Pontiac 400

[classiccardude69]

I recently bought a 400 to put in my firebird and want to make some descent power out of it. Ive been researching different parts and am not too sure what to get yet... I'm wanting to make at least 500 hp to the wheels so.. uh... anybody have suggestions?

[b-man]

I can tell you one thing, it won't be cheap.

I know a guy who built up a 550 HP street 400 that he ran in a 2nd-gen Firebird, he liked to go around messing with Vipers with it. Something like that would put out close to 500 HP at the wheels, he ran a Tremec TKO 5-speed.

He had about 12K invested in that 400 engine if I recall correctly. It wasn't built using a stroker kit to increase the cubes, it still used the stock 3.75" stroke crank. He ran a big solid cam that was about 250/260 @ .050 and ran a set of ported iron RAIV heads, pretty much the equivalent of out-of-the-box aluminum Edelbrock heads.

It liked to drink fuel to the tune of about 6 MPG, it was a pretty serious street 400.

I would highly suggest looking around and perhaps posting your inquiry here, a forum that is Pontiac oriented:
http://forums.performanceyears.com/f...ysprune=&f=418

Good luck.

[Fast01]

Check out Butler Performance. They specialize in Pontiacs and their crate engines start at 500hp and 550ft.lbs. on 91 octane for about the same cost as a comparable BBC.

[68Formula]

Butler has a nice reasonably priced stroker kit (no replacement for displacement). http://www.butlerperformance.com/pro...s.html#494_501

Herbert sells solid roller cams and lifters relatively reasonable as well. http://www.dougherbert.com/8620bille...h=83_84_87_657

Get a set of 300-305cfm KRE heads from SD Performance, and also order your Edelbrock RPM intake through them, and they can port match it to the heads for a reasonable price. http://www.sdperformance.com/listPro...?categoryID=11

Finally, a set of Doug's headers and a 3" dual exhaust with X crossover.

If everything is tuned right, you should hit the numbers.

[George]

I posted this under your post in project updates:

400 .035 over with 455 crank (the increased bore and 4.25 stroke make it a 461 I think), aluminum heads and EFI. This will make 500-600 hp easily.

After I finsh my 67 firebird I want to do a 68 Bird with either that engine or a 400 0.065 over (same bore as 455 0.03 over) and put in a 4" stroke crank to get 440ci.... Trying to get peak HP at a little higher RPM with the shorter stroke. And also do aluminum heads to cut weight and increase compression, and EFI.

HPP did a 440 Pontiac build that made 500+ hp at 6,000+ rpm, but that was at 11.5:1 compression ration and 108 fuel. I would do 9.5:1 or a little higher with aluminum heads to run on pump gas and mid 400 hp ranges I would guess.

Edit: Actually here is their 468 build (which is a 0.065 over 400 block with 4.25" stroke crank) that is pushin 640 hp on pump gas over 6k rpm, so maybe my theory of the shorter stroke doesnt help highend power and the ability to rev faster is negated by less hp....
http://www.highperformancepontiac.co...est/index.html

[Lowend]

500HP at the wheels is a tall order for any N/A street motor.

Not to sound condescending; but have you ever driven a car with that kind of power? It's un-usable 99% of the time.

[classiccardude69]

Thanks for all of the feedback guys! I can't wait to start building it up, but I need to focus on some bodywork and getting another job to work up the engine. haha Pontiac's aren't cheap!

[classiccardude69]

This is some great info on real world pontiac motor builds:

http://forums.performanceyears.com/f...d.php?t=520102

a littlebit of everything

[MonzaRacer]

Screw the hp rating, build for a solid fat torque curve.
RPM heads and a 455 crank with mains tuned down, and since Pontiacs dont need rpms you should get away with hypertec pistons to save cash.
Check this, pretty sweet deals here on pontiac rotating assemblys:
http://www.ohiocrank.com/pont_rotate.html

[L n L]

Some good advice above, and some not so good.

As mentioned above, there are not as many REAL 500rwhp cars on the road as you suspect. Sure, there are some people that will play with the correction factors on the dyno and get the numbers boosted....

My current motor made nearly 560 on an engine dyno, with dyno headers. On a chassis dyno, a little under 430.

My '67 Firebird had an iron headed 455. At one point, on a chassis dyno it made about 360rwhp (but a BUNCH of torque). It was able to run mid-11's with a race weight of about 3450 and 3.42 gears.

The Firebird blew up torque converters, rear ends, u-joints, etc.... You start playing with that kind of power and any kind of traction, and you HAVE to get the rest of the system to match - and that is where things start getting expensive.

I'd personally stay away from the Butlers. They know how to build REALLY fast race motors, but don't really have first hand experience with performance street Pontiacs. I'd suggest Kevin Swaney of Tin Indian Performance http://www.tinindianperformance.com/
Another good choice on the west coast is Ken "Ace" Brewer of Pacific Performance Racing. Ken Keefer is who I'd use if I were closest to Florida.

Lee Atkinson

[Lowend]

I should note:
My car had a 383 making in the 470-500HP range at the flywheel.
I had traction problems going from 3rd-4th gear on the freeway while on 265/40/16 Kumho 710 Auto-X tires.

If you really want to make huge HP with a Pontiac, I would suggest contacting Paul Caselas at http://mustang-corral.com/ we used to work together and Paul built more than a couple of brutal Poncho motors.

[Lenie]

I stuck with the 400 and put a lot of good parts and money into it to hopefully get high horsepower and torque. It's now a 461 and I can't wait to start it up but I have a ways to go before that'll happen.

[Roadrage David]

Ok sins everybody is bragging around here are my 2 cents .
Chek out the outhouse Firebird VS Auston Martin story!!! and some video,s. https://www.pro-touring.com/forum/sh...ad.php?t=60351

Thats A stroker 400 into a 461 ci CVMS engine (with 530crank hp. if you whant to beat the crap out of everybody you dont need more then 580 crank hp with a poncho injun mill.) who is the builder of the fastest pontiac engine Today at 6.52 in the 1/4 mile.
he is the most hounest man out there and hase one of if not the best head porters in the country doing his heads.(forget the CNC port jobs)

At the 500 hp level pontiac Injun mills are no more ecspensif then BBC the storys about the costs have been days gone by.

500 wheel hp is doable. but this meens 630 crank hp. you need a sollid roller cam for that!! and serius ported e-heads and ore kaufman heads. you need 320/330 cfm heads. and or waight till the new year because edelbrock wil come out with the Victor heads who wil flow someting like 375/ 400 cfm out of the box. withs wil save you portwork money!!!!!!!!!!!!.

A 2 bold stroker engine wil take around 700hp before your in the danger zone . 4400 high speed cruising rpm al day long with a 461 ci stroker. with 6000/6200rpm bursts. i do my highspeed races with a 3.42 rear ratio but wil go to a 3.08 when the engine upgrade is done.
haveing said al this in order to make the same performance with a sbc you need 75 uptil 100 more hp to get the same amound of torque.. not to mention the increase rpm.
A 440 engine with a 428 crank, is the best street engine bare none for what pontiac is consirned.
if you do have the $$ a aftermarked block with a 4 inch stroke 3 inch mains and a big bore for a 477 ci ,wil blast of with massife amounds of torque and rpm upto 7000!!!.......

[PT_79_TA_461]

get a 461 stroker kit, if you have a .030 over boar then its a 467, top it off with some KREpower.com High Port heads and ask them for a cam spec for your aplication.

thay made 632 HP on a 467 pontiac...

[classiccardude69]

Thanks for all of the responses! I really have to make some descisions!!!