DuPuis Family Cobra Build

[Ted]

Are you able to drive it? If so, are you happy with the feel of acceleration it has? If the compressions are good and you are happy with it then put in the cam you want and the heads you want. Save the new engine for a winter project down the road when you have a better idea of what you want. On the other hand, with the heads off and the cam out you are not that far away from a rebuild.

There's not a good way to drive the car as-is without pulling the transmission, putting a new clutch in, and putting it all back together. That's way too much work. Right now there's a problem (I think with the throwout bearing) so the clutch won't disengage and it makes quite the noise when running. I could try starting it in gear and driving it as-is just doing clutchless shifts to get an idea. Might be worth doing, or I could really break stuff.

The T-5 should work out Ok. Most people that break them do so with a bad shift. (ask me how I know) The 41% overdrive gear will really make a highway trip less stressful on the ears as well as the gas tank.

I had an '69 Nova with a built 396, 3:73 gears and a Muncie 4 speed. The national speed limit was 55, and at that speed the motor was really wound up. Buuut..... at 55, slip it back to 3rd gear......

Good thing gas was only around 38 cents a gallon.....

I've heard that on the bad shifts. I'm pretty good with a manual, so I'm less concerned about that. Plus I'd be upgrading the internals anyway, which helps to address that. So to me that seems a more logical one for sure.

 

[PaulS]

https://www.ebay.com/itm/2015-Musta...090865?hash=item287be1da31:g:2ZkAAOSwze9cuKJ5

 

[Ted]

https://www.ebay.com/itm/2015-Musta...090865?hash=item287be1da31:g:2ZkAAOSwze9cuKJ5

The Coyotes are really popular in the Cobras, and I did think about them for a bit. Coyotes weigh around the same as 302s, so there's that. I don't want to do a Coyote for a few reasons:

1) Don't want to deal with the modern cam phasers and all those bits that come with Coyote engines. Yes I realize the computer handles them and they're basically trouble-free, but this is supposed to be more of an old school car. Coyote isn't old school.

2) The sound just isn't the same. Coyote engines sound good, yes, but a DOHC 32-valve V8 doesn't sound the same as a pushrod V8.

3) The Coyote engine does not fit in the engine bay very well. A 302 is physically much smaller, and thus easier to work on.

4) I ordered this car for a 302/351, and so the motor mounts are wrong.

I'm sticking with the 302/351 based block, and at this point I'm settled on the 302-based block. The question is just what I do from there.

 

[PaulS]

The Coyotes are really popular in the Cobras, and I did think about them for a bit. Coyotes weigh around the same as 302s, so there's that. I don't want to do a Coyote for a few reasons:

1) Don't want to deal with the modern cam phasers and all those bits that come with Coyote engines. Yes I realize the computer handles them and they're basically trouble-free, but this is supposed to be more of an old school car. Coyote isn't old school.

2) The sound just isn't the same. Coyote engines sound good, yes, but a DOHC 32-valve V8 doesn't sound the same as a pushrod V8.

3) The Coyote engine does not fit in the engine bay very well. A 302 is physically much smaller, and thus easier to work on.

4) I ordered this car for a 302/351, and so the motor mounts are wrong.

I'm sticking with the 302/351 based block, and at this point I'm settled on the 302-based block. The question is just what I do from there.

There are a lot of them on ebay. From about $1,700 to $14,000. If I were doing this I'd go the reman or crate route. You've been disappointed once with the private route. There's still plenty of work to do without having to fix the motor.

https://www.ebay.com/sch/i.html?_fr...acat=0&LH_TitleDesc=0&_odkw=5.0+coyote+engine

 

[Ted]

There are a lot of them on ebay. From about $1,700 to $14,000. If I were doing this I'd go the reman or crate route. You've been disappointed once with the private route. There's still plenty of work to do without having to fix the motor.

https://www.ebay.com/sch/i.html?_fr...acat=0&LH_TitleDesc=0&_odkw=5.0+coyote+engine

I also like building engines myself. So @jesse 's idea of buying a short block and then building it how I want seems like it might be the way to go.

 

[FormerHangie]

I also like building engines myself. So @jesse 's idea of buying a short block and then building it how I want seems like it might be the way to go.

There are lots of engine builders that offer a 331 stroker short block. If you're wanting 400 hp out of this engine I'm guessing you'd want the extra displacement.

Some of these are quite reasonable, and some of them are pretty expensive. Seeing that you're not racing said car, you probably don't need the latest and greatest (and most expensive).

