What power levels have you guys pushed a stock 440 block to?

Thinking of doing somthing stupid...Just kinda bored and I have access to one more really nice 440 block. Was thinking of doing another 440Source build and going with a 528 with the +..03 over -30 dished pistons and a .075 head gasket for about 9:1 and then adding a TorqueStorm blower....for street strip fun....

Ours recently ran 9.92 @ 135mph in a 3,680 lbs. car. 505" RB.


I'll let you do the math to figure out HP since every time I post it people want to question the number.

My first thoughts are how to get high hp with less stress? How about e85, low compression, high boost, moderate rpm? I am speculating here,,,,,,,a moderate cam to work from say 4800 to 6,000 rpm with good boost, could a guy build 800 hp and have it live?

Low rotating mass and low rpm is in my efforts.

I had three 505 cu. in stock 440 blocks crack in between the main cap and cylinder 1 or 3 (don't remember for sure). Around 745 horse power . All three lasted 3 years each. Around 450 passes each.

After 3rd one cracked , I switched to a Bill Mitchell Aluminum block, and went to 540 cu. in. Freshened every 3 years, everything looks good. Freshened 3 times so far. Last time we went to 548 cu. in. 797 horse power with 760 ft. lb. torque. About 450 to 475 passes between freshen ups.

My dream wheel says right at 700. That's enough for a stock block.

I have gone 9.48 with a stock block in a 2750lb race car...And then add my 250lbs to that...no power adder...I was thinking of going a little beyond that.

Stock block half filled, aluminum rods, stock crank, 500hp nitrous shot in Dale Gebharts gremlin and it didn't blow up 900hp?

How much stroke can you fit with aluminum rods?

Either way, I pulled the 400/512 out of my Duster tonight, and when I go thru it, I am going to measure a few things, but doing basic math, it looks like I am right around 10.4:1 compression....Putting in say a .085 head gasket, could drop me to 9.5:1, switch cams and add boost. At 7psi, this thing would make 50hp more than my big Hemi....

My dream-wheel says about 750 at sea level.

IMO if you are using a blower on a production 440 block use a stock stroke and long alloy rod. Turn up the boost!

Yep I can report exactly the same type of history with running a stock block. I tried concrete, main girdles, 4 bolt caps. About three seasons and they would start to lost ET, take them apart and could not reuse them because of cracks and cylinder distortion. I know the aftermarket blocks are expensive but calculate the machine work costs on a stock block and if you plan to race for more than a couple seasons the aftermarket block investment makes dollar sense.

I went 143MPH and 5.00 in the 1/8 at 3100#

Turbo

If you go blower like that go with a procharger. Get something you can grow into. Not something already maxed out.

any thoughts on using a 400 block instead of a 440 ?

I got 699.2

its more a question of how long can you push a stock block at a given HP level. at 600 hp probably as long as you want it to...over that the clock ticks faster and faster.

A lot depends on what stress levels the block sees, and intensity. My first beef, is the non center weighted cranks and weak block. There usn' t enough metal above the mains, and cast two bolt main caps are only good for so much. If it is a MUST DO, then working with a stock 440 block at the minimum i would offset grind a 440 crank to 4.0 inch stroke going to a sbc 2.1 bearing. Custom aluminum BME 396 forging rods, 7.10 long or longer to get a light piston in there. At .030 overbore you have 475 cubes. I would opt for a low compression ratio, 9.0? The lower ratio increases the dwell time of the power stroke ,
. E85 allows excellent boost and timing curve, plus cools the incoming charge. If a guy doesn't go above say 7 psi, i would hope 750 reliable hp could be made with a turbo? And live. Just my speculation. I built a 475 like discribed, and it had a good life normally aspirated.

Before I bought my Indy Maxx block, I did a lot of research and figuring. If I stuck with a stock block, it would have had gotten this girdle system: https://www.bcrproducts.com/caps_and_girdle_system.html

I think the Indy block was right around $5k to the door at the time. It didn't make sense at that time to invest in the stock block and try to make it live north of 1000hp on nitrous. My low deck 451 had 100's of passes in the 9.30 to 9.50 range at 3500lbs with a factory stock 440 crank(low deck mains) and stock main caps with a 3/8" girdle and is still sitting in the corner as a spare. My machinst was an old school Super Stock guy that would balance stuff damn near perfect and the bobweight came out pretty light on that setup. Don't get greedy with the timing, and I think you can make them live.

