hp from 327? anyone
#21
02-05-2007, 03:29 PM
RE: hp from 327? anyone
I did not intend to edit your post, sorry about that, but nothing was changed. Hit the edit button instead of quote button.
No I am not confusing gross with rear wheel power. Gross power was measured with a naked engine, no accessories, no fand or water pumps, no alternators, exhaust was optimized, timing was optimized manually. etc. Tha factory was allowed to use any trick including lyingto state power ratings. Very similiar on how someengine builders now test engines on the dyno, and then claim big numbers. The government said that this way of measuring was not truthful, and insurance companies started charging more for high power cars.The SAE then came up with the net rating. Now power had to be measured at the flywheel with all the accesories connected and running. Including fans, water pumps. alternators, AC compressors, etc. The exhaust and intake system had to be as sold on the car, andhad to be connected and operational. No optimization allowed.
If you look back in car publications of the early 70s, you will see numerous references to this.
http://www.caranddriver.com/idealbb/...?topicID=77216
from
http://www.answers.com/topic/horsepower
hp (SAE)
In the United States the term "bhp" fell into disuse after the American Society of Automotive Engineers (SAE) recommended manufacturers use hp (SAE) to indicate the net power of the engine, given that particular car's complete engine installation. It measures engine power at the flywheel, not counting drivetrain losses.
Starting in 1971 automakers began to quote power in terms of SAE net horsepower (as defined by standard J1349). This reflected the rated power of the engine in as-installed trim, with all accessories and standard intake and exhaust systems. By 1972 U.S. carmakers quoted power exclusively in SAE net hp. The change was meant to 'deflate' power ratings to assuage the auto insurance industry and environmental and safety lobbies, as well as to obfuscate the power losses caused by emissions-control equipment.
SAE net ratings, while more accurate than gross ratings, still represent the engine's power at the flywheel. Contrary to some reports, it does not measure power at the drive wheels.
Because SAE gross ratings were applied liberally, at best, there is no precise conversion from gross to net. Comparison of gross and net ratings for unchanged engines show a variance of anywhere from 40 to 150 horsepower. The Chrysler 426 Hemi, for example, in 1971 carried a 425 hp gross rating (often considered to be underrated) and a net rating of 375 hp.
No I am not confusing gross with rear wheel power. Gross power was measured with a naked engine, no accessories, no fand or water pumps, no alternators, exhaust was optimized, timing was optimized manually. etc. Tha factory was allowed to use any trick including lyingto state power ratings. Very similiar on how someengine builders now test engines on the dyno, and then claim big numbers. The government said that this way of measuring was not truthful, and insurance companies started charging more for high power cars.The SAE then came up with the net rating. Now power had to be measured at the flywheel with all the accesories connected and running. Including fans, water pumps. alternators, AC compressors, etc. The exhaust and intake system had to be as sold on the car, andhad to be connected and operational. No optimization allowed.
If you look back in car publications of the early 70s, you will see numerous references to this.
http://www.caranddriver.com/idealbb/...?topicID=77216
from
http://www.answers.com/topic/horsepower
hp (SAE)
In the United States the term "bhp" fell into disuse after the American Society of Automotive Engineers (SAE) recommended manufacturers use hp (SAE) to indicate the net power of the engine, given that particular car's complete engine installation. It measures engine power at the flywheel, not counting drivetrain losses.
Starting in 1971 automakers began to quote power in terms of SAE net horsepower (as defined by standard J1349). This reflected the rated power of the engine in as-installed trim, with all accessories and standard intake and exhaust systems. By 1972 U.S. carmakers quoted power exclusively in SAE net hp. The change was meant to 'deflate' power ratings to assuage the auto insurance industry and environmental and safety lobbies, as well as to obfuscate the power losses caused by emissions-control equipment.
SAE net ratings, while more accurate than gross ratings, still represent the engine's power at the flywheel. Contrary to some reports, it does not measure power at the drive wheels.
Because SAE gross ratings were applied liberally, at best, there is no precise conversion from gross to net. Comparison of gross and net ratings for unchanged engines show a variance of anywhere from 40 to 150 horsepower. The Chrysler 426 Hemi, for example, in 1971 carried a 425 hp gross rating (often considered to be underrated) and a net rating of 375 hp.
#22
02-05-2007, 06:16 PM
Join Date: Oct 2006
Location: Northern VA (but still in the south)
Posts: 4,010
RE: hp from 327? anyone
So, if I get modern heads. Say, the vortec ones. Mild cam, likeGriff said. Use the 700cfm carb and edelbrock intake I have, maybe get beehive valve springs, update the exhaust and ....then what? Piston ideas? I have a bare 327. What would be a good crank? Does it even matter?
#23
02-05-2007, 06:21 PM
RE: hp from 327? anyone
You should wind up with a nice engine. The short stroke can stand a lot of revs so I wouln't make the cam too mild. You can always put in bigger gears to make up for the loss at the bottom end.
#24
02-08-2007, 11:27 PM
Join Date: Oct 2006
Location: Northern VA (but still in the south)
Posts: 4,010
RE: hp from 327? anyone
Well, the question is kinda moot now. I am getting a 350 for the ride now, so I will probably be building this up stock for another project or e-bay. The parts will come from the 283 except the crank, I have a stock one here. Thanks for all the info. or maybe I'll build it up as part of a blog/series/updates on the forums, who nows. Again thanks for all the help guys.