A professionally built short block sounds like a good place to start.

 

[Ted]

There are lots of engine builders that offer a 331 stroker short block. If you're wanting 400 hp out of this engine I'm guessing you'd want the extra displacement.

Some of these are quite reasonable, and some of them are pretty expensive. Seeing that you're not racing said car, you probably don't need the latest and greatest (and most expensive).

A professionally built short block sounds like a good place to start.

Yeah, the more I think about it the more I think that would be a good way to go. The 331 is what appealed to me initially as it's superior geometry wise to a 347, and the shorter stroke should help a bit on being rev-happy. Plus I'm thinking I'll go flat tappet solid lifter cam rather than roller as there's a significant cost savings, and if I use the correct oil (Valvoline VR1 Racing seems to be popular) I shouldn't need to worry too much about wiping out cam lobes. So to that end, don't need a roller block per se.

Since it's a street car I agree I don't need anything too fancy, so a base 331 short block from a reputable builder should do the job. That would also let me use the heads I have already (pick pistons accordingly) and not worry about the bigger valves.

So I think what I've settled on is pull the drivetrain, try to sell the engine as-is, rebuild the T-5 if it looks good when I take it apart (and rebuild it with a mid-shift setup), buy a 331/347 short block, and then build the engine up from there.

 

[ed hunter]

Newbie here, just joined the site. Just getting into flying which is why I came aboard. However cars are my hobby. I built a FFR cobra 10 years ago with a 351 and a T5. I currently race a 05 363ci/tko swapped mustang in the american iron group with NASA (national autosport asso.) - road racing, no drag stuff. Solid roller, custom camshaft, shaft rockers, external oil pump, all the nice stuff. A very fun car to drive fast, we reach 150-155mph on the big tracks. I also build a 96 racecar for my son also powered with a 363ci engine. Nothing fancy, hydraulic lifters, OTS camshaft, canfield heads. Actually more fun to drive than the other one because it's lighter by 300lbs.. For the FFR I'd go with the 351 block - it's bigger and just looks better in the engine bay. If you go with the 331 you can make a 302 block last, but if you want the power of the 347/363 you'll want the boss block or dart block and they weigh nearly the same as the larger 351 windsor block. If you're going to hammer on it that is. A zero balance 363 revs plenty fast.... The 05 car is carbed, the 96 car runs a holley sniper system (throttle body injection). Ask away if you've got questions....
That said, I'm more than happy with the 351 in my FFR. Its a 74 block, 60 over, with a mild camshaft and flat tappets, AFR195 heads, airgap intake, and 650 carb. Runs like a top and more than enough power for such a light car. Dyno'ed years ago around 350hp to the tires. And a T5 will last if you dont' do tons of burnouts because the car is light.
Anyway I have to have 5 posts on here so this is #1.... ed

 

[SoonerAviator]

Newbie here, just joined the site. Just getting into flying which is why I came aboard. However cars are my hobby. I built a FFR cobra 10 years ago with a 351 and a T5. I currently race a 05 363ci/tko swapped mustang in the american iron group with NASA (national autosport asso.) - road racing, no drag stuff. Solid roller, custom camshaft, shaft rockers, external oil pump, all the nice stuff. A very fun car to drive fast, we reach 150-155mph on the big tracks. I also build a 96 racecar for my son also powered with a 363ci engine. Nothing fancy, hydraulic lifters, OTS camshaft, canfield heads. Actually more fun to drive than the other one because it's lighter by 300lbs.. For the FFR I'd go with the 351 block - it's bigger and just looks better in the engine bay. If you go with the 331 you can make a 302 block last, but if you want the power of the 347/363 you'll want the boss block or dart block and they weigh nearly the same as the larger 351 windsor block. If you're going to hammer on it that is. A zero balance 363 revs plenty fast.... The 05 car is carbed, the 96 car runs a holley sniper system (throttle body injection). Ask away if you've got questions....
That said, I'm more than happy with the 351 in my FFR. Its a 74 block, 60 over, with a mild camshaft and flat tappets, AFR195 heads, airgap intake, and 650 carb. Runs like a top and more than enough power for such a light car. Dyno'ed years ago around 350hp to the tires. And a T5 will last if you dont' do tons of burnouts because the car is light.
Anyway I have to have 5 posts on here so this is #1.... ed

Nice post. Early on in the thread we suggested a 351w with one of the Edelbrock carb/head/intake packages which make it pretty easy to get 400HP+ with proven results. Ted seems to think it won’t be as “rev-happy” as the stroker 302.

