New block source

[pbf777]

https://www.youtube.com/watch?v=8KLNJ8d8Vqc

I've watched this video a few times.  Way beyond my pay grade.

     Unfortunately, since the basic architecture, is based on the original Ford FE dimensions, and it was determined to cram more "stuff" in the same space, something had to go, so bad architecture in the result of the loss of any material available joining the blocks' valley wall to the outside water-jacket wall other than at the ends is adopted, and significant strength of the block is lost.  Perhaps another reason motor mounts attached to the poorly supported the exterior sides of the block were deleted?  Look at the completed unit as he man-handles it about, I bet if you mount a dial indicator to the measure the movement, one could just push by hand on the walls and record indicator reading movement.  The cylinder head mountings and related fasteners are what provides rigidity at this point, but this is not "good" engineering.         

      This result as presented is not unpracticed, particularly with the import crowd, but this doesn't make it right, and many have realized this from in service experiences.  And I know....... so-and-so and the other guys are making thousands of horsepower with "no-problems", well perhaps look a little closer; the sleeves loosen, displacing material in the bottom where they were originally press-fit, the sleeves shake so much they, the gasket and the cylinder head chafe, movement of the deck structure is so that fluid seal cannot be maintained by the head gasket nor does it survive.  But, for short run time instances, "it works", what else are you going to do?           

      If determined to have an aluminum block with sleeve insertions perhaps one possibility for consideration would be if the installed sleeves particularly at the upper flange actually interlocked instead of just butting, and this flange with say an angle, versus the flat 90° perpendicular to the vertical boring, machining to its' lower surface about it's circumference thereby creating sort of a hook that could engage the reverse in the block boring sleeve-stop relief, this providing the effect of drawing the blocks' surfaces inward as downward force is applied to the sleeve, from the seating of the cylinder head and the fasteners upward pull?  Yes, more difficult to create but so what, it's not an incapable machining center, and it's not an inexpensive product when completed.         

      Just a thought from the peanut-gallery.              

     Scott.

[cammerfe]

The sort of thing you've just mentioned, Scott, is one of the reasons I post here and read what others think, also. One thing about alternative fuels and the use of significant boost is that there's a 'horsepower knob', or even more than one. How much boost do you want for this particular run? Turn the knob. And in addition, the duration of the 'spray' and the jets in use, and more than one stage of spray all feed into the equation.

I'm told that it took the M2K Racing group about 2500 HP to get to their 300.4 MPH. Maybe I need 5000, all told. Probably for a duration of round about 20 seconds We'll see.

KS

[cjshaker]

I'm told that it took the M2K Racing group about 2500 HP to get to their 300.4 MPH.

KS

A big part of their issue is traction....all the way through 4-5th gear and 200mph. That 2500 hp doesn't come into play until they get the car to hook above 200. If they had a variable boost program that ramped up boost based on speed, and coupled that with testing to find where the optimum was (basically a form of traction control), I think they'd either be a good bit over 300, or wouldn't require that much power to get there, as the power would be better utilized at lower speeds. Every time the car breaks traction, that's a lot of speed lost in a fraction of a second.

[blykins]

Aluminum blocks are only worthwhile if:

1.  You need to move weight around.
2.  High horsepower and you have a higher risk of damaging/windowing the block (aluminum easier to repair).
3.  You rebuild often.  Sleeves are replaceable.

Otherwise, what Mr. Conley said is correct:  doesn't matter the flavor of the aluminum alloy, it's still aluminum and will expand because of the heat transfer coefficient and modulus of elasticity.  You will lose horsepower over a cast iron block due to loss of ring seal. 

[cammerfe]

Repair---yes, as necessary
Weight---somewhat of a consideration
Making alterations such as provision for more head studs, etc---very valuable
ring seal---depends on the sleeves as well as the block support, yes?

Engine controls such as to be able to change the boost/power curve---one of the most important things
Aerodynamics to load for traction---that's what wind tunnels are for

KS

(Thank you all for your input!)

[blykins]

Repair---yes, as necessary
Weight---somewhat of a consideration
Making alterations such as provision for more head studs, etc---very valuable
ring seal---depends on the sleeves as well as the block support, yes?

Engine controls such as to be able to change the boost/power curve---one of the most important things
Aerodynamics to load for traction---that's what wind tunnels are for

KS

(Thank you all for your input!)

The ring seal will be directly affected by the aluminum material.   The strength of the sleeve doesn't really mean anything when it's sitting inside a material that moves with heat. 

BTW, I'm not criticizing your choice of aluminum here.  In this case, I think it's prudent, and at this power level, I don't see any other option.  I would consider making it a solid block though; no water jackets.  If you're going to run alcohol, it will run cool and the solidity of the block will give strength. 

