NA Engines: Factors that increase torque

[pdq67]

Would somebody PLEASE post up a link to pictures of Mr. Fueling's 454 aluminum torque truck heads!

Thanks,

I had it saved and then my old hard drive went south on me.

pdq67

[Newold1]

I already did but here it is again.

www.feulingparts.com/aboutus.php

[pdq67]

Thanks,

pdq67

[PFM]

Great start and subject. My two cents worth, having a broad TQ curve is my goal with most builds. With 8 speed gear boxes and clutchless gear changes and such peak TQ at the upper end of the rev range will be that next push. If you do not live in that 8 speed gearbox world then that broad TQ curve and maybe 5 gears is a blast to drive on track. I will add into the mix a dynamic tunable intake, Porsche style, will provide more TQ under the broad curve than anything else I can think of besides the obvious of compression or other items already excluded. The cam profile picks the peak TQ RPM but an intake can help to broaden that TQ curve.

This thread will be fun to watch.

Stay Tuned

PFM

[pamotorman]

if you build boat engines you find out quick nothing works except more cubic inches or a supercharger. trying different heads and cams is a waste of time and money. the lake or river is nothing but a big dyno JMHO

[PackardV8]

if you build boat engines you find out quick nothing works except more cubic inches or a supercharger. trying different heads and cams is a waste of time and money. the lake or river is nothing but a big dyno JMHO

The lake also gives the engine builder the luxury of infinitely long WOT pulls to see, hear, feel what works and what doesn't. It does punish the builder who didn't err on the side of caution. A cutting edge build which will survive many 1/8-mi pulls can eat itself within minutes on the lake.

Interesting in that the lake seems to like builds which might do well in some EMC classes; smaller bore, longer stroke, lower RPM redline, broad torque curve.

[pamotorman]

if you build boat engines you find out quick nothing works except more cubic inches or a supercharger. trying different heads and cams is a waste of time and money. the lake or river is nothing but a big dyno JMHO

The lake also gives the engine builder the luxury of infinitely long WOT pulls to see, hear, feel what works and what doesn't. It does punish the builder who didn't err on the side of caution. A cutting edge build which will survive many 1/8-mi pulls can eat itself within minutes on the lake.

Interesting in that the lake seems to like builds which might do well in some EMC classes; smaller bore, longer stroke, lower RPM redline, broad torque curve.

changes in heads and cams made some difference in pickle fork hydo drag boats but in twin engine cigarette type boats nothing seemed to work but more inches or a super chargers. i found out that jet boat engines will not stand up to the same CR as a prop driven boat because you can run the jet boat WFO all day long where the prop boat will get going too fast and need to back off the throttle once in a while.

[Olefud]

[quote="NewbVetteGuy"][quote="Zmechanic"]In terms of total charge density coming from intake, for a N/A engine that's TO THE MAX with 127% VE (as compared to pumping displacement), the rule of thumb breakdown is:
100% cylinder displacement
4% Fill of combustion chamber
18% Inertial ramming
5% Wave tuning

Can you define "intertial ramming" for me? I'm surprised Wave Tuning effects are listed as so low...

Inertial ramming concerns the kinetic energy of the intake charge. This enables the charge to continue flowing beyond the flow rate of the actual pressure difference between the port and cylinder, i.e. inertia. The somewhat tricky part is that the inertia goes up with the square of port velocity thus requiring a relatively small yet good flowing port. I’ll leave it to the experts but, in general, the smaller the better until it isn’t.

Wave tuning deals with acoustical waves and are RPM sensitive-can go negative- depending on the tuned length. The exhaust has even more important inertial factors similar to ramming but obviously the exhaust doesn’t “ram” into the cylinder. It’s best not to say it sucks either.

[digger]

In terms of total charge density coming from intake, for a N/A engine that's TO THE MAX with 127% VE (as compared to pumping displacement), the rule of thumb breakdown is:
100% cylinder displacement
4% Fill of combustion chamber
18% Inertial ramming
5% Wave tuning

Can you define "intertial ramming" for me? I'm surprised Wave Tuning effects are listed as so low...

Inertial ramming concerns the kinetic energy of the intake charge. This enables the charge to continue flowing beyond the flow rate of the actual pressure difference between the port and cylinder, i.e. inertia. The somewhat tricky part is that the inertia goes up with the square of port velocity thus requiring a relatively small yet good flowing port. I’ll leave it to the experts but, in general, the smaller the better until it isn’t.

Wave tuning deals with acoustical waves and are RPM sensitive-can go negative- depending on the tuned length. The exhaust has even more important inertial factors similar to ramming but obviously the exhaust doesn’t “ram” into the cylinder. It’s best not to say it sucks either.

it is not inertia, inertia is analogous to mass and has nothing to do with velocity squared "V^2".

kinetic energy is V^2 this is why velocity is important.
many fluid dynamics equation relate V^2 and pressure as energy changes from kinetic energy to potential energy etc
But I believe these forms of equation originally come from the momentum equation when being derived, of course for a fluid the momentum comes from

mass flow rate x velocity

The mass flow rate itself is velocity dependant so there are two velocity terms in momentumof a fluid

for a solid body it is mass x velocity so not v^2

[Olefud]

Acceleration is first order; energy is second order with velocity I believe –at least according to Newton’s Second Law. Same for gas and solids –gas is just a whole bunch of little solids. However, gas can be tricky in that velocity is a vector quantity and the individual molecules can be moving in different directions with turbulence. So we don’t want turbulence.

Could go deeper but the inquiry is for general direction.

[Newold1]

I have built a lot of marine offshore engines both recreational and racing marine endurance engines and I can tell you from personal experience that in almost every given build based on engine and size that I have seen many increases in performance that were attributable to increases in torque that came from cam, head and intake system changes and were not solely attributable to an increase in cubic inches, superchargers or turbochargers. The idea that cubic inches and boost are the only means of increasing measurable torque increases or increased boat performance is absurd and not based on all cases.

[wyrmrider]

I'm with Stroker McGurk

[MadBill]

Stroker would have been proud of a guy's circle track work I read of in the early eighties, before we had such an unlimited array of custom parts. He was boring SBC's right into the water jacket for wet sleeves and getting 480 c.i. out of them. Think his name was Connolly..

[wyrmrider]

On my truck block offshore motors we did heads, cams, intakes and cubic inches and blowers with intercoolers
and I agree with you 100%
Inboard/ outboard
too much cam is bad

[Morgo]

Ehh..
"In terms of total charge density coming from intake, for a N/A engine that's TO THE MAX with 127% VE (as compared to pumping displacement), the rule of thumb breakdown is:
100% cylinder displacement
4% Fill of combustion chamber
18% Inertial ramming
5% Wave tuning "

I was writing the question about all those statements how the hell you define them separetely (like how the Inertial ramming isn't the wave tunining.closely related but not all the same.
But