 

[ed hunter]

Ted seems to think it won’t be as “rev-happy” as the stroker 302.

It won't be.... the rotating assembly is heavier, the bearings are larger.... But it'll be more than enough to leave double black marks as long as you want to! Torque is where it's at.... Rev's break stuff. My 363's are limited to 6500rpm. My buddies I race with, who run the coyote engines, rev theirs to 7600-7800. They sure sound cool, but most of them break stuff quicker than I do. I've got 4-5 race seasons on my junk and its still going strong... BTW, if someone is looking for SBF parts, or FFR parts, shoot me a PM. I've got quite the collection of spare parts... not necessarily a good thing...

Oh, just say no to an edelbrock carb.... These lightweight cars need a holley or equivalent double pumper... IMO. I'm particular to the quickfuel variety myself.

 

[Ted]

Welcome, @ed hunter ! Glad to have you hear and appreciate the input. I'll give you the summary of my thinking on engines for this kit.

When I ordered the kit I originally ordered it planning a 351. My logic was that rather than do the 302 stroker, I could get a 351 short block cheaper (notably cheaper). Also, the individual throttle body setup I want to do is cheaper for the 351s, so there would be a cost savings there.

Really for me the goal with the car is lightweight and also very responsive, as well as making the right sounds. I'm not going super light in all respects - I am adding in HVAC and will put in some Dynamat to cut down on the aluminum panels rattling and increase the days for comfortable driving as it will be a street car. But my understanding is that a stock 302 engine will be around 50 lbs less than a comparable 302, and the lighter weight rotating assembly should be more responsive. So, two positives there for the ultimate goal, albeit with an extra cost. The solid cam rather than hydraulic is part of the responsive and feel - I'm trying to reduce the number of areas where lag can occur. Plus I like the sound better.

You're the first person to make the point that a 302 looks too small in the Cobra bay. I've not spent much time around the real things to evaluate, but that's an interesting point. I'm generally going for something that's also going to be easy to work on, and so extra clearance is a good thing.

So, that's where I am. Certainly interested in your thoughts engine wise, but the 331 is appealing to me. 400 HP is the goal, and I think that'll be plenty of power. I'm not going for something that's going to set any records, just something that I enjoy driving.

Any thoughts on the T-5? The G-Force straight cut gears are very appealing, but some of what I've read say they're not available anymore (haven't checked). G Force also makes some helical gears that I know are still for sale, but it seems the Astro Performance A5 kit is more popular and would make enough power for what I want. I need to tear into this transmission first to see how good it is (and if it's usable at all).

I figure I'll take a video of the current engine running and then put it up for sale, see if anyone local on the Factory Five group will be interested in buying it.

 

[ed hunter]

Post #3... maybe in a bit I can attach some pics! When I built mine I just wanted a nice cruiser. I wasn’t planning to race it, etc. I’ve always loved the look, so with my wife’s blessing I ordered the kit. The patriots had just won the super bowl and FFR was having a big sale. So I became a pats fan even though I’m really a saints guy!
Look at pics of a 302 vs a 351 in the engine bay. You’ll see what I mean. I put big block valve covers on and it looks even better. When I bought the kit I wasn’t going to spend a lot on the engine, etc. . I bough a carbed 302 with iron heads. Then changed my mild. Bought a 351 off some kid in Atlanta, he had it in a drag car. Swapped the heads, intake, oil pan and it’s still running strong. Mine has a standard mustang WC T5 behind it. I have drag radials on the back, 315’s I think. I don’t think the Astro gear set is worth the expense. I don’t think G-force still makes their kit, heard they got their parts from Astro anyway. I had a Astro t5 in an old racecar and broke it too, along with a couple other t5s. 3rd gear is the weak spot. If you’re sold on the t5 check out levy racing. He builds good ones, but for the money get a TKO. My advuce would be just get a good t5 and run it. If you break it then get something stronger. But as light as these cars are it’ll last a while. Most break when you hop the rear anyway. We run .82 5th gear ratios on track but the .64 o/d is good for the street. IMO you don’t need helical gear set on the road. If you’re going to launch at 5k and pull the nose up on drag launches.... ;-)
I run 355 gears in the rear. Stock clutch diff. Manual brakes, no power steering. Wish I had power steering. If you’re going to auto cross def want PS. Did you get the 3 link rear? Hopefully the koni shocks and not the bilsteins. If you need parts LMK. I think I’ve got the Bils that came with my kit you can have for cost of shipping. I too would like to go with the Weber look efi but it’s too much , esp now that I’m wanting to fly. I decided I need a cheaper hobby than cars so why not airplanes...

