400 sbc

[logan]

just picked up a 400, casting code 3951509 2 bolt main. motor was complete less valvetrain, and intake/carb. I've been thinking about motor combos, 372 383 or possibly building the 400. I have a 350 available but also a mildly built 72 307 ( cam, valvetrain, intake, carb). What im after is a dependable, high revving motor, built for street use. what would you do?

[slowcamaro]

dependable? high revving? and street use?...sounds like its going to be one major compromise. I'm not trying to bash here, but why does everyone feel the need to destroke an engine?

On the street you have no class restrictions, but yet you're throwing away essentially free power. Build the 400, you'll make more power, assuming that you fit it with equally fitting components.

A cam that would be on the large side for a 350 is going to be be much more mild in a 400...Same goes for cylinder heads, heads with large runners for a 350 just wont feed the 400 equally as well.

The parts you will need to upgrade to make the 372 or 383 rev are the same parts you'll need to upgrade on the 400.

Destrokers are for class racing...or engines made from spare parts...but seeing as your 400 has a complete bottom end, why put a shorter throw in there.

[/guy with 400]

[CarlC]

What are your performance expectations and budget?

What do you consider high-rev'ing?

[megaladon6]

how much power are you looking to make? and what kind of driving?
how high do you want to rev? if you use a strong, light bottom end you can rev the 400 pretty well.

[logan]

i want to be able to rev it at 5500 all day, peaks 6500. I like to drive my cars, with alot of power down low. im on a pretty skimpy budget, my 4x4 gets alot more money thrown at it.

[megaladon6]

that's pretty easy. i'm have no where near the level of experience that some of the other guys have but my .02c...vortec heads, cam around 230-240 duration at .050 and .500 lift, 10:1 compression, performer RPM intake, and a 750cfm carb and you'll have a very fun, very streetable, pump gas engine. WAG on power, i'd say about 425hp and 475tq or more.
throw a 200r4 or 700r4 overdrive behind it and around 3.xx gears (depends on what kind of car) and you can even get decent MPH on the highway.

[TTOP350]

I have a 440 that i built out of my 509 block. AFR heads and a mini ram. It pulls 22mpg on the highway with 30lb injs and a STOCK chip in my 89 formula. It also revs to 7k and runs EASY 11s with real street tires.

[Texas Hotrod]

You want to be able to rev it at 5500 all day and you like to drive w/a lot of power down low. Which one is it??? A 400 can do either one, but will be happier at lower revs.

Anyone who knows 400s, knows that the 509 block is the one to have. 400 main journals are larger than a 350's, so crank strength is hardly ever an issue. The block has a high nickel content and is quite stronger than the 4X4 4-bolt blocks. I have a stock block 400 (stock crank/rods) in my Biscayne. It's had a 6-71 blower on it for the last 10 years w/o any issues.
People add 4 bolt caps to a 400. Don't do it, it'll weaken the block.

Keep the stock crank (have it crack checked), install a good set (Eagle) of 5.7/6" rods & forged pistons and it'll be good for 6K+ RPMs. BUT... It's foolish to rev one any higher. Depending on the cam, it'll make max power before 6K anyway.
I have a Comp Cams High Energy 292 in one, along with a good set of heads, Victor Jr. intake and an 850 Holley. It has always been a good combo for me.
Comp Cams now has a Thumper series of cams that sound good/run great.
I'm the 4th one to agree that you'll be blowing the whole combo if you destroke it.

[70camaro406]

Definitely build it as the 400, or 406 if it needs bored. My 406 will hit the rev limiter in an instant, and it's set at 6700. I usually shift mine at 6500 at the track, but it has AFR 210's 100% CNC'd and a solid roller cam with 250-259 duration @ 0.050. It also is strong down low. So like what others earlier had said, don't throw away displacement. BTW, I have a 509 block too, just use ARP bolts throughout, and you'll be fine. That's what I did.

[CarlC]

People add 4 bolt caps to a 400. Don't do it, it'll weaken the block.

