Topic: 400 pontiac engine weight vs Chevy Big Block

[Joker (§ir£Ðragon)]

One thing to think about. I know cost is a big factor. But if the fear of stripping bolts keeps you awake at night, aluminum is easier to repair them in. We use aluminum for the main support of some of our molds at work. Since we have to constantly put them in and take them out of the machines we are constantly stripping bolts. Most of them would be junk by now if they were made of anything harder. But the aluminum is child's play to rethread.

[72blackbird]

A 450 hp 400 is easy and could be done for less than $4500, including e-heads. That motor would also have forged KB pistons and  Tomahawk 5140 rods, PRW stainless roller rockers, etc.so it would be reliable. But for $4k you could also build a 400/462 stroker capped w/ ported 6x-8's or 6x-4's and make 475-500 hp and 525 ft/lbs.

The budget 462 stroker would be plenty of motor- you'll need some wide slicks or drag radials on 17 x 11's to hook up with that much power on tap. It's nice to fantasize about all aluminum 540's making 750+ hp, but in reality an aluminum headed, 550-575 hp 462 stroker is overkill, unless you run the Silver State Classic on a regular basis.

Geno

[72blackbird]

Sorry, guys, add $1000-1500 to those prices if you have a pro build it- that's my cost and with me building my own motor.

Geno

[RainMan]

A 450 hp 400 is easy and could be done for less than $4500, including e-heads. That motor would also have forged KB pistons and  Tomahawk 5140 rods, PRW stainless roller rockers, etc.so it would be reliable. But for $4k you could also build a 400/462 stroker capped w/ ported 6x-8's or 6x-4's and make 475-500 hp and 525 ft/lbs.

The budget 462 stroker would be plenty of motor- you'll need some wide slicks or drag radials on 17 x 11's to hook up with that much power on tap. It's nice to fantasize about all aluminum 540's making 750+ hp, but in reality an aluminum headed, 550-575 hp 462 stroker is overkill, unless you run the Silver State Classic on a regular basis.

Geno

A 462 stroker sounds good to me . I would do all the work myself also .  So thats using a 4.25 stroke crank with a 4.12 bore 30 over?

[RainMan]

One thing to think about. I know cost is a big factor. But if the fear of stripping bolts keeps you awake at night, aluminum is easier to repair them in. We use aluminum for the main support of some of our molds at work. Since we have to constantly put them in and take them out of the machines we are constantly stripping bolts. Most of them would be junk by now if they were made of anything harder. But the aluminum is child's play to rethread.

I just cant see where retapping a thread after being stripped would leave very much strength afterwards?

[72blackbird]

Yep- $4k for a 6x- capped 462 that should make 475-500 hp. I have two blocks to choose from, both 481988's, but one is already .030 over and the other .040, so I'll have to see which pistons are available for a .040 or .060 overbore and go from there.

I'm using PPR's stroker kit and going with a Crower 60919 w/ 1.65 roller rockers. I might even pop for the forged crank upgrade, since it's only $300 more.

Geno

[RainMan]

Yep- $4k for a 6x- capped 462 that should make 475-500 hp. I have two blocks to choose from, both 481988's, but one is already .030 over and the other .040, so I'll have to see which pistons are available for a .040 or .060 overbore and go from there.

I'm using PPR's stroker kit and going with a Crower 60919 w/ 1.65 roller rockers. I might even pop for the forged crank upgrade, since it's only $300 more.

Geno

Geno ,how do you find the characteristics of the engine having more stroke than bore . Does it seem sluggish ,or slow to rev? 

[72blackbird]

RainMan,
The engine perameters of a 4.25" stroker 400 have already been worked out- they rev well due to the smaller BBC bearing and 3" main (vs. a standard 455). The 400  may be undersquare but with that long stroke it will make alot more power than with the 3.75 crank- the high piston speed from the 4.25 stroke is what fills the cylinders faster and makes that power at TDC. It also puts high loads on those pistons, which is why you don't build a stroker with cast pistons.

The 455 is the slow revver, due the larger 3.25 main journal diameter. If you look at BBC's and Mopar 440's both of those have much smaller main journals and are also good revvers. The rod/ stroke ratio also comes into play here- the 400/462 stroker has a 1.6, vs. the 455 Pontiac 's 1.57. A stock 400 has a 1.77 ratio for comparison, which explains part of the reason that motor is also a good revver.

Geno

[RainMan]

RainMan,
The engine perameters of a 4.25" stroker 400 have already been worked out- they rev well due to the smaller BBC bearing and 3" main (vs. a standard 455). The 400  may be undersquare but with that long stroke it will make alot more power than with the 3.75 crank- the high piston speed from the 4.25 stroke is what fills the cylinders faster and makes that power at TDC. It also puts high loads on those pistons, which is why you don't build a stroker with cast pistons.

The 455 is the slow revver, due the larger 3.25 main journal diameter. If you look at BBC's and Mopar 440's both of those have much smaller main journals and are also good revvers. The rod/ stroke ratio also comes into play here- the 400/462 stroker has a 1.6, vs. the 455 Pontiac 's 1.57. A stock 400 has a 1.77 ratio for comparison, which explains part of the reason that motor is also a good revver.

Geno

Ok I was wondering how you get 462 cu inches . I guess if you take a stock 400 with a 4.12 bore ,and get the cylnders rebored  out .04  ,then you end up close to 462 by my calculations with a 4.25 crank

What is BBC ,the con rod bearing?

[Joker (§ir£Ðragon)]

Ok I was wondering how you get 462 cu inches . I guess if you take a stock 400 with a 4.12 bore ,and get the cylnders rebored  out .04  ,then you end up close to 462 by my calculations with a 4.25 crank

Right. It would then be the same cid as a .030 over 455 Olds in a slightly smaller package.

[Porter]

Don't mean to jump right into the conversation but what are e-heads?  Thanks!

[72blackbird]

I personally wouldn't bore out a standard bore 400 .040 over unless it needed it- the good 70-75 481988 blocks are starting to get hard to find. And as far as identifying a motor by it's CID, like a 454 (BBC) or 383 (SBC or Mopar), I admit I like the 462 name for a stroked 400 Pontiac w/ a 4.25 crank, but even a 460 (.030) or a 466 (.060) still could be confusing unless you called it a Pontiac.

BBC- Big Block Chevy
e-heads- Edelbrock aluminum heads

Geno

[brndncrbtt]

Rainman,
      I am looking into building a 400 stroker for my Marty as well. I was looking at exactly what your looking for. I will share a tip I got from other guys on the forum.... Talk to Jim at CVMS. http://www.centralvirginiamachine.com/. Believe me I looked around and got in touch with a lot of builders. His prices are great and he builds then to suit your needs. Its well worth the call.