I was just wondering if anybody has used or heard about the Edelbrock performer power packages for the 400 Sbc. Do they make good power for the money? I've heard they're kinda tame for the 400. I don't know much about cams and intakes, or the 400 sbc but I just recently bought a 400 for my 85 trans Am And I'm lookin to run low 13's.

 

A 400 is very easy to get into the 13's rather everything will depend on your budget. So if you state your budget we can find a kit that will help you attain your goals. To get into the 13's a simple rebuilt will do that with a little head work, 4 barrel Carb, and good exhaust system. State your budget and we can give us a better idea of how to build this engine. The 400 should be built as a torque monster.
I'm in the process and will be shooting for 11's with my 408

 

The Performer package has a dinky cam and tiny intake. It will run alot like a stock LG4 as far as its power curve. The numbers will be higher, but the curve will be the same shape and occur at the same RPMs.

Not a good match.

The 400 should be built with parts that flow. You guys can build all the low-RPM motors you want, I want to go fast. That's how I build 400s.

Try a cam with around 225-230° intake duration and 10° more exhaust duration than intake duration, such as a Comp XE274H; the best-flowing set of heads you can afford; some 1¾" primary headers, as opposed to the 1-5/8" Edelbrocks; a bigger intake; and a Holley carb, preferably a 750. You'll get thae same or more torque, at least 1000 RPMs higher peak, and probably 125 more HP, for the same cost as the Perf pkg if you spend less than $800 on the heads. You can get iron Dart heads or Pro Actions for that much that will meet the requirements.

 

My budget right now motorwise is probably ranging close to 800 bucks. I've already paid for the motor it came out of a 69 chevelle and I think it's from the years 71 through 73 not really shur, but it had pretty good power in the chevelle. I've already got a set of hedmen shorty headers and Y-pipe picked out that's gonna run to my gutted cat and through my 3" Hooker catback system. So now I've got about 600 bucks and I'm looking for a good cam, intake, and carberauter combo for this 400.

 

Here is what I would do: I dont know the condition of the bottom end, but the three items that will work well with that combo:
1. Comp Cam XE-274 Kit $149.00
2. Edelbrock RPM Maniford $120-150
3. 750 Holley Carb $240-300
I dont know what heads you are using but thats where the 400 lacks performance. In the future you can get some better flowing heads to complient the big cylinder bores of a 400. They can be had from $650 (S/R Heads: good) to 1450 (AFR 210: best)


David

 

A couple questions, Are you sure it is a 400, If so do you know what pistons (flat top/ dish) and oversize if any. What heads?
Has anyone done a compression test to make sure the cylinders are about equal? If not there is no sense adding anything to this engine because it would most likely die an earlier death. If it were mine and these things were unknown, after doing the compression test, I would rip off the heads to see what you are working with!

Anyway, my guess is that is probably the typical 400 find, dished pistons, stock heads with the big 76cc chambers making low compression. If this is the case, it seems going with anything bigger (more duration and overlap) than the Edelbrock 400 performer cam is flat out stupid, You would have NO bottom end Torque to get you going! On a $600.00 budget, about the best you can do is the something like the performer package. The Performer 400 cam kit is about $137.00, it specs out at .050 214in. 214 ex. 0442 lift in. and ex. and 112 lobe sep. I would recomend saving yourself some money and going with the Summit Racing SUM-K1103 cam and lifter set. It is only $79.00 and probably a better cam, its specs are at .050 214 in. 224 ex. lift is .442 in. .465 ex. and 112 lobe sep. after that pick up a set of Z28 style valve springs and then possibly buy an Edelbrock Performer Manifold or equivalent and a 600- 650 cfm Carb.

On the other hand,
If this is a High compression engine with Flat tops and good flowing heads then something different would be alot better!
Keep us posted and good luck,
Tony

 

RB made some good points...although I tend not to agree on the 1 3/4" headers....hear me out. IF you DON'T already have headers, it would be preferable to get the bigger tube headers, but since, AFAIK, SLP is the only maker of 1 3/4" headers that aren't long tubes, for the 3rd gen, the cash layout for NEW SLP headers outweighs the power gained on a MILD 400 ( peak RPM below 6000 RPM ). Now this is my OPINION from seeing several dyno tests, and 1/4 performance data from several different 400's. Let me clarify.

