Realistic HP
 

I am probably the worst person for going over the top and I know Keith Craft has built me a very good SBF engine that produces well over 600bhp on pump gas, we have had the engine running on the dyno here and its everything I asked for and more! This 358 based engine has 320bhp @ 4000rpm and then it increases by a whopping 200bhp by 5000rpm to 520bhp and then all the way to 600+bhp, and very smooth.
I know its going to be a bit like Jay Leno's 427 Cobra on the street very lumpy and then WOOOOOOOOOOOOW.

I ran a genuine 270 -300bhp in a 289 Mustang engined Zephyr car many years ago and what a delightful free revving kick in the pants engine, so to my mind it all depends on the combination of gearing, transmission etc, I would go for the original Cobra horsepower with more reliability, as for eg a friend has a FE390 Cobra which would be very lucky to have 350 hp and quite frankly its not enough, but if that was a SBF it would be plenty and very lively in a Cobra.

FE390 -427 for the street strive for 450bhp!!
Driveability if you can hop in the car without thinking and go on a run thats what you want, but in my case it will be limited road use and when I do care and attention to preheat the oil and warm up nice etc etc, but I intend on doing some runs like a similar car on CC, John Marsey he has a similar setup in the JBL Boss and he enjoys giving it a blast.

I would say the most power you can make while having a nice drivable motor. Good idle and stable temperature gauge. My Kirkham made 500 HP and 550lbs of torque while it had smooth idle, it was great. Fast good handling but lousy brakes (Wilwood). What you will feel the most is torque, it will give you that "seat in the pants" feeling. Ant, I am a bit skeptical at your 600HP SBF. On the track maybe, the motor will not last long and your torque will be low. It is true that the SBF breathes very well and can make good power.

Emmanuel

I have 400 horse in my 428 PI engine and it is more then enough for me. I'm not a speed, gearhead or track guy. I specifically had mine built for street use and reliability. It is VERY responsive.

I think talking big HP numbers is a testosterone booster for us males. Or a you know what extension. We all talk 500-600 HP, but I bet if we were all honest and have taken our car to a dyno test, alot of us would be deflated when we found out the real HP numbers. Talk is cheap. Even if our cars were
500-600 HP, how often will you use that on the street, probably never. On the track is a different story, but again how many of us consistenly take our cobra's to track and race these cars.

I had my engine dyno'd and have all the print outs as well. I highly recommend it as it cuts down on any issues (not 100% of course) once you get it in the hole.

How much is enough?
 

I absolutely love my 342 Roush. Great power to weight ratio with dynoed 420HP and about 375 ft/lbs of torque. Never overheats, even in stop and go Florida summers and will push you back in your seat whenever you get on it. A big block will add a couple of hundred pounds of weight to the front end and not be as comfortable a "daily driver". I drive mine every day and can cruise around at 35 MPH as well as track it up to 6000rpms with nothing but smiles.:cool:

My (iron) big block ERA has 52% of its weight on the rear wheels and is very comfortable, and temps stay at 170/180 degrees. While only about 400/425 HP, that's plenty for spirited driving and going on all-day runs around the state. Still quicker than most anything on the road, and still gets almost 15 MPG. I'm satisfied.
IMO, a 427 Cobra should have a big block FE.

Some of us just like fast cars because they're fun. That's about it. There's nothing to prove.

Hooking up pointless? I would say it's everything. I think everyone gets on it from time to time. So when you do,(and if you dont, just sell it to someone who will) you won't wrap yourself around a light pole because of cheap hard rubber tires.

I build for the rpm range the motor will happiest in terms of the driver and car, and then for the street its usually a budget decision of how much power in that range. With those two variables, the hp "happens" at the right time and 400, 500, or 600 it's all fun. Its really more of a torque curve plan for me when I build a street motor.

I dont see any reason to purposely strangle a motor if you can make more power in that rpm range you want, but not wanting to spend the dough makes perfect sense to me, and building with a hp number in mind has always been an odd concept for me for a street car. Drag racer, different story

With that being said, too much power? Don't push the pedal down so much.

realistic is what you can afford. how much do you want to spend on the engine? do you have to upgrade other parts and are you willing to spend the dough? then, can you actually use the hp you have budgeted for? lightweight drivetrain is easy hp, always there, and seldom breaks.

how much faster is a 600/600 engine than a 500/500 in the quarter, or even 400/400? then take the same comparison on a road course and see who can use the hp in the twisties.

