perf-list-digest Thursday, July 16 1998 Volume 01 : Number 030



=======================================================================
Ford Truck Enthusiasts - Performance
Visit our web site: http://www.ford-trucks.com/
- - - - - - - - - - - - - - - - - - - - - - -
To unsubscribe, send email to:
majordomo ford-trucks.com
with the words "unsubscribe perf-list-digest" in the body of the
message.
=======================================================================
In this issue:

Re: FTE Perf - Cylinder Head Intake Ports/Runners
Re: FTE Perf - Cylinder Head Intake Ports/Runners
Re: FTE Perf - Cam Recommendation_very long.
RE: FTE Perf - Cam Recommendation
FTE Perf - Rhodes Lifters
Re: FTE Perf - Cylinder Head Intake Ports/Runners
Re: FTE Perf - (Fwd) Re: 460 builds
Re: FTE Perf - (Fwd) Re: 460 builds
Re: FTE Perf - Rhodes Lifters
Re: FTE Perf - Cylinder Head Intake Ports/Runners
Re: FTE Perf - Cylinder Head Intake Ports/Runners
RE: FTE Perf - (Fwd) Re: 460 builds
RE: FTE Perf - Cam Recommendation
RE: FTE Perf - 460 builds - vacuum
Re: FTE Perf - Cylinder Head Intake Ports/Runners
RE: FTE Perf - Cylinder Head Intake Ports/Runners
Re: FTE Perf - 460 builds - vacuum
Re: FTE Perf - Cylinder Head Intake Ports/Runners
Re: FTE Perf - Cylinder Head Intake Ports/Runners
FTE Perf - anyone done 5.4 mods?

=======================================================================

----------------------------------------------------------------------

Date: Thu, 16 Jul 1998 07:55:19 +0000
From: "Gary, 78 BBB"
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> From: "George"
> Subject: FTE Perf - Cylinder Head Intake Ports/Runners
> Date: Wed, 15 Jul 1998 18:52:55 -0700

> I've heard pros and cons about smoothing the intake port/runner
> inside surfaces. Some say don't as the rough surface provides
> turbulence that creates a better air/fuel mixture for combustion
> purposes. Others say smooth is better for faster delivery. Both
> sound reasonable but I'm not sure which is valid. Maybe both with
> lots of variables?. I'd appreciate any comments.

I've often thought of this myself. Theoretically the rough surface
keeps the otherwise still air layer at the surface moving so droplets
get re-mixed into the air stream to keep it stable but in reality you
can only get so much fuel in that stagnant air layer so once it's
saturated no more can drop out right?

I'm thinking for low rpm, stop and go driving the rough surface might
give better economy and better throttle response but for performance
purposes I would guess the smoother the better. The manifold plenum
is really where all the mixing work takes place anyway and as long as
you have a hot spot and some roughness there I would think the
runners and ports would work better smooth?

Racers can make up for a lot by running rich mixtures but this isn't
practical for street engines. Racers don't need atomization in the
manifold, they just make sure there is enough fuel in the mix so that
all oxygen molecules (atoms?) are used in combustion which gives them
all the power they can get. Add a cold mixture for more density and
you need even more richness to make sure it burns all the oxygen.

Street engines need a combination of compromises to get the best
compromise of economy and performance so we run exhaust through the
manifold for a hot spot to "singe" the fuel and further vaporize it
and rough manifold surfaces (probably because it's cheaper) and
smaller manifold than head ports to prevent reversion etc. all of
which just happens to work out in the manufacturers best interest.

I would venture that a compromise between these two extremes might be
where we want to go but have no real data to support this, anyone?


78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 08:08:04 +0000
From: "Gary, 78 BBB"
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> From: sdelanty sonic.net
> Date: Wed, 15 Jul 1998 21:15:00 -0700
> Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> less drag, but I don't know if that's really true... A golf ball
> with a dimpled surface has less drag and flies farther than a
> perfectly smooth ball. Why? Damned if I know...