 

[Ted]

I'm not planning on racing mine, either, but I do expect to have some track days. I want a nice cruiser, but as a former sport bike guy I do appreciate the "reduce weight and add lightness" philosophy. Reality is this will be the lightest car I've had by a good margin so I suppose there's a good point to say that I won't notice the difference in terms of the 50 lbs from the 351 vs. the 302/331, especially factoring in the torque benefits. What I will notice though is the revvy/responsive. One of my goals with this car is to make it very revvy/responsive, and also to do things I haven't done before. That's part of the goal behind the individual throttle body EFI. Real Webers would be great, but not feasible.

I'm going to be running a 3.73 rear end from a parts car I got. Haven't torn into it but my initial checks of it seemed solid enough. I'm going to be running vacuum power brakes and electric power steering (goal is the alternator to be the only engine-driven accessory). My wife is going to be driving the car and doing some autocross isn't out of the question. I did go for the 3-link rear and the Koni shocks/FFR coil-overs all around. I'll definitely let you know if I need parts.

On the engine, having something that looks small isn't necessarily a bad thing since like I said, I do want clearance. I used to work on Jaguar V12s. I've had lots of time working in cramped engine bays, and I'm now at the point were, at least for this car, having more room to work isn't a bad thing.

 

[Ted]

This coming weekend is looking like a good time to get some work done, so I'm trying to plan out what I want to do.

If I look at things linearly, I would pull the rear end out of the parts car as that's what I need to work on next. However if I do that, then the car becomes immobile, and I don't want to leave it in my driveway. So I think what I will probably do is work on pulling some of the other things that need to get pulled without making the car essentially impossible to move:

- Fuel tank
- Inertia switch
- Engine and transmission

Who knows how much time I'll have which will determine what I work on.

Once I get the engine and transmission out, my intention is to start tearing into both of those to see what's usable and what's not. I'm hoping the transmission can at least be a good core to start from and that the block is rebuildable. This weekend I started the engine for two of my car guy friends, and they (and I) became pretty convinced it had a rod knock in it. The other option is it was built by a complete idiot, which is of course possible. So we'll see what's in there when I pull things apart.

Although the next big item on the car itself is the rear end, it's probably smartest to be working forward on the engine and transmission since the engine will take some time at the machine shop and ordering the rotating assembly if everything looks good.

I'd really like to get the car into a "go-kart" phase at some point when it's warm enough to actually go-kart the thing some, but there are a lot of steps between now and then.

 

[-KLB-]

Would almost wonder if it is cheaper find some used 70s ford junk rear axle to shove in to keep it a roller, or a trailer axle.

 

[Ted]

Would almost wonder if it is cheaper find some used 70s ford junk rear axle to shove in to keep it a roller, or a trailer axle.

I'm not interested in that. This is a parts car and the goal is to remove parts from it, not add to it. Plus then I'd have to somehow bolt that on the parts car and then it's something else I'll have to get rid of. My plan is to use the rolling stock that came with the parts car temporarily for the roller and go-kart phases, and then buy the new wheels and tires close to actual use. Maybe I'll look for black Friday deals or something.

 

[Ted]

While doing a bit of Googling I managed to fine a 4x Weber setup that was cheaper than what I'd seen previously. Before they were all around $4k. Here under $3k:

http://www.carburetion.com/Products/ProductDetails.aspx?part=K302-IDF44
http://www.carburetion.com/Products/ProductDetails.aspx?part=K302-IDF48

The original intent included using a carb. I'd wanted to do Webers because that's another bucket list item, but at $4k for the setup I wasn't about to do that. However <$3k is more reasonable as I'd be spending around that if I went for the individual throttle body EFI setup.

For now I'm just going to bookmark it, but I think what I'll do is wait on running the fuel lines until I actually purchase a fuel device.

 

[PaulS]

I'd want to get a good look at that axle too, especially the differential and bearings. Simple stuff to check when it is not installed.

 

[Ted]

I'd want to get a good look at that axle too, especially the differential and bearings. Simple stuff to check when it is not installed.

