400/451 or 440/493?

I talked to an engine builder who quoted me a fairly good price on a 440/493 motor. I asked him about a 400/451 and he said that'll be a little more. Everywhere I look the 451 combo seems like the holy grail of stroker motors haha. I know the 440 would be a monster because of the obvious more displacement.

It can depend on what you plan to use the car for. For all out racing car the 400 is the strongest in the crank webbing area and the 400 has the largest bore so many like to use it. For a street car that may get raced every now and then like I do the 440 should hold up fine up to about 650 hp. I use the 440 block for my 493 build and one reason was also because the 440 raised block has a better intake selection also and I knew most of the time my car is just street driven and not run hard. Mine is around 600 flywheel hp and its been in my car since 2011 with no problems at all. You just need to weigh out your options of how you plan to use the car as the 440 will hold up fine up to so much hp (around 650) but over that the stronger 400 is the better choice as long as it takes the intake you plan to use. Ron

Yeah I don't plan on hitting the track. At least no time soon. Intakes shouldn't be a problem. Im planning on running an eddy rpm. I like the fact that the 400 is stronger also.

[quote=]I talked to an engine builder who quoted me a fairly good price on a 440/493 motor. I know the 440 would be a monster because of the obvious more displacement. [/quote] (1) a good price (2) 50 more cubes. if everything checked out I would absolutely go with the RB. EDIT that is what I was gonna add, what Andy said: the height of the "V" is roughly ~3/4 taller out at a 45 angle on the RB than the B so if it is setup up for a B now, the RB would kick the headers/ex up that much which may or may not make a fitment prob and the alt/ps would be slightly different but those would be easy to work around, that would be the main thing that would make me possibly want to go with the B & I believe most if not all RB's weigh a bit more otherwise I'd definitely want the 493 cubes in there. You're talking a thousands of dollars purchase, be SURE to check things out head to toe

Another reason people like the 451 low block is because it revs faster.

Just depends what parts you have on hand. If your car is set up for a low deck then I'd go that way, if you already have a RB in the car then that is the easier path.

About the only combos I recommend anymore are the low deck 470 or the 505 RB. I don't see much reason to mess with anything else for a street/strip type of build.

I've built and raced a lot of pump gas B and RB stroker motors. On your deal using the 400 block I would look at using a 4.250 stroke crank kit with BB Chevy rods sizes(2.200) in the 400 block with a decent set of heads and matching cam This combination makes between 505 and 512 C.I., the longer stroke will out pull and out rev the shorter stroke cranks with the stock Mopar rod journal sizes IHTHs

I built the 505" 440 based block combo.

I used the Molnar 4.25 crank and 7.1" Chevy sized journal rods

Everything fit with no grinding and this is the funnest motor I have ever built! It has more torque than you can ever use on the street.

Put some good heads on and you will have a motor that is easy to drive but will lay down impressive times at the dragstrip.

Yep, a 440 block with a 4.25 crank (2.20 rod journals) with 6.800 or 7.100 long rods is a very, very good combo. Set it up with dished pistons for 10.5 compression with zero deck height and then add a set of new Trick Flow heads and you'll have a solid 650 hp engine that runs on pump gas.

Once again, listen to your Uncle Cab.

20 years ago the 451 was the Holy Grail because 400 blocks were nearly free. But it is, in reality, only another way to build a 440. Yes, by using aftermarket parts you can trim the bobweight quite a bit, but you could also do that on any 440. So don't waste your time on a 451.

If you're just going to build a 440, build the 440.

The fun comes in when you get stroke out to 4.250". This engine has become the most popular thing to do with a 400 block. And you get 511 cubic inches, which is 60 cubic inches over the 451. That's with a 4.375 bore, which is becoming the standard size for this motor.

Also, do yourself a favor and use only the big block chevy 2.200" rod journal and 0.990 wristpin sizes. These are pretty much standard for building strokers. The Chrysler s1zes will actually limit your choices.

And sonic check any block before you invest in it. Chrysler casting quality was not so good.

Good Luck!

R.

Im doing a 451 right now. I was just building something fresh. I did think about a 4.15 or 4.25 stroke it I think the 451 will serve me well. The 431 worked real good.

Personally, I like the 400 block as it leaves more room in the engine compartment and for all the world a 500" low-deck looks like a 383; guess that's the old secretive downplayer gene in me. My last 2 BBMs were 440 blocks in early B bodies, and they were a pain to work on on the right side.

Another thing I like about the 400 block is the bigger cylinders help unshroud the valves/flow a bit.

Your situation may well differ, and it's just my opinion. Next BB I want to build would look like a stock 383 Road Runner but lays down 11s through mufflers...