A smooth ball has more surface area in contact with the surrounding
air so more friction. I flies straighter for the same reason, less
influence from the surrounding air. That's my take on it anyway :-)

The bumps aren't really bumps but interupted surface so there is less
surface for the air to grab since the movement through the air keeps
it from dropping into the depressions and hence it only skims the
high spots??

78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 08:15:00 +0000
From: "Gary, 78 BBB"
Subject: Re: FTE Perf - Cam Recommendation_very long.

> From: "George"
> Subject: Re: FTE Perf - Cam Recommendation_very long.
> Date: Wed, 15 Jul 1998 17:11:34 -0700

> Sleddog says to stay with the 110 separation angle; you've got the
> cubes and don't need any increase. Another thing, Comp Cams states
> that their High Energy cams (216 advertised duration) are not
> intended for higher compression due to lobe design and an increase
> in c/r could cause preignition and detonation. That's part of the
> reason I'm going crazy trying to decide on a cam. Every manufacturer
> has different ideas on what the public needs and since most have a
> high rpm marketing mentality, the desired combo of torque AND rpm
> confuses their customer reps. We who want it all really confuse
> them.

The wedge design of the 460 helps a lot in this area. It's more
forgiving of conditions that normally cause detonation so we can
stretch the limits a bit usually.

Do I remember it right.......110 separtation is better for rpm and
114 is better for low end torque?

The bottom line is what kind of dynamic compression does the cam
provide and at what rpm ranges? The more you pack in the cylinder
the higher the dynamic compression or cylinder pressure which is the
primary factor in detonation as I understand it?

78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 08:19:30 +0000
From: "Gary, 78 BBB"
Subject: RE: FTE Perf - Cam Recommendation

> From: Sleddog
> Subject: RE: FTE Perf - Cam Recommendation
> Date: Wed, 15 Jul 1998 23:08:53 -0400

> i like closer lobe seperations, but then i know someone who ran more
> rpm with the 460 than i ever have and his cam has 114 deg. guess i
> need to start rethinking things a little. (of course he has over
> 300 duration at .050) and my engine analyzer thinks it should barely
> make power, and can't explain how he turned so many rpm's with it!

This brings up a good point.......does the lobe separation change as
the duration changes? That is the desired separation? It makes
sense to me that as the duration gets bigger the lobe separation
might get smaller or bigger, not sure?

78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 08:05:43 -0500
From: ballingr ldd.net (William L Ballinger)
Subject: FTE Perf - Rhodes Lifters

I've never used variable duration lifters, so I'm wondering about the
noise you guys have mentioned associated with them. What do they sound
like? And how loud are they?

I wonder if I have them, and are what's making my engine sound like
crap. I've had a lifter bleed down before and thought I'd lost a
piston, because it has that metallic clatter like a piston slapping (but
louder) and seems to come from the intake valley, like a loose piston
will.

Any opinions, or info would be appreciated. It clatters worse when
cold, and when cruising/light load, but less under accelleration. It
seems to be louder at idle and goes away at about 1800 rpms.

I'm probably dreaming, it's probably the pistons.
- --
Come on over to my Back Porch
http://www.ford-trucks.com//lc/lc.php?action=do&link=http://www.ldd.net/scribers/ballingr
Ballinger
ballingr ldd.net
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 06:31:59 -0700
From: sdelanty sonic.net
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

>> less drag, but I don't know if that's really true... A golf ball
>> with a dimpled surface has less drag and flies farther than a
>> perfectly smooth ball. Why? Damned if I know...


>A smooth ball has more surface area in contact with the surrounding
>air so more friction. I flies straighter for the same reason, less
>influence from the surrounding air. That's my take on it anyway :-)
>
>The bumps aren't really bumps but interupted surface so there is less
>surface for the air to grab since the movement through the air keeps
>it from dropping into the depressions and hence it only skims the
>high spots??

Hmmmm, so does all that apply to a textured intake runner also?

