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The chev 302 was around in 68-69. It was created to compete in the Trans-Am racing series. It uses the same 4" bore as the 350/327 but has a short stroke from the 283. The 302 is a large journal crank and no 283's came in large journal so to build one you need to buy an aftermarket 3" stroke crank unless you can find an original 302 engine.
Factory street engines were rated at 290 HP (engine) with 290 torque at 4200 rpm. Race engines were good for 450 hp when fitted with a crossram dual 4 barrel carb setup.
These are a high reving engine. When built up they could easily live at 7000 rpm but that's where the short stroke engine builds HP. Because of the short stroke, torque is low when compared to a 350.
87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
454 Big Block buildup now in progress for the 2001 racing season
Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662
Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association
302 Chevy motors were produced in 67,68,69 for the camaro Z-28 ,,, 67,were small journal, they all were screamers , mine is always at 9,000 rpm, they always need low gears , manual tranmissions ,
Stephen, I am also in Calgary.. I bought my car this year and am stressing over what to do as far as mods go.. I would REALLY appreciate talking with someone as knowledgeable as yourself over coffee or something of the sort. I am new to the sport and trying to learn as much as i can as fast as i can while still working I'm also shipping out to St Jeans Quebec for some military training on the 26th of jan and will come home with $4000 of our valuable cdn dollars.... I need something to look forward to when i come back.. Other than my girlfriend, you seem like an understanding guy
No, Stephen is correct...they were "rated" 290 HP&TQ. Their actual Gross HP was higher. But I wouldn't said 390 Gross HP. I've driven a 69 Z/28 when they were still fairly new and along with the Camaro LT1 (rated 360HP IIRC).
I thought the LT1 felt quicker (and definitely more torqueier). If I had to guess, I would say a stock 69 Z/28 302 was around 325-340 Gross HP.
Gta-Paladin:
My knowledge comes from being a mechanic for over 20 years. As for your mods, what I've done to my car isn't what the everage person would like to do to their street car. Mine is a full blown race car and can never see street use again.
Come to the next CDRA meeting (see web site) or you can find me at the track in the spring.
I've never heard of it referred to as a "Zapper", but it was a decent engine as far as factory engines go.
I had a partner at work who had a '68 coppertone Z. His 302 would do 7,000 RPM launches right out of the box. With a little tweaking, he basically pounded most of the big cube engines within a 50-mile radius into embarrassment, including the infamous large-mouthed Mopar hemi-drivers (that was most satisfying to watch). I only got to drive it once, and torque sucked eggs under 3,000, at which point it flattened out and just kept pulling until the end of the track.
Honestly, I didn't like to even stand near the hood when he revved it, knowing I have a thick skull but not quite thick enough to fend off push rods. A well-built 302 is very comfortable at 8,500 RPM for hours on end.
The factory laughingly rated the output at 290 HP, and I'm sure that at some point in its wide RPM range it crossed the '290' mark, so it wasn't a total fabrication. I guess they just stopped looking at the dyno after a certain point, like 5,250 or so. This is from the same company that rated the 1971 Corvette 454 at 270 HP - yeah, right... At least it fooled the insurance companies for a while.
Higher gears and a manual are almost a necessity to get the most out of one of these. All said, it can be a very respectable little engine, but not as a daily driver or emissions-friendly car.
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Later,
Vader
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Actually Vader, we use to call those and the early 2nd Gens "Zap 28s". It was an early 70s term I guess. But after 1972, we stopped using the term due to lack of "zap".
7,000 rpm???? Definitely more balls in revving the motor than me. I had a tendency to "break things" past 6,000 rpm. Guess that is why I own a tune port...Won't see 6,000 rpm in my wildest dream.