perf-list-digest Thursday, July 23 1998 Volume 01 : Number 038

Ford Truck Enthusiasts - Performance
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In this issue:

FTE Perf - Friction/Drag
Re: FTE Perf - Race truck update (a little long)
FTE Perf - Re:Laminar flow
Re: FTE Perf - building a 400
RE: FTE Perf - Re:Laminar flow
FTE Perf - building a 400



Date: Wed, 22 Jul 1998 06:28:03 -0500
From: ballingr (William L Ballinger)
Subject: FTE Perf - Friction/Drag

> Do you mean drag; in this case Parasitic?
> Which I believe is more what is being described.
> The Boundary Layer is Parasitic drag just exactly like that on an
> aircraft
> or anything that moves through the atmosphere.
> CS

I think that's what is meant, as the two are paralell in result.
Friction has the same effect in it's arena as drag has in its'.

- --
Come on over to my Back Porch
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Date: Wed, 22 Jul 1998 06:40:59 -0700
From: "George"
Subject: Re: FTE Perf - Race truck update (a little long)

When you say 'top end' are you referring to rpms or speed? If it's higher
speed you're after, a gearing change would be your only alternative until
you rebuild the engine to produce higher rpms. I don't know what the rear
differential ratio on a ranger is, the 4cyl engines or what a 400 duration
cam would be.

George Miller

Well I debuted my '89 ranger this weekend. It was definitely a blast to
run on the road course. I was very surprised at how well I had the truck
suspension set up for my initial try. It cornered very well with only a
little understeer exiting the corners. I believe torquing my sway bars a
little more may correct that. The engine (2.3 4cyl. F.I.) however is
grossly under powered. It is basically still stock other than a set of
ceramicoat headers and a custom i.e... homemade cold air intake. I plan
on building the engine to the allowed specs over the winter but what can
I do now to help out on the top end? I was thinking of getting an
adjustable cam timing gear to play with until I actually swap the cam
and pistons out. Will this help put some more horses into the stock cam
profile. FYI The engine has 157k miles on it and the allowed engine mods
are a 400 duration cam, 1.59/1.89 valves, .045 overbore, lt. wt.
pistons, and balancing of all rotating parts. On a humorous note I
discovered how dependant I had become on Anti-lock brakes. First lap I
was coming down the first straight wide open about 95 mph hit the brakes
and did 2 complete 360's before the corner, I got it back under me
grabbed another gear and kept on going like nothing happened. I probably
didn't need a harness then as the suction in my seat wouldn't have let
me go anywhere. Well I ended 4th out of seven but a full 4 sec. behind
3rd place. I had a hell of allot of fun though.

Road racers can do it turning left and right.

gottago seeya bye
Brett ITT 41
Improved Touring Truck
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Date: Wed, 22 Jul 1998 12:51:39 -0400
From: "Neal B. Forbes"
Subject: FTE Perf - Re:Laminar flow

George and CS bring up an interesting points which also, seems to me,
introduces the concept of correct mixture. There is a difference in physics
between suspension (atomization is a better word) and vaporization. Smoke
is a suspension of solid in a gas. Gasoline vaporizes in air and loses all
liquid characteristics. It is no longer "wet" until the air is saturated
and can no longer "hold" any more vapor. Vaporization, in physics, is a
change in "energy state". CS is correct-- you have to heat something to
vaporize it. The heat drives the molecules in the liquid to move faster
and away from each other and when they lose contact, that is vaporization.
The liquid has now become a gas. When that gas cools, the molecules slow
down, approach each other and cleave together (condensation), reforming the
liquid. Correct mixture control is a tough project of turning cold liquid
gasoline into hot vapor in the right ratio for good thermodynamics in the
combustion chamber. Rivers of gas in an intake manifold are a problem of
carburetion, not internal texture. The carb jets simply spray (atomize)
liquid gasoline into a moving air stream to assist the process of