Steve
Homepage: http://www.ford-trucks.com//lc/lc.php?action=do&link=http://www.sonic.net/~sdelanty

== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 06:36:49 -0700
From: "George"
Subject: Re: FTE Perf - (Fwd) Re: 460 builds

Need guideplates and hardened pushrods too. Any suggestions??


dar6 jps.net
78 Bronco Ranger XLT (460 powered)


I have the stock guideplates that came with my heads & will use them. I'll
wait until I assemble to measure the rocker arm geometry and order pushrods
at that time.


== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 06:50:01 -0700
From: "George"
Subject: Re: FTE Perf - (Fwd) Re: 460 builds

my experience is still coming, never learn enough - just wish i had more
time/money and a real place to do work. then i could go nuts! like a
sheetmetal crossram "box" intake and nitrous and blowers. . . .


anyway, my buddy in an FE found that tossing the rhoads in favor of
standard lifters it ran better all round (280 comp cam if i remember right)

my 460 with rhoads only pulls about 12" of vacuum (keep thinking psi, but
12" would be about .5 psi. that is inches of h20 wich i think that those
gauges are, right?) still got to get a pipe tap so i can put a vac gauge
on my new motor - see what that pulls.


oh yes, that CR will definatley make a difference. i went from 11.5 down
to 9:1 and i really felt robbed :( but it will run all day on the cheapest
gas!!!

my new one will be 12.3:1 and i can't wait to hear that high compression
pop from an early exhaust valve opening and high CR at idle.

variable duration lifters is just covering up a poor cam selection or bad
parts combo IMHO. i do not beleive you can get something for nothing when
it comes to cam design. did you know that not only rpm, but oil viscosity
and temperature and spring rates and oil pressure all effect the operation
of variable duration lifters to some extent.

sleddog

So you're still running Rhodes? 12" sounds real scary if you have power
brakes.
I mounted a vac guage under my hood, running off of a tree on the manifold.
Makes carb idle adjustments real easy.

Feorge Miller


Sleddog doesn't like variable lifters but I've never had any problems. He
has more 385 experience and could maybe enlighten us on their drawbacks.
They provide me with a solid minimum of 16" of vacuum.

You're used to the 8.0:1 c/r, so be prepared for a new world when you go to
10.0:1 and big valves. That 385 was designed for a high c/r. Mucho fun.

George

ps: how did the Sanderson Headers fit? Are they shorties or full flow?

== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html




== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html


== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 07:02:17 -0700
From: "George"
Subject: Re: FTE Perf - Rhodes Lifters

I've never used variable duration lifters, so I'm wondering about the
noise you guys have mentioned associated with them. What do they sound
like? And how loud are they?


After the oil reaches operating temp, they sound like a solid lifter. Rhodes
packs a warning notice in the box about the noice.

I wonder if I have them, and are what's making my engine sound like
crap. I've had a lifter bleed down before and thought I'd lost a
piston, because it has that metallic clatter like a piston slapping (but
louder) and seems to come from the intake valley, like a loose piston
will.

Any opinions, or info would be appreciated. It clatters worse when
cold, and when cruising/light load, but less under accelleration. It
seems to be louder at idle and goes away at about 1800 rpms.

I'm probably dreaming, it's probably the pistons.


Come on over to my Back Porch
http://www.ford-trucks.com//lc/lc.php?action=do&link=http://www.ldd.net/scribers/ballingr
Ballinger
ballingr ldd.net


Sounds like a bad lifter to me. Have you ran a compression test?

George Miller


== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 07:17:48 -0700
From: "George"
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

Both theories sound good to me but I'm no engineer. As you say, coin may
have a lot to do with personal preferences.

