Build the 289 or 302???

[66 Racer]

Hey guys,

I have a 289 and a 302 that i am considering rebuilding for my 66 coupe. Which would offer more HP, well, obviously the 302 has more cubes, but is there a torque advantage with the 289 stroke?

That is my only consern, if there is no real advantage in torque or horsepower over each engine other than the cubes with the 302, i will probably build the 302 with the 289 block.

Thanks guys

[fordkid68]

well this is just me but I would rebuild the 289 and have it board out to A 302. but thats just me I love the 289's for some reason the 302's dont impress me. also I am not sure but I think I remember hearing something about the 289's getting in the power band sooner.

hope that helps.

ford kid

[gofastmercury]

Well, the 302 and 289 have the same bore at 4.00 inches. the difference is in the stroke, 289:2.87, 302:3.00 . the blocks are almost the same, the 302 has slightly longer bores to help stabilize the piston on the bottom of the stroke. Because the 302's longer stroke, it makes more low end torque, but they both make the most power at hight rpm. I put a 302 crank in 289 block andd called it a 289. Impossible to tell from the outside. More cubes=more power.

[4.7L-stang]

I (being the compleate nerd that I am) ran a computer simulated drag race between 2 65' stangs. One had a 289 and the other had a 302. The 302 won the race by 0.0001 seconds.

[gofastmercury]

told ya the 302 was faster.....

[Rev]

I put a 302 crank in my 289 block. It's bored .030" over, so it's actually a 306 CI. A 289 with it's shorter stroke might be able to spin a little faster than a 302, but only minimally. My opinion is that for a street driven car, you shouldn't set your engine up for more than 6000 RPM anyway. You can do that with a 302 without too much trouble. Anyway, I think the 302 is the best choice.

Rev

[Dark Knight]

use the 289 block... and build a 331 or 347... heheh... but TELL everyone that it's a 289 :-)

[John Z]

Originally posted by fordkid68
well this is just me but I would rebuild the 289 and have it board out to A 302.
ford kid

You can not bore a 289 to a 302 about the most you can pick up with boring is 298 and that's with a 0.06 overbore. As said by others, the increase cubes to 302 comes from the stroke.

In general, longer stroke gives more torque, shorter stroke gives faster reving, but this would be for an engine with the same displacement. In general when you increase the displacement by stroking, you get more torque, but this may also produce more horsepower as torque and horse power are related by the equation
hp = torque*RPM/5252
Ever notice that torque and hp are equal at about 5200-5300 rpm?

[mustangman65_79]

I would say build the 289, but thats me, I also like the faster reving because of the smaller stroke. BTW, I thought I read somewhere that a 289 does have a smaller bore? Also,a stock 289 vs a stock 302, the 289 has a higher compression ratio.

[John Z]

Originally posted by mustangman65_79
BTW, I thought I read somewhere that a 289 does have a smaller bore?

No both are 4.005 stock

Also,a stock 289 vs a stock 302, the 289 has a higher compression ratio.

No, compression ratio is mostly determined by the heads, head gasket and shape of the top of the piston. From the Mr Fomoco page http://fomoco.com/index.asp?Dept=4&Tool=0
Disp Engine C/R
289 C 9.8 to 9.5 depending on year
289 A 10.3
289 K 10.5
302 F 8.5 to 10.0 (higher in early years, low in 73,72
302 J 10.5
HTH

Sorry that the spacing gets messed up when the message is posted. Hope you can follow the format.

[mustangman65_79]

About the compression, I guess I was close. I forgot that a few 302's had the higher compression, what about the newer ones? Arn't most of those around 9:1?

[fordkid68]

Originally posted by John Z
You can not bore a 289 to a 302 about the most you can pick up with boring is 298 and that's with a 0.06 overbore. As said by others, the increase cubes to 302 comes from the stroke.

wow thakns for correcting me. I have always thought you could bore out A 289 to A 302. I have thought that for about a year now. but I forget where I heard it at. well now I am correct.


sorry for posting uncorrect info.


ford kid

[fastback brian]

Um ok. The 289 and the 302 blocks are the same on the outside. It not the best idea to use a 289 block for anything but a 289. The 302 block is maybe a bit stronger in the bores but that doesnt matter much. A 289 can withstand big HP levels much better than a 302. But if you have a good crank and set of rods then build the 289. You will never have a problem of finding 302 parts, good 289 parts are getting rare.

[mustangman65_79]

I agree, with is why I'm so happy that when I buy that '65 fastback GT, I am also getting a HiPo block along with. While I'm driving the car, I can be building up the HiPo. I know that a "K" Car has HiPo block stock, but the orignal motor blew up many, many years ago. SO long ago, that it was still under warrenty

[66 Racer]

Man, Im still undesided, but here the buildup i would do with the 302 if i use it...

-85 5.0 block crank rods .030, or hone the current .020
-10.5:1 pistons
-66 289 heads w/ 54cc chambers, exaust port work
-Performer intake manifold
-Holley 600cfm carb
-Comp cams extreme energy flat tapet cam

the 289 would be the same except for the 289 stroke

But the thing that makes me want to use the 302 is because i dont currently have any access to any machines to fabricate a clutch equalizer support for the block side since ford stoped making them in the block casting in i believe 75. Do you guys happen to know if i can purchase one, but more importantly where?

I dont really want to use the 289 just because they are getting rare, I see it as a peice of history and i wanted to preserve it, that or use it for something really important like a strocker engine, since the cylinders are SLIGHTLY shorter it might need less prep work for clearancing the rotating assembly. One thing im probably going to do though after getting my car running againe is to start loading up on 289s, i REALLY liked my 289 and i dont know if the 302 will really do the same.