I have installed a 400 crank and.060 over pistons in my 351m with a Weiand dual plane manifold and a Edelbrock 750 carb.---a comp cam 484/518 lift.---

Does anyone know the aprox. horsepower with these changes?

EDIT:

Whoops, I'm just not doing things right today.
The cam lift is .510--.526. Duration at .050 is
Intake 211 and exhaust is 223.


Thanks,Seneca

 

The Stock 400 came out of the factory with about 156 HP.

 

Actually, stock 400's varied in HP ratings every year. Most were around 170 though. Just a guess, but I'd bet you are on the healthy side of 250, that's fairly conservative. What condition is the motor in, and what's the mileage on it? For good information, you can check out Bubba's M-Block page. It's an excellent source of information.

 

DD2K says HP = 317 @4500 RPM Torque = 434 ft-lbs @ 2500 RPM

That is with headers. With stock manifolds it will be less.

 

We have both gross and net HP #'s here.

 

150 HORSES FROM A CAM SWAP, and intake......ROFL...I don't think so Tim..... nice try though....... must be them damn desktopdyno's.............

 

A stock 400 with 170 HP is a choked up smog motor. By going from a 2V to a 750 CFM 4V, add headers and a free flowing intake and a cam with 211/223 duration @0.050 and 300 + HP is possible.

 

so your saying 150+ from cam intake and headers.......lol

I have built plentyof 351m/400's, and yes a simple timing chain change can wake them up, but 150 horse, i'd have to see that for myself on a dyno.........

 

That's cam, intake, headers, and carb(750 CFM).

I've had 2V 289's with 200 HP. I've had 351C-4V's with 300 HP. Getting 300 ponies from a 400 cu inch engine isn't hard.

Just remember this is at the flywheel, not the drive wheels.

Read the HOT Rod magazine article, that should be in the archives here.

 

I have never built a 351m/400 that ran good with a 750 carb, you must be doing alot of head work

like i said, i'd like to see that on a dyno.............

 

Hey Danlee,

Think you could do me a favor and run these numbers through the desk top dyno.

408cid
282/292 cam
flat top pistons
600 cfm Edelbrock carb
Edelbrock preformer intake
dual straight pipes with the stock manifold
zero decked block
milled heads .010
MSD blaster coil

I built this engine about six months ago but never got it on a dyno. Feel real strong but I'm just wondering if anyone has a ball park figure. Thanks

Sanders

 

Buzz,

I wouldn't build that engine that way. The 750 Carb is overkill, but that was the spec he gave me.

Sanders,

I'll run the figures, but give me the CC's for the heads. Also I need the cam lift or the make/model.

 

Danlee,

Here is the cam specs:
Adv. Duration: 282°/292°
Duration @ .050'': 204°/214°
Gross Lift: .280''/.295''
Lobe Seps. 112°

The heads stock are around 78 CC's and I milled them down a bit so I'm going to say the heads might have a 77cc combustion chamber.
The block and the heads are 78 351M car motor.

Thanks

 

Hey Sanders,

the statements to your engine nearly match to the stage I
want to come with my 400.

It already fitted with edelbrock cam, carb and performer intake
together with dual pipes and flowmaster muffler, stock manifold.

Because of a piston rings blow-by I need to do something.

I`m planning a 0.015" head milling, a set of badger flat top
pistons, a set of edelbrock valve springs and a set of roller rocker
arms.

Maybe you ( or anybody here ) can give me some advice what I
have to watch for.

Can I use my "old" pistonrods, do I need a special head gasket
or special piston rings ?

What is the difference between "pedestal" and "rail" rocker arms ?

Thanks for your help !

 

Tom,

The best way to clear up piston blow by, would probably be boring your cylinder walls out .030. On a 400 it would give you a 408 and it really tightens your motor up.

I used remanufactured connecting rods when I built my motor. My old connecting rods were probably fine but you never know.

If you are using the Edelbrock 2172 cam, you vehicle is going to be very cold natured.

Can't help you with the rocker arm question.

Good luck,

Sanders