This thread is about friction, though. A fully vaporized charge has no
change in friction, and turbulence does not alter the vaporized state in
terms of adding or subtracting heat. So, George, MHO is that surface
texture does not effect the tendency of a liquid to stay vaporized, and a
mixture will stay vaporized whether it is moving or not, provided that the
temperature stays the same. Anything rubbing against something else
creates friction manifested as heat but I gotta think that the effect of
charge rubbing the inside an intake runner is so tiny as to be negligible.
So, CS, IMHO the discussion about significance of the internal texture of an
intake runner should center around the ease of movement of the charge from
the carb to the chamber. Incidentally, air in the boundary layer moves more
slowly than the air above it because it contacts to wall and is slowed down
by friction. Smoother textures make less turbulence in the boundary layer
which makes slicker flow with less work. The tendency of condensed fuel to
revaporize near the port is because it is hotter there. But a correctly
mixted charge has no liquid to start with. Now we can start a thread about
how hot is too hot? Recall the rage about intercoolers awhile back. (>:

We could go on to the geometry of runners and talk about straight vs. bent,
single vs. gang, single plane vs dual and on and on. But all changes in
geometry are after the same goal--reduce the turbulence by straightening the
path of the charge from the carb to the chamber, and isolate each chamber's
feed so that that chamber does only the work it needs and not another
chamber's work. An eight runner tunnel ram is the epitome of an intake
manifold and approaches the concept of a header.

We could also have a great discussion of the mixture but that needs to
encompass the carburetor and all the cool things about them. So CS, now we
can talk about the desirability of supplying correct mixtures to the
manifold and how that effects performance. I guess I am assuming that
this thread is about a correctly mixed charge that has got to get to the
chamber and what can we do (that the factory doesn't) to get it there best.

Neal Forbes

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Date: Wed, 22 Jul 1998 12:21:03 -0600
From: "Dave Resch"
Subject: Re: FTE Perf - building a 400

>From: "Dale and Donna Carmine"
>Subject: FTE Perf - building a 400
Yo Dale:

Been on vacation a few days, but coming back and catching up on my reading,
I just couldn't resist the temptation to jump in on a thread related to hot
roddin' my favorite honkin' Henry motor.
>>A set of Hooker Headers and a full dual 2.5 In. Exhaust system with a
>>balance tube should be part of the build.
>I will probably use 3" single exhaust because of the auxiliary fuel tank.
>True duals are possible, but there's just not much room for two mufflers
>when both pipes have to come down the right hand side.

I will second Chris' recommendation on the dual exhaust system. It can be
done, even w/ everything on the right side of the truck. If necessary, you
can stagger the mufflers (not sure if that would be ideal for performance,
or if it would even be significant) or rotate them to take up less width.

The only reason I would go w/ a single exhaust is if I had to keep a single
cat for emissions legality, and then it would be a performance toss up
between a cat-back dual system and a big single, and the big single would
be a lot cheaper, so I would probably chose it for that reason.

>>You are looking for a longer EX timing then intake.
>I haven't selected a cam yet. someone else has suggested the comp cams
>260H, I believe that this is a symmetrical grind, do you prefer the
>asymmetrical grinds?

My understanding of why you would want a longer exhaust valve duration is
to make up for the smaller exhaust valve head diameter (relative to the
intake valve) and to make up for the cylinder head's (relatively) lousy
exhaust-side breathing. If you can get good heads to work w/, you can do
some porting on the exhaust side. I have been told that the pre-'77 heads
are better, and that '70-'71Cleveland 2V heads are the best. Some
machinists have even told me that post-'79 heads ('80-'82) are better than
the '77-'79 vintage.

Personally, I am leaning strongly toward a Comp 265DEH cam in my next 400
project (which will hopefully go into my truck!). My performance desires
are major torque below 3K rpm w/ a healthy amount of torque up to 4.5-5K
rpm. Even though my engine rarely sees the upside of 3K rpm, how quickly
it can get there (i.e., wind up) is a big contributor to satisfactory
performance for me. I used to be pretty conservative in my cam choices,
but I am beginning to see the longer duration light, thanks mostly to our
Sleddog big cam evangelist.

