427 SBC test debunks 128 debunckers

[RevTheory]

David may have done some thermal coating on the valves so, rather than hash out two-year-old stuff and get the thread locked, we should ask him for some details on the build. He always seems to answer non-agenda questions.

[Scotthatch]

David may have done some thermal coating on the valves so, rather than hash out two-year-old stuff and get the thread locked, we should ask him for some details on the build. He always seems to answer non-agenda questions.

Do you feel like there is something special about the build?

[digger]

From a purely technical standpoint, I agree with Jon.

Take away the emotions. Take away everything but the equation being exactly about the math, and Jon is right.

It’s okay. Scientists and engineers are wrong all the time, they take the criticism, go back to the drawing board, and keep trying. Outside of SAE and other academic journals, there are no peer review for 100% of automotive articles written. I’d like to think the break down of the topic and discussion here is as close as we can get for the average enthusiast. Instead of everyone getting all huffy-puffy, why don’t we actually talk about fitting data to an equation like it’s done in academic, science, and engineering circles?

My 2 cents.

Generally speaking there is nothing wrong with curve fitting like David has done if the bounds are clear and assumptions stated.
It's the same that complicated curves can sometimes be approximated to be linear within certain ranges.

Right, exactly, but it wasn't initially advertised as such and that's where Jon is coming from in regards to him and David's initial argument on here (another thread).

Maybe I'm a robot, wouldn't be the first time I've been told as such, but I could care less what someone has done. I base their contributions on exactly what they are proposing at that given time. Has David contributed a lot to the sport? Absolutely. Does he have a good reputation amongst many enthusiasts? Absolutely. Does that make him infallible? No.

Is 128 wrong? Only when, as Digger correctly stated, it is applied to everything but the very narrow range that it works for (pump gas, 400ci+/-, single carbureted, 2 valve, V8). It wasn't initially advertised as such and that's where the "trolls" are coming form. This is was so obvious in the original thread that I'm blown away when people don't see it this way. People need to start taking a 20,000ft view of things posted on this site...

The key word is initially. Jon knows the caveats, these have been covered ad nauseam.

[Carnut1]

Almost don't need the chart on the head it's a 23 degree head most well done ported are about the same ....if you figure the used cfm on the engine it 340 cfm so with 309 cfm in the head that's a port efficiency of 110 % so to get that you are looking at like a 270 to 275 @ .050 cam ...

That sounds like a big cam for a street motor to me. True it is a 427 but still. What if you managed a bit more flow on a similar sized engine would you be able to shrink the cam and keep the power? Thanks, Charlie

[SchmidtMotorWorks]

I always wondered why if the end result gives you what you are looking for then why are the numbers that get you there wrong?

I never understood why some get so upset because someone else simplifys a problem.

Your statement relies on the false premise that the results meet the claims; they don't.
The range of applicability is not what was claimed.
If it were, the formula would look very different.

Not upset, just setting the facts straight.

[David Vizard]

Digger,

Your comment :-= It's been pointed out by others that temperature is more important than static CR as far as knock Is concerned.


I am very much inclined to agree on this point. When we pulled to temperature down 120° F the resistance to destination is gone up considerably.

[RevTheory]

Do you feel like there is something special about the build?

I don't know but I'd like to find out rather than have the same 4 or 5 guys get the thread locked before David has a chance to go through it. I know David has used some heat management tricks quite a bit on other builds but he kind of made it sound like this one was "out of the box."

[David Vizard]

David may have done some thermal coating on the valves so, rather than hash out two-year-old stuff and get the thread locked, we should ask him for some details on the build. He always seems to answer non-agenda questions.

Do you feel like there is something special about the build?

What would be the newsworthiness of the build has no special's attributes?

DV

[David Vizard]

Do you feel like there is something special about the build?

I don't know but I'd like to find out rather than have the same 4 or 5 guys get the thread locked before David has a chance to go through it. I know David has used some heat management tricks quite a bit on other builds but he kind of made it sound like this one was "out of the box."

Rev Theory, I'm glad you brought this up as nothing is going to be revealed until the negative comments, bad manners and attendant BS is done with.

DV

[Scotthatch]

Almost don't need the chart on the head it's a 23 degree head most well done ported are about the same ....if you figure the used cfm on the engine it 340 cfm so with 309 cfm in the head that's a port efficiency of 110 % so to get that you are looking at like a 270 to 275 @ .050 cam ...

That sounds like a big cam for a street motor to me. True it is a 427 but still. What if you managed a bit more flow on a similar sized engine would you be able to shrink the cam and keep the power? Thanks, Charlie

Sure ...it's a balance .... I was kinda hoping it was something other then a 23 degree head that had more flow

[GARY C]

I always wondered why if the end result gives you what you are looking for then why are the numbers that get you there wrong?

I never understood why some get so upset because someone else simplifys a problem.

Your statement relies on the false premise that the results meet the claims; they don't.
The range of applicability is not what was claimed.
If it were, the formula would look very different.

Not upset, just setting the facts straight.

Except the results do, I have seen it over and over...It was never meant to be a one size fits all like you are wanting and I was never led to think it was based on the wording in the write ups.

Not saying that you couldn't go one step further and start changing cams in small degrees on the dyno and improve it but who is willing to invest as much in testing as they have in their entire build.

Building a really good engine the first try is the purpose of his work, adding the next 25 horse may require a second mortgage on your house.

[RevTheory]

Rev Theory, I'm glad you brought this up as nothing is going to be revealed until the negative comments, bad manners and attendant BS is done with.

DV

I sure hope you've poured a tall cocktail and aren't holding your breath because the same 4 or 5 guys won't stop until this thread gets locked. Hell, they've got several of poor Charlie's threads locked and he's probably the nicest guy on here!

I'd sure like to see them stand down a little as they're just turning this place into yellowbullet.

[GARY C]

Do you feel like there is something special about the build?

I don't know but I'd like to find out rather than have the same 4 or 5 guys get the thread locked before David has a chance to go through it. I know David has used some heat management tricks quite a bit on other builds but he kind of made it sound like this one was "out of the box."

Rev Theory, I'm glad you brought this up as nothing is going to be revealed until the negative comments, bad manners and attendant BS is done with.

DV

Your best off to just ignore them, they will not go away or you can block them.

No reason to ignore the interested people because of the others.

[user-30257]

Rev Theory, I'm glad you brought this up as nothing is going to be revealed until the negative comments, bad manners and attendant BS is done with.

DV

I sure hope you've poured a tall cocktail and aren't holding your breath because the same 4 or 5 guys won't stop until this thread gets locked. Hell, they've got several of poor Charlie's threads locked and he's probably the nicest guy on here!

I'd sure like to see them stand down a little as they're just turning this place into yellowbullet.

Yellowbullet doesn't tolerate myths or BS.

[GARY C]

Rev Theory, I'm glad you brought this up as nothing is going to be revealed until the negative comments, bad manners and attendant BS is done with.

DV

I sure hope you've poured a tall cocktail and aren't holding your breath because the same 4 or 5 guys won't stop until this thread gets locked. Hell, they've got several of poor Charlie's threads locked and he's probably the nicest guy on here!

I'd sure like to see them stand down a little as they're just turning this place into yellowbullet.

Yellowbullet doesn't tolerate myths or BS.

I am beginning to thing ST does not tolerate dyno sheets.