Suggestions for FE 428 specs
 

I'm working through the details of an FE428 for the ERA 427 I have a deposit on. I don't plan to track the car so it will just be driven on the streets - 1,000's of miles of twisties and back roads where I live. My starting point is Keith Craft's FE 428 street crate:

•Horsepower: 550 hp
•Torque: 550 ft/lbs
•Block: Fully Machined Production Block
•Crankshaft: Scat or Eagle Cast Steel
•Stroke: 4.250" or 4.375"
•Connecting Rods: Scat or Eagle I-Beam 6.700"
•Pistons: Diamond Forged
•Timing Chain: Ford Motorsport Double Roller
•Camshaft: Comp Cams Custom Hydraulic Roller
•Lifters: Hydraulic Roller
•Cylinder Heads: Edelbrock Stage II CNC
•Valves: SI 2.09/1.75
•Rocker Arms: T&D Roller
•Intake: Edelbrock Performer RPM Port Matched
•Waterpump: Edelbrock Aluminum
•Carburetor: Quick Fuel 780cfm
•Valve Covers: Keith Craft Logo w/Breather
•Wire Looms: Smoothie
•Oil Pump: Melling High Volume
•Oil Pan: Moroso Front Sump
•Balancer: Pioneer SFI
•Ignition: MSD Distributor w/Keith Craft Logo Moroso Plug Wires
•Gaskets: Felpro
•Fasteners: ARP
•Oil: 1 Case Joe Gibbs Hot Rod
•Compression: 10:1
•Fuel: Premium Unleaded Only
•Firing Order: 1-5-4-2-6-3-7-8
•Timing: 39 Degrees @ Full Advance
•Oil: 10w-30 or 15w-50 Joe Gibbs Hot Rod
•Max RPM: 6200

I think 550 hp is a bit more than I need in a street car, so I was thinking of taking that down to 450 - 485 hp. Experienced engine builders like Keith Craft can pretty much hit any target. I know mentioning an FE and gas mileage in the same sentence is always good for some laughs, but I'm wondering what I'll actually gain in fuel economy by giving up the 65 - 100 hp. Does anyone have any first-hand experience with that? All I keep reading is 8 mpg with an FE428, no matter what, so maybe I'd be giving up performance for very little gain in fuel economy. To round out the drive-train picture, I'll be using a Tremec 600 and Peter at ERA has suggested a 3.31 rear for the best of both worlds for street driving. Also, to tame this engine down to the 450 - 485 mark, what changes would you make to the specs above? So far, I've thought of a milder cam, lowering the compression just a bit and perhaps eliminating the CNC porting. I've only done minor tinkering with cars (change out water pump, set timing and dwell...) so I have a lot to learn and appreciate all the experience on this forum.

Regards,

Kevin

i would go with the 550hp, remember your gas pedal is not a on off switch you can make it go as fast as you want. if you want why not install a throttle stop so you limit wide open throttle?. in 6 months to a year you wished you would of went with the higher hp.

I'd basically leave it alone. If you're dead-set on the 3.31 gears (not a fan), then I would knock the .050" duration on the cam down a little bit.

The best person to ask is your engine builder....who are you going to have build it?

For increased fun...
 

Kevin, we've had a zillion threads on the solid versus hydraulic cam thing, but I will tell you what I did on my build. Forget the horsepower/torque issue for a moment and instead concentrate on the "fun" factor. I went with the shorter stroke (4.125"), solid flat tappet cam, and a light aluminumn flywheel. All of that makes it "revvier" and really increases the fun factor while driving it. Now, in full disclosure, Barry R. likes the choice of a revvier 4.125" stroke while Keith C. says you should almost always go with the bigger stroke for more power (so he doesn't) -- I don't know which side of that fence Brent falls on. It's just a different view. But for pure fun, I think what I did was right and, if I were to do it again, I would do it exactly the same way.

