thelargechic

Okay so I recently purchased a 72 corvette, some of you have possibly seen the thread. Anyways it came with a sbc 400. I'm curious as to what kind of power it could make
Engine does not appear to of been ran long at all, fresh rebuild basically. (I'm not a complete engine expert so I'll tell you what I know)
It has an edelbrock performer intake manifold, 650 double pumper carb, 461/461x heads. (Cam is a complete mystery) and a set of headers. I apologize for being lacking. As I don't know much about the engine other than what I have listed. Hopefully someone can give me a ballpark number.

Stu's81

Without knowing what camshaft you have, the best way would take it somewhere and have it ran on the dyno.

thelargechic

The car is a work in progress lmao. Unfortunately not an option atm

toobroketoretire

First of all mechanical secondary "double pumper" carburetors don't belong on street engines; especially street engines with an automatic transmission and stock gears. They are special purpose carburetors that are made specifically for track or drag racing where the engine speed can be kept at 4000 rpm or higher. Street engines need either vacuum secondary or AVS carburetors to prevent bogging at low rpm when the throttle is suddenly opened.

thelargechic

Idk if it has stock gears however it is a 4 speed.

thelargechic

The 400 is bored. 30 over and it for sure has 461X heads with 2.02's

MotorHead

So I should swap out my 825cfm DP Drag Race Demon when I am in city traffic ?

Seriously dude repeating nonsense over and over in different threads is not going to change anyone's opinion. Best just stick to what works for you because the repetition of your opinion is getting old.

To the OP, with no other info than posted, as an guess that engine could be making between 3-400 Flywheel HP with those heads.

thelargechic

Thank you haha. Just looking for a ball park number, now to make sure the thing actually works

bashcraft

Wow! So much BS packed into just one post.

74modified

Really? Still spouting this, especially when it doesn’t pertain to the thread subject.
Just because you can’t make one work below 4000rpm, doesn’t mean other people can’t. Ya think any “special purpose” drag racers launch at less than 4000rpm? I wonder how they get them to work?
I wonder why mine, (several of them), have worked for years on the street?
Sorry thelargechic, I would have to agree with Motorhead

thelargechic

Okay so tearing into engine here
406ci
replaced the 461X heads (they need work) with 291's with roller rockers, 1.94 valves and screw in studs, cam I found out is the stock cam that came in the engine, using a 650cfm/750cfm holley carb (can't remember off the top of my head) edelbrock performer intake manifold, pistons are stock, and of course the set of hedman exhaust headers.

Kacyc3

I used a 234/244 @50 .489/.510 112 lsa cam in my 406 it pulls to 6k an dmakes for a fun car to drive, no idea what kind of power it makes with the L98 heads. Now is the perfect time to replace the stock cam, lifters and valve springs just make sure the heads can support the amount of lift you will be using.

bmans vette

My 67 Camaro ran fine with its 750 dp with mechanical secondaries. Guess it did not know any better.

71454Chevelle

7t9l82

Still spewing this?

ajrothm

7t9l82

It appears unanimous, too brokes brain has a vacuum secondary. Sorry I couldn't resist.

thelargechic

Okay so update on the engine specs
406ci
edelbrock performer intake
750 holley vacuum secondaries (for the moment)
291 heads with 1.6 rockers and .500 lift springs
pistons are dished
cam is .447/.447 with i believe 260 duration. Lift would be raised by the 1.6 rockers
Set of Hedman headers
That's about all the info I'm going to be able to give

Shark Racer

I'd guess about 300 hp, maybe a little more.

bluedawg

325ish hp and 375ish torque.