440 block horsepower limits

[ValiantRacing]

I am not on the big block section to often, and maybe this has been covered before, but i wanted to get some input on the limit of a RB block, i have a friend with 500ci in a Duster, dont the know the HP numbers, but he has gone 9.40s, at sea level and 9.80s with DA at 6000. I keep telling him you need to back this thing off, he already had rod go through the side of block on the last build.

What do you guys think is max HP?

 

[PROSTOCKTOM]

With a girdle I think 800 is safe. Your friends car isn't there yet, but that is a really subjective number. The rotating assembly weight can have huge effects on this.

My friend John is running 5.40 in the 1/8 and 8.42 in the 1/4 with an OEM RB block with a homemade girdle.

Tom

 

[fishmens67]

700 hp with a 440 block is about max and still on borrowed time.
Better off starting with a sonic tested 400 block.
Don't waste your time with a girdle on a 440 block, it does nothing to strengthen the main webbing.

 

[AndyF]

800 hp will crack them. They can run for awhile with cracks in the main webs but eventually the cracks will get big enough that it will blow up.

 

[Garrett Ellison]

The rotating assembly weight can have huge effects on this.

My friend John is running 5.40 in the 1/8 and 8.42 in the 1/4 with an OEM RB block with a homemade girdle.

Is he running aluminum rods in that? What stroke is he running?

 

[Oldiron440]

Depends on how your making the power, I’ve seen a 500” with.700” cam and B1 heads push the crank out the first pass and I’ve seen 500” with a Pro Charger run all year going 9.20s in a 3800 lbs Road Runner.

Higher rpm big power is safer than 650 tq at 2500 rpm so turbo an supercharged applications sould be safer than na or nitrous.

The standard number for years has been 700 hp max so was 7000 rpm and I have always pushed that even with a 4.15 stroke.

 

[PRH]

Not all oe blocks are created equal……..nor is every engine combo.

My feeling is that at 650+, especially with high CR and high rpm……..it’s not a question of “if”, it’s a question of “when”.

Some will hold up longer than others.

 

[PROSTOCKTOM]

Yes, BME (Bill Miller) aluminum rods. 4.375" stroke.

Tom

 

[PROSTOCKTOM]

Don't waste your time with a girdle on a 440 block, it does nothing to strengthen the main webbing.

Maybe not, but it absolutely will keep the main caps from walking around.

Tom

 

[33IMP]

Maybe not, but it absolutely will keep the main caps from walking around.

Tom

..... and keeping the mains from moving around might lessen the stresses on the main webbing. Stiffer is better, imo.
Agree with oldiron too. Turbo power is MUCH easier on the block than equivalent nitrous power. Or N/A.

 

[PRH]

I built a 14:1 493 for a customers S/G car years ago.
It was just under 700 hp.

He used to put about 100 passes a year on the car.
I freshened it at +/-300 passes.
Everything was mint.
It didn’t even show any signs of cap walk(I was very surprised).
It got the usual stuff replaced, heads touched up, put back in the car and run for another 300 passes.

Back out for another freshening, still running perfect, no loss of performance.
But…..the #4 cap came out in 2 pieces(bearing was still fine), big crack going from the #4 main up to the cam tunnnel, and the crank was also cracked on #4.

It got a real block next time around.

 

[496 polara]

Well I hope my 505 will live for a while at least. At least longer than the 8.75

 

[MOPARMAGA]

I am not on the big block section to often, and maybe this has been covered before, but i wanted to get some input on the limit of a RB block, i have a friend with 500ci in a Duster, dont the know the HP numbers, but he has gone 9.40s, at sea level and 9.80s with DA at 6000. I keep telling him you need to back this thing off, he already had rod go through the side of block on the last build.

What do you guys think is max HP?

I don't see why a rock block and light rods, aluminum main caps in a light car couldn't live a while at excessive HP numbers.
On my b engine I'm going to dowel the caps on the sides to hope cap walk can be tamed.
I made 685-690 . That's nothing special just studs and factory caps.
Now since I'm putting in a bigger cam solid roller vs a lesser solid flat tappet, ported tunnel ram and ported heads I'm choosing to rock block it and building a dry sump oiling

 

[fishmens67]

I made 685-690

I see a BME or Indy aluminum block in your future when 700hp isn't good enough and you're looking for 8 or 900 hp. lol
I'm told you're still pretty young, so you're gonna want to keep up with the Goodwrench guys in the future.