I've spoken with Keith Craft and a couple of small builders in CT. but am still open as to who builds it and will give you a call to discuss. You're not a fan of the 3.31 gears? Would like to understand more. I'm not a high RPM guy - more of a low-end torque fan for street driving. So, I thought the 428 would handle the 3.31 well and would give me good cruising RPM's rather than having the engine screaming. With all that torque, I thought it'd be able to rev through the gears well. Not having the benefit of driving or riding in Cobras with different configurations, it is somewhat of a shot in the dark. As for wanting more hp later that may be true but, at 57 I'm a bit more settled down than some of the younger folks. I'm no stranger to speed and accelleration. Back in the mid-70's I drag raced motorcycles - 10.97 1/4 mile, the first third of that mostly on one wheel (technology has improved significantly since those days). I do plan to take a driving course if I wind up with more hp. Another consideration is that I plan to keep the car and potentially hand it down to my son - another reason to stay below the "killer hp" level. Also, in my original post I mentioned wanting to understand what to expect with fuel economy - silly with an FE, I know, but I think going out for a cruise and getting 12 or 13 mpg would be preferable to getting 8 and having all that extra power that would seldomly be called on. Not sure if that's even possible.

So, I'm open to suggestions and appreciate the help.

Regards,

Kevin

If you decide to go for the 475 HP range you don't need some of the above high dollar stuff to do so. I built for torque and used the 4.25 stroke crank in a 428, ported/larger valves 1961 390 HP iron heads (essentially same as low riser 427 or CJ heads now), 1963 low riser dual 4bbl intake, 9.0 pistons and flat tappet hydraulic cam with Ford adjustable rockers, etc. It made 475 HP at around 5500 rpm and 530 ft lbs of torque on the dyno. I'll lose some of that with the S&H air cleaners, exhaust and accessories in the car.

I also went with a 3.31 rear but with a WR toploader. It was a highly recommended combination for a non-overdrive transmission. I'm not sure what your first gear is with a Tremec 600.

If you go the 550 HP route, yeah - you'll probably need most of the above with a 428 block.

Kevin,

You and I think along the same lines. For a street engine, I like longer strokes, more average hp/tq, and "sane" rpm levels. My street builds are generally hydraulic roller engines, about 10-10.5:1 compression, and usually peak at around 5500-6000 rpm.

With the FE stuff, all of the aftermarket crankshafts cost the same...no matter if it's a 3.98", 4.125", or 4.250". I always advise to go big.

Gas mileage is directly proportional to the weight of your right foot. :) With a TKO 600, you will see your 12-13 mpg if you spend a lot of time cruising in overdrive. My favorite transmission/rearend combo for a Cobra falls somewhere in the 3.50-3.70 rearend ratio range, coupled with a TKO 600, .82 OD. You still get the lower cruising rpm (with 3.50, 55mph is at around 2100 rpm, 70mph is at around 2600 rpm) and the acceleration is that much more enjoyable.

I think you're putting too much of a wall between a 485hp engine and a 550hp engine. These days, there's not that much difference in part requirements. Generally it's just some head porting and a cam change. Unlike 30-40 years ago, 550hp is not considered a race engine, but I would venture to say that 500-550 is more of a "street standard". It doesn't take 12:1 compression, 7000 rpms, a huge cam, etc. It's done rather easily.

I get a lot of emails from customers wanting to do engine upgrades a year or so into the ownership of the car. They get used to the horsepower and want a little more. My advice is to get the most out of your money in the rpm range and parameters that you want to run in. Cams all cost the same price. Crankshafts all cost the same price. Personally, I'd like to get the best bang for my buck.

For your situation, I would do a 390 with a 4.250" crankshaft....445 cubic inches. Ported Edelbrock heads, ported Performer RPM intake, and a hydraulic roller. No maintenance, great reliability, 525-ish horsepower, gobs of torque.

Kevin, for what you want, I would do exactly as Brent suggests. If the FE doesn't break down in the first 1000 miles then it will outlast both you and your son (likely grandson, too).

All good considerations, guys - lots to think about. Patrick, excuse my total lack of Cobra experience but, with all that torque and power doesn't a faster revving engine tend to just smoke the tires easier? I was thinking longer stroke for torque would feel really good and I'm too old to be doing burnouts all over town...

Kc fe
 

Two of my buddies have KC FEs, 600 and 619 hp. They are easy to drive around town. I would strongly suggest you go with Keith's 550 motor. You will not regret it.
It's a great motor for a Cobra.

And you don't burn the tires off unless you put the pedal to the floor:)

For the record my Cobra has a small block but I love driving Coach and Lainhart's Big Block Cobras.

Dwight

Every Cobra "needs" 500 plus HP:LOL:

No, just the opposite. You're more likely to break the tires loose down low as you're taking off, not when you're up in the 4200-6200 RPM range. Revving a big FE to the low 6000s is really a lot of fun, but it's not what everybody wants.

