302/Cobra Engine Build

[rtk11]

What's the weight difference?

About 50 pounds between a 302 Windsor and 351 Windsor.

 

[rtk11]

To the OP: Since you’re building a Cobra, have you seen this post on the Factory Five forum?

https://www.ffcars.com/forums/38-2002-roadster-archives-read-only/52689-351w-de-stroked.html

 

[Ted]

Ted, how many AMU’s do you think you are gonna spend on this engine?

Much of it depends on how this engine looks when I tear into it. Depending on that, I may end up dumping it and looking for a different donor engine. But if it looks good, I'm thinking around $2k all in, $2,500 tops. That includes carb/intake, not necessarily alternator and for water pump it depends on which route I go.

There are guys who build cars with huge motors and huge brakes and huge sticky tires, and wind up with a car that is brutal and not very satisfying to drive. For track day and street use you want something with enough power but not so much that all you do is turn the car until it's pointed at the next corner and step on the pedal. Balance is the key to a satisfying car for Ted's intended use, and I think he's on the right track. Lap times aren't important, driver satisfaction is.

Also, power and weight cost brake pads and tire rubber to run.

Speaking of track days, @Ted DuPuis may want to check with some of the organizers of track days in his area (Heartland Park? Hallett?) to make sure the roll bar he's getting is acceptable. From the pictures it looks like a good one.

And you've hit the nail on the head. As for the roll bar, it's the Factory Five spec'd one. They make a competition version of the roadster that's for track only use and has a different roll bar design, but I'm not looking for a track only car, just a track occasional car.

We’re talking about a 351w vs a 302, lol. It’s not like I’m suggesting he shoehorn a blown 460 in it. You can do a mild amount of work to get a 302 to 350HP, or a mild amount of work to get a 351w to 400HP. The cost is the same either direction you go, so why not get a bit more bang for the buck? You don’t see Chevy guys recommending a 305 over a 350 for the same reasons.

The 305 is a 350 with a smaller bore and the same block. Weight difference is negligible and they have the same external dimensions. 302 vs. 351 you save about 50 lbs (all over the front wheels) and plus you have a 1" shorter deck height as I recall which makes everything bolt up nicely in the car.

Best part? If I get it on the road and decide I made a bad choice, I can always build up a 351 (or whatever I feel like) and swap it in. That's part of why I'm also looking to have fun with this first engine on a budget, maybe try some new things. Now I don't want to swap the engine out after I build it, but it's not really a huge deal if I decide to. And Ford engines (of all types) are cheap enough. I'll just try to provision so that I can handle more power later on if I choose to make a change.

But as @FormerHangie correctly pointed out, the goal is balance in a car that's about visceral driving enjoyment.

 

[FormerHangie]

About 50 pounds between a 302 Windsor and 351 Windsor.

50 lbs up in front of the front axle is significant. Will it turn a faster lap time? Probably. Will it be more fun to drive? Not to my tastes. Will it use more tires and brakes? Certainly.

I did a track day at Atlanta Motorsports Park earlier this year in a turbo four Mustang, weight around 3500 lbs, 300 hp/350 ft lbs torque. Granted, I was pretty rusty, but it was all I could do to get the pedal to the floor for a few seconds per lap. On most of the participation type road courses that track days are held on, it's hard to use all that much power.

Here's a clip of a Lotus Elise at Heartland Park. Notice that he barely touches 100 mph.

 

[Tarheelpilot]

No electric water pump (cost, and no benefit in my opinion).

Keep your bottom end stock. No gain to be had there.

Hypereutectic pistons are more fragile than cast and forged. No reason to upgrade from cast, other than ego.

Focus on breathing: cam, headers/exhaust, intake, carb, cool air. Cheap and efficient gains. Match your rear gear and trans accordingly.

Drag racing and built (assembled) engines since 1983, for what my 2 cents is worth.

I agree. Stock short block and get a goood engine builder to recommend cam, head, intake and carb to be properly matched then top with an exhaust that optimizes exhaust scavenging. Throw all the lightweight accessories on board and you’ll have a bulletproof engine that likes about any gas that will be fun in a cobra clone. Also agree on mechanical water pump and electric fans.

This was pretty much exactly what I did to my fox body notch back mustang. Felt like twice the engine over stock.