[frnkeore]

The ring seal will be directly affected by the aluminum material.   The strength of the sleeve doesn't really mean anything when it's sitting inside a material that moves with heat.

Brent,
You'll need to explain this in more detail for me and maybe others.

Extremely high output, aluminum, block and head, engines have been around, for many years.

[blykins]

The ring seal will be directly affected by the aluminum material.   The strength of the sleeve doesn't really mean anything when it's sitting inside a material that moves with heat.

Brent,
You'll need to explain this in more detail for me and maybe others.

Extremely high output, aluminum, block and head, engines have been around, for many years.

Aluminum has a high coefficient of expansion along as a different modulus of elasticity than cast iron.  It moves.  It expands with heat.

An aluminum block will generally be down in horsepower in comparison to the exact same combination with a cast iron block.   On a 700-750 hp FE, the difference can be about 5%. 

If you want a visual proof of how much aluminum expands and moves around, take two engines, one of them cast iron with aluminum heads, and the other all-aluminum.  Put a solid cam in them both.  With the cast iron block and aluminum head combination, the lash will grow about .006".  On the all-aluminum engine, that number goes up to .014". 

The aluminum expands so greatly that a lot of the operating parameters changes dynamically.   The compression ratio will also change, as the block will "grow" in the deck height, which puts the piston further down at TDC when it's hot.  The main bearing clearances also grow (the same way rod bearing clearances grow on aluminum rods), so we end up setting them tighter at design-time. 

When the block expands and moves around the cylinder sleeve, it can take the rigidity away from the cylinder, which will decrease ring seal. 

This doesn't mean that aluminum is inherently bad, it just means that there are pros and cons of using an aluminum block and you have to know what the design parameters are for the build before you choose an engine block.  Paying an extra $2500 to lose 35-40 hp may be a deal breaker to some, while others just want the novelty of owning an all-aluminum engine and are willing to pay for it.

In a round track/dirt racing application, the weight savings is a big pro.  On a bracket race scenario, you basically break even when it comes to weight loss and horsepower loss both.  However, if you're making some big horsepower or refresh the engine regularly, aluminum is easier to repair and sleeves are changeable. 

Yes, extremely high output, aluminum, block and head, engines have been around, for many years.  However, just because they've been around for many years doesn't take away from the inherent properties/nature of that combination.

[jayb]

Again (and I feel like I'm beating a dead horse here), I find it hard to believe that you will have anywhere near a 5% loss in power with an aluminum block over a cast iron block.  I've dynoed plenty of both, probably more than anybody else on this forum, and haven't seen that kind of loss; the results I get seem to be pretty predictable, regardless of the block material.  Some day I'm going to do a back to back comparison with the same engine, and all the same components except rings and block type, so that I have data to really find out what the truth on this is.  In the mean time, I'm sticking with aluminum, because I think that in the vehicle the weight savings of an aluminum block trump whatever the power loss (if any) is.

[blykins]

Again (and I feel like I'm beating a dead horse here), I find it hard to believe that you will have anywhere near a 5% loss in power with an aluminum block over a cast iron block.  I've dynoed plenty of both, probably more than anybody else on this forum, and haven't seen that kind of loss; the results I get seem to be pretty predictable, regardless of the block material.  Some day I'm going to do a back to back comparison with the same engine, and all the same components except rings and block type, so that I have data to really find out what the truth on this is.  In the mean time, I'm sticking with aluminum, because I think that in the vehicle the weight savings of an aluminum block trump whatever the power loss (if any) is.

I feel like I'm kinda whoopin the dead horse as well.   

Some of us have done the back to back comparison.   Even if you discount my information, I know that Barry and Blair both have done back to back comparisons, as well as the Craft boys.  It's a pretty standard comparison across the board with 30-40 hp being the number most stated.  I believe that Lance Smith was the last one to do the test and he posted the results on Facebook, which I'm not a member of.  I do believe it was a 482 against a 482 with Pond blocks and there was a 40 hp difference.  Maybe someone can hop on there and locate his post.  It's been a couple of years ago. 

I know you tout the Shelby block over the others and that's fine.  I think Blair has noted that the Shelby block doesn't lose *as much* but it still loses.  Personally, I would never ask anyone to pay $7500-8000 for an engine block that doesn't dress them and cook them dinner too, so I don't have any data on that particular block combination. 

FWIW, this isn't just an FE thing.  It's pretty prevalent across every engine family. 

[jayb]

I would be interested in seeing a back to back comparison.  I believe that the Craft data was from two different engines, dressed up the same way as far as I know.  But that is different than the same components in, and on, two different blocks.  Still not a believer...

[blykins]

I would be interested in seeing a back to back comparison.  I believe that the Craft data was from two different engines, dressed up the same way as far as I know.  But that is different than the same components in, and on, two different blocks.  Still not a believer...

