Brianr390

I've been deciding whether or not i should stroke my 289 motor. It's the original motor for my 65 mustang but i would like to make around 350 and up rwhp. I will mainly be using it for a daily driver so i would like to get some decent mpg. My question is can a 289 with better heads, intake, cam, etc make upwards of 350 horsepower without having to stroke it and still be a daily driver. The cost doesn't really matter to me because i have to rebuild the motor anyway and i was going to get a lot of aftermarket parts for it, even if i don't stroke it. Any and all answers will help.

andrewmp6

Shelby got 300hp out of the 289 so 50 more couldn't be that hard today with modern heads and cam.

Coupe

I have a 302 crank in my 289' it does not rev as quick as a 289 anymore, I think if I were doing a new motor for my car I would see how much I can get from that shorter 289 stroke so I can get some quick revs back....or stroke it to 347, I can't decide lol.

Starfury

If you want the mileage, keep the 289. If you want some extra torque, stroke it. You can't have both. You can build a stroker for optimum mileage, but it won't be quite as efficient as a low-cube motor.

I have a 331 and I love it. I do wish I had gone with a roller cam, which would help with both efficiency and power, but I still like the power it puts out.

TomKat

i say keep the 289 make a demon out of it

BuckeyeDemon

you can pretty much make the same hp with a 289 as you can with the 347. all you need to do is spin the 289 to a little higher RPM and make sure your cam timing reflects that.

however, spinning the engine and thus matching the cam for that slightly higher rpm, implies you give up a little of the low end quality.

with regards to torque, you basically will get a lot more torque from a 347. this should be obvious since peak torque is basically where your VE% is the highest. this simply means you are filling the cylinder the fullest. at such low rpm's, small induction and camshafts don't impact torque like it does HP. so the amount of torque basically comes down to how much volume you have (i.e. cubic inches).


so, in my opinion, excluding cost, go with the 347, that allows you to keep the rpm's just a little lower (assuming the same HP between both options) and more torque.

in addition, if you go to the preferred aftermarket crank and rods, your piston can get a whole lot lighter (if that even matters to you).

toybreaker

Stroke it. Externally you won't be able to tell the difference. 331 or 347 will make 350 rwhp a lot easier than 293ish cubic inches will.

MonsterBilly

I totsally redid my 289. including cam, heads, headers, intake, carb, lifters, oil pump, dizzy and ignition and a 150 shot of NO2.

i wind it out to 7k rpms and the really rips. however i feel like I should have gone 347.....