George Miller


to this point, i have formulated this opinion - it is only opinion so take
it the way you want:

for low rpm engines (maybe up to 4500-5500 for a 460) i think the roughness
in the intake runner and port of the porting marks, or the casting sand
will prevent raw fuel that is clinging to the walls from just running right
in to the chamber. basically improving mixture quality. maybe also
helping to richen mixtures when the throttle is opened up suddenly (like an
extra accelerater pump?) then again it may also grab exces fuel from an
accelerator pump that is too big a shot. can't decide which theory i like
better yet. anyway:

the smoother polished ports may work better at higher rpms 6500+ rpms by
reducing the friction, and therefore the speed differentiation between the
boundery flow and the full flow af the air fuel mixtures. at the higher
rpms, less fuel droplets fall out of suspension anyway due to the increased
turbulance and less time spent in runner.

in a dry manifold, such as efi nozzles next to valve or direct injection i
think that a well polished runner and port will always be of an advantage.
note, extrude honing is used more on the "modern" hot rods than on the
older motors, maybe for this reason - maybe not. maybe these builders just
have the money for it?

any thoughts?

sleddog


> I've heard pros and cons about smoothing the intake port/runner inside
> surfaces. Some say don't as the rough surface provides turbulence that
> creates a better air/fuel mixture for combustion purposes. Others say
smooth
> is better for faster delivery. Both sound reasonable but I'm not sure
which
> is valid. Maybe both with lots of variables?. I'd appreciate any
comments.
>
> George Miller
>



== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html


== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 11:17:14 +0000
From: "Gary, 78 BBB"
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> From: sdelanty sonic.net
> Date: Thu, 16 Jul 1998 06:31:59 -0700
> Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> >The bumps aren't really bumps but interupted surface so there is
> >less surface for the air to grab since the movement through the air
> >keeps it from dropping into the depressions and hence it only skims
> >the high spots??
>
> Hmmmm, so does all that apply to a textured intake runner also?

I think the dynamics are different between pushing a solid object
through air and pushing air through a tube but the friction aspect
may be plausible if you could get a uniform surface like a golf ball
with flat highs and dimpled lows, evenly spaced and of the same size
etc.. Since I'm not educated nor a scientist I can only guess here
:-)

78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 10:58:51 -0400
From: Sleddog
Subject: RE: FTE Perf - (Fwd) Re: 460 builds

i'd say 430-450 is reasonable. a little bigger cam and a solid 460-470
would be reasonable, assuming no accessories and good tune of course.

sleddog

- ----------
From: Darryl A. Regan[SMTP:dar6 jps.net]
Sent: Thursday, July 16, 1998 12:07 AM
To: perf-list ford-trucks.com
Subject: RE: FTE Perf - (Fwd) Re: 460 builds

. Is 450hp a reasonable expectation with the following
combo?? 460 cubes, 10:1 cr, edelbrock performer intake, 750cfm carb, 2.19
inch intake
and 1.725 exhaust valves, assuming good headwork, pocket porting maybe port
matching,
.494 lift intake and exhaust, 218 duration intake and exhaust, 110 lobe
separation,
headers, 2.5 duals into 3 inch 2 chamber flowmasters, roller rockers, 14x3
inch open
element air cleaner and chrome valve covers (I heard they give that last 20
hp):-).
Someones dyno software put me at about 480hp and 500 plus torque. Wish I
still had the
info. Funny thing about you wanting the rockers,, I have had them sitting
here for about 9
months!!


dar6 jps.net
78 Bronco Ranger XLT (460 powered)



== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 11:16:21 -0400
From: Sleddog
Subject: RE: FTE Perf - Cam Recommendation

well, changing duration changes the overlap period, so to keep overlap the same, you would need to change lobe centers.

sleddog

- ----------
From: Gary, 78 BBB[SMTP:gpeters3 ford.com]
Sent: Thursday, July 16, 1998 4:19 AM
To: perf-list ford-trucks.com
Subject: RE: FTE Perf - Cam Recommendation

> From: Sleddog
> Subject: RE: FTE Perf - Cam Recommendation
> Date: Wed, 15 Jul 1998 23:08:53 -0400

> i like closer lobe seperations, but then i know someone who ran more
> rpm with the 460 than i ever have and his cam has 114 deg. guess i
> need to start rethinking things a little. (of course he has over
> 300 duration at .050) and my engine analyzer thinks it should barely
> make power, and can't explain how he turned so many rpm's with it!

