I stopped buy Chuck Lofgrens shop yesterday for help with a trans. We got to talking about his DragPak FS/D Challenger. His car is spotless, both underneath and everywhere else. Just like his one owner 1970 Sixpak Cuda (!)
Chuck put the newly allowed aluminum 6.1 block in the car, and picked up 35 hp.
The old block only made 665 hp, the AL motor made 700! Pretty good gain IMHO.
Now the problem is it carries the front wheels out to past the 60 clocks! His best et to date is 9.55, and he wound up with a class trophy in F Super Stock, entering in SS because he didn't have enough points to run in FS at the Nationals.
Ma Mopar also wants all the DragPack cars at an upcoming event at Route 66 in Joliet, and is paying handsomely to get them there! Nice!

Never mind

The block only

Kevin

Must be fake news. No way an aluminum block can make as much, let alone more power than its iron equivalent

Al, you certainly have a lot more experience than I do in this area but I can see how a very well engineered aluminum block with thick strong sleeves could provide a better ring seal that a iron block that might be more flexible. Of course ring seal equals power.

If this is the block I am thinking of it has more strengthening ribs in the valley that I have ever seen in a block.

That being said there could be lots of other factors with a completely different engine that could have accounted for the horsepower.

Bill

The NEW aluminum MP block certainly seems to be contributing to a lot of performance gains. Including the first ever 7 second Factory Shootout Pass

So is it the block or not?

Confused in Peoria

Maybe I did not use enough sarcasm or the right emoji

Greg stated that the ONLY change was the block. Also what was credited for the first 7 second pass, the new aluminum block.

Is there ventilation between the main webbing above the main bearing and below the bores in those iron or aluminum blocks?

I noticed the LS guys are running ventilation in there to get some breathing back and forth and keep from having high and low pressure areas in the crank case so I went to look at my blocks and noticed on the BGE block there is vents there already between the center bores at least but they are not on the 5.7 blocks. I don't have a 6.1 block here now and have never got to look that close at any of the non-production blocks. There could be some other changes unrelated to the material that are helping HP production also.

There are lots more things related to material that can alter HP between the blocks than just ring seal. Temp should be more uniform allowing more compression(don't sound like they took advantage of that here). Vibrations should be dampened better allowing more stable valve train dynamics.

I considered scraping my Keith Black aluminum block because I read on the Internet that I would lose horsepower by using it. I started buying 40 year old stock cast blocks again.

Ill pay you 50Cents per pound, I will cover shipping and throw in a case of beer just so you don't have to use that HP sucking device. If you are very prompt about shipping and the block is still useable in my 9 passenger wagon I will throw in a 76 440 6pk max wegee hemi block from a motor home.

Some good points were made on the gains being possibly more than ring seal, although I heard the stock 6.1 blocks didn't like much overbore?

Never mind

stability of a casting under load is the reason - you would be suprised how much a casting can move under power - roush actually has a dyno jig to do the measuring and does quite bit of testing for the big three. Sooner or later there will be an aftermarket block for the Genn III

Wasn't that part of what the "new" KB was going to be working on?

I tried what I saw in a video, putting a snap gauge in a vertical cylinder bore of a stock block, so the tension of the gauge was all it was held in there by. I could squeeze the block and make it drop out. If I can do that, you have to wonder how much the blocks twist, flex and distort under severe loads.

Never mind

"An aluminum block as stiff as cast iron is impossible:"

True if cast identically - not true if designed differently

You need to think in three dimensions i.e. a trussed design

Hey, that's great for the guys who want to run a FS deal. What's Tony doing for those who don't have the budget to do that or just want to run a traditional S/SS class car?

I'm going out on a limb here that the 6.1 block used in that build was the older version.
The new version we use in the super charged combo is not available with lifter locations to support a 6.1 cylinder head configuration. Not yet anyway it is in the master plan just further down the list.

Mike

That's the picture you gave us in my other post?
The lifters are not in the stock location.
R U saying production heads won't work?
Matt

9.55 with 700 horsepower.

i'm guessing the " factory stock" rules are pretty liberal when it come to weight reduction.

Scienced out race car, 3200 lbs shipped. Radial slicks. Wallace calculater says 726 hp, and that is probably based on bias tires and less efficient trans.

I showed a few pictures in my earlier post.

One had lifters in stock location none of the raised X webbing in cam tunnel area.

Other has the heavy bracing and obvious lifter relocation.

You will have a hard time bolting older heads onto the newer relocated lifter config.
The rocker gear is not stock in the newer heads as you might think.

Again they will get around to providing the new casting with a standard lifter location and the older heads will all fit and pushrods and rockers won't be an issue.

My FS/D stocker has a minimum weight of 3370 with driver as a 392 combo. This combo uses the 6.1 block with cnc'd Apache heads and T&D rockers which requires machining of the head. I believe our best pass at Indy last year was 9.37.

Mike

Never mind

A new challenger that weighs 3200 is far from “ factory stock”.
What dealer can a purchase a new 3200lb challenger at?

Wow !!!
Your not serious?
Matt

FYI they are RACECARS not streetcars. They are race by racers not your average Joe either. They understand how to get everything out of what they have HP wise, something the average guy is not even close on nor would want to spend the money on. It aint hard to get weight out of cars at all, especially production cars.