What is harder on them the RPM and horsepower or low end torque?

I know the junkyard LS guys don't like to work them down low. 800hp+ with a loose enough converter and running them to 8000RPM. I guess when you are leaning on them really hard if you drop them below 6500RPM they can bend the factory rods.

Reducing static CR with thick head gasket = bad idea.

The 400 block is considerably stronger vs a 440 block in the main web. I am a 400 block fan. IF, and that is a big IF, you can find a good one. Check for core shift and sonic check is a must. I had 4 blocks and only one I used for this build.

At 2860 lbs I have ran 5.44 in the 1/8. I have not scaled my car in years but I might be close to 2900 now. What is that, 8.60's in the 1/4? That is up in the 800's pretty good. Block filled. Steel caps and no girdle. I did have to sleeve #8 due to a crack 3 years ago but this block has been run every summer hundreds of passes since 2019....

In general, cylinder pressure drops with rpm so the same boost at 6500 is harder on the bottom end than at 8500 rpm. From what I’ve seen of the LS guys the boost targets are pretty flat, so if it drops a couple thousand rpm on a shift you get increased cylinder pressure and the stress of the rod being slowed down too. For oem stuff we have to be very aware of timing and boost at the various engine speeds to keep the engine safe, and it isn’t realistic to map a drag engine like that- they can’t be held at full load that long.

I thought force/stress on the block itself is primarily a function of weight and rpm though.

I went aftermarket block with mine just because I don’t like to gamble and I hate worrying, lol

Well bearings are here, boosted cam is ordered, and its like 15* in my garage, so gonna hide in the house for a day or two, but it looks like we are going to find out if a 400 will be ok making really good HP with a little boost.

Anyone know the weights of the various blocks? I had heard the after market Callies Hemi blocks I have are over 300lbs...What is a 400 block weight?

A Callies block is around 295 lbs and a 400 is bit over 215 lbs

Isn’t your duster for sale?

some of the later 440 and 400 blocks are a tiny bit lighter, I've seen from 210 to 225 lbs. on both blocks depending on how much crud is in the cooling passages, I think

It's ALWAYS going to be a roll of the dice. OLD production blocks, questionable casting quality, water jacket corrosion levels, can all play into the scenario. After all that there is the chance of accidental detonation if you experience a "Hiccup". Having said all this I'd still try it, you never know it might just work! No guts, no glory!!

Yes



So I am knocking about 100lbs off with the 400...Cool, the car weighs 3203 with the big Hemi...

my World iron block weighed right about 300lb with caps . Added 90lbs to Plymouth over a stock 440 block , everything from stock block was swapped to World block .

Tex

do those ls motors come with fully counter weighted cranks?

See what I mean!

We are at 1350 ft. BTW and that was with a DA of over 3,000.

We have run the stock blocks up to +700hp and if RPM is limited to 6400 or so, they live long enough for me like that.

Have you ever thought about the stress a blower puts on the bottom end through drive pressure?
Dragging 100+ hp off the crank snout can lead to a bending moment in the crank. It will use the front main as a fulcrum. That increases the stress on the second main with it trying to keep the crank from flailing about like a jump rope.

Roots blowers put massive loads on cranks. Centrifugals are a bit easier on them but still have significant loads.

Think about the belt tension alone. Guys keep wrapping those belts tighter and tighter without thinking about where that load is going.


If you're going to push a stock block you're much better off going turbo.

f you're going to push a stock block you're much better off going turbo.
I've heard this before, my current 230 block has held together at 792 HP @the crank.

I am a little worried....So going to keep it mild if I can...The direct gear drive ones are nice, but I can't fit one.

And at this point with what the chassis updates are going to cost me, it might not get a blower, or I might leave the Hemi in it.

Just think what you could get out of it with a turbo.

It's not as much the stock block, but a good tune is what will help make the stock block live.

agreed, but after seeing cap walk in my megablock 528 and seeing it go away when i bought a fully centerweighted crank for it, i am sold that is a big help, along with light rotating assemblies, and moderate rpm.

That's the plan