Only by adding stock straight-bolt caps. Splayed caps do strenghten things up, but by the time the block is properly prepared and splayed caps are added it's better to just drop the cash on an aftermarket block.

Check my website for details on my old 406. It was a blast to drive and super reliable.

[86Cutlass383SR]

I'm no engine expert either, but I'll add my 2 pennies worth too. To make a smaller displacement engine make the same power (all internal parts between the 2 engines being the same) means the smaller engine will have to spin higher rpm. More rpm means more wear and friction...less engine life and dependable. A larger engine can do the same or more work at less rpm. Less wear, more dependably...and usually more efficiently.

There's an old saying thats been around for many a years...still holds true today..."Ain't no replacement for displacement".

Yes...I know a blower is replacement but he's on a budget...we won't go there in this thread.

Doug

[Scott Parkhurst]

Definitely build it as the 400, or 406 if it needs bored. My 406 will hit the rev limiter in an instant, and it's set at 6700. I usually shift mine at 6500 at the track, but it has AFR 210's 100% CNC'd and a solid roller cam with 250-259 duration @ 0.050. It also is strong down low. So like what others earlier had said, don't throw away displacement. BTW, I have a 509 block too, just use ARP bolts throughout, and you'll be fine. That's what I did.

This is the same basic setup I'm running on a 383. It'd be killer for a street 406 too!

Here's the story on it: http://www.compcams.com/Community/Ar...?ID=1945664039

AFR 210 CNCs, a solid roller, and an Air Gap make for a solid combination.

~SP~

[66chad]

Just thought I would throw a few ideas into the mix.

To keep things cheap you can run a roller cam in the old style block with o.e.m. hydraulic rollers and not the expensive retrofit ones. I am doing this right now to a 406 boat motor.

I bought a tray and guides from a vortec style block $15. The o.e.m. hydraulic lifters new ebay $45. You simply have to tap and stud three holes in the block to hold down the tray and you will have a cheap and dependable roller motor.

This is very simple and will save alot of money. On ebay there is a guy selling the tray for this exact purpose.

I also bought Procomp Aluminum heads bare $385 the valve kit $165. The heads look great.

Good luck on your project

[slowcamaro]

This is the same basic setup I'm running on a 383. It'd be killer for a street 406 too!

Here's the story on it: http://www.compcams.com/Community/Ar...?ID=1945664039

AFR 210 CNCs, a solid roller, and an Air Gap make for a solid combination.

~SP~

406 CI
10.5:1 Compression
Brodix 221cc Track 1 Heads 2.08/1.6 valves
1.6 Comp Pro Magnum RR
Comp Hyd Roller Lifters
Comp Hi-Tec Pushrods
244/244 .597/.597(w/1.6)
Victor Jr Intake
Holley 850 DP
SRP Pistons
6" eagle 4340 H-Beams
Eagle 4340 Crank
ARP Head & Main studs

Sounds like maybe I'll have to go a little bigger on the cam when its time to go solid roller...

[another69]

Logan- I think there are a few reasons to de-stroke a 400: 1- you already have a good (forged,etc) 3.48" crank (you'll need spacers). 2- you already have a set of good heads that have runners meant for a strong 350 (180-195cc)- a 377 with a bigger bore than a 383 SHOULD breathe better. 3- you're planning on a constant high rpm, peaky motor (gets old fast on the street). All else being equal, a longer stroke will most likely destruct sooner as rpms climb.
All that being said, I currently have a 406 and I would NEVER destroke it- I'm pretty happy with it on the street. I've always been curious if a lightweight crank/ rods/ pistons would give better throttle response though?

[indyjps]

a reliable high revving engine will always cost more in good valvetrain parts to make it live. the only reason I see to destroke a 400 is circle track use.
Im a little biased due to gathering parts for a mild 434.

[logan]

I ended up getting a good deal on a 406 with everything for it, except pistons and top end. thanks for all your opinions.