My personal belief about how to seriously improve M-block performance:
You have to get the compression ratio up! W/ the stock factory post-'71
pistons and open chamber heads, the CR is a measly 8.2:1. Since the 400
piston has a compression height that is compatible w/ Cleveland pistons, it
seems like a no-brainer to me. Other than the cost of the pistons, the
main expense in going w/ Cleveland pistons is having the connecting rods
bushed to take the smaller pin that the Cleveland pistons use. It is well
worth the expense, IMHO.

You can get TRW forged pistons for the 351M (L2466F), but they cost an arm
and a leg, the CR only goes up from 8.0:1 to about 8.6:1, and you still
don't get the extra cubes of the 400. Unfortunately, nobody makes a good
400-specific piston. You can't even get a stock replacement for the 1971
high compression pistons (9.0:1), as far as I know. (Maybe somebody like
Venolia will custom make them, but then your into major buckage again.)
OTOH, you can get a nice set of hypereutectic cast Cleveland pistons for
just a few more bucks than cheap stock replacement low CR 400 pistons.

One of the big fears many M-block owners have about higher compression
ratios is the pinging problem. So far, in the M-block engines that I've
built w/ higher compression ratios, the pinging is no worse than w/ the
stock low compression engine, and in some cases the pinging actually seems
to be less of a problem. The last 400 I worked on w/ about 9.4:1
compression pings less than my stock 351M w/ 8.0:1 CR. Go figure.

Dave R. (M-block devotee)

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Date: Wed, 22 Jul 1998 14:35:39 -0400
From: Sleddog
Subject: RE: FTE Perf - Re:Laminar flow

some of the fuel is vaporized. some of the fuel is in droplets, suspended
in the air column. not all of the fuel is vapor. and, to complicate
matters different fuels have different charactoristic as to how much will
turn to vapor. for example, turbo blue race gas when run in my four
wheeler will cool the carb so much that it will freeze in cold weather, and
have ice on it in hot weather. pump gas does not do anything - the carb
remains hot all the time. i attribute this to that fuels' ability to
vaporize well/quickly. this is also VERY noticable on my friends pull
truck - the carb stays cool even after a WFO run on the track. (BTW-this
fuel does require rejetting for max performance!!.)

so, since not all fuel is vapor, surface texture does matter. Sometimes,
it is arguable, you want droplets entering the chamber, and vaporizing
there, as the same mass of fuel takes up more volume vaporized than as a
homogenious (correct term?) mixture of suspended fuel droplets. so, in
this situation, the mixture can be richened up as more air is pumped into
the chamber. but, the other side is that as vaporization occurs, the
charge is cooled, and at some point will also increase the total amount of
air into the chamber (note: this is one reason alchohol makes more power,
the other is its richer a/f ratio.).

gets complicated doesn't it.


- ----------
From: Neal B. Forbes[SMTP:jawbreaker]
Sent: Wednesday, July 22, 1998 12:51 PM
To: perf-list
Subject: FTE Perf - Re:Laminar flow

major snippage - see previous post!

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Date: Wed, 22 Jul 1998 19:13:53 -0700
From: "Chris Samuel"
Subject: FTE Perf - building a 400

- -Date: Tue, 21 Jul 1998 21:30:42 -0500
- -From: "Dale and Donna Carmine"
- -Subject: FTE Perf - building a 400
- -
- -Hi Chris,
- -Thanks for the input on the roller rockers. Sounds like the $$ are better
- -spent elsewhere.
Well... Don't disregard them just don't expect to get any 25 HP out of them.
The reduction in friction is still worth something! Your Call.

- -I already have the Edelbrock performer sitting in my garage and got a good
- -deal on a 750 cfm performer carb that is on the way now.

OK, good choice. I got one sitting too! (because I took it off) But add the
Carb tuning kit Carter calls it a Strip Kit. Edelbrock calls it something
else that I have forgotten right now. The Edelb. kit is slightly more
complete. Pick up the 1" thick 4 hole spacer after you get it running they
are cheep and putting it in after its running and then re-tuning will let
you evaluate its effect before and after.
Add an O2 Sensor as it will make tuning much easier!
- -
- ->Slow down the Mechanical advance in the distributor and limit the total
- ->advance. Then add more to the static timing.
- -Interesting......I thought that quicker advance was the order of the day,
- -but I guess you can't get any quicker than the initial static time.

