You can make it work you just give up a little bit of power from a 400 block. But average street/strip build probably won't notice it anyway.

Do the valves contact there, or is that for airflow??

Anyone know the details of Trick Flow's build? I suspect that one and Dulcich's aren't as apples to apples as it's made to appear.

That is to transition the large Trick Flow chamber to the smaller bore by removing the ledge that would shroud the valve. It isn't as good as a larger bore, but it's better than nothing at all.

Casually brushing off a 60 HP discrepancy Claiming that the heavy pistons and rods cost 25 hp, is this legit? The cam specs still are weird to me, the cam that TF sells is a 243 int./247 exh, 0.600 int./0.600 exh 108 cl Hyd roller cam that is clearly listed, The MM claims the cam was
Are the TF cam and the Comp solid that was used really equivalent? I don't see a 60 HP- roughly 10%, but there are others here that know much more about that than I do.

Yeah Brad, the article is full of inaccuracies.
The Trick Flow build uses a hydraulic roller 243/247 @.050, not a solid flat tappet. They can't even figure out what cam they are running. In the body of the article, they say it is a solid roller 242/248, and the photo caption says it is a 248/248 solid roller. There's more, but I don't feel like wearing out my thumbs.
Who knows what the heck they built, but it's weak, IMO.

Same thought here.

Gotcha. Thanks.

I usually test this type of motor at a 300rpm/sec rate.
At that rate, the weight difference of the pistons and rods would be worth almost nothing.

Fwiw, I felt like the TF dyno numbers seemed a little high...... Especially when there are a few posts of 500"-ish motors making about the same power.

I'd like to take my TF 470 down to Westech and run it against the Mopar Muscle TF engine. I think it would be interesting.......

I don't know all of the details but they had 1.60 rocker arms and a plastic intake manifold. I can see how they made the power that they made but there might have been a few "tricks" behind the scenes. I don't think we'll know since I don't think they ever published any pictures.

I'm thinking Trick Flow may very well have done what they advertised. We have one 440/446 Trick Flow build using a Edelbrock RPM intake and a 6-bbl set up. Solid roller cam 238/242 @ .050 112 LSA .600/.600 net lift and 9.9:1 compression. Both set-ups made right at 590 HP. This is dyno graph for a 6-bbl run. Date and time are wrong on the graph, I didn't reset the computer after shutting everything thing down. This really isn't in response to fast68 post but the above AndyF post.

dyno graph

6-bbl dyno run

Admittedly, the 600hp+ 440 based motors I've tested all had cams with more duration than the hyd roller TF used in their build, so they should be tuned to a higher rpm.

That being said, I've also found that at that power level, going from a 2" x 3.5" header down to a 1 7/8" x 3" header(hooker 1 7/8" super comp in this case) would cost some power. It's just one element that's makes me question the 620hp number.
I'm not saying that's not the number they saw from their dyno, I'm just questioning if that's the same number I'd see from the same build.

The horsepower tv 505 used the TF heads and intake, and a bigger cam than the TF cam, and only made about 20hp more.

I'm thinking if I pulled that TF top end off a 446 and bolted it onto a 505, then swapped from 1-7/8" headers to 2" headers, added 10deg more duration and .050" lift, I'd see more than a 20hp difference.

Truth!

What does cubic inches have to do with horsepower? More torque, yes, but not horsepower. The heads, cam, and induction are going to dictate the horsepower capability
The cubic inches will only dictate where that peak horsepower occurs. If a larger motor makes significantly more horsepower than a smaller motor, there is a problem with the valvetrain not being stable enough to allow the smaller motor to rpm like it should. That never happens, right?
For example, their peak was at 5600 rpm, and so was my 505, but Trick Flows was at 6200 rpm. Since horsepower is a result of rpm, I'd say the valvetrain was a disaster on the MM build. If they could have gotten to 6200, the horsepower results would have been considerably different.

These particular motors we are discussing are not max effort race motors.
They are are hot street/strip, mild bracket type motors.
None of them is making "maximum" use of the heads, and my experience has been with that type of build, the cubes make more power.
Oem 440 4bbl motors are rated at 40 more hp than a 383 4bbl, with the same heads & cam.
Mopar Performance crate hemis are another example. The 426 and 472 are basically the same except for the stroke/cubes, with the 426 rated at 465hp and the 472 at 525hp.

