Yeah, i noticed that when i got my exhaust i got more power, and when i rebuilt my motor i got way more power than before, but that may be to the minor parts we added.
He said 120 rwhp for stock, I say 129. I guess we lose the 9 rwhp with 25 years of wear on the engine. Dave
Most that dynoed at 120 rwhp were bone stock and probably needed a tune, right after they got the car. One was a lady that joined the forum a year or so ago, don't remember the name. One was a guy on another forum, I wanna say mustangsandmore.com, but I can't remember. I think both could gain some power with a good tuneup, but with that much age on'em... its hard to say. I know I can actually tell my valve springs aint quite what they used to be, floats earlier and she just doesn't have as much power before valve float either.
so a nice rebuild to the 302 and a tune up (taking out the detune of the emission control) will make the block stronger??? Or does it need a whole new exhaust system. We don't have emission tests in Mexico, so I could take those ugly parts that are making weak my engine. Is this possible??
It will make the power output stronger, not the block itself, and often make the engine more efficient. The block itself can only handle so much power before it breaks, period. A true dual exhaust helps a lot on power and efficiency.
When working at navistar all the engines were dyno'd at the crank with all the accessories and a simulated exhaust restriction (not the actual exhaust system) to get SAE NET HP and TQ. FWIW, since they are turbo engines the IC was Air/water instead of Air/Air to keep things more consistent. That's the only real change to the engine. All the emissions/fuel economy work for the light duty engines was done in vehicle on the rolls which uses simualted road loads (2 wheel drive vehicles only.)
500 hp from a n/a 289? Must spin it up to 10,000 rpm. Anyway, seems like everyone's forgetting that the 70s is when automakers were doing wierd things to pass emissions. Retarded camshafts, retarded ignition timing, massive doses of EGR, low compression, restrictive exhaust systems to keep heat in the engine, etc. Made for some real turds. First thing guys would do after their cars were out of warranty was strip off the pollution gizmos, put on reworked heads, 4 barrel carb and intake, dual exhaust and a new cam and timing set. Made it feel like the power doubled, and it probably did.
My cousin's 289 makes about 400 at the flywheel, I don't doubt 500. I agree on most parts about the smog engines, but the heads on the 74 really weren't that bad. Same casting as the 72, similar to the E7's on the Mustangs. Slightly better intake, slightly worse exhaust.
All 289-302 heads from that era were horrible. They were originally designed for little 221 cid motors. The runners had steep approach angles to the valves, the combustion chambers weren't very efficient, ports and valves were way undersized. Ford's only interest was in making a narrow engine package that fit between the shock towers of Falcons, Fairlanes, Mustangs, etc. Efficiency was not the target. The larger head that Ford came up with for the 351W is what the 289 and 302 should have had all along.
http://www.jason.fletcher.net/tech/flowdata/castiron.htm 289 outflowed the E7 intake and the famed 351 on exhaust stock. The pre 68 heads were horrible, the 68 and later heads were interchangable with the E7s, aside from the 77-86, those sucked something fierce. Got a set I use to block animals from crawling in a hole under my house.
I always hated to admit it but head design is where Ford could have learned something from the "C" guys. Their small blocks had very good (for the time) flowing heads. Major part of the reason the small "C" engines generally made more power and were so popular.
I agree. I just hate to see the 68-76 heads get such a bad rep, then hear guys recommend E7's. There really isn't that much difference. A bit of research and I was rather disappointed by my 1970 casting 351 heads. Big valves, but the exhaust port sucks, as usual. From what I hear, the 351 heads have a bit more meat, so they can be ported further, but still... The small heads probably do something to do with Ford small block being popular, the smaller runners make for quicker throttle response. It feels torquey.
Can't say that I've ever heard anyone recomend E7s for any performance application. Most guys give them away, then get either GT40s, GT40Ps, or aftermarket. I ran a set of fully ported 1970 351Ws for a lot of years. Put on a pair of very slightly ported (valve pockets and exhaust runners only) Gt40Ps. Made a noticable difference.
