones on their stern drives. I owned four boats with that package. I am proficient in tuning both, but I have to say that the current crop of EFI choices are a heckuva lot easier to set up and tune than a carburetor.

 

[SoonerAviator]

I was thinking a 650 CFM would offer a little more margin. You sound like me, I would rather have a properly sized carb favoring the least CFM for the job, and the formula for determining that isn't rocket science. I think Ted said he was going with 370 or so CI.

Over the years I've seen people put Holley 850 double pumpers with mechanical secondaries on 5500 RPM street car engines with less than 400 CI and couldn't figure out why the engine ran like crap.

I've used both, I guess my preference is the Holley but I don't disagree the Edelbrock is a good carb. I've used the marine version on a couple of boats, and for years Mercrusier put Weber AFB clones on their stern drives. I owned four boats with that package. I am proficient in tuning both, but I have to say that the current crop of EFI choices are a heckuva lot easier to set up and tune than a carburetor.

Yeah, lots of guys thinking bigger is better with a big carb on a small bock motor. They’ll run, but it often results in poorer throttle response that can be difficult to remedy with jetting. If there’s forced induction being used, then the higher cfm makes plenty of sense. Many factory 302/351 motors had 500cfm carbs on them. 600-650cfm gives room for a hotter engine build or stroker applications.


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[Ted]

Appreciate the thoughts. My plan is to build the fuel system such that I could o carb or EFi, that way I have the flexibility if I decide to change.

I don’t know much about the different carb options for the 4-bbls, but 700-750 cfm seems about right for this build.

One thing I’ve considered (still am considering) is a velocity stack EFI setup. Look and sound of Weber’s without the timing hassle. It’ll be easier for when Laurie drives too, of course, since the car will start right up consistently.

The cheap EFI is usually a “you get what you pay for” setup. Of course I’m used to doing programming on OEM stuff which has a lot more options.

 

[Ted]

I've made a bit of progress on the build, but not a huge amount. The main thing at this point has been drilling out the foot boxes for both the driver and front passenger and starting to paint those panels. One tip that I got was to not rivet any panels in until I got to a point where I could determine I absolutely had to. That's good advice. I realized those F panels I riveted in should not have been riveted in yet, and I don't know why Factory Five recommends that. It gets in the way of the upper control arm tube, and apparently even body shops recommend not riveting them in because it makes it harder to adjust the hood pins. Oh well, lesson learned.

I have someone local who wants to buy the engine and transmission (and some other bits) from my parts car, so in a few weeks we'll probably pull it into the garage and rip those parts out for him, and then I'll pull the rear end as well (which is the biggest part I need for the Cobra). With that I'll end up adding the "Cobra" brakes (bigger rotors, more stopping is more better) and putting in the shorter width "fox body" axles, which will make 315s fit better in the back and are a couple inches narrower than the SN95 (which is what this parts car is).

The backorders from Factory Five have been pretty slow. At this point I've had the kit for about 7 weeks and I just got an eMail today about some of the items being shipped. Unfortunately none of them are the lower control arms, which I actually am ready for right now (and have been for several weeks). I talked about this to someone who's been building Factory Five kits for 20 years and he said the front lower control arms have been backordered as long as he's been doing these kits. When he was selling kits to people as a distributor he kept lower control arms in stock, gave those to people with the kits, and then when the backordered ones came in he kept them on the shelf to repeat the process. Pretty funny. With that said, the customer service has been very good thus far and I can still very positively recommend them.

 

[EppyGA]

Been almost a month and no update.

 

[Ted]

Been almost a month and no update.

Yeah, I know. It's been embarrassing how much no work has been getting done on it.

Factory Five at this point has sent me all of the parts that they owed me. At least I think they have, I have a few boxes that I need to open up just to confirm and do some more inventorying.

Part of the issue has been a more travel, as well as a busy Thanksgiving and my wife leaving her old job and starting her new job. She leaves today for 10-day indoc, making me single dad over that time. This weekend we might get back on it some with the kids while she's gone. At the very least, now that I have the lower control arms in hand I can bolt up the front suspension and then feel like I've made more progress. I'd also like to continue drilling and painting the aluminum panels, at least as much as I can get the kids interested in doing that.

There are a few garage items I need to do that may also be possible for this weekend. I finally bought LED lights for the ceiling in the garage, which are very much needed. I might be able to at least start getting those up. I also need to finish drilling holes in the cement for the lift and get those anchors mounted.

Yeah, slow progress. Who wants to come help?

 

[Matthew]

Yeah, slow progress. Who wants to come help?

My brother will be in town in another week or so, I'll tell him to ship his tools.

 

[EppyGA]

Congratulations on your wife's new job!!

 

[Ted]

Thanks, she's proving (once again) that she's a better pilot than me.

 

[Ted]

One other thing I'm thinking about doing in the near future is getting the cutouts done in the fiberglass. Factory Five was supposed to do this, and they didn't. So they agreed to (and I have this in writing) pay for a body shop to do it. The body is just sitting around anyway, and so it might be worth dropping it off to get those cutouts done. That lets me make progress without actually having to do anything.

