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Another 400 Build Question

Started by 73ChargerSE, February 07, 2006, 05:41:09 PM

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73ChargerSE

I tried to use the search but nothing really came up.  What I want to do is build a pretty stout 400, but reliable and streetable, but that i can also take out to the track a weekend or so a month.  What would be a good bore size for this motor? What would a good affordable piston brand to go with and what size pistons? With a bigger, what cam would be the optimum cam?  I want kind of a rumble in the cam so the car sounds pretty tough, but not so low of an idle that it wants to die.  I read the thread about the combo for the 400 that Charger_Croatia will most likely do.  That's probably what I'm gonna go for with my Charger, but the eingine i plan on really building is my Coronet's.  I'm just looking for a relatively cheap build with performance.

71charger_fan

A stock rebuild with a four barrel intake, headers, and the equivalent of the factory Road Runner/Superbee cam should put you into the 14s. The block will most likely be decked a little and your heads surfaced. Combine that with the steel shim headgasket and you've got a nice streetable rebuild that'll make power and perform like a factory 440 car would have back in the day. That's what I did to my 400 and I've run a best of 14.49 in the 1/4 which is pretty much what the contemporary road tests had the 440 cars running 30 odd years ago.

daves68

Here's something I read about and am considering for a 400 just sitting in the garage. This comes from the August 1998 issue of Mopar Muscle Magazine, pp 20/21.  Quote -" Federal-Mogul's Barry Rabotnick notes that when starting out with a 400, it is possible to use a .030-
over 440 piston, such as the L2388F30 to reduce deck clearance and raise compression. In this example, the 400 engine would require only an .008 overbore to achieve a .008 deck clearance and a 9.2:1 compression ratio using 88 cc heads (452's). Just remember when doing this that piston to valve clearance becomes critical and should be carefully checked"  Sounds interesting.  Give FM a call and see what they say.
I like the idea of not milling the block and creating a bunch of block to head to intake sealing problems.

RD

get a set of 9.5 to 1 KB pistons (i know chryco hates them hehe), but they will do what you want. get a set of 516 heads cheap, rebuild them with hardened valve seats.   get a .484 purple cam, a performer rpm intake and a 750 eddy carb.  buy some headers and there ya go.
67 Plymouth Barracuda, 69 Plymouth Barracuda, 73 Charger SE, 75 D100, 80 Sno-Commander

73ChargerSE

Quote from: RD on February 07, 2006, 10:33:38 PM
get a set of 9.5 to 1 KB pistons (i know chryco hates them hehe), but they will do what you want. get a set of 516 heads cheap, rebuild them with hardened valve seats.   get a .484 purple cam, a performer rpm intake and a 750 eddy carb.  buy some headers and there ya go.

Which pistons?  The 440 ones or the 400?

Also, would it be worthwhile to get new valves?

RD

they are KB240's and they are 400 only pistons.  you will need to get new valves if you were to enlarge them to 2.14/1.81 size.  If you are willing to spend the money to rebuild these heads, you might as well put the larger valves in also. 

As far as I know, you are unable to use 440 pistons because of the piston height in relation to the rod length.
67 Plymouth Barracuda, 69 Plymouth Barracuda, 73 Charger SE, 75 D100, 80 Sno-Commander

73ChargerSE

Would I just use the stock rods with the new pistons and rings? Also, what rings would I buy?  Sorry I'm asking so many questions, I just want to get it right  ;)

RD

yes, you will use the stock rods.  your machine shop will recondition them hence hone them to perfect shape and tolerances.  they will also mount the rods to the pistons.  as far as the rings go, your machine shop can recommend a good set without breaking the bank.  If you could, find a forged crank from a 71 or earlier 383 or 361 and get your entire rotating assembly internall balanced.  this will cause your engine to cause less wear on your bearings, hence longer engine lifespan.  you will need to get a different stall converter since you are doing a bigger build.  find a nice 2400-2800 stall (either TCI, or B&M is fine).  Make sure you let them (the store) know that it is for an internally balanced motor so they do not sell you one with weights attached to the converter.  Find a nice cheap balancer, again your machine shop can help you.  You do not need a fluidamper balancer.  They are good, but are expensive.  You can find a nice good one for half that price.  if you have any other questions as far as finding parts or what I am saying, just let me know via pm or on this post.

good luck.
67 Plymouth Barracuda, 69 Plymouth Barracuda, 73 Charger SE, 75 D100, 80 Sno-Commander

Runner

look seriously at more stroke.  if you can spare a few extra hundred dollars then the cubes you get will make a world of differeance in the power you make

71 roadrunner 452 e heads  11.35@119 mph owned sence 1984
72 panther pink satellite sebring plus 383 727
68 satellite 383 4 speed  13.80 @ 102 mph  my daily driver
69 superbee clone 440    daughters car
72 dodge dart swinger slant six

Chryco Psycho

the L2388 piston could work in a 400 JUST
the compression distance is 1.926 which is .101 taller on the 440 piston & the 400 piston is 1.825 compression height & sits .109 below deck so in a 400 block it would be .008 below the deck , no other 440 piston could do this & not hit the head

73ChargerSE

Quote from: Runner on February 08, 2006, 10:25:36 PM
look seriously at more stroke.  if you can spare a few extra hundred dollars then the cubes you get will make a world of differeance in the power you make

I'm on a pretty tight budget because of my parents  :icon_smile_dead:

I'm planning to do most of the reassembly in my shop class.  I've already got it down almost to the block and ready to get sent out.  I may just send it out and get it hot tanked because the insides of it are so clean and there isn't much of a ridge at the top of the cylinder.  When I get the pistons out I'm going to check the taper and hopefully I wont have to do any machining.  But with the 9.5 to 1 I don't need to do any kind of bore do I?  When the time comes, I'll probably pull this engine and do what i want with it.  This is just to get it up and running so I can maybe start running high school drags for my senior year and to have a little fun with.