Shouldn't be hard to do. A low deck 470 with Stealth heads and a Performer RPM would do the trick. Squirt everything with factory engine paint and a lot of people won't know it isn't stock. The HP manifolds will easily support enough power to run 11's, the key is getting the correct cam and compression. A Holley will work or run a 800 cfm Eddy carb for more of the stealth look. You can easily make 550 hp with a setup like that and it will idle smooth and run on pump gas. That is enough power to run low 11's if the car isn't a complete tank and it can hook up.

The 470 is definitely grabbing my attention. Mopar magazine even has a 2 part article on a 470 their building with trick flows.

Offset grinding a regular 440 steel crank will get you 470 cubes then you can peruse Andys' and the magazines' builds are good fodder. If you stay Mopar you only need some 440 rods then the KB pistons are the only real expense as far as the short block. Have your shop turn the counterweights to 7.250 when they turn the mains down to the 400 size then it'll go back to em later for balancing

ive wondered about this. when my 451 cracked a cyl and hurt my ootb edelbrock head i called muscle motors about a stroker kit. i was really leaning towards a 511. they were pretty adamant that with a standard window head that 470 was the right kit, and if i went to a max wedge head then the 511 would be the better choice. i went with the 470 kit but sometimes i wonder if i should have went with the 511. over all im pretty happy with the 470, but the damn thing better run better than my old 451!

It is now going to become a three part article. I have some intake and carb testing to do for part three.

I have a 470 and by the dyno numbers,

My 505 has been painted up to look like a stock motor. With the Stealth head it fools a lot of people. I tell them it's an RV 440 with a cam and headers that I gave a nice paintjob.

Mine ran easy 11's at the track first time out on pump gas, through the mufflers, 3.55 gears and on street tires. I drive it everywhere.

I'd love to do up an early B body 4 door with a low deck block and make it all dirty and crusty looking under the hood. Tell everyone it's a 361. Dirt and rust blowing out behind it as you trip the beams with a high 10...

What do you all think of a 383/450 are there any disadvantages to that? Sorry for all the newbie questions, this is my first Mopar and my head is spinning on which direction to go. A 383 is what's in my b body now.

The 383 has a smaller bore size so it doesn't breath as well. Also, most of the good performance parts are built for the larger bore size. A 4.375 bore size is very popular so there are a lot of ring choices as well as piston choices. A 400 block requires a 0.035 overbore to get to 4.375 so it is a very common size to use.

Check your local Craigslist for a 400 block. I see 400 blocks for sale on a regular basis where I live, not sure about your area.

Gerald post all you want there ain't no limits and that is the purpose of Moparts. Just me I'd get a 400 block a 440 steel crank 440 rods (those would be fairly cheap) and the big expense would be the KB 280 pistons & offset grind the crank. that'd give you a ton of cubes (470) in the same B width pkg you have in there now so the alt/ps would fit back up perfect & if you have HP manifolds/good mandrel bends ex system it would fit right back up also. Post any Q's and how you decide to go

I ended up coming across a freshly built 440 from Nash performance that I'm looking into buying. It's nothing wild but something I can up grade once funds become available.

My 505 has been painted up to look like a stock motor. With the Stealth head it fools a lot of people. I tell them it's an RV 440 with a cam and headers that I gave a nice paintjob.

Mine ran easy 11's at the track first time out on pump gas, through the mufflers, 3.55 gears and on street tires. I drive it everywhere.

I'd love to do up an early B body 4 door with a low deck block and make it all dirty and crusty looking under the hood. Tell everyone it's a 361. Dirt and rust blowing out behind it as you trip the beams with a high 10...
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GY3 your eng looks great ! Ron

400 has biggest bore,lighter,better rod ratio,you can also do a 400/499,of for that matter a 400/512,i even have a 400/540

Blazin' Bob, you keep talking about using 440 rods and an offset ground crank. You can have one OR the other. Offset grinding a 440 crank to a 3.91 stroke means you will use a big block chev type rod.

Chuck Senatore said it in his book and it is still to my mind the best advice; build the BIGGEST shortblock you can afford. When you get better heads it will move the torque peak up and the horsepower will go with it. But you CAN run a 220cfm head on a 500" block, that is also called a Cadillac 500. They moved those 5000lb boats around pretty well.

It feels like s a neat trick to grab a forged 440 crank out of your stash and drag it to your machine shop where the guy trims down the mains to 2.625, trims down the counterweights to 7.250 and offset grinds the rods to 2.200. BUT, WHERE IS THE MACHINE SHOP THAT'S GOING TO DO THAT FOR YOU AND WHAT WILL IT COST???