This brings up a good point.......does the lobe separation change as
the duration changes? That is the desired separation? It makes
sense to me that as the duration gets bigger the lobe separation
might get smaller or bigger, not sure?

78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html



== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 11:26:35 -0400
From: Sleddog
Subject: RE: FTE Perf - 460 builds - vacuum

still in there. haven't gone for a new cam. my plans got changed alot and
often in last year by finding the best deal on a set of heads and intake
and getting a new truck to use for competition - putting 77 back on the
street again. hopefully over winter i can pull the cam in favor of a
bigger one and toss good lifters in and new valve springs etc. and a new
t/c.

on my new engine i need to drill and tap to get a hose into the manifold -
the p-o-s from offy has no threads from the factory. thinking about
putting it in the carb spacer as the manifold has a ton of "betty crocker"
all over the place from when it was ported and built up and ported again. .
.

that 12" was never a problem trucks brakes worked better than my new truck!
i do have a vacuum resivior (sp?) though. was there when i bought truck
so i don't know if it even works or helps any.

sleddog


- ----------
From: George[SMTP:maga55 ix.netcom.com]
Sent: Thursday, July 16, 1998 9:50 AM
To: perf-list ford-trucks.com
Subject: Re: FTE Perf - (Fwd) Re: 460 builds



So you're still running Rhodes? 12" sounds real scary if you have power
brakes.
I mounted a vac guage under my hood, running off of a tree on the manifold.
Makes carb idle adjustments real easy.

Feorge Miller




== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 11:30:27 -0400
From: "John Miller"
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

I'm thinking that the golf ball theory is related to "Bernoulli's law",
with the ball spinning, you have what amounts to tiny little airfoils due
the low and high pressure areas, creating lift, since it is on all sides it
helps to "push" the ball through the air like squeezing a wet pumpkin seed
between your thumb and index finger, like how a sailboat works "sail
against keel". This is NOT anything more than my "thinking" and only for a
few moments after reading this thread, so please let this inspire thought
and don't take this as a truism, I'm kind of thinking aloud. In regard to
moving an intake charge faster through a space I'm thinking the less
friction the better, correct? This is a good topic.... think on.... :)


John
>
> >
>
> > >The bumps aren't really bumps but interupted surface so there is
> > >less surface for the air to grab since the movement through the air
> > >keeps it from dropping into the depressions and hence it only skims
> > >the high spots??
> >
> > Hmmmm, so does all that apply to a textured intake runner also?
>
> I think the dynamics are different between pushing a solid object
> through air and pushing air through a tube but the friction aspect
> may be plausible if you could get a uniform surface like a golf ball
> with flat highs and dimpled lows, evenly spaced and of the same size
> etc.. Since I'm not educated nor a scientist I can only guess here

== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 11:34:16 -0400
From: Sleddog
Subject: RE: FTE Perf - Cylinder Head Intake Ports/Runners

wet flow is different than dry flow.

sleddog

- ----------
From: Gary, 78 BBB[SMTP:gpeters3 ford.com]
Sent: Thursday, July 16, 1998 7:17 AM
To: perf-list ford-trucks.com
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> From: sdelanty sonic.net
> Date: Thu, 16 Jul 1998 06:31:59 -0700
> Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> >The bumps aren't really bumps but interupted surface so there is
> >less surface for the air to grab since the movement through the air
> >keeps it from dropping into the depressions and hence it only skims
> >the high spots??
>
> Hmmmm, so does all that apply to a textured intake runner also?

