who has built a 289 street strip mav or comet

Well anyone following some of my post probably know I bought a boss clone motor,well I thought it was a 302 boss but turned out to be a 289 boss, well I removed the topend,put new rings and bearings in it,it has 9.75 to 1 comp.,a 505 lift cam with 224 dur. @ 50 and I found some 170 tfs heads. Performer rpm intake,c4 trans. 3500 stall 9in conv.,I'm thinking 3.70 gear what will it run I'm hoping 12 flat is that possible,I've had no 289 exp.,heard they really run good but.........love to get some input guys

 

To me that reads like a mild 325-350hp motor. With a race weight of about 3200lbs I think youll be closer to 13 flat.

BTW, What are you doing with the old cleveland heads? Saving them for the next build?

 

do you think its going to weigh that much, my last 1 weighted 2700 lbs,i was thinking 2800 at most,but im not sure till i can weigh it,with the motor ,i wont get to that point for several weeks yet,ive got the body almost done,put the disc brakes off the 76 on it,i got my hedman headers in today and my 157 tooth 50oz flex plate, the heads setup im saving for a stroker setup in the future,im going to turn 1 of the 70s into a race car and use it

 

Sounds like a worthy project.
How about some photos to document the progress?

 

ill try to get more tommorow i had another thread going with the car,on the body,i kinda got lazy and didnt keep up with the pics the motor is togather im painting it tommorow ,putting the flex plate on and the new fab valve covers i got from kjm for 60.00 bucks lol

 

I was saying 3200 race weight, with you in it, fuel, etc. How much it weighs when you leave the line. Thats what you need to figure how much HP it will take to hit your number. If its a gutted race car you will be lighter. still 100 pounds per tenth of a second? so 12.6 if you are at 2800 pounds at the line. just saying that I dont see 12 flat with that combo. but still fast enough to be alot of fun.

 

The 289 has a better rod/stroke ratio and from the 4-5 I have seen and tuned on a dyno only lost about 10-15 ft of torque 4rpms and below but outperformed a 302 with comparable parts....past 5krpms


The cam you have is to mild.....You need something that is gonna let that thing spin to 7k Id even build it for higher say 7500rpm red line shifting at 6800rpm

I would personally run e85 and make it have 12.5 to 1 comp ratio to 13.5 to 1

if I was going premium gas 11.to1 to 11.5 to 1

I would run a solid roller cam or a solid lifter at min......

Just how I would do it.....

no reason you couldn't hit 425 to 475 fwhp using the above recommended formula......

It wil be soft down low but steep gears and high torque converter or manual shifts would help that out....

and damn it all if a high winding 289 doesn't sound 10 times more wicked than a torquey built 302.....

fwiw a 331 stroker kit has about the same rod/stroke ratio.......

 

157tooth 50 ounce flexplate, hmmm that doesnt sound right. I am not familiar with the combo you have but I would think it should be a 28 ounce flexplate

 

Guess I should have read all of your threads, but sometimes I just get lazy about trying to follow all of the threads and work on my Maverick trying to get it ready for this seasons racing..............sorry if the questions have already been asked.
So, are the heads Boss 302 heads?
Is this car going to be a street car or race car?
Weather you have Boss heads or are using the TFS heads, the cam sounds a little anemic @505 lift. If you use that cam I doubt very much you will make it into the 12's with 2800lbs. Kind of like Ryan said, maybe 350hp at the crank.
As for the 289, they like (depending on the pistons and bottom end you currently have[hopefully it's not stock]) they like a lot of RPM.
I had a 289 HiPo (real deal) in my 64 Comet with reworked 69 351w 4brl heads and shim head gaskets, close ratio top loader 4spd, 4:56 gears and ran in the low 13's with street tires and mid 12's with slicks and open headers. I had a wicked cam somewhere in the mid to high .5 something lift...........drove it on the street and at the track on weekends.........shifting at 7,500/7,800....................and that was a heavy car...........with the interior gutted I still think it was over 2700lbs.
Also, the preformer intake needs to go for something that will give you a little more power and more RPM.............................IMHO

 

Well Cornedbeef that sounds like a sweet build if he was looking to start over. But with the parts he already has what do you think it would run? thats the question here. Theres no doubt he dosnt have all the fastest stuff, but will it hit 12 flat like he asked? I havent run 289s but I dont think he will make it.

 

I PREDICT IF IT GETS A PERFECT TUNE AND HAS AT LEAST A 1.80 60 FT TIME OR SLIGHTLY BETTER(in other words he is hooking) HE WILL RUN 12.7S TO 13.5S

That motor at best is 325/360hp but that still equates to 280 to 320 to the rear wheels and with the light weight of a mav....good traction....good driver....the aforementioned times are attainable.......

 

btw my old 306 roller ran mid 12s in good weather........that cam was only .499 lift.... alphabet cam "e" 220 duration..... 10.4 to1 comp ratio...roller rockers....roush 200 heads 2.02I 1.60E valves..... 3200 stall c4 3.40 gears 26 inch mickey thompson drag radials.....there was more to be had(low 12s)....I just didn't care I enjoyed driving it more than I did racing it.....

That motor is somewhere in Missouri these days collecting dust.......Maybe someday Alan will put it his or his sons maverick....

 

havent ran 1/4 yet ran 8.teens with a 1.71 60ft ,i think its got 7.80s maybe with alot of playing around i was leaving it in drive and it shifted before 60ft,now i can shift it so i think it will pickup,i also added a shift kit it was very sloppy on shift, i ran a 3.73 gear with a 26 tall by 8 inch slick never spun a tire just left,but shifted at prolly the 30ft mark

 

When my car ran 7.80s it went 12.40s in the quarter.

 

nice combo 13.0 to 13.6 in the quarter depending on tires........