This engine due to the head design has a tendency to ping on the junk gas
that we have. Limiting the total advance is step one. And adding it slow is
step two... but adding it slow will kill the Throttle Response... so you add
some of what you took out to the initial advance which will absolutely wake
up the engine in the low to mid range. add the Mechanical slow to allow you
to get higher in the revz and leave the vacuum alone to keep the part
throttle "tip in" response good, but check the total. When I got around to
checking mine everything was Ok but the Vac. Adv. totaled about 4 billion by
it's self!
- -
- ->A set of Hooker Headers and a full dual 2.5 In. Exhaust system with a
- ->balance tube should be part of the build.
- -I will probably use 3" single exhaust because of the auxiliary fuel tank.
- -True duals are possible, but there's just not much room for two mufflers
- -when both pipes have to come down the right hand side.
- -
You are soooo right here and the 3" system will work well, if you use
mandrel bends and a good muffler. I used the 8" dia Super Turbo and ran 2.25
pipes off the collector because you can make the bend on the drivers side
before the K/member, on the 4x4 that is. But it geets difficult with
anything bigger:(
My new system runs dual 3" down the right side!) PITA to do though!
But on a 2x4 why not run 2.5's down beside the Trans and join after the
Trans. into a single 4" pipe and muffler? That would wow the kids! If you do
join after the Trans I would add the Balance tube even though you are
connecting the two pipes. Locate it just after the torque converter.

- ->I have left the camshaft out of this as I do not know enough to address
- ->Do you need to pass an emissions inspection?
- -NO
- -
- ->Automatic or Manual?
- -auto
- -
- ->Street or off road?
- -Street
- -
- ->Final Gear Ratio and Tire Size?
- -current rear is a 3.50 locker, no plans to change. Tires are stock, need
- -both wheels and tires but I don't know what I'll end up with yet.
- -
- ->You are looking for a longer EX timing then intake.
- -I haven't selected a cam yet. someone else has suggested the comp cams
- -260H, I believe that this is a symmetrical grind, do you prefer the newer
- -asymmetrical grinds?

YES YES YES Asymmetrical and Dual Pattern cams rule! Particularly in the C/M
Heads as the exhaust port was not one of Fords Better Ideas!
Single pattern cams are for Chubbyz not Fords! or Buicks or Pontiac, or even
Moparz, etc. Most of the single pattern cams are copies of Chubbyz. Way old
Tech! Not that you can't make power with one, there are just too many
examples for me to be that foolish!
But if I am making camshafts I am going to make them in such a way as to
maximize my "Return On Investment" or ROI. So Copy the Chebby stuff if it
works there it will work eberywhere!! Yep max ROI! Stockholders be happy!
Bean Counters... Happy! Everybody happy... even you cause you don't know any
better cause I own the Magz. due to my advertising budget...
Oh... Sorry... This isn't suppose to be a rant!
Try this one in your d/top dyno;) it would be IMHO about as big as you would
want to go for what you describe. after this you are spending money in the
bottomend to get it to live above 6000 RPM, and you need a converter. This
cam is listed as 2000-4500 RPM with float 6500RPM I have seen this cam run
and it makes power just as advertised, you should have about 325-350 HP or
Adv Durat. D 0.05 Open 50 Close 50 Max Lift Lift(Valve)
I 272 216 1BTDC 35ABDC 107 0.524
E 284 228 51BBDC (3)BTDC 117 0.519
These #'s are direct from Crane, as they are available on there web site I
have taken the liberty of reproducing them here; I hope that is Ok by them!

- -Basically this is a 4000 lb, 2wd truck. The only alteration from stock is
- -the locker. Needs to be a smooth around town and freeway performer where
- -will see most of it's use with an ocassional jaunt into the mud or snow. I
- -think I would be very happy to get 275-300HP. With the stock 351M it won't....

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