 

[MOPARMAGA]

I see a BME or Indy aluminum block in your future when 700hp isn't good enough and you're looking for 8 or 900 hp. lol
I'm told you're still pretty young, so you're gonna want to keep up with the Goodwrench guys in the future.

Yeah, definitely planning on a real block build.
Unless this power level is fine for me... we'll see

 

[PROSTOCKTOM]

I see a BME or Indy aluminum block in your future when 700hp isn't good enough and you're looking for 8 or 900 hp. lol
I'm told you're still pretty young, so you're gonna want to keep up with the Goodwrench guys in the future.

BME doesn't make engine blocks and Indy would be the last place I would suggest buying an aluminum block from.

I know of way to many guys that have had issues with Indy aluminum blocks including the Indy aluminum AMC block I own.

Tom

 

[ValiantRacing]

The combo is, 13-1 comp, solid roller cam, Indy 295cc heads Indy intake, it does go past 7k at the stripe, he is running 4.56 now and told put 4.10s in. We will see this weekend how fast it is, we are racing and the weather looks really good.

 

[fishmens67]

BME doesn't make engine blocks a

I meant Bill Mitchell, he lists them for $7200.

 

[MOPARMAGA]

BME doesn't make engine blocks and Indy would be the last place I would suggest buying an aluminum block from.

I know of way to many guys that have had issues with Indy aluminum blocks including the Indy aluminum AMC block I own.

Tom

View attachment 1716409598

I'm not going to trash the Indy Maxx block but I did attempt to bore a unfinished bore block to 4.375 with .006 for honing and it was already big at the bottom by .010. unfortunately the guy had to buy new pistons and we had to deck the block also, sleeves were all over the place on heights.

 

[MOPARMAGA]

The combo is, 13-1 comp, solid roller cam, Indy 295cc heads Indy intake, it does go past 7k at the stripe, he is running 4.56 now and told put 4.10s in. We will see this weekend how fast it is, we are racing and the weather looks really good.

Hoping for the best.

 

[PROSTOCKTOM]

The combo is, 13-1 comp, solid roller cam, Indy 295cc heads Indy intake, it does go past 7k at the stripe, he is running 4.56 now and told put 4.10s in. We will see this weekend how fast it is, we are racing and the weather looks really good.

Is he racing a SRP?

Tom

 

[Newbomb Turk]

Just because the block isn’t broken doesnt mean the rings are sealed.

Or the decks aren’t moving like crazy.

If you want to make that kind of power it’s just dumb to spend all that money to compromise ring seal and gasket sealing.

I know for a fact, a FACT because I got it from the horses mouth that a certain Pro Stock engine that was borderline making the show had a gasket sealing issue.

It wouldn’t show up in a leak down test until the engine had 8-10 pulls on the dyno.

But it showed up on the blow by meter.

Ring seal matters.

 

[AndyF]

I built a 14:1 493 for a customers S/G car years ago.
It was just under 700 hp.

He used to put about 100 passes a year on the car.
I freshened it at +/-300 passes.
Everything was mint.
It didn’t even show any signs of cap walk(I was very surprised).
It got the usual stuff replaced, heads touched up, put back in the car and run for another 300 passes.

Back out for another freshening, still running perfect, no loss of performance.
But…..the #4 cap came out in 2 pieces(bearing was still fine), big crack going from the #4 main up to the cam tunnnel, and the crank was also cracked on #4.

It got a real block next time around.

We've seen that a few times. Engine is still running fine with good oil pressure but when it gets pulled down the block is cracked and the crank is junk. So it was going to blow up in the near future, it just hadn't come apart yet. These are typically 700 to 750 hp combos. Trick Flow or Indy heads, race gas, solid roller combos.

 

[MOPARMAGA]

We've seen that a few times. Engine is still running fine with good oil pressure but when it gets pulled down the block is cracked and the crank is junk. So it was going to blow up in the near future, it just hadn't come apart yet. These are typically 700 to 750 hp combos. Trick Flow or Indy heads, race gas, solid roller combos.

Great. Lol, I'm building a bomb

 

[ValiantRacing]

Is he racing a SRP?

Tom

No at Sonoma Raceway, SRP closed in 2023 that was a huge lost for so many of us, not many places for us to go anymore, his best pass was a 9.51