Need advice for 400 build

[rayderluvr]

I have a bone stock 400 HP in a '73 Charger. I have considered stroking and alluminum heads, etc., but now am leaning towards using the stock heads, intake, and exhaust manifolds to maintain a true stock appearing engine. I would like this to be a quality build, but want to limit cash input as after body, interior, and suspension work I will be low on funds.
What would you expect the cost to be to rebuild this motor to near stock specifications? I would raise compression to 9.5 or 10 as from what I have read those ratios would be good on "convenience store gas". I would also want to add a bigger (or should I say better) cam to increase torque and power, but with enough vacuum to run power brakes.
Any thoughts on the cost and what I might expect for horsepower/torque? If you have an opinion on what cam would be best for this combo (or suggest a beter combo), feel free to advise....


Thanks for your input!!

 

[RustyRatRod]

The biggest two expenses in will be pistons and cylinder head work. Pistons are around 500 give or take. Cylinder head work depends on what you want to do. Before you ask, it will be totally senseless to try and raise compression by milling. The bluprinted compression ratio of the 400 is down into the 7s. You'd have to mill well in excess of .100" off the heads and or block to make a big difference. Even then, you would likely not be at 9:1. The expense alone in milling heads/block and intake would equal or surpass buying the KB240 pistons. Since the 451 stroker pistons can be had for the same price, it's kinda dumb not to go ahead and procure a stock 440 steel crank and simply build a 451. Minus the cost of the crank, you'll have the same amount in the engine.

 

[Beekeeper]

The biggest two expenses in will be pistons and cylinder head work. Pistons are around 500 give or take. Cylinder head work depends on what you want to do. Before you ask, it will be totally senseless to try and raise compression by milling. The bluprinted compression ratio of the 400 is down into the 7s. You'd have to mill well in excess of .100" off the heads and or block to make a big difference. Even then, you would likely not be at 9:1. The expense alone in milling heads/block and intake would equal or surpass buying the KB240 pistons. Since the 451 stroker pistons can be had for the same price, it's kinda dumb not to go ahead and procure a stock 440 steel crank and simply build a 451. Minus the cost of the crank, you'll have the same amount in the engine.

Well said, this would make the most sense for quality build and the 451
Has been proven over and over and they run like a raped ape

 

[rumblefish360]

IF you stick with the stock displacement, then just simply raise the compression as you planned and look for a cam with increased lift to take advantage of the heads flow capability. More duration will equal more power as well but raise the RPM starting point. Depending on your gear ratio, you'll have to be careful on how much you increase the duration.

Do you know what cam is in there now and what your gear ratio is?

 

[fatecaptured]

Can someone please demonstrate how a rapped ape runs?....:dancing_monkey:

:beavisnbutthead:

 

[Beekeeper]

Can someone please demonstrate how a rapped ape runs?....:dancing_monkey:

:beavisnbutthead:

Lol the one at the end of your post seems to be warming up

 

[Garys1969RR]

Ha ha, took a run in my 69 RR 451 on this cool september morning after fixing the brakes, and those were my words exactly! "This thing is running like a raped ape! " It screams, howls and screeches as it runs! Thats how I would describe it. Build a 451, hard to go wrong with this set-up! Good luck.

 

[mach123]

I hear and read about a 470 and say better then the 451, are they getting that with a 400, please explain. Thanks

 

[RustyRatRod]

I hear and read about a 470 and say better then the 451, are they getting that with a 400, please explain. Thanks

The 470 to *me* is the stupidest engine to build. I hear and read people talkin about how great it is. 20 more cubes for a 700 dollar crank. That's what you're lookin at. Stupid IMO.

 

[rumblefish360]

The 470 to *me* is the stupidest engine to build. I hear and read people talkin about how great it is. 20 more cubes for a 700 dollar crank. That's what you're lookin at. Stupid IMO.

I'd rather do a 500 & lack cylinder head. You can always get more head later.

 

[RustyRatRod]

I'd rather do a 500 & lack cylinder head. You can always get more head later.

Puzackly. I mean if you're GONNA buy a crank buy a CRANK, right? lol

 

[rumblefish360]

Well, that's the way I see it. If you have the money to stroke the 400, you might as well go right to a 500, do not pass go, do not collect $200, just go to the 500.

The issue of not having enuff head would for the most part be the same between engines. You can always upgrade later. Until then. A 470+ cube engine is an over built engine that IMO, will perform no better than a 440 until the proper head (& other parts) is used.

If the over all short block build cost is to much money, stick with the starting displacement (400) and enjoy it. It'll move the car well. Save money for later. A proper and well done Stroker is pricey. A basic rebuild w/performance bolt on's and a cam is a lot cheaper.

Both can perform well.