That is a valid comparison.  You have to remember that a lot of guys do the same combos over and over.  When you do "recipe" engines, i.e. a specific displacement, specific head, specific camshaft, specific intake, specific compression ratio, and you do it often, you know what to expect.   When you see a 40 hp difference between said recipes and the only difference is the block material, that's an adequate comparison because there's a large sample. 

I'm in the process of trying to find two exact builds, but not having much luck.  I have many builds that are very close to each other (aluminum/cast iron being different, but the cam may vary by a degree or two between builds, etc., and I know that some may find fault with that.

It would be one thing, Jay, if I were the only one making this statement.  However, I see this statement being made from many, many, others.....including FE builders, SBF builders, and Chevy builders.   

Here are some interesting reads for all open, objective minds here and may help the OP on some block design for his project.  I know Frank will like this since he will probably end up there anyway.

https://www.speed-talk.com/forum/viewtopic.php?t=15355

https://www.speed-talk.com/forum/viewtopic.php?t=9759

And specifically for the OP:

https://www.speed-talk.com/forum/viewtopic.php?t=4890&postdays=0&postorder=asc&highlight=block&start=30

[jayb]

Dogma doesn't cut it for me, Brent.  I think back to the first intake comparo I did, when everyone said an F427 was a great manifold and the Edelbrock Streetmaster wasn't, and it turned out the opposite was true.  I remember hearing over and over from multiple people how you can't run more than about 10:1 compression on pump gas, and yet I've run multiple Drag Weeks, 1000+ miles over the week with engines from 12:1 to 13:1, pump premium fuel.  Those are just two examples of all the misinformation that is perpetuated because people just repeat what they've heard.  When I was working as an engineer, we used to have a saying:  Data, not dogma.  I have yet to see back to back testing data that shows a significant advantage for a cast iron block.  While the points you make about aluminum moving around are certainly true, the rings ride on a sleeve in the aluminum block that is actually better for ring seal than gray cast iron.  If the sleeve is clamped properly between the deck of the block and the cylinder head, and the correct rings are used, I'd be surprised if the power in an aluminum block was down more than 2% over a cast iron block, and maybe not even that much.  Block design and sleeve thickness certainly enter into that equation, and most of my experience has been with Shelby blocks and fairly thick sleeves, but getting back to the original thought of a billet block, if the design is correct I'd bet you don't give away much in terms of power.

One other thing to consider is the prevalence of aluminum blocks in OEM applications.  If ring seal was a big problem there, wouldn't oil consumption also be a problem?  And wouldn't that make an aluminum block very unattractive to an OEM?  Yet there are hundreds of thousands of them out there.  Whenever these discussions come up, that fact seems to be lost. 

I'll say again that I'm not convinced a cast iron block offers any significant power advantage.   JMO, of course 

[Joe-JDC]

I am a bit of a skeptic here on this argument.  If the water temperature is controlled with a good thermostat, radiator, and water pump, etc., then there should not be any moving around after the engine gets up to operating temperatures, and the ring seal should be stable, as well as power production.  That is where I have my doubts on losing a lot of power, if any.  I realize the aluminum grows, but it stabilizes, and if the clearances are all done correctly, then at operating temperature the output should be very close between the two engines if everything else is the exact same parts used, everything, down to everything but the block and rings.  Bore dimensions and hot piston clearance would have to be exact, or the looser piston to wall clearance would win regardless of which block is being tested.   Joe-JDC

[blykins]

Mechanical engineer here, so I like to see data myself. 

There is simply too much data out there regarding the horsepower differences between aluminum and cast iron blocks.   If you read through the Speedtalk links I posted, there are dozens of guys out there who shared similar data.   Yes, most are SBF/SBC/BBC, but the FE is not unique here. 

I've spent the past hour trying to find some dyno sheets or online posts of stuff I've done.  I know there have been a couple of builds with all-aluminum engines that I've done where I saw a noticeable difference.  These were engines in the 700 hp range.  Most of my all-aluminum stuff was done several, several years ago, so the data is harder to locate.

I'll be more than happy to address the OEM stuff.  For one, GM/Toyota/Nissan/Ford has more R&D data than Shelby, Dart, Pond, etc.  Spending several million dollars in R&D to mitigate weaknesses is not out of the ordinary.   Aluminum blocks are lighter, which helps fuel economy.  Aluminum is also easier to cast.  Is oil consumption a problem?  It absolutely can be.  Go check out the allowed oil consumption rates of some newer all-aluminum engines.  My father-in-law's Impala is allowed a quart per thousand miles before being deemed "bad".   

I'm sure Mr. Conley has some input from the auto manufacturer POV.

As an aside, go put one of your 13:1 engines on the dyno and make a loaded pull with pump gas and report back.    And just because an intake manifold made more power on one specific engine doesn't mean it will be that way with all.   C'mon Jay!  (I still love you.)