 

[Bill]

If you’re just looking for high rpm, high horsepower, would you consider the Coyote motor and have 435 streetable, reliable horsepower? If you want the lope from a crammed engine, the Coyote has plenty of programmers that can program in the lope.

I had a '14 Mustang GT 5.0 Trackpack for a while, and I will say, that Coyote is one rev happy motor. It's the first car I've ever owned with an engine that acted like it was from a Japanese sportbike. If you haven't driven one, Ted, try it, the thing LOVES to rev and revs quick.

 

[Ted]

I had a '14 Mustang GT 5.0 Trackpack for a while, and I will say, that Coyote is one rev happy motor. It's the first car I've ever owned with an engine that acted like it was from a Japanese sportbike. If you haven't driven one, Ted, try it, the thing LOVES to rev and revs quick.

I've never driven one, but everyone I've talked to has said it's a great engine.

There are a few problems with it for me. First one is that I want a carb and distributor. Why? Goal is a simple, old school build. Minimal wiring. I will put some touches that will make it nicer to drive on the street since that's the goal, but I want an old school engine. Somewhat ironically, I've done very little work with carbs and distributors in my wrenching career, and since I like to do something "new" whenever I pick a new vehicle. In this case, "new" is old.

 

[weilke]

Cool air I'm planning on. The Cobra kits have a functional hood scoop, and I figure I'll put on an air cleaner with one of those air cleaner lids that is also an air cleaner. Maximizes the total area thus reducing restriction.

For a toy car, and if you have the capability to rebuild engines, an air cleaner seems like an unnecessary feature. It's a 100k explorer block, if you wear it out you just tinker a couple more weeks and replace it with a different 100k explorer block.

 

[PaulS]

My buddy has a ff cobra with the coyote engine which is about 470 hp, it's really too much for that little car. My son has a Mustang with the coyote engine, about 430 hp, that car flies and the stabilization software keeps you out of trouble. Looks like they cost about $8,000..... not sure what my buddy spent.

 

[Ted]

For a toy car, and if you have the capability to rebuild engines, an air cleaner seems like an unnecessary feature. It's a 100k explorer block, if you wear it out you just tinker a couple more weeks and replace it with a different 100k explorer block.

Fair point, but I'd rather have an air cleaner of some sort on. If nothing else, we got insects. And small children.

I am thinking about just throwing this engine in with minimal work, and then I can work on another engine that's "better" depending on how I feel about this engine, swap over the winter.

 

[weilke]

Fair point, but I'd rather have an air cleaner of some sort on. If nothing else, we got insects. And small children.

I am thinking about just throwing this engine in with minimal work, and then I can work on another engine that's "better" depending on how I feel about this engine, swap over the winter.

I don't think engine top ends worry much about insects. It's all carbon, right ? Silica from gravel roads may reduce your engines lifespan from 20 times of what you need to 10 times of what you need.

I would just hang it in there all stock to get the car rolling and then play with a second engine until you have it right.

 

[Ted]

My buddy has a ff cobra with the coyote engine which is about 470 hp, it's really too much for that little car. My son has a Mustang with the coyote engine, about 430 hp, that car flies and the stabilization software keeps you out of trouble. Looks like they cost about $8,000..... not sure what my buddy spent.

There are people who do 700 HP ones. I figure at ~375 HP and ~6 lbs/hp, that's plenty stupid fast. Really even with a stock 302 drivetrain out of a Mustang it'll be a lot of fun, but the ~375 HP I think will be exactly what I'm going for performance wise while keeping weight down.

I don't thin engine top ends worry much about insects. It's all carbon, right ? Silica from gravel roads may reduce your engines lifespan from 20 times of what you need to 10 times of what you needs.

I would just hang it in there all stock to get the car rolling and then play with a second engine until you have it right.

I'll do something beyond stock, but I think the idea of driving it a season with a "tame" motor and adjusting it over the next winter is probably a good way to plan on going.

 

[Ted]

One thing I'll add in is that I'm debating on the transmission. The T-5 is the cheap way to go, but I'd also rather not blow one up. Of course, they're also cheap.

 

[SoonerAviator]

The 305 is a 350 with a smaller bore and the same block. Weight difference is negligible and they have the same external dimensions. 302 vs. 351 you save about 50 lbs (all over the front wheels) and plus you have a 1" shorter deck height as I recall which makes everything bolt up nicely in the car.