GUARANTEED IT'S NOT FREE. And, if you don't have a 440 crank stash you have to buy one of those too and that sets you back $150 or so.
So now you have a 40+ year old crank made out of 1053 or something like that, not a super alloy by a long shot, and you have $600+ invested and for what? A 3.9" stroke.
Contrast that to a brand new 4340 crank, 4.25" stroke, mains and counterweights where you want them, for maybe $100 more. 4340 is WAY superior to 1053.

One other thing to consider and that is engine driving characteristics. If you're not a class racer then what works to make your car feel stout is torque, and that means cubic inches. I'd much rather have a low rpm torque monster that doesn't need super valvegear, than a high rpm screamer that needs the valvesprings changed every year and the lash set every month.

There is no magic here, none whatsoever. A 511 will run stronger with a stock port window than a 470. Every time, all else being equal. They may both make exactly the same hp, but the 511 gets there first.

Figure out the largest shortblock you can afford, and build it.

R.

My deal fell through on the 440 so HP engines out of N.C is going to build me a low deck 470. I seen they competed in the amsoil challenge and did pretty well and their builds come with a warranty also.

Andy, why the 470 and not the 499 (4.125 stroke) or 512 (4.25" stroke)?
I know when you get into the 500+ engine size the stock cylinder port size starts to become a issue.

I kept hearing the pistons were too short...bad rod ratio and the oil support ring wasn't good on a 512 for a street motor and that a 470 would be better overall in a street car.

No oil support ring in the 512, just the 499, and it is not a big deal.
Also, short compression height has little to do with overall piston skirt length. Skirt length is really limited by how close the piston comes to the crank at the bottom of the stroke. The compression height can change what ring pack you use and how far away from the top of the piston you can locate the top ring (usually nitrous applications.)
The shorter compression height pistons usually don't need long skirts because the rod pin is pushing/pulling towards the top of the piston, not the bottom. Only the intake stroke where the crank is pulling the piston would make it rock a bit more. On the up strokes (compression and exhaust) and power stroke down, the piston will rock less with the shorter compression height (given the same skirt length.)

I can see where offset grinding a 440 crank and using GM 2.20" rod journal rods would be cost effective for a more budget type build.

As mentioned, 20+ years ago the 451 400 block combination was great because of the low cost, but it basically was a large bore 440 with shorter and lighter pistons in a slightly stronger block.

Now the low cost of stroker cranks, rods and stroker pistons has made these combination quite affordable.

My friend has an older 470" 400 stroker using the Mopar rods journal sizes, but he had to custom order pistons for his application, and that was around $1,200/set?

I was going to do the 440 but after talking to this builder he quoted me around $150 less than the 440 which really isn't much but since my car has a 383 I just decided to do the low deck and be done. So far it's going to have trick flow heads, hydraulic cam 246/246 @.50 cam with 542 lift, edelbrock rpm intake, and 750 carb. Hopefully that's a good combo..not sure what kind of rockers yet

Sounds like a good combination.

I forgot to mention one reason the short compression height pistons have shorter skirts is to make the pistons lighter.

There are a bunch of reasons why I prefer the 470 in a B block to the larger engines. Piston height, rod length, windage tray fitment, torque peak RPM and hp peak RPM, etc. It just seems to me that the 3.91 stroke "fits" in a B block since all of the supporting parts such as rods and pistons etc. also "fit". When you run the numbers the 470 inches "fits" with a standard port cross section to put the torque peak at a "good" point. A normal car with normal gearing can use the torque peak and hp peak to run well. So like I said, a bunch of reasons like that.

Thanks Andy, I was thinking the stock port cross section was part of the reasoning. How well does the McFarland calculation match up with max torque RPM?

I know what you are saying about the windage trays. I had to really mess with the Jegs 4.15" stroke windage tray/gasket to fit on my 505 RB stroker. Likely would have fit real nice with a stud girdle to raise it 1/4".

You may want to consider more carb than a 750, even for a street only vehicle. Have you considered exhaust yet?

I agree. I have the rest of the package pretty close to identical save for it's in an RB block.

It's a torque MONSTER and very docile on the street. It's like you supersized a 440 with no downside! 3" Dynomax Ultra flows with turndowns in front of the rear axle.

I like the way you think! Engine looks great too.
I try not to bring it up too often since I've talked about it so many times but I really liked the 451 I had in my DartSport, it ran 9's with Eddy heads and a 590 purpleshaft cam at 3050 pounds. Low maintenance and a ton of fun! I've also owned a couple 500" low decks and they've been fun too but that 451 was pretty darn impressive for what it was.
ThumperDart's 470 has always been a strong runner, and I'd also like to try a 470 next due to the reasons AndyF has already mentioned.