I plan on that. I'm going to be putting in new axles anyway to shorten it, and so while in there I want to check the bearings, clearance, etc. and make sure everything looks good.

 

[ed hunter]

What gear ratio in the rear?? Mines got 3:55 I think. It makes a difference with 1st gear functionality too.

 

[ed hunter]

What year is the donor?? Sorry for not looking back at the prior posts. If it’s a SN chassis the axles are 0.75” longer per side than the fox. The housing is the same. I’d replace all the bearings anyway, easy to do with a press. At very least the pinion bearing as they make a hell of a racket when they’re bad. I did not go the donor route when I built mine, but bought used parts where I could. Didn’t want nor have room for a parts car.

 

[Ted]

What gear ratio in the rear?? Mines got 3:55 I think. It makes a difference with 1st gear functionality too.

The rear is 3.73s. I'm aiming for a 2.9x 1st gear and 0.6ish 5th gear, which I think should get the RPMs about perfect.

What year is the donor?? Sorry for not looking back at the prior posts. If it’s a SN chassis the axles are 0.75” longer per side than the fox. The housing is the same. I’d replace all the bearings anyway, easy to do with a press. At very least the pinion bearing as they make a hell of a racket when they’re bad. I did not go the donor route when I built mine, but bought used parts where I could. Didn’t want nor have room for a parts car.

The donor is a '95. Yes, I'll be replacing the axles with the slightly shorter ones so those bearings will be easy and cheap to replace at that time. I probably will do the others too just to make everything simple and new. I'm also going to paint the axle with POR 15, and I figured I'd put new hard lines on to replace the old rusted brake lines too. So it'll look and be "new"/fresh when it goes in. I have a 20-ton press.

 

[Ted]

I started working pulling things off the parts car today, and expect more work done tomorrow.

I pulled the gas tank, accelerator pedal cable, and started working on prepping for pulling the engine. I think I should get the engine and trans pulled tomorrow.

The accelerator cable is old enough it has some of the plastic cracks but the cable itself moves freely so it’s useable.

The fuel tank I’ll see when I open it up. The top has some surface rust on it. I need to at least pull the pump and fuel sender to see what it looks like underneath. Maybe some POR15 will be enough maybe I’ll buy a new one. If there’s any internal rust I’ll buy a new one.

The rear end, we’ll see what I find once I tear into it. When I pulled the driveshaft today a small amount of fluid leaked out of the nose seal. So I at least need to get in there. However I’m shocked with how tight it is - almost zero play between the input pinion and the axles. That’s a good sign, but who knows what’s inside.

Tomorrow’s aim is to pull the transmission first and then the engine. If I can do that I can then move the car away from the house and pull the rear end, which is what I really want. But once the engine and tranny are out I’ll start tearing into them.

 

[Ted]

Engine and transmission are out of the car! Really not too bad of a job to do. I had the back of the car jacked way up and that made getting the transmission out easy enough.

The transmission seems to be original or close to it, but everything feels tight externally. So we’ll see about that. The starter is new.

The engine, this will be interesting. It’s not a Cobra intake or GT40p heads as advertised, but the engine has been gone through to some extent. I’m thinking poorly. The noise and clutch issues seem to be related to the flywheel being loose. Literally, it wobbles back and forth and the rear main deal looks new but installed wrong. We’ll see what I find:

 

[Sac Arrow]

I'm certainly glad Ted is talking T5 manual transmission. Whew. For a while I thought he might throw a slushbox in there.

 

[Zeldman]

The noise and clutch issues seem to be related to the flywheel being loose. Literally, it wobbles back and forth and the rear main deal looks new but installed wrong. We’ll see what I find:

I am interested in what you find, and a little worried as well. I was sort of expecting you would find the clutch plate in backwards, or the throwout bearing in backwards.

 

[Ted]

I'm certainly glad Ted is talking T5 manual transmission. Whew. For a while I thought he might throw a slushbox in there.

Ahem.

There is no car I have ever driven for which I wanted a slush box. Even my Lincoln Town Car I was debating swapping in a manual transmission.

 

[Ted]

I am interested in what you find, and a little worried as well. I was sort of expecting you would find the clutch plate in backwards, or the throwout bearing in backwards.

I’m curious but not worried. It is what it is and I’m rebuilding the engine no matter what. If the block is FUBAR then I just go with a short block. No big deal.

 

[SCCutler]

I think a Town Car with a 5-speed would be wicked cool. Raylan Givens, eat your heart out!