I think the dynamics are different between pushing a solid object
through air and pushing air through a tube but the friction aspect
may be plausible if you could get a uniform surface like a golf ball
with flat highs and dimpled lows, evenly spaced and of the same size
etc.. Since I'm not educated nor a scientist I can only guess here
:-)

78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html



== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 09:01:08 -0700
From: "George"
Subject: Re: FTE Perf - 460 builds - vacuum

That reservoir would do it for the vacuum. In this desert heat, rubber
doesn't last long. I have to continually check my vacuum lines for leaks.


still in there. haven't gone for a new cam. my plans got changed alot and
often in last year by finding the best deal on a set of heads and intake
and getting a new truck to use for competition - putting 77 back on the
street again. hopefully over winter i can pull the cam in favor of a
bigger one and toss good lifters in and new valve springs etc. and a new
t/c.

on my new engine i need to drill and tap to get a hose into the manifold -
the p-o-s from offy has no threads from the factory. thinking about
putting it in the carb spacer as the manifold has a ton of "betty crocker"
all over the place from when it was ported and built up and ported again. .
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 09:05:34 -0700
From: "George"
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

Friction differences?

George Miller



wet flow is different than dry flow.

sleddog

- ----------
From: Gary, 78 BBB[SMTP:gpeters3 ford.com]
Sent: Thursday, July 16, 1998 7:17 AM
To: perf-list ford-trucks.com
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> From: sdelanty sonic.net
> Date: Thu, 16 Jul 1998 06:31:59 -0700
> Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

> >The bumps aren't really bumps but interupted surface so there is
> >less surface for the air to grab since the movement through the air
> >keeps it from dropping into the depressions and hence it only skims
> >the high spots??
>
> Hmmmm, so does all that apply to a textured intake runner also?

I think the dynamics are different between pushing a solid object
through air and pushing air through a tube but the friction aspect
may be plausible if you could get a uniform surface like a golf ball
with flat highs and dimpled lows, evenly spaced and of the same size
etc.. Since I'm not educated nor a scientist I can only guess here
:-)

78 F-150, 2wd, 460, C-6, 235's
78 Bronco 351M, Np 435, Np 205, 33's
78 Lincoln Town Car, 460, C-6, 19.5' long!
9000#, in ground vehicle lift, Woooo Hooo!

- -- Gary --
== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html



== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html


== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html

------------------------------

Date: Thu, 16 Jul 1998 09:18:30 -0700
From: "George"
Subject: Re: FTE Perf - Cylinder Head Intake Ports/Runners

Someone noted that the fuel/air is 'mixed' in the manifold phlegm. If this
is true, then further turbulence wouldn't be required and smooth runners
would speed mixture delivery?

George Miller


I'm thinking that the golf ball theory is related to "Bernoulli's law",
with the ball spinning, you have what amounts to tiny little airfoils due
the low and high pressure areas, creating lift, since it is on all sides it
helps to "push" the ball through the air like squeezing a wet pumpkin seed
between your thumb and index finger, like how a sailboat works "sail
against keel". This is NOT anything more than my "thinking" and only for a
few moments after reading this thread, so please let this inspire thought
and don't take this as a truism, I'm kind of thinking aloud. In regard to
moving an intake charge faster through a space I'm thinking the less
friction the better, correct? This is a good topic.... think on.... :)


John
>
> >
>
> > >The bumps aren't really bumps but interupted surface so there is
> > >less surface for the air to grab since the movement through the air
> > >keeps it from dropping into the depressions and hence it only skims
> > >the high spots??
> >
> > Hmmmm, so does all that apply to a textured intake runner also?
>
> I think the dynamics are different between pushing a solid object
> through air and pushing air through a tube but the friction aspect
> may be plausible if you could get a uniform surface like a golf ball
> with flat highs and dimpled lows, evenly spaced and of the same size
> etc.. Since I'm not educated nor a scientist I can only guess here

== FTE: Uns*bscribe and posting info www.ford-trucks.com/faq.html....


To access the rest of this feature you must be a logged in Registered User Of Ford Truck Enthusiasts

Registration is free, easy and gives you access to more features.
If you are not registered, click here to register.
If you are already registered, you can login here.

If you are already logged in and are seeing this message, your web browser is blocking session cookies. Change your browser cookie settings to allow session cookies.




Advertising - Terms of Use - Privacy Policy - Jobs

This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford is a registered trademark of the Ford Motor Company.