 

[RustyRatRod]

Both can perform well.

Wise words from a wise rumblefish.

 

[Funship32]

Well...I'll wade into the fray just to give my opinion, Rayderluvr. I'm not an engine rebuilder per se in that I've rebuilt engines in the past but it is my hobby and NOT my job. 400....rebuild...don't have a lot of $$...okay...I get it. First thing you'll need to really do is sit down an ask yourself what your "goal" is. Does the engine need to be rebuilt or are you looking for more HP? Do you want a good "general" use engine or a 8000 RPM screamer? Regardless of what you want, if you rebuild you best "plan" on is new pistons. Depending on how many miles the block has, you'll probably have to have it bored .020-.030 over. If you go cast pistons you can keep the cost down opposed to Forged or Hyperutetic<sp> slugs. However you should keep your RPM down to..I'd say no more than 5500 RPM to be safe if you run cast. Good thing about new slugs though is that you can increase your CR in the process. Win-win there. And yes, you could go with Alum heads BUT from what I've read, you have to plan on a point drop in your CR if you do such due to heat transfer. You could go with roller rockers..lifters..the hyperutetic pistions..etc..etc..but honestly, from what I've read, you won't need too unless you are really going to wind the engine up and if you start to go down that road, you'll probably want to look at a new torque converter, rebuilt trans..etc. So my advice? You can increase your HP by doing a good rebuild on sound priniciples- new pistons that give better CR, new flat tappet cam, new intake manifold, good exhaust setup. You don't need to shoot for a 8000 RPM screamer but can rebuild what you have and come up with better HP numbers than you have now and keep the cost down. Again just my 2 cents.

 

[rayderluvr]

Thanks for all the input. I do not plan on ever running the engine over 5500 RPM, just want a a good running engine with good torque and reliability. I am not looking for lowest cost, but best bang for my buck. Can I make good torque and ~400 HP for less than $5,000? Less than $4000? (with someone else building the engine)
Another way to ask....What do I need to do to whip Chevelle 383 stroker and a el camino with a 350 HP fuelie GM crate motor? )

 

[court9155]

Thanks for all the input. I do not plan on ever running the engine over 5500 RPM, just want a a good running engine with good torque and reliability. I am not looking for lowest cost, but best bang for my buck. Can I make good torque and ~400 HP for less than $5,000? Less than $4000? (with someone else building the engine)
Another way to ask....What do I need to do to whip Chevelle 383 stroker and a el camino with a 350 HP fuelie GM crate motor? )

What you need is your stock 400 with small nitrous

 

[rumblefish360]

I would say you have a big problem.a k of dead presidents I think.

 

[Garys1969RR]

There was a guy at the drag strip last nite had a 496 stroker in a 72 Dart. And he was running 11.40 at 125 MPH thru the mufflers! Drove it to the track. Of course he had a tunnel ram with 2 holley 4 bbl carbs on top, and ported Eddy RPM heads Ha Ha. Guess what I'm saying is that these motors will take you about any where you want to be, from mild to wild. My 451 Road Runner was running 13.80 at 100 MPH with stock ex manifolds. So pick a target, set a budget and enjoy the ride!

 

[Funship32]

Thanks for all the input. I do not plan on ever running the engine over 5500 RPM, just want a a good running engine with good torque and reliability. I am not looking for lowest cost, but best bang for my buck. Can I make good torque and ~400 HP for less than $5,000? Less than $4000? (with someone else building the engine)
Another way to ask....What do I need to do to whip Chevelle 383 stroker and a el camino with a 350 HP fuelie GM crate motor? )

The old addage comes to mind: Speed costs money, how fast do you want to go? :laughing11: Here, read this as it may give you some ideas:
http://www.moparmusclemagazine.com/techarticles/engine/mopp_0805_mopar_engine_build_guide/

 

[Garys1969RR]

Oh yea Ray, I have about 3500.00 in my 451. That includes buying a 400 for 300 dollars. A 440 crank and rods for 175.00. 400.00 to machine crank and grind the rods .010 undersize, and turn down the counter weights. 900.00 machine shop to boil block, bore and hone, balance with mallory metal. Install cam bearings etc. A good used 509 cam and lifters 75.00. Used 906 heads 25.00 (that was a deal). Home ported. Head work 200.00. 700 Holley dbl pump came on a 400, so 100.00 for that. Holley intake, 100.00. Then Ross 14cc dome pistons 660.00. (You can save with a cheaper piston). Rings, gaskets bearings prob another 300.00 or so. Torque converter 150.00, used. Best 1/4 mile time of 13.76 @ 103 MPH. Stock HP manifolds, w/o mufflers. Street tires. Thats my budget build, and its a 451! Good luck.