Best part? If I get it on the road and decide I made a bad choice, I can always build up a 351 (or whatever I feel like) and swap it in. That's part of why I'm also looking to have fun with this first engine on a budget, maybe try some new things. Now I don't want to swap the engine out after I build it, but it's not really a huge deal if I decide to. And Ford engines (of all types) are cheap enough. I'll just try to provision so that I can handle more power later on if I choose to make a change.

But as @FormerHangie correctly pointed out, the goal is balance in a car that's about visceral driving enjoyment.

Whatever floats your boat. The entire 50 lbs should be behind the front "axle" in every FF Cobra I've seen and I doubt most people would ever discern 50lbs difference in engine weight when driving it. If you want 350HP-400HP it's less work to achieve it with a 351w for obvious reasons. Also, if you were seriously considering upgrading later on, it would be wise to get the TKO transmission now. It's your barbecue, but part of my "visceral" enjoyment of driving such vehicles is the acceleration capable due to having lots of torque on tap. I suggested the 351w because it gives you the best of both worlds (honest 400HP/TQ without remotely stressing bottom end) with the ability to go 408w stroker if you found the need for more power later.

My final recommendation for one-stop shop (and very popular among the FF Cobra forums): 351W short block from CL ($300), Edelbrock #2092 Performer RPM Power Pack (includes everything but carb) ($2,500), Edelbrock 750CFM carb. Bolt it together (recommend a high volume oil pump), have fun. Honest 400HP/410TQ at under 10:1 compression, weighs same as a stock 302 w/GT40 heads and no worrying about valve/port machining. Rock solid and will breath to 6K RPM all day long. Final answer! Gets you a fun project with brand new top-end for right around $3K (you can always spend another $400 if you want new forged pistons for some reason).

 

[Ted]

Whatever floats your boat. The entire 50 lbs should be behind the front "axle" in every FF Cobra I've seen and I doubt most people would ever discern 50lbs difference in engine weight when driving it. If you want 350HP-400HP it's less work to achieve it with a 351w for obvious reasons. Also, if you were seriously considering upgrading later on, it would be wise to get the TKO transmission now. It's your barbecue, but part of my "visceral" enjoyment of driving such vehicles is the acceleration capable due to having lots of torque on tap. I suggested the 351w because it gives you the best of both worlds (honest 400HP/TQ without remotely stressing bottom end) with the ability to go 408w stroker if you found the need for more power later.

My final recommendation for one-stop shop (and very popular among the FF Cobra forums): 351W short block from CL ($300), Edelbrock #2092 Performer RPM Power Pack (includes everything but carb) ($2,500), Edelbrock 750CFM carb. Bolt it together (recommend a high volume oil pump), have fun. Honest 400HP/410TQ at under 10:1 compression, weighs same as a stock 302 w/GT40 heads and no worrying about valve/port machining. Rock solid and will breath to 6K RPM all day long. Final answer! Gets you a fun project with brand new top-end for right around $3K (you can always spend another $400 if you want new forged pistons for some reason).

All fair points. Keep in mind underhood access and maintenance are other reasons for wanting to stick to a 302. I've spent enough time wrenching on Jag V12s shoehorned into XJ12/XJ81/XJ-S bodies that I appreciate having more space to get my hands and a wrench.

I took a look at the Edelbrock Performer RPM Power Pack for the 302 out of curiosity:

https://www.wildhorses4x4.com/produ...MIi8yUyePJ3AIVjYCfCh384Q26EAkYASABEgJc6fD_BwE

And that is worth considering as an alternative. The aluminum heads reduce weight (a goal) and that gets a similar dyno curve to the other idea I was considering.

I'm leaning towards the idea of the TKO first. I doubt I'm going to upgrade the engine significantly from what I put in, but that may change. Also, I'm going to be pushing the torque rating on the T-5 with what I'm planning on from the get-go, and I like a transmission that's more solid/firm shifting. I loved the TKO in my XJ-S. Decision to be made...

 

[Zeldman]

I am thinking about just throwing this engine in with minimal work, and then I can work on another engine that's "better" depending on how I feel about this engine, swap over the winter.

