Ok, I got a sb 400 chevy and everywhere I look it comes up in the 180 area for hp. It says this is net. I found a site that said GROSS hp is somwhere in the 220 area. What's the deal? Anyone know how much torque these things make? I forget the year (gotta look it up) but it was out of a van and from the mid 70's era. 4bbl carb (quadrajet). Any help will be appreciated. Thanks.

 

BIG torque, very little HP. Lotsa cubes that can't breathe very well. 350-375 ft/lbs wouldn't surprise me, but the torque curve falls off real quick as RPMs rise. Restrictive heads, intake, exhaust, low compression (8:1) and a teeny tiny cam all conspire against a stock 400 engine from making power.

Give it a little better cam, little better heads and a free flowing exhaust and that stock 400 can easily pick up 100+ HP. The good thing is that the stock combo is so bad almost anything you do to it will make more power.

 

Gross is basically tested on a dyno with no power accessories. No power steering alternator, fan, etc...
Net is tested at the rear wheels

 

Gross is as above. Net is at the crankshaft with all accessories and exhaust as it would be when installed in the car. The factory doesn't rate any of their cars in rwhp although it would be easy to believe they do when some of their engines are so under-rated (LS1 for example).

Jody

 

Ok, makes sense. Well since I'm running an elec fan and manual steering rack and no a/c the only thing really gonna be hooked up is the alt. So I guess I should be over 200 hp from the get go. I also have long tubes and custom exhaust going on. XE 268,vortech heads,edelbrock intake all in the future of theis street brawler Thanks for the help.