With such a light car I feel that stroker motors are too much.
I ran a, as close to, stock 427 FE first in my car and was very happy with the power to wait ratio with 360hp to the rear wheels. Cam came on about 3000rpm. Very controllable.
Due to engine problems I was talked into all new crank rods and pistons to get away from the 40+ year old parts.
482 is very fun but way too much for the street. I haven't dyno'd the car yet but she is a beast.
It is all in making sure you are pointed straight when you nail it. :LOL:
I ran out of road quick with the 427 but with the 482 it is unbelievable.
I like it but for my next Cobra it will have a high revving stock stroke 427.
It is what I fell in love with 24 years ago in my first car.

I'm the wrong guy to ask because I'm a striaght line guy & run a Pro-Street Mustang. To me realistic Horsepower is all the Horse & Torque you can get/afford. My car is totally custom as every little thing had to be beefed up to withstand the sudden come-on of 1200 horse. It's a domino effect. You can't just put a beast in a car that isn't set up for it. You'll hit the gas & twist the frame, crack the windshield, drop the tranny, twist an axle, etc, all in a split second. Whatever you do, set the entire car up to handle the motor.
Regards,

I thank so many guys make an undriveable car which then sits in the garage or at the curb without being driven and enjoyed ...for that is the best tjing about a Cobra... The driving of it !! Lekker!!!!!:p

Actually, at 600 hp if I had another hundred or so I'd probably drive it more.:D

I didnt really build this engine for the street, the only criterial I had was to be able to use pump gas so I could do some fun miles on the street, torque is 515 ft Ibs @ just over 5000rpm not bad for a 373 cuin engine, but once it comes on song on the track, the lighter weight etc of the smallblock should give a handling benefit. I have driven two big blocks on the track one and FE390, and an Hilborne injected LS7, and I think they are better for the street.

anything over 300HP/Ton (rear wheel ) is a bit touchy.

2500lb = 375HP

3000lb = 450HP

4000lb = 600HP

This is like the BB/SB argument. There is no winner because not all people want the same thing. Build the car for what you want and ignore the fact that your buddy brags about his 800 horsepower that is useless except on a long straight stretch. These are not 6,000 pound cars that you are building and you should build it to your satisfaction. I got all kinds of crap because I had my 418 stroker built to just around 530 horsepower instead of over 600, but no one ran away from me on the road course and it ran well on the street. And if I were building another one it would most likely be a 408 with less than 500 horse.

Ron :)

Ron there is a winner
 

Ron61 There is a winner, It's a stroker windsor motor in the 390-427 range. Unless you have an All Aluminum motor, you loose in the weight department. The bottom end of a 351 windsor motor assembly is about 10-15 pound lighter. This makes for a faster revving motor. The FE weight is one of the heaviest bottomends out there. Heads, The best FE head is now into the 420 cfm range with off set pushrods, and rockers. The top windsor head are flowing in the 370 range. In a cobra with a 2,700 weight the torque of the FE may beat the windsor off the line but catch up in the mid range of the power band. Remember that lighter spinning assembly. Top end is just who runs out of HP last. I like my FE motor and like the way it looks in an SC cobra engine bay. I also like 600ft of torque and 550 HP to play with. This was 100 more of both than I had last year. The only thing I will do different with my car is advance the cam timing to kill some of the bottom end. TOO MUCH TORQUE. For racing, windsors are the way to go, they are cheaper to build and have alot more speed parts to work with. Windsor motor are also 40 years old but have stayed in the lime light better than FE. I will leave the BOSS and CLEVELAND motors go for another time.:eek::LOL::LOL::LOL: Rick L. Ps the cammer motor is a whole different animal. I am waiting to see how a KCR cammer matches up with a cobra. BRUTAL with an unlimited speed possibility.%/

:)

Rick,

I had a 418 stroker for racing and a 408 for the street. The 418 put out around 530 horse and the 408 around 490. I have owned every FE engine that Ford has built including the 332 PI and all are good, but I stand by my statement that like the BB/SB there is no clear winner. It all depends on what you want to do with the car. Myself I much prefer the Stroked 351 Windsor in a Cobra to a BB. Since my racing has always been road racing, I don't have to worry to much about 200 MPH top end that the BB will give. I still have one BB car and it is a 69 with 42,012 original miles on it and still has the original old Polyglas Tires. Fun to drive at times but won't begin to corner like my Cobra did. Please note that in my prior post I said I had Windsor Strokers. But I also know of a couple of very good running 302s around here. The worst engine I ever had in a car was a 1965 427 Tunnel Port with two huge Holly Carbs that you could stand in. I traded it after about a month for 390HiPo as it wouldn't run on the street at all unless I was in 1st or 2nd gear. Some drag racer wanted it for his Mustang and I was more than happy to part with it and he paid to have the swap made. But once you got it above 6800 RPM it really took off.

Ron :)