I changed to drag racing one year for some unknown reason. I used a warmed over small block until I got used to going in a straight line, then I put in the over built big block on alky. I went from averaging 135 in the quarter to averaging 195-197. Glad I went slow first because it was a whole different ride.

Pretty much can't go wrong the Edelbrock packages. They do all the R&D for you. It would not hurt to give them a call and tell them what you have and what you want. They may suggest a different package or make one just for you. Great company.

But with a classic car you need the classic lumpa lumpa lumpady lump idle.

 

[jsstevens]

[snip]
But with a classic car you need the classic lumpa lumpa lumpady lump idle.

Yes you do. And I find it amusing that the manufacturers program the computer to give you that in modern muscle cars-simply because that's what the hotter cams, etc. caused the old ones to do and now people associate that lope with power. It's completely unnecessary with modern tech, but was part of the compromise forced b the older tech.

It's similar with electric guitars. When the guitars became popular, the tube amps were state of the art and despite the best efforts of the engineers, they had distortion and other more subtle artifacts. Couldn't be designed out at the time. But now, that's the sound that people associate with electric guitars and so tube amps (and really fancy FET based amps) are how we get that sound.

John

 

[Ted]

I changed to drag racing one year for some unknown reason. I used a warmed over small block until I got used to going in a straight line, then I put in the over built big block on alky. I went from averaging 135 in the quarter to averaging 195-197. Glad I went slow first because it was a whole different ride.

Pretty much can't go wrong the Edelbrock packages. They do all the R&D for you. It would not hurt to give them a call and tell them what you have and what you want. They may suggest a different package or make one just for you. Great company.

But with a classic car you need the classic lumpa lumpa lumpady lump idle.

I agree with your point about walking before running, and part of why targeting ~375 HP I think is a good number out of the box. Fast enough to be interesting but to not be insta-death. My wife and I both have backgrounds riding sportbikes (me liter class, her 675cc), and our supercharged E55 isn't exactly slow. But we're still talking a different experience.

Also completely agree about a lumpy idle. That's a must.

Yes you do. And I find it amusing that the manufacturers program the computer to give you that in modern muscle cars-simply because that's what the hotter cams, etc. caused the old ones to do and now people associate that lope with power. It's completely unnecessary with modern tech, but was part of the compromise forced b the older tech.

It's similar with electric guitars. When the guitars became popular, the tube amps were state of the art and despite the best efforts of the engineers, they had distortion and other more subtle artifacts. Couldn't be designed out at the time. But now, that's the sound that people associate with electric guitars and so tube amps (and really fancy FET based amps) are how we get that sound.

Funny story about that. A coworker of mine was involved in the EFI/ignition system for Victory motorcycles when they first came out. During the R&D phase they had the engines running beautifully, perfectly smooth. The managers said "Wow! Ok can you make it misfire and rumble at idle?" the engineers, not being Harley guys, didn't understand the request. So the rough idle was engineered to perfection.

 

[SoCal RV Flyer]

I had a good experience with a Meziere electric water pump. Used on on my LS1-powered 914 conversion. 310 bhp, 2380 lb.

Meziere 300 Series Electric Water Pump: Meziere WP300S: Water Pump.$451.00JEGS High Performance(11)Free shipping, no tax

A light car with a torquey V-8 and a high drag coefficient ought to do just fine with five gears.

The Type 901 Porsche trans has a dogleg first gear. With the V-8, 2nd worked wonderfully as "1st" ...and gave me a standard H-pattern.

 

[Ted]

I had a good experience with a Meziere electric water pump. Used on on my LS1-powered 914 conversion. 310 bhp, 2380 lb.

Meziere 300 Series Electric Water Pump: Meziere WP300S: Water Pump.$451.00JEGS High Performance(11)Free shipping, no tax

That was essentially the one (obviously I was looking for SBF). I saw they had ~35 GPM and ~55 GPH versions. I was figuring that 35 is plenty fine most of the time, but for the track 55 is the way to go with a price premium.

I think I'm going to go with an electric water pump just because I've never done it before, and that makes it a fun experiment.

 

[rtk11]

All fair points. Keep in mind underhood access and maintenance are other reasons for wanting to stick to a 302. I've spent enough time wrenching on Jag V12s shoehorned into XJ12/XJ81/XJ-S bodies that I appreciate having more space to get my hands and a wrench.