—-

Saw a nice Marauder today. Always wanted one of those...

 

[Ted]

I think a Town Car with a 5-speed would be wicked cool. Raylan Givens, eat your heart out!

—-

Saw a nice Marauder today. Always wanted one of those...

My '92 Town Car, with a 22-year-old Ted with hair that was spiked due to the wind in Wichita:

I then took it autocrossing that day:

I really did enjoy that car, especially after doing a few upgrades - giant Addco anti-roll bars (1.25" front and 1" rear), 17" wheels and tires off of a 2005ish Town Car, electric fan, Magnaflow exhaust (quiet, but a very nice tone).

What I really wanted to do with that car was replace the 4.6L V8/AOD-E with a Triton V10 and a 5-speed.

 

[SCCutler]

After my own heart; that would have been sweet.

Would the 10 have easily fit?

And, would the shifter have been a big, honkin' truck shifter, or could you have engineered a reasonably attractive short-throw rig?

I think I'd still be happy with a nicely-sorted V8 (5.4?), quiet but free-flowing exhaust and a nice, tight suspension. Last-generation bodywork, best in black, like every livery car in NYC.

 

[Ted]

I never did any hard measurements, but I think the V10 would've been fine. The only potential clearance issue area would've been the hood, and cowl scoops can always be added. That would look funny on a Town Car.

Given the location of the transmission tunnel to the seats, the shifter would have had to be pretty long. But, it would've been enjoyable and still reasonable on throw. Regardless, it's a moot point now. I actually really liked that early 90s body style, probably because that's what I remember from growing up in New York.

I'm thinking more about the engine and transmission, and wondering what I'll find in there and the engine. My son loves taking things apart with me, so I'll probably wait until a day when he can help me.

 

[Ted]

A couple other comments before I forget about them.

After having the T-5 out of the car, I'm quite certain I want to go this route instead of the TKO. It is noticeably smaller and very noticeably lighter weight, so I'll be happy about that for weight reduction and ease of installation.

One thing I'm wondering about is the oil pan. It looks stock, but it's an aft sump, which surprises me. I thought all 5.0s were front sump. Does anyone know the SN95s enough to know if that was stock? This oil pan looks to be in good shape so if it works and doesn't hang low on the Cobra, I think I'll likely use it. The aftermarket deep sump pan that came with the first parts car is pretty, but it's too deep and will hang below the frame. For obvious reasons you don't want that if you can avoid it.

Once I tear into things if the block looks good and not overbored too badly, I'll probably order a rotating assembly and take it to the machine shop. He said the engine was rebuilt with flat top pistons, so I'll be curious to see what's in there. I'm assuming a stock bottom end right now, but we'll see.

 

[Ted]

I figure over the weekend I'll start tearing into the engine. While I'm doing that, I'm thinking about one big thing that I don't have yet determined, and that's the camshaft. I've had to refresh my memory on some of the variations of camshaft inputs, and also take a look at some dyno runs that I can find to get a few ideas on things. As a reminder, current plan for the engine is:

- Ford 302 stroked to 331
- Compression still not certain, but probably something in the 9.5-10.5:1 range
- 4x Weber carbs
- Edelbrock Performer RPM heads with 2.02/1.60 valves
- Planning on using some Comp Camps 1.7:1 roller rockers I have
- Redline around 6,500 RPM max
- 3.73 rear end
- ~400 HP goal

This is a street car but goal is the experience and the sound, so I want a lopey idle.

I'm thinking a tight lobe separation angle will be what I want, and that should also help the low end a bit. I don't care about low vacuum at idle since the only vacuum accessory I'll have will be power brakes and that's fine. I'm also going with a solid flat tappet cam for a few reasons. One is cost, another is sound, and another is the general goal of removing slop anywhere I can. Yeah, solid cams have extra maintenance requirements of adjusting valve lash, but that's fine on this car. It's not a daily driver.

I'm leaning towards this Isky cam. I've always liked Isky, and talked with Ed Iskenderian before he passed about some of his cam modifications for my V12 Jaguars at the time, so I think that would add some old school cool to some extent. This cam looks like it fits what I want well:

https://www.summitracing.com/parts/isk-381333/overview/make/ford

I imagine the RPM range they have listed is based off of a 302, so the 331 would push it down a bit, and then the 1.7:1 rockers would push it back up a bit. Yeah, it'll like to rev, and that's a good thing.

