i have a 283 with 041 heads about 9.5:1 comp, 204/214 .050 dur, .422/.444 lift cam. 600cfm perf carb and performer intake. it has manifolds from a 305 which are clogging it up, a 3" flowmaster catback, and a 9"x2" filter which i think is also choking it out. its coming up on dyno2000 as 305ft lbs of trq and about 270 hp. i'm only 15 so i havn't driven many cars yet. from a idle at about 600rpms it will spin the tires (245/60-15s) pretty good(its also got a 3.23 rear). do you think this is good trq for a 283?

also, on DD2000 when i put on the headers it comes up as 340ft lbs and 325hp. does this change sound about right?

 

Are you sure its a 283, if so thats decent torque out of a 3.0" stroke.

 

yea, its a 283, i thought it was a 350 when i got it, payed $75 for the engine. the guy i got it from didn't know what it was so called a place to check the #s before i got it and they said it was a 350. when i got it home i checkit it on mortec and it came out as a 283, then i took it apart and measured the stroke and it was 3".

i can't wait to see what it'l do with headers.

when you hit the gas in 1st idling at about 10mph it feels like your getting hit from behind it hits so hard but it backs off a lot after about a second. it dosn't lose all of the power, it still feels good but it hits so hard for about a second. is this normal?

 

well yeah, in 1st gear it's always like that...
look like you got a great deal 75$ wow!

 

Did you measure the bore? Because it might be a 302, they share the same casting #'s as 350 blocks.

 

don't believe dd200 it tends to inflate the numbers. that's way more than i think you'll get out of a 283. quick ID of a 283, drilled crank snout? small dampner? 2 piece rubber ring dampner? canister oil filter? breater and/or hose on back of block, near china wall. since there have been any 283's built in the last few years it's hard to tell what might of been changed on one.

 

its a 283, its got a 3.905" bore .030 over, we thought it was a 302 also but we checked it out. everyone whos driven it that knows cars say its got in the high 200s or low 300s.

 

thats an awful lot from a 283

 

ditto

 

I can't see a 283 having to be too built-up to make that kinda power. The corvettes from the late 50s and early 60s and even some chevelles in the late 60s had 283s with alot of power... the '57 Vette i think was about 290hp or something, and probably higher than that later, so 300 ft-lbs is probably not too much for a 283.

Nice numbers though.. better than my 350 actually, lol

 

i think that the hp/trque numbers from any cars before mid 70's were measured at the crank, after that period, at the wheels

we're actually talking about this on another thread right now.....

so try 290........ figured for drivetrain loss

 

No, thats not how it was measured. You are on the right track though...

In the early '70s and before, engines were measured in gross horsepower, meaning that they were dyno tested with no accesories hooked up (meaning less drag), no air cleaner (less restriction), and usually open headers.

After this, they went to SAE ratings, which is far more accurate to what the car will actually make, was tested with all of the car's accesories, the entire exhaust system the car will use and with all emitions and air cleaner in place.

That is the main reason that HP numbers seemed to drop from 300+ to about 150 seemingly over night in the '70s.

Actually, i read that a '66 426 Hemi was tested in SAE format, and it made only about 370hp.

 

well hot damn you answered my question before them and it wasnt even what we were discussing

thanks

 

283, actually. 1 HP per cubic inch. Rochester mechanical fuel injection, 11:1 compression, solid lifter cam. Very tweaky, many were converted to dual 4bbls (rated at 270 by the factory) so you could live with them.

Sounds like a .030" over 283. DD is pretty complimentary, and gives numbers like they used to rate 'em (gross flywheel HP). Also very dependant upon flow data, and doesn't take into account flow at various valve lifts.

283's are alright, but a similarly-equiped 305 will outrun them.

 

i don't tihnk you can run 2.02 valves on a 305, can you? arn't the bigest vlaves you can run something like 1.94? also a 283 revs much quicker so you could build it to make more power at higher rpms. a 305 will make more trq but a 283 would probably eat a 305 up at about 5000 and up.

 

naw you can use 2.02valves

 

eeks sorry about the size