 

[SaltH2OHokie]

It cranked fine once I got it off of the bad tooth on the flywheel, so it sounds like it's only got 1 or 2 teeth stripped off.

I had a 6 speed 7.3L Ford that I put a clutch and flywheel in, both purchased new from Southbend. Within 6 months, it was exhibiting signs of teeth missing from flywheel or Bendix. Turned out to be flywheel. Dreading dropping that giant tranny again so soon, I got really good at finding "hills" to park on in my very flat home area. Finally called Southbend, explained situation and they sold me a ring gear only. Pulled tranny, pulled flywheel. 5 teeth out of ~160 (ish? Going from memory) were damaged.

That should have been 1/30+ plus starts resulted in the flywheel being in the bad spot. I'm here to tell you that it was 1/1 if I cut the truck off in a busy drive thru so they could hear me over the engine, or in front of a business where it would be embarrassing to hear the sound of metal just barely scraping metal at high frequency. 100% of the time, it was on those 5 teeth.

Removing and replacing the ring gear using nothing but a friend and two torches was a real life lesson in thermal expansion and contraction.

P.S. I feel like the answer to all your engine questions is "LS".

 

[Ted]

Last night I did get into the garage and spent some time turning wrenches on it again after you all guilted me into it.

Main thing I did was install the lower control arms which arrived and were powdercoated to match the frame. I personally think the precision on location of the lower control arm mounts could be a little better than it was. It's hard to keep consistent but the rear lower control arm mounts there was enough play to shove a washer in between the control arm bushings and the mounts. I elected to do that in order to prevent too much preloaded bending in those mounts. Lower control arms are torqued down, and then next should be installing the front coil-overs (which I've already assembled and the front spindles/brakes. None of that should be too time consuming and then it looks/feels like there's actually progress having been made.

With Laurie out of town until next weekend that should give me some time in the evenings to work on it. As of now there are no transports scheduled this weekend or next, so I'll probably have the kids at home and work on some projects around the house and outdoors given the warmish temperatures that are currently forecast.

I had a 6 speed 7.3L Ford that I put a clutch and flywheel in, both purchased new from Southbend. Within 6 months, it was exhibiting signs of teeth missing from flywheel or Bendix. Turned out to be flywheel. Dreading dropping that giant tranny again so soon, I got really good at finding "hills" to park on in my very flat home area. Finally called Southbend, explained situation and they sold me a ring gear only. Pulled tranny, pulled flywheel. 5 teeth out of ~160 (ish? Going from memory) were damaged.

That should have been 1/30+ plus starts resulted in the flywheel being in the bad spot. I'm here to tell you that it was 1/1 if I cut the truck off in a busy drive thru so they could hear me over the engine, or in front of a business where it would be embarrassing to hear the sound of metal just barely scraping metal at high frequency. 100% of the time, it was on those 5 teeth.

That actually makes sense. Think about it looking at a propeller. Because you have compression strokes in a piston engine, those provide resistance that will tend to bias an engine towards stopping in approximately the same section relative to TDC on whichever cylinder's compression stroke finally stopped it. So on a V8 engine I'd tend to think you'd have more of a 1/4 chance of getting it on the bad spot. When you figure that you probably have some cylinders a bit stronger than the others, it's not necessarily surprising that it'll stop in the same location. Plus, Murphy's Law.

P.S. I feel like the answer to all your engine questions is "LS".

LS swaps are popular for good reason. That said, I don't see any good reason to do one in a Cobra other than because you really like LS engines. The car is set up for Ford engines (and can be set up for any flavor of Ford you feel like from FFR). There's one guy who put a 383 Chevy in because he's a Chevy (Corvette especially) person. I'm all in favor of doing something unique, but LS engines are so common that using one seems not unique even if it might be unique for the application.

What I decided on engine wise at this point has been a 351W because it's much more economical to do that vs. a 347 both in terms of short block build and also some of the accessories I want in the crate motor, including the velocity stack intake. The part that I'm still wrestling with is the extra 50 lbs over the front wheels that you get with a 351W based block vs. a 302 based block. While I am going for "reduce weight and add lightness" I'm not going for completely bare bones, and I'm also doing aluminum heads, so I'm thinking that balances out. Basically a 351W with aluminum heads gets pretty close to a 302 with iron heads.

 

[Ted]

I’ve made a bit of progress today. I’ve got both front spindles on the car, ball joints bolted up. I bought reconditioned spindles from someone who then went with the FFR spindles (supposedly better geometry, but an extra $500 or so) so I have fresh spindles, new hubs, reconditioned calipers. FFR has adapters to attach the spindles to the upper ball joints. They say to use the factory spindle to strut bolts, which are really expensive (like $40/side new). That doesn’t make much sense to me.

We also painted a few more panels. The drivers outer footwell panel has a few pieces of aluminum that go to push out part of it. We riveted that together. What I was advised to do for most of the panels was once drilled and painted, use a few clecos to hold them in place and don’t rivet until absolutely necessary. There’s enough assembly that’s way easier without panels in the way.

The kids are having fun. Today my son wanted to apply the silicone between the aluminum panels (that’s recommended to reduce rattling) and one of my girls wanted to paint the panels.

Nexr comes more panel drilling...