Given that a tight lobe separation angle increases cranking compression and lower RPM dynamic compression, I'm thinking that might push me towards a lower compression/flat top piston. That'd work out pretty well as most of the rotating assemblies out there end up in the ~9.5:1 range with my heads, including valve reliefs. That's the other thing - with 2.02 valves that should be pretty reasonable on clearance while meeting power goals and sound pretty awesome with a good lopey idle.

 

[ElPaso Pilot]

I figure over the weekend I'll start tearing into the engine. While I'm doing that, I'm thinking about one big thing that I don't have yet determined, and that's the camshaft. I've had to refresh my memory on some of the variations of camshaft inputs, and also take a look at some dyno runs that I can find to get a few ideas on things. As a reminder, current plan for the engine is:

- Ford 302 stroked to 331
- Compression still not certain, but probably something in the 9.5-10.5:1 range
- 4x Weber carbs
- Edelbrock Performer RPM heads with 2.02/1.60 valves
- Planning on using some Comp Camps 1.7:1 roller rockers I have
- Redline around 6,500 RPM max
- 3.73 rear end
- ~400 HP goal

This is a street car but goal is the experience and the sound, so I want a lopey idle.

I'm thinking a tight lobe separation angle will be what I want, and that should also help the low end a bit. I don't care about low vacuum at idle since the only vacuum accessory I'll have will be power brakes and that's fine. I'm also going with a solid flat tappet cam for a few reasons. One is cost, another is sound, and another is the general goal of removing slop anywhere I can. Yeah, solid cams have extra maintenance requirements of adjusting valve lash, but that's fine on this car. It's not a daily driver.

I'm leaning towards this Isky cam. I've always liked Isky, and talked with Ed Iskenderian before he passed about some of his cam modifications for my V12 Jaguars at the time, so I think that would add some old school cool to some extent. This cam looks like it fits what I want well:

https://www.summitracing.com/parts/isk-381333/overview/make/ford

I imagine the RPM range they have listed is based off of a 302, so the 331 would push it down a bit, and then the 1.7:1 rockers would push it back up a bit. Yeah, it'll like to rev, and that's a good thing.

Given that a tight lobe separation angle increases cranking compression and lower RPM dynamic compression, I'm thinking that might push me towards a lower compression/flat top piston. That'd work out pretty well as most of the rotating assemblies out there end up in the ~9.5:1 range with my heads, including valve reliefs. That's the other thing - with 2.02 valves that should be pretty reasonable on clearance while meeting power goals and sound pretty awesome with a good lopey idle.

Bah. Sounds like a lot of work.

Why don’t you just bolt your body kit onto a rolling Tesla chassis, and pipe in the sound.

Plus, the car would be faster.

 

[FormerHangie]

I figure over the weekend I'll start tearing into the engine. While I'm doing that, I'm thinking about one big thing that I don't have yet determined, and that's the camshaft. I've had to refresh my memory on some of the variations of camshaft inputs, and also take a look at some dyno runs that I can find to get a few ideas on things. As a reminder, current plan for the engine is:

- Ford 302 stroked to 331
- Compression still not certain, but probably something in the 9.5-10.5:1 range
- 4x Weber carbs
- Edelbrock Performer RPM heads with 2.02/1.60 valves
- Planning on using some Comp Camps 1.7:1 roller rockers I have
- Redline around 6,500 RPM max
- 3.73 rear end
- ~400 HP goal

This is a street car but goal is the experience and the sound, so I want a lopey idle.

I'm thinking a tight lobe separation angle will be what I want, and that should also help the low end a bit. I don't care about low vacuum at idle since the only vacuum accessory I'll have will be power brakes and that's fine. I'm also going with a solid flat tappet cam for a few reasons. One is cost, another is sound, and another is the general goal of removing slop anywhere I can. Yeah, solid cams have extra maintenance requirements of adjusting valve lash, but that's fine on this car. It's not a daily driver.

I'm leaning towards this Isky cam. I've always liked Isky, and talked with Ed Iskenderian before he passed about some of his cam modifications for my V12 Jaguars at the time, so I think that would add some old school cool to some extent. This cam looks like it fits what I want well:

https://www.summitracing.com/parts/isk-381333/overview/make/ford

I imagine the RPM range they have listed is based off of a 302, so the 331 would push it down a bit, and then the 1.7:1 rockers would push it back up a bit. Yeah, it'll like to rev, and that's a good thing.