Anybody know how light you can build a challenger before adding a fiberglass body parts(doors, fenders, etc)?

Body in white as a start, moly, maybe 2800? Just a guess.

Theory is fine, but a real engine development program ON THAT PARTICULAR ENGINE trumps theory

Let me guess: "you delete your posts because you know you're wrong!"

So funny!

I think what poly is getting at (and he can correct me if I wrong) is anything you do to an Al block to make it sturdier can also be done to an iron block to make it sturdier and in the end the iron will be sturdier. You can't compare a steel gas can to an aluminum iceberg. Had the iron block had HSS cylinder liners, ribs over the cam tunnel area... it may have made more HP.

I get such a charge out of people that can't accept the posibilty that what i wrote about has been done. I used to think that way sometimes, 45 years ago.

New Gen 3 powered Challengers will easily go down to less than 3200 with factory body and interior panels. All that and power windows.
Doug

Come now Greg, we all know theory is way more important than practical application. Some people cling to old theories and ways of thinking. It is one of the largest factors that to this day still holds back Mopar guys.

No truer words have ever been posted on Moparts. As a whole we are our own worst enemy.

My hero, Bob Glidden, said in an intervue,
"We are all idiots, the guy that trys the most stuff wins"
Bob averaged 95 hours a week trying things to go faster, from what i heard. I am betting he most always thought outside the box.

Most TRUE innovation in the world comes from trial and error....

I called to get one of those blocks at Prefix...Got the P# and the price, and they can't get one, allegedly....I was told to call the dealer.

Of course.
Where do I apply to have the laws of physics, properties of metals, inertia, heat transfer, etc. suspended for my project? Because my own ideas are better...

Knowing Chuck's exposure to technology and acceptance to change, I cannot dispute the gain. Possibly some members should live in a dyno cell, as the afore mentioned Engine Masters winner does.

So, what exactly are you building?

Man that's what I was thinking. What is it going in and are you going to "race it"

The thought of a aluminum G3 in my 99 Dakota is very interesting.

This block is available to everyone or just the favored few racers?

It's hard to think outside the box when the head stuck inside the box is located deep inside an anal cavity.

"Old theory": quench, developed and patented by Harry Ricardo before WWI.
But we know better now...

Of course we know more now! - Engine design and development has continued to expand beyond his original work - You are beginning to sound like a first semester engineering student!

Have you tried the dealer?

There used to be a few dealer associated people on here I thought?

Prefix may not be that involved with these blocks as they were in the past.

I know they are being produced maybe not as fast as we would like but they exist.

Mike

"You are beginning to sound like a first semester engineering student!"
How odd - that's what people said about me... when I was 12.

Did you notice that you disagreed with something I didn't say? No?

I'd love to explain, really. But the most adamant of my critics has demonstrated his lack of comprehension of the subject, so I'll just let you all believe whatever you want. M'kay?

I'm not trying to be a Male sexual reproductive organ here
But on your http://victorylibrary.com/mopar/m-table-c.htm#SBC

Some of the 6.4 hemi data is wrong, bore is 4.09 and stroke is 3.724 ,Deck is 9.28 not(B) 4.055(S) 3.795 (DH) 9.25
Thank you for posting all the information on that list it has be very helpful

That would make .0000000000000000000000001% of my free information, yes?

Yes and I have enjoyed using/reading the other .999999999999999999999999%

I ask for no further negative posts or comments. Feel free to disagree, but attacking each other is not doing this thread any good.OP

I apologize if it comes off as I'm attacking, that's not my intent.

In this writeup I am comparing aluminum with gray cast iron, common material of engine blocks.

Getting back to science, the problem comes from the relative spring rates (moduli of elasticity) of the metals involved. In relative terms, aluminum is a 10, gray cast iron is a 20, and nodular iron and compacted graphite iron are 30. So it is easy to see that using aluminum would give some problems with stiffness.

HOWEVER, another factor jumps in here and that is how stress applies to bending. We call it different things, but flexing or bending is a way that power is lost in an engine block. Stress is what produces strain, or motion. Stress in a beam in bending is proportional to the moment (bending force) and proportional to the distance from the neutral axis. It is inversely proportional to the moment of inertia. Moment of inertia almost always involves a dimension to the fourth power. So if, for example, you have a main bearing web 1" thick, and you increase it to 2" thick. the distance from the neutral axis increases by factor of two, while moment of inertia increases by factor of 16, 2 to the 4th power (2x2x2x2). You have a 2 in the numerator and 4 2s in the denominator so the increase in resistance to bending is actually increased by a factor of 8, 2 to the 3rd power, or 2x2x2.

If you followed me this far and think it through, it means that to increase the thickness of a beam to compensate for the aluminum extra springiness, you don't have to increase the dimension by 2, you have to increase it by factor of cube root of 2, which is 1.26. So your 1" thick main bearing bulkhead is now 1.26" thick and equally as stiff, and if you want to make it stiffer it doesn't have to be much thicker. Another 0.24" and it is now 1.69 times as stiff as the 1" cast iron.

This only applies in bending, not in straight tensile or compressive stresses. But bending or flexing adds friction and reduces ring seal so it is more important.

R.

Dogdays, thanks for the info!