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How much HP can I expect with my 400?


bkfirebird
11-19-2003, 02:58 AM
I just picked up my Chevy 400 small block and I'm looking to spend no more then 3 grand on the motor and go all motor, I was just wonder how much horsepower/torque can I expect to have if I build the 400 and do everything myself

SuPeRcAr_MaN
11-19-2003, 02:46 PM
I believe the Pontiac 400 motor, which is probably very similar, puts out 365 HP stock. I heard you can easily bring it up to 400+. I wouldn't know the exact engine modifications that are the best bang for the buck because I am trying to learn them myself.

Tomsriv
11-19-2003, 11:59 PM
Well, you will have to give more information. It doesn't cost much more to raise the compression and install a radical camshaft. That will get you 350-400 hp easy. But, you may need to upgrade the rest of the car to match the motor. The torque converter and the carburator may need to be changed. Is this a street car? Is economy of concern? What kind of car is the motor going into?

PWMAN
11-20-2003, 08:27 PM
Well if you can do all the machine work, and build the engine yourself you could build a 500+ HP beast with 3K in parts. First you want to buy some really good heads, aluminum is a must and with 2.08/1.60 valves. Those should cost around $1200, but will easily give you 100 HP more than stock heads. Get flatop pistons, zero-deck the block, and you should be good for 10-10.5:1 compression which is very optimal for a pump gas aluminum head engine. A solid lifter cam, and good rockers will really help your output a lot. A roller cam gets a little pricy, so solid is good enough. You just have to adjust the lash every couple months(depending on how much you drive it of course), but the power gain is worth it. If this is going in a car get a single plane manifold, if hood clearance is a concern get the Edelbrock Torker intake, of not get a high rise single plane like the Weiand X-celerator. And a 750 carb, I personally use Edelbrock carbs, but for some reason most Chevy fans use Holley pieces of crap. The only good holley carbs are the double pumpers, or the Street avenger series. Well of course there's always the dominator, but thats just for racing.
Don't let anybody tell you you need forged internals at those HP levels, cast pistons and crank are fine. Maybe nearing 500 HP you might want to look at a good set of rods, just for peace of mind.

bigbob
11-28-2003, 05:21 PM
iv gota 70's chevy 400 small block, it is the one with a 4 bolt main cap. its in a 66 nova and we threw donw 650 at the wheels. but then again we bought just the short block{no pistons,heads, etc} and built it from nothing. bored 40 over, 10.5-1 compresion pistons, storked...asl motor obviously.

Tomsriv
11-29-2003, 02:00 PM
The January 2004 issue of Chevy High Performance has a build-up of a 490hp 400 that runs on 87 octane. Its pretty amazing. It uses 68cc vortec heads.

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