Given that a tight lobe separation angle increases cranking compression and lower RPM dynamic compression, I'm thinking that might push me towards a lower compression/flat top piston. That'd work out pretty well as most of the rotating assemblies out there end up in the ~9.5:1 range with my heads, including valve reliefs. That's the other thing - with 2.02 valves that should be pretty reasonable on clearance while meeting power goals and sound pretty awesome with a good lopey idle.

I didn't realize that the Webers were back in the plan. Did you find a set for not too much money?

 

[ElPaso Pilot]

 

[Ted]

Bah. Sounds like a lot of work.

Why don’t you just bolt your body kit onto a rolling Tesla chassis, and pipe in the sound.

Plus, the car would be faster.

Said in my best John Wayne or Sam Elliot voice:

"Life ain't just about numbers, son."

Actually I have no problem with people putting a Tesla powerplant in a FFR car. Factory Five's motto is "Built, not bought." The whole point of it is to build your car, the way you want to build it, and that you end up with something that's uniquely yours and not cookie cutter.

I really laugh at the people on the forums who will say it's sacrilege to do a Tesla powerplant in it. If they were talking about an original Cobra, sure, but these are replicas. Put whatever you feel like in it - and people have done that. Every variant of Ford engine ever produced, Chevy motors, there's one Hot Rod that was even built with a Chrysler 331 Hemi (and it sounds awesome).

For me, though, the 302 stroked to a 331 I think will be the best bet, especially with a big lopey cam.

Looked like they lucked out there when the back of the car spun around. That didn't seem to be intentional.

Personally I don't care a whole lot about the sound of burning rubber, I want to hear the roar of an engine. So for me that doesn't do a whole lot.

I didn't realize that the Webers were back in the plan. Did you find a set for not too much money?

I found a company selling the full setup for about what it was going to cost to buy the EFI individual throttle bodies, fuel injectors, ECU, etc. And then I would have to program the ECU, and while I know how to do that just fine, it just doesn't have quite the same spirit and simplicity of going all mechanical. So I think that's what I'm going to go with. Also saves me the hassle of plumbing a return line for EFI.

 

[PaulS]

Said in my best John Wayne or Sam Elliot voice:

"Life ain't just about numbers, son."

Actually I have no problem with people putting a Tesla powerplant in a FFR car. Factory Five's motto is "Built, not bought." The whole point of it is to build your car, the way you want to build it, and that you end up with something that's uniquely yours and not cookie cutter.

I really laugh at the people on the forums who will say it's sacrilege to do a Tesla powerplant in it. If they were talking about an original Cobra, sure, but these are replicas. Put whatever you feel like in it - and people have done that. Every variant of Ford engine ever produced, Chevy motors, there's one Hot Rod that was even built with a Chrysler 331 Hemi (and it sounds awesome).

For me, though, the 302 stroked to a 331 I think will be the best bet, especially with a big lopey cam.



Looked like they lucked out there when the back of the car spun around. That didn't seem to be intentional.

Personally I don't care a whole lot about the sound of burning rubber, I want to hear the roar of an engine. So for me that doesn't do a whole lot.



I found a company selling the full setup for about what it was going to cost to buy the EFI individual throttle bodies, fuel injectors, ECU, etc. And then I would have to program the ECU, and while I know how to do that just fine, it just doesn't have quite the same spirit and simplicity of going all mechanical. So I think that's what I'm going to go with. Also saves me the hassle of plumbing a return line for EFI.

Yikes, that's the problem with light weight and a lot of horsepower, too much throttle and the rear wheels want to be in front. I saw a brand new Mustang freshly impaled on a telephone pole last year. Apparently he had turned off the stability control and launched too aggressively from a stop sign. Not good.

 

[Ted]

Yikes, that's the problem with light weight and a lot of horsepower, too much throttle and the rear wheels want to be in front. I saw a brand new Mustang freshly impaled on a telephone pole last year. Apparently he had turned off the stability control and launched too aggressively from a stop sign. Not good.

A lot of people who build Cobras carry over the ABS and traction control from factory Mustangs when they do the builds.

I personally hate both of those items. Not that I'm Dan Gurney or any of the greats of racing - I'm not, not even close. But I did cut my teeth on vehicles that lacked any such crutches and I'm happier operating without them, even on liter class sport bikes. It takes mature and judicious use of the throttle, brakes, and clutch, and also knowing proper ways to expand your envelope and learn the power band of the engine.

I'm not sure those guys did that.