With all due respect Ted, we’re talking about 1” taller deck on the a 351 vs a 302. That isn’t going to make a big difference in terms of ability to access things on a Windsor motor. If you were talking Cleveland build, that’d be different.

Which now brings up a different point: If you’re not going with a Coyote motor, what about building a Boss motor? Put 351 Cleveland heads on that 302 (or better yet, install a 351 Cleveland) and you’ll have ginormous ports that won’t give you a bunch of torque (without torque plates in the exhaust ports), but PLENTY of breathing for high RPM operation.

 

[Ted]

With all due respect Ted, we’re talking about 1” taller deck on the a 351 vs a 302. That isn’t going to make a big difference in terms of ability to access things on a Windsor motor. If you were talking Cleveland build, that’d be different.

I haven't looked at engine bays of both options close enough (and that really involves actually looking at how hands and tools would get in in 3 dimensional space, not just a photo). I'd agree that the 1" deck height difference shouldn't make a big difference, but it all comes down to where that 1" is.

Regardless, I'm not putting a 351 in, at least not to start. Feel free to say "We told you so" if I decide I should've gone with a bigger engine after the fact, but I'm not interested.

Benefits of 351: More displacement, more power/torque potential
Benefits of 302: Less weight, 350-400 HP still attainable, lighter rotating assembly

I want to go with the lightweight engine/lightweight car for this build, and make something that's more rev-happy than I've had in the past. That's part of the build goal. If I were going to put a V8 in a Jag, I'd be going with a 454 or a 383. That's a much bigger, heavier car.

Which now brings up a different point: If you’re not going with a Coyote motor, what about building a Boss motor? Put 351 Cleveland heads on that 302 (or better yet, install a 351 Cleveland) and you’ll have ginormous ports that won’t give you a bunch of torque (without torque plates in the exhaust ports), but PLENTY of breathing for high RPM operation.

That'd be an option, although it looks like some mods are required to make those bolt up. I am thinking about maybe going for some of the Edelbrock bolt-up aluminum heads. Gets my weight down a bit more (since that's one of the goals) and vs. getting the GT40 head ported, probably results in a bit better result. Figure I'll call up the Edelbrock folks once I actually get my donor engine in-hand.

 

[rtk11]

That'd be an option, although it looks like some mods are required to make those bolt up. I am thinking about maybe going for some of the Edelbrock bolt-up aluminum heads. Gets my weight down a bit more (since that's one of the goals) and vs. getting the GT40 head ported, probably results in a bit better result. Figure I'll call up the Edelbrock folks once I actually get my donor engine in-hand.

Fair enough, Ted. Here’s Edelbrock’s “Clevor” or “Mock-Boss” heads that are a direct bolt on to a Windsor block (so you don’t have to plug any water passages, etc.). http://www.edelbrock.com/automotive/mc/cylinder-heads/ford/performer-rpm-clevor.shtml

 

[Zeldman]

Dare to be different.... think V10....

 

[Ted]

Dare to be different.... think V10....

I used to have an Excursion with the V10 (actually I've had 2 of them) and it's a great engine. I've always thought putting one in a Mustang would be a great combo. Maybe with a 6-71 on it. Hey, I just got an idea for another car...

But the thing is really heavy. That'd completely screw up the handling of the Cobra. Plus I'm not doing overhead cams.

 

[StevieTimes]

If I had skills like some of youse guys seem to, this is my dream car:
http://www.mustangandfords.com/feat...tang-body-on-a-2014-gt500-chassis-yes-please/

I love the look of the 1969 Mustang Fastback, but I'm not fond of the slop in the '69 steering wheel, and the level of tech back then. If I could have the inside be from a newer Mustang, and all of the new niceties and power everything, A/C, backup camera, etc, I'd be in heaven.

 

[N747JB]

500hp and 550 lb ft. pushing 2900 lbs is a good time.

You have all the cool toys!

 

[N747JB]

I understand wanting to build it yourself, you’ve got the tools and skills to do it, I ended up buying a crate motor from ATK for my 74 Bronco. 302/300HP sounds good, we swapped the oil pan, but other than that it was a drop in add oil and go motor. I haven’t driven it a lot and probably never will, but so far so good with it.