Witnessed a mild 406, 9:1, Edelbrock RPM intake, worked Q-Jet, Cam was a Lunati flat tappet grind really close in specs to the Comp Cams XE274, ported and polished big valve '70-71 LT-1 heads. The motor made 320 RWHP at @5700 RPM. This was with full-length 1 5/8" Hooker headers. Owner swapped in 1 3/4" headers, with no other changes...AFTER tuning it again with the new headers, the motor DROPPED almost 20 ft/lbs of torque at peak torque. Peak torque also moved up in the RPM range. Peak HP was improved by 8 HP, and it moved the peak HP up a few hundred RPM as well. It did improve HP from 3000 RPM up anywhere from 2-8 HP.

Again the above is a pretty MILD 400. Remember, that cam that sounds lumpy in a 350 can become really tame in a 400.

Now on the other hand, there's a guy I worked with that used to build SBC's for the race crowd. He put together a pretty nasty 408 ( long rod...5.7" motor ). It had some highly ported Bowtie heads, a single plane Weiand intake, a nasty Crower solid roller cam, 10.5:1 compression. This car ran 11.50's in a 3800lb car. he went from 1 5/8" headers and 3" exhaust, to 1 3/4" headers w/ the same 3" exhaust, no other changes. Now granted, just like above, this car was tuned after the header change. He dropped 3 TENTHS from the big tube headers ALONE!! The car wanted SO much more fuel / air on the top end it was scary. And the car was tuned VERY WELL before the header swap. That's an EASY 30-50 HP kick in the pants. He also noted that the fastest times for the car came shifting about 600 RPM HIGHER than before...it just pulled better on the top end.


This is just me, since I won't build a stock small rod 400 to make peak power past 5800 RPM. They WILL rev past that if the bottom end is in good shape, that's just not me.

So draw your conclusions.

Now, with a supposed good running 400 and $600, what do you do?

FIRST OFF, find out what's in the current 400 you just bought. If it's got the stock heads ( more than likely 882 castings ) etc. This will make a HUGE difference in the power gains you will see from adding better parts.

A stock 4 barrell, 400 from the early 70's made @ 270HP and near 400 ft/lbs of torque. You're not going to go much beyond that in the HP category with stock type heads....

I like hard facts when it comes to engine build ups, so if you're asking me what I ( key word 'I' ) would do to a good running 400 if I had $600?

Well, I'd go a BIT past $600, since I know the following combo is proven. BUT if you shop around, you could probably keep it at $600.

Stock Vortec heads...no mods needed. Say $450 for a new set.
Comp Cams XE268H cam..... $95 or so.
Performer Vortec intake @$150? ( we got it used at the time for a parts swap...)

I'm sure a Performer RPM would probably pick up a few HP, but we used what we had.


400 SBC, stock Vortec heads ( these were actually take offs from a late 90's Chevy truck ), compression ratio w/ the 64cc Vortec heads was right at 9.8:1, Performer intake for Vortec heads, Q-Jet, XE268H cam, 1 5/8" shorty headers.

This run was made on a FLYWHEEL dyno, with the Y-pipe actually hooked up to the headers, and a straight thru 3" pipe after that to vent the exhaust.

This combo made 365 HP and 440 ft/lbs of torque. The HP peak was right at 5500 RPM, perfect for a street driven engine.

Good enough for cheap?

REMEMBER, you have to drill the steam holes in the heads for the 400. Shouldn't cost much, it CAN be done at home, but depends on how comfortable you are doing it.

NEW, that's more than $600....but I guarantee it will take you awhile before you get tired of that combo.

With 20 percent drivetrain loss, that's REALLY close to 300 REAR WHEEL HP. Not wimpy by far.

I won't predict ET's, simply because traction, suspension, driver, air, etc makes too many variables to guess.


Anyway..