I built two very similar street strip RB motors years ago, a 446 and a 493. Both had rpm heads that were prepped the same, and flowed within a couple cfm of each other.
Both had Holley sd intake manifolds with 850dp carbs. Both were tested with the same 2" hooker headers. Both had cams from the same lobe family, and both used 1.5 rockers.
Both were right about 10:1cr.
The 446 cam was 254/254-110 in at 106, the 493 cam was 250-254-112, in at 108.
Desktop dyno said the 446 would actually make more power than the 493(which is when I decided that it was pretty much worthless for determining how to build bb mopars with modest flowing std port heads).
The actual dyno had the 493 making about 45-50hp more than the 446, along with a bunch of extra TQ.

This is what I find is more typical with that type of build. The hp/ci doesn't change all that much, and more cubes just nets more horsepower.
When the hp peak is at a fairly conservative rpm, if you start higher(more torque), you end higher.

I would say the big crate engine builders(R-M, Shafiroff, etc)must agree, since the displacements just keep going up, and the hp along with it.

As always, your results may vary.

With the correct pushrods the lift is .770 with a checking spring and 0.750 with a roller cam spring. Cam lobe is .445 so rocker arms are 1.73 with a checking spring and 1.69 with a roller cam spring. Probably would be right at 1.70 with a flat tappet or hyd roller spring.

??? is this a hyd. roller cam ?

My engine has a solid roller cam in it. Comp HXL/HXX lobes that Dwayne came up with.

The cubic inches aren't what makes the extra power. There are other differences that contribute to a power gain that are relative to the additional cubic inches. The factory horsepower ratings have never been considered trustworthy, but let's give them the benefit of the doubt. Would a larger bore help the cylinder head breathe better? In most cases, yes. So, the .070" difference in bore size would give the 440 an advantage. Maybe not 40hp, but an advantage no less. Also, The horsepower ratings were only 400 rpm apart, and all else being the same, there should be more of a spread than that for almost 80 cubic inches. Compression ratios were not very accurate, so that's another variable. And finally, considering that the 440 was an upgrade in many cars, customers were not going to spend extra money for the upgrade unless the numbers were impressive. Marketing does tend to make results biased to the sellers advantage.

Sorry, but the 472 has quite a bit more camshaft than the 426, which would allow it to carry the torque curve to a higher rpm, which = more horsepower. Rpm not cubic inches.

This is pretty typical of a build that likely has valvetrain issues. Let me guess, they both had Harland Sharp rockers just bolted to the cast in stands. If you can't carry the torque curve on a smaller motor because the valvetrain becomes unstable, it doesn't have a chance of making more horsepower. Because, say it with me now, rpm makes horsepower! Diesel trucks have pretty small horsepower numbers, but they make enough torque to pull enormous loads. Why? They don't rev high enough to make a lot of hp.
The desktop dyno is simply a calculator that uses mechanical formulas to determine a result. It can't account for inefficiencies or deficiencies in the actual motor, or incorrect data input. A Mopar motor is still an air pump, just like any other internal combustion engine, and the same formulas still apply.

If the hp/ci doesn't change with differences in cubic inch, then there is definitely a problem. The cylinder head, camshaft, and induction has the ability to move a certain amount of air, based on effiency and cross sectional area. A formula one motor, that turns over 15,000 rpm with roughly 280 cubic inches, has a very high hp/ci ratio, but if the cubic inches were increased, that ratio would drop drastically, because the rpm would fall as well. The same thing with Pro Stock engines. I realize they are highly refined race engines, but the mathematical rules still apply.

What are R-M and Shafiroff building? A pile of big block Chevys with really good heads. That means either rev it to the moon, or increase the cubic inches to get the power at a lower RPM. A bigger port is going to need a bigger valve since it is the biggest restriction in the port anyway. That adds weight to the valvetrain, which is harder to control at higher rpm without exotic parts. Anyone who is willing to spend the money for those parts is going to want a custom build, not a crate motor.

Again, if I had peak power at 5600 with 505ci, and a 242/248 HYDRAULIC roller, why is a 446ci motor with a 242/248 SOLID roller peaking at the same rpm? Oh, and let's not forget the half a point of compression and the high rise single plane manifold the 446 had.