 

[FormerHangie]

All fair points. Keep in mind underhood access and maintenance are other reasons for wanting to stick to a 302. I've spent enough time wrenching on Jag V12s shoehorned into XJ12/XJ81/XJ-S bodies that I appreciate having more space to get my hands and a wrench.

I took a look at the Edelbrock Performer RPM Power Pack for the 302 out of curiosity:

https://www.wildhorses4x4.com/produ...MIi8yUyePJ3AIVjYCfCh384Q26EAkYASABEgJc6fD_BwE

And that is worth considering as an alternative. The aluminum heads reduce weight (a goal) and that gets a similar dyno curve to the other idea I was considering.

I'm leaning towards the idea of the TKO first. I doubt I'm going to upgrade the engine significantly from what I put in, but that may change. Also, I'm going to be pushing the torque rating on the T-5 with what I'm planning on from the get-go, and I like a transmission that's more solid/firm shifting. I loved the TKO in my XJ-S. Decision to be made...

That Power Pack sounds like a nice setup. I like that the pieces are matched to work together, that's really important.

 

[Ted]

I understand wanting to build it yourself, you’ve got the tools and skills to do it, I ended up buying a crate motor from ATK for my 74 Bronco. 302/300HP sounds good, we swapped the oil pan, but other than that it was a drop in add oil and go motor. I haven’t driven it a lot and probably never will, but so far so good with it.

The great thing about projects is that there are enough options such that everyone can pick what's best. The crate motor phenomenon is great since it allows people to buy professionally assembled engines that meet a spec. You pay for it, but someone else has done the guess work and it can be nice to just throw an engine in rather than build one. And really, the prices are pretty reasonable for what you get.

In my case, I enjoy the engine building process enough that I'll be happy doing some work on it myself, but we'll see what level I end up choosing for that.

That Power Pack sounds like a nice setup. I like that the pieces are matched to work together, that's really important.

I figure I'll give them a call on that. The main problem I have with that setup is it's a flat tappet cam. Nothing wrong with those per se, but it's hard to get as good of a profile as a roller cam. When I compare their dyno numbers with the dyno numbers on the GT40-head build I was looking at (which used a roller cam), the Edelbrock numbers are a bit lower, and you have to spin up to 6,500 RPM to get those numbers. What I'd be curious about would be if they had (or could recommend) a package including a roller cam. If I'm going to rev higher I want there to be benefits to it, not rev higher for less power. I'm betting the flat tappet cam is a lot of the reason for that.

 

[Chip Sylverne]

It was pretty much common knowledge back in the day that Windsor heads sucked. The firebreathers were the Clevelands, or in the case of the 302 the Aussie Clevelands. Easily modded for a 302W block. It was called the Boss 302.
If you're gonna build, build.

 

[mondtster]

It was pretty much common knowledge back in the day that Windsor heads sucked. The firebreathers were the Clevelands, or in the case of the 302 the Aussie Clevelands. Easily modded for a 302W block. It was called the Boss 302.
If you're gonna build, build.

The GT40/40P heads and even the E7TE heads aren't too bad. Before I spent a bunch of money on any stock head though, I'd seriously consider aftermarket options. You can often get brand new aftermarket performance heads for not much more than you'd spend on reworking stock castings.

 

[SaltH2OHokie]

Maybe with a 6-71 on it

Well, not on a 6.8L, but why not stick a 6-71 blower on your choice of junkyard 302's (since you seem to want a Ford engine...), underdrive the blower to 5-6psi and let her eat. Don't even look at the bottom end, just feed it more fuel and keep the boost low. You'll get your hp #'s and look good to boot. Then when/if it pops, $400 for another junkyard 302 and a weekend of wrenching and you're back again.

 

[Ted]

Well, not on a 6.8L, but why not stick a 6-71 blower on your choice of junkyard 302's (since you seem to want a Ford engine...), underdrive the blower to 5-6psi and let her eat. Don't even look at the bottom end, just feed it more fuel and keep the boost low. You'll get your hp #'s and look good to boot. Then when/if it pops, $400 for another junkyard 302 and a weekend of wrenching and you're back again.

I thought about that, and it would give a good Mad Max look to the car, and like you said if I just go through junkyard 302s it'd do the job fine. That might be a consideration for a future engine. Goal is to start out with the 302 however I build it and drive it like that for a while, then maybe let it evolve.