HTH

 

First thing to do is to identify what you bought.

remove a valve cover and get the cylinder head casting #.

Many of the heads that came stock on 400 SBC's
are a waste of time. Like 624 and 882's.

Do a compression test to determine the condition of the motor.
Should be 150+ psi on all cylinders.

I would not buy the Edelbrock power package for the 400.

It's too tame and you can buy simular or better components
for less $$$.

Here's my recomendation for a budget 400 that will go low 13's or high 12's.

A 400 short block in good condition.
A high rise dual plane manifold like a edelbrock performer rpm
Professional products Typhoon, Weiand Stealth intake.
You can buy all these used in good condition.
For a cam I would use a Crane Power Max #113821
H-288-2 or a Comp XE 274H-10
I would buy a used Edelbrock 750cfm carb or a used holley 3310
750 Vs carb.
A high perf mechanical fuel pump and 3/8" fuel line.
1/58" headers will do nicely. Hedman, flowtech, hooker.

Cylinder heads will make or break this combo. Get the best heads you can afford.
For gm heads look for 441,487(x), 336 or 920.
These are all large chamber 76cc heads that will respond well to home porting and larger 2.02x 1.60 valves.

There are many good afermarket hi perf heads that can be bought good/used for low bucks like World/ Dart Sportsmans
Vortecs, Performer RPMs etc.

A HEI distributor with hi perf ignition wires and MSD coil will get the job done.
I would use a 3.73 rear gear and sticky tires like BFG drag radials
or M/T ET streets.

www.cranecams.com

www.compcams.com
www.holley.com
www.edelbrock.com
www.professional-products.com
http://www.mickeythompsontires.com/
http://www.bfgoodrichtires.com/bfgapp/index.jsp

You can research the details online yourself.

 

Those heads never came on the early 70's 400 Blocks. I was checking out casting numbers on this website and it said that the casting numbers 624 and 882 are off of later 70's model blocks, but mine is an early 70's probably out of a GTO or a firebird, but I'm still not quite shur. I was also talking to a friend of mine at a local speed shop the other day and he said that the Edelbrock Power package would be perfect for my set up. Simply because I don't have the money to upgrade my Stock Torque converter or my transmission.

 

The 400 small block Chevy never came in Firebirds or GTOs. The 400 in those was a Pontiac motor, something altogether different.

You will be very disappointed in the Performer package on a 400, I guarantee. It's simply not enough induction. It will run like a tractor motor - big grunt off idle, absolutely nothing past about 3500 RPM whatsoever. I think the speed shop guy wants to make a $1000 sale. For $1000 you can build one hell of alot better 400 than that combo.

What head castings do you have now? Which block casting? What date or age? How ar eyou so sure that your 400 doesn't have the heads that the other 95% or so of them have?

 

the 400 is an AWESOME low-buck performance engine. it makes gobs of torque and can make huge power at low rpms, ensuring longevity.

the thing to remember when building it is that you can easily build too much torque into it if you're not careful.

for the street, tons of off-idle torque means nothing but wheelspin. you have to make sure the torque is there, but not till 2,000 rpm plus.

super fast el-cheapo street engine:

400 dish piston shortblock (dish pistons so you can run 87 octane! trust me, you'll make all the power you need)

vortec heads shaved .020 with additional mounting holes for the 400

4.90 to 5.10 lift, 3.00 to 3.10 duration (advertised) cam (long duration tu cut bottom end torque a bit)

single plane hi-rise intake (dual planes make too much off-idle torque)

750 cfm carb

1 3/4" headers (1 3/4" vs 1 5/8" to cut off-idle torque)

gm hei

this combination (with '70 350/300 heads milled 0.40 instead of the vortec heads) consistently ran 12.40s on horsepower (11.80s on nos) in a daily-driven 70 chevelle with 3.31 gears, a turbo 350 with a stock vette 3-bolt converter, street (non-drag) radials and full exhaust. on regular gas! shifted at 5,500 rpm and finished the quarter just after shifting into 3rd. it was hell on wheels in the mile, too!

the old adage is true: "there is no substitute for cubic inches".