Kevin, I'm running a 4.25" stroke 428 with a hydro-roller cam and most of those parts from KC equaling 462ci and 10.5cr. I'm running ported Ebock heads a PI intake and a Race Demon 1050 carb. Although I don't really know what the HP is, the math says around 550 like the combo you are describing. The drive train I'm using is a TKO 600 RR with a 3.46 rear and I usually get about 10mpg farting around town but up to about 14/15 if I can keep control of my right foot. That power and gear combo seems to work very well for me. More power than I can ever hope to put down in the low RPM range which makes it very easy to cruise in but also a theoretical top speed of about 160. Just because it's easy to cruise in doesn't mean that I can drive it like a Honda though, if I get careless with the throttle she'll turn around and ***** slap me in a heartbeat. I think that's one of the things that I really like about her!

Yeah, the thought that a spin-out, even in a straight line accelleration can happen so easily is a scary thought for an inexperienced driver. I've been driving motorcycles all my life and am still alive, so apparently I do have at least a bit of common sense and restraint, but I'm still a bit fuzzy on what not to do in these cars. I understand not coming off the throttle too fast and the effects of weight shift. Also, importance of smooth shifting. Guess I need to get out somewhere where I can't hit anything if I spin and find out for myself. I've read that driving schools won't send you out in your car with an instructor unless you have dual roll bars (easy Patrick :rolleyes:) so have to look more into that when the time comes.

I really appreciate all the info...

Regards,

Kevin

Kevin, these cars can be really twitchy, and it's easy to get in over your head before you even know it.:( Considering you've not driven a 500+ HP, 2500 lb. 90" wheelbase car before, my recommendation -- and please don't take offense -- is that you have your engine builder zip tie your vacuum secondaries closed, or if they're mechanical then disconnect the linkage, after he breaks it in and tunes it up nicely. Drive it that way for a good while until you get used to the car and then snip the zip tie or hook the linkage back up.

Patrick, no offense taken. I do understand the danger and appreciate the advice. I think it is wise to limit the power initially and will do so. Think I'll go with vacuum secondaries because they open a bit more gradually and won't give the sudden increase in power that mechanical secondaries provide.

Thanks,

Kevin

Even after 2 years of driving it, you can still kill yourself instantly, so I don't know that a zip tie will save you from yourself.

I'd build it as spec'd and be responsible, careful and don't let your ego or your testosterone get to you. And don't bury the pedal unless the road ahead looks like this:

http://static.panoramio.com/photos/original/743322.jpg

Actually, I was thinking of Tin-Man went I wrote that. Remember, his never even made it out of the garage.:( Even with the secondaries zip tied closed, Kevin's still going to say "that's the fastest damn car I've ever been in."

Kevin, please pay no mind to these folk who spout doom and gloom at every chance.

Every time someone wants to build an engine, it always seems someone, uh, like say Patrick, has to post a warning about the lightweight short wheelbase Cobra and crashing it. These people seem to think that every person building a new engine is 16 years old with no driving experience and "you know what" for brains.

In fact, they'll always seem to dig up one or two of the same youtube videos that show some person racing on a track beyond their skill level or someone who has never driven a car before and decides to try for the first time in a Cobra on a narrow avenue with telephone poles dotting the street on both sides. :eek:

You know yourself better than anyone here. Do what you feel is proper and comfortable.

So the zip tie suggestion is a no-go?:(

Conversation with engine builder:

Me: Oh, one more thing - can you please zip tie my secondaries so they won't open?
Engine builder: Huh? :confused:

Seriously, the zip tie idea makes a point but I'd probably not actually do that. I'm capable of being careful when I know the consequences. I'd love to find a road like the photo that elmariachi posted or an abandoned air strip - somewhere where I could just let loose without worring about hitting anything. Not sure if there is anything like that around here but will check with the locals. Probably won't be able to get on a track with a car set up for street.

And, Rodknock, I've seen the youtube videos of spin-outs and crashes. I also know that there are thousands of guys that have driven for years without incident. I guess what it all boils down to is how much engine is too much for the street...and the answer varies from person to person. I'll be meeting with some locals this Spring and maybe I'll get a couple of rides that will answer the question for me before I have to make a final decision on the engine specs.

Thanks again for all the helpful (and sometimes amusing) advice.

Regards,

Kevin