whats the 400s weak link

[fast360]

i was doing research on a 400, and i dont know what the weak link is i have heard that they scatter easy the only thing i can think of is the crank. i have a 383 the has alot of good parts that i gutted like a crank i as far as i know they will interchange, i figure why not the extra cubes i want a short stroke high rapping engine and im going to try to get 500 hp out of and i want to add nitrous it getting eddy heads, singe plane etc..

[Ghoste]

I would say their weakest link is that people are cluing in to what a good engine they are and you can't get them for dirt cheap anymore.  They get a bad reputation for having a cast crank but they are fine for most street applications.  Cobra Jet Fords were all cast crank and so wer a lot of teh high performance Chevs.  We Mopar guys are spoiled whenit comes to crankshafts IMO.
They are lower compression which may or may not be a weak ling depending on your point of view.
If the crank part worries you, get a stroker crank for it and really up the cubes.  That's the hot ticket today.

[deputycrawford]

My question is, how long can you go on stroke in a 400, and for that matter a 440, before the rod ratio gets bad enough to shorten engine life. I wouls like to run a 4.50 crank in a 440 but am worried that it will be smoking after 10,000 miles.

[Chryco Psycho]

any reductiion in rod ratio will increase side loading & wear on the pistons & increase stress on the rods which is why I try to stroke to the point whereI can maintain rod ratio & sacrifice some CI

[deputycrawford]

That is sound adivce. What would you say is the maximum stroke you would put in a 400 or 440 and drive it on the street long term? What is your top choice of blocks for stroking, 400 or 440?

[Chryco Psycho]

400 is cheaper as you can use the 440 crank to get 451 ci & drop 7 lbs from the rotating mass
505 CI in a 440 using 7.1" rods works too with similar gains

[deputycrawford]

Ok. I guess I have a decision to make. I have a 400 that was pulled out of a wrecker that ran. I would just use the block. I also have a 440 that is still in the truck that has 18,000 miles on it. It runs. I would also only use the block. Money is an issue so should I just use the 400 and put a steel 440 crank in it? My 383 in the car should pull 12's when im done but is the original block and heads. My thought was to go big with the 500 but if a 451 is going to be a whole lot cheaper then ill just have to shift at 6500 and go with the 451. What would you do? I want some where in the 600hp range.

[Headrope]

Did you mean to type "I want some where in the 600hp range?"
That's gonna take a whole lot more than just stroking. And if money is an issue might be something out of your range - heck, the bucks necessary for that much HP is probably out of the range of many on this site.

[firefighter3931]

What would you do? I want some where in the 600hp range.

I'd stroke the 440 with either a 4.15 or 4.25 crank to maintain a descent rod ratio. The other thing to consider is the piston skirt. Too short of a piston becomes unstable in the bore. The biggest i'd consider in a lowdeck for streeet use is a 470ci combo with a 3.91 stroke. Still a reasonable rod ratio and enough piston skirt. My next build is going to be an RB based stroker with either a 4.15 or 4.25 crank. With the right heads and cam it will make 600hp easy on pump gas. My 440 with the right boltons would make ~ 580hp with a mild flat tappet and 10.5:1 compression so 600+ is a cakewalk with another 50-60 cubes.  

Ron

[deputycrawford]

Ok, thanks. I kinda like using my 3500 stall and 4.10 gear, even for a big block. I should probably just go for the 500 and get some ported Indy EZ heads with a low .600 lift solid cam. That will most likely get me where I want. I just don't want to granade my original block; and my engine builder wants to build my third engine. They like me there..lol  I spend lots of money there. I say money is kind of an issue but I usually go pretty big in the end anyway. Thats not good right?...lol I will let the 400 block sit and pull the 440. Darn, more work. Thanks for the info anyway...lol

[cudaken]

 Need 600 HP, have you looked at a Blower?

                             Cuda Ken

[firefighter3931]

Need 600 HP, have you looked at a Blower?

                                           Cuda Ken

That's cheatin ! 

Ron

[MOPARHOUND!]

My question is, how long can you go on stroke in a 400, and for that matter a 440, before the rod ratio gets bad enough to shorten engine life. I wouls like to run a 4.50 crank in a 440 but am worried that it will be smoking after 10,000 miles.

There is a builder in Colorado that has built several of the 4.50 crank engines with the factory 440 block, approximately 540cid depending on overbore.   He goes smallish on the camshaft, making for low rpm torque monsters on the street.   Expense is the main drawback, as presently there are no economical 4.50 cranks on the market (around $1,800 for a Callies???).   You would think the piston would be radical, but it is actually less radical than a 451 piston (440 crank in a 400).

Check out www.440source.com for their stroker kit for the 440.   The 496 RB stroker (4.15 crank, 4.36 bore) in the Charger is all I hoped for and more.   Pieced mine together, and had $6300 in parts and machining, then I bought the Eddy heads and TTI headers.   Around $8350.00 now.  

On the subject of 400's, increasing compression, bolting on a 4 barrel, cam change, and header does them a world of good.   Weakest leak would be, by comparison to a 440, the smaller crank main journal size.   Other cons are the 400 4 barrel intakes are inferior to the 440 due to size, 400 blocks have more core shift and distortion than 440s on average-contrary to popular belief.

EDIT: Looks like they are now offering the 4.375 stroker crank in their kits, 528cid, cool.

[deputycrawford]

Thats cool. I guess I would go for the 540 and start saving the money; AGAIN. As long as a 540 will go 40 to 50 thousand miles before freshening I'll do it.

[RD]

from what I understand ( i do not have one) long stroke motors wear the main and rod bearings a helluva lot quicker thus lowering longevity.  something to ponder on.