How come the chevy 350 engines were rated for such low horsepower?

Question

I looked at the specs for the carbureted 350 motors used in 1973-87 trucks and they are rated for such low horsepower? What i don't get is if they are such low powered engines how come they can stand up to some really tough loads? My fathers 1977 chevy c30 dually has a 350 engine in it bone stock and i had it loaded with 4 tons of stone and was still able to make speed limit fairly easily. Is it all in the gearing? It's not just my fathers ive seen a lot of the old k10's and k20's loaded down to the max and still be able to chug right along. can anyone tell me why?

Answer 1

its called under rating...gm lied about horsepower specs on the downside...like the 1967 z28 302cid camaro, they said 290 horses, it really turned 410 horses....it had to deal with insurance, and emissions...my 1986 suburban is rated at 210 horses at 5000 rpm...i bet it turns 250 at 5500 rpm, cuz she doesnt feel like a boatanchor. chevy c10s were usually equiped with a 3.48 read end , givimg them about 10:1 gear reduction in first gear.



and for what mikel said, the chevy big 10, which was a heavy duty half ton has a gvw of 6001lbs :) they brought it out to get past emissions with a half ton truck, my grandpa has a 1977 big 10 with no emissions equipment and a built 350...it hauls azz, and passes inspection easy...and suburbans are decently quick too...ive hit 40(uphill) and came to a complete stop without any skidding in under 100 yards, and thats all factory 350

Answer 2

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I own a shop, and a set of Chevy Small Block Code books. If you will look on the passenger side of the block, in the front, just below the head, there is a pad that has some numbers & letters stamped on it. If the engine hasn't been built, then I can tell you what it is, or should I say was from the factory. The letters are the most important to identify the engine build. There should be some such as a few numbers followed by H7P, PHC, or any random combination of three digits. These letters identify the engine, and I can use the books to tell you what it was from the factory. The horsepower of these engines differ, but on the bright side most of the truck engines are four bolt main engines. Some were 160 horsepower, and some were 195 horsepower, so the only way to tell is to get that code. Part 2: I don't know why someone keeps following my answers, and voting them as bad answers?? I am 100% sure of my answer, and have the books in which I can scan the information, and email it to you. I have alerted Yahoo of this issue, and for someone to just go down the list, and vote bad answers to all of them, is someone trying to get best answers. This is against the rules of Yahoo Answers, and if someone does this intentionally, they will loose their privledge to answer questions. They can see how anyone votes, and following someones answers only to vote bad answer can be seen. I wouldn't do that, as that will only lead to being banned from playing. Glad to help out, Good luck!!!

Answer 3

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RE:

How come the chevy 350 engines were rated for such low horsepower?

I looked at the specs for the carbureted 350 motors used in 1973-87 trucks and they are rated for such low horsepower? What i don't get is if they are such low powered engines how come they can stand up to some really tough loads? My fathers 1977 chevy c30 dually has a 350 engine in it bone...

Answer 4

In the '70's, the industry was hit with new 'clean air' emissions rules. These engines had low compression, catalytic converters, air injection pumps, and other changes that were mandated in an effort to clean up the exhaust emissions.



Interestingly, there was a threshold, I think it was GCW or gross curb weight of like 6000lbs, where the mandates didn't apply and I think it was around '74 or '75 where the fastest production vehicle made in America was the Chevy Suburban (over the limit), faster than Vettes, Goats, Stangs, everything!

Answer 5

Brett is leading you in the right direction; allow me to explain it. Essentially, horsepower is a function of torque AND rpm. Engines have an optimum point at which their torque begins to drop off; however if the drop is relatively slow, horsepower will continue to climb as rpm climbs. Torque is how hard the engine can twist that driveshaft, while horsepower is how quickly it can spin the driveshaft up. That makes torque very important for a hauler, while horsepower is important for the sports car.



A drag strip car produces relatively little torque at low rpms; however, it is designed to produce prodigious amounts of torque as rpm climbs - this is what makes them fast.



A diesel 18 wheeler produces relatively little horsepower for its size; however, it is designed to produce a huge amount of torque at low rpms, and a relatively flat amount of torque up to a relatively low rpm in comparison to the drag car. This is what makes them capable of hauling huge amounts of weight, slowly but surely.



That 350 in that 87 truck can very easily put down very respectable horsepower numbers with a simple head/cam change - but it is not 'configured' at the factory for speed.

Answer 6

Chevy C30

Answer 7

Mostly torque at low RPMs, plus the gearing in rear and transmission



Like say a 1979 350. It only makes 165 HP @ 3800 RPM, but it makes 270 ft lbs of torque at 2400 RPM



Then look at say a 1978 corvette 350. 220 HP @ 5200 RPM, and 260 ft lbs torque @ 3600 RPM



Makes 55 HP more, but 10 ft lbs less torque and to get the power and torque the engine has to spin to a higher RPM to do so. So that means they used a bigger cam, more compression, bigger valves, etc to get the engine to make more power higher in the RPM range. Doing that though gives up low RPM torque needed to pull/tow/haul heavy loads

Answer 8

The diference is horsepower and torque. A two stroke dirtbike will get up to 80 mph quickly but won't pull a load. An old tractor geared low will pull a house down.

Answer 9

1978 Corvette Specs

Answer 10

its chevys amazingness