Most Streetable HP from a 289?

[Dinobyte]

I am trying to compare BB to SB, within California where SB100 type rules are coming to neighborhood near you.

I am exploring options, and wanted to hear from the Vintage Small Block crowd regarding the potential build up possibilities of a 1965 blocked 289.

I would like to achieve 425 or so HP...what would it take to do this with a 289 block?

Will the engine still be streetable? Will pump gas still work in it?

Thanks for the feedback in advance.

Dinobyte

[Cashburn]

I believe anything more than 375HP or so is asking too much of a 289. See: http://www.cobraautomotive.com/horsepower.htm

Great shop, down the street from us

[mrmustang]

Ditto the 375HP limit, especially if you want to run pump gas and still have a reliable engine.

Bill S.

[maverick]

H/P Pert near on a pump-gas, hyd-roller, idle @ 850rpm, run fine-last a long time SB.

[Tongue Pirate]

I know it seems all fun & games to think "BIG" hp when building a motor for these cars but Streetable & Big HP in these cars may be 2 different things all together. I may be running in the mid 300 range now with the WEBERS & it is a scary little car. I just purchased a second 64' 289 in which to rebuild as my backup motor. Knowing what i know now, running 3.54 rear gears I may shoot for the 370hp range but not much more. Don't think it's worth spending the money on something I can already scare the crap outta myself with. Rolling at about 1/4 throttle in second gear I can punch it & the tires get loose. That seems plenty enough for the street!

[maverick]

Fun stuff with these 'little" motors.!

[DavidNJ]

Originally Posted by Cashburn

I believe anything more than 375HP or so is asking too much of a 289. See: http://www.cobraautomotive.com/horsepower.htm

Great shop, down the street from us

Thanks for the link. It does look like a shop that has their act together.

[speed220mph]

Here's a bit over 375 hp from my HP289. Compression is near 10:1, s I can use pump gas. Major porting work was done on the stock HP heads with 1.94/1.60 valves. Don't have cam specs other than lift which is 0.505 in. Stayed with std. flat tappets and rockers. Considerable work done to bottom end. Pertronix ign. and 3X2 carburetion work well. The 3.73:1 gear makes it easier to leave stoplights than the original 3.50:1 gear. Engine fitted to a Cobra would work even better, considering the ligher weight. A five or six speed with a 3.73:1 or lower gear would definately allow a peakier, higher hp engine than a four speed. Just don't over-cam it.

[KevinM]

It depends on if you want to stroke the motor. 375 is reasonable for a 289 with AFR 165 heads. Put a 3.250" crank in it and stroke it to a 331, use AFR 185 heads, and 425 HP is entirely reasonable and streetable.

Kevin

[Cashburn]

We are visiting Joe Lepine this weekend in regards to some new orders, I will speak with him about the 331 concept on the 289. It might do that 400HP as Kevin suggests.

[Dinobyte]

Okay, couple of ideas have suffaced for this motor. One is the stroked 1965 year block 289 to hit the 425HP. Eliminates the California SMOG issue.

The other two involve the big blocks, but first I tried to do a comparison of HP to Weight.

We are going to assume a BDR with a TKO600 (no engine yet) weighs in at roughly 2000 lbs.

Below are engine weights:

289 w/425 HP- 460 Lbs / 2460 Lbs Total Car Weight (HP to Weight ratio of 1:5.7882)
351 (392) w/430 HP - 510 Lbs / 2510 Lbs Total Car Weight (HP to Weight ratio of 1:5.8372)
390 or 428 w/525HP - 650 Lbs / 2650 Lbs Total Car Weight (HP to Weight ratio of 1:5.0476)

If we take the HP and calculate the HP to Weight ratio of just the engine, we have the following:

289 w/425HP weighing 410 lbs = .9647 lbs per 1 HP
351 w/430HP weighing 510 lbs = 1.186 lbs per 1 HP
390/428 w/500HP weighing 650 lbs = 1.3 lbs per 1 HP

So the target is somewhere between the 351's 1.186 and the 289's .9647 HP/Weight ratio. To achieve that on the outside, the 390/428 combo will have to hit at minimum 550 HP, which would put it at a 1.1818 lbs per 1 HP.

COST
Not knowing what the cost will be for the 289 will be, I will use Keith Craft's Stroked 331 cost of $6300 x 1.2 for fudge or $7,600. $7,600 divided by 425 HP would mean a per HP cost of $17.88.

The Ford Racing 351W stroked to 392, I will assume a cost of $6500, putting the per HP at $15.12.

One option for the 390/428 which makes me think this is possible, as per Keith Craft's website, is a 390 stroked out is hitting 525HP. The cost of this motor is $9,000, or $17.14 per 1-HP.

The key to making this work for the vintage motors is having the base SMOG gear, and not having too wild of a cam or too much carburation (i.e. single 4 barrel and a within reason cfm rating).

Okay guys, shoot holes in my assumptions.

Cheers
Dinobyte

[KevinM]

Figure the 392 Windsor at 500 HP easy. The earliest 351 blocks are 1969. California did have smog rules in that year. They weren't real hard to meet, but they were there.

Kevin

[tpiini]

My S.V. has a 289. It's a June '66 engine. I have no idea how much HP it's making, but it runs on 91 octane, gets 13 MPG while cruising and will do a 10-second quarter.

And (hint hint) it'll be for sale very soon. You'd only need a PCV valve to make it CA legal.

Tom

[Allan A]

I was able to get 358 HP at the wheels with this motor. Runs on pump gas and so far has been very reliable.

http://www.gessford.com/cobra/images/CSX7034.htm

[Tongue Pirate]

Allan, You have that overhead shot in higher resolution? Would love to use it for background on my computer. Awsome shot!

[Allan A]

Hyde,

Sorry, I shot it with an old Mavica from the top of our office. Need to buy a good camera one of these days.

Allan

[Tongue Pirate]

Well then I'm just going to have to copy your idea!

[Unique 289_FIA]

352hp to the wheels with my small block stroker. That should be right around 425 at the flywheel, particularly through these side pipes.

[DavidNJ]

Determine your usage and configuration first. Street driving? Open track days? Drag racing? And emissions of course!

Also your configuration. Current 17" or 18" tires? 15" Nitto 555R drag radials? Or 15" Goodyear tires designed for a Ford Galaxie? And your tolerance for a tricky launch.

Then you can better make the tradeoffs.

A bigger displacement, lower tune motor is easier to drive around town. A high reving, flat torque curve engine may be easier on the track. A bigger displacement, high power motor will crack a stock block!

[maverick]

If weight is the major consideration:

Keith Craft aluminum 427/482 stroker.............640+hp and 470#s, 10.5:1 comp ratio, hydrau. roller cam............. pretty fair pwr/weight ratio.