Okay, so I have the option of picking up a nicely restorable '67 Coupe with a recently rebuilt 289 & 4-speed in it.

Question: about how much HP can you squeeze out of a 289? I've heard that they're rated (stock) at around 200 HP, but then I've seen a few that get up to 390 HP, so it's a little confusing. I know it depends on the parts you use on the engine, but would the cost of said parts on a 289 be more than just picking up a good-condition 351?

Thanks in advance for any advice offered.

-Thom

 

What will you be doing with the car, drag racing? Why are you so obsessed with horsepower? For a street car, it's torque that makes a car fun to drive, and these little engines are amazingly torquey for their size.

To answer your question, the 2 barrel is about 200 HP, the common four barrel is about 225 and the rare high performance version is 271.

With a four speed and a 225 horse car, it will be peppy enough to be fun to drive. Making lots of horsepower requires that you shift the torque peak to a higher RPM, which in many cases makes the car less fun to drive.

Low and midrange torque makes a car fun to drive while horsepower wins races. For me adding, small tube full length headers to enhance the low speed torque is about all I would do to it to add to the fun factor unless it had some too tall gears in it. Then I would gear it a little, but that's just me.

 

well, stock speaking the 351 will have way more torque than the 289, so it's a better base. the 289 is quicker spinning up and lighter, so that's that advantage.
from that base if you improve breathing it will help power (exhaust, intake, heads, airfilter). it will increase the whole torque curve. then with a camshaft you can move this torque curve up and down, depending on what you want with the car. a 289 will fit into a 67, but if you want torque you can shove in a 390 as well, but that'll probably ruin handling ;-)

 

Those hp ratings are actually over ratings since they were GROSS power ratings. The 200 and 225 hp versions are in reality like 160-185hp, and the 271hp hipo is probably an honest 225hp tops. But yes, SBF's are torquey, and horsepower is just a way of measuring torque at a certain rpm.

What the engine is used for dictates the build, and for a street car you're better off generally selecting components that make their power in the rpm range in which the car is used MOST. That means on a street car we're you're spending 99% of your time below 3,500rpm you want an engine that makes best power in the mid range so it runs well at low rpm, makes decent power in the upper rpm, but makes best power in the mid rpm range. ALL engines are a compromise on where you want power.

 

No auctually the 271 hp produced 275 hp . but add headers and an aluminum intake get more hp. 225hp 229-230hp Get more with headers an a aluminum intake, plus that will take a little weight off of the engine,read the march mustang monthly.

 

But when MM tested their Hi-Po to Shelby, they tested it the old way - gross horsepower (no accessories, etc.) - see the picture of the engine on the dyno (pg. 38). Modern SAE net rating, introduced in the early 1970s, rate the engine in 'real-world' setups, with full accessories, exhaust, etc. They are typically 15%-20% less than the older gross HP ratings. By modern-car HP ratings the 200 HP 2V would be about 170 HP, the 225 HP 4V would be about 190, the 271 HP Hi-Po about 235, and the 306 HP Shelby about 260 HP.

Compare that to the 93 Cobra 5.0s, which were factory rated at 235 net HP but were actually about 270. In net HP, that is a little better than the Shelby 289.

To get 390 HP from a 289, would make it a pretty unpleasant driver - lots of cackle, smell, and not much low-end torque.

 

I read the article, I'm old school not new school,I only own one mustang.65FSTBK built Sep. 19th of 64.

 

If my 65 were a fastback, it would be old school too! Mine was a plain-jane coupe so I modernized it. I wouldn't do that to a 65 fastback though, I'd just enjoy it, even if it were a 6 cylinder.

 

If its the original 289 to the car, and it was me getting it i would just rebuild it with a bit more "punch" but not too much and just drive the hell out of it. By a bit more "punch" i mean maybe an electronic ignition, headers, aluminum intake and a slightly bigger carb, and if you really feel the need a slightly bigger cam but i do not think that you would need a bigger cam.

 

I ave a 66 with the original 289. i have hyper pistons to add a little compression, intake, 4bl carb, headers, port match, roller rockers , T5, MSD ignition, and a huge a$$ cam.
It is a blast to drive and really pisses people off when i get on it. especially when i take it to about 6k rpm's. i feel like a little kid doing something bad.
i built it to bash on it. i tear it up all the time and plan on driving it until the wheels fall off. However, I always want more juice. But i think everyone here wants a little more.
I think there is about 5k into my power plant. i could have put that into a 351 and more but like the fact that it is the original engine.