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Date: Sun, 7 Sep 1997 12:28:46 -0600 (MDT)
From: owner-fordtrucks-digest ListService.net (fordtrucks-digest)
To: fordtrucks-digest ListService.net
Subject: fordtrucks-digest V1 #199
Reply-To: fordtrucks ListService.net
Sender: owner-fordtrucks-digest ListService.net


fordtrucks-digest Sunday, September 7 1997 Volume 01 : Number 199



=======================================================================
Ford Truck Enthusiasts - 1979 And Older Trucks Digest
Visit our web site: http://www.ford-trucks.com/
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email to the same address with the word "help" in the body of the
message.
=======================================================================
In this issue:

RE: carburation problem ["Gary, 78 BBB" ]
Oooops! ["Gary, 78 BBB" ]
Re: Timing, vacs, my new 302 ["Mark Mech" ]
302 and clutch ["Mark Mech" ]
Re: Split [Kelly Farough ]
RE: carburation problem [Kevin Kemmerer ]
RE: Timing, vacs and stuff [Kevin Kemmerer ]
RE: Timing, vacs, my new 302 [Kevin Kemmerer ]
Re: Timing, vacs and stuff ["Gary, 78 BBB" ]
Re: timning, advance, etc. ["Gary, 78 BBB" ]
Re: carburation problem ["Gary, 78 BBB" ]
Re: 302 and clutch ["Gary, 78 BBB" ]
Timing ["art l" ]

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

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Date: Sun, 7 Sep 1997 09:33:08 +0000
From: "Gary, 78 BBB"
Subject: RE: carburation problem

> From: Tim Baker
> To: "'fordtrucks listservice.net'"
> Subject: RE: carburation problem
> Date: Sat, 6 Sep 1997 15:10:09 +0100
> Reply-to: fordtrucks listservice.net

> carb may be too big---check out Hot Rod Tips and Tricks prior
> issues----check library----show you how to drill and adjust ports to
> make carb. tuneable at idle..
>
> ----------
> From: SARHOG aol.com
> Sent: Saturday, September 06, 1997 10:11 PM
> To: fordtrucks listservice.net
> Subject: carburation problem
>
> My engine is running very rich, especially at idle, and I can't
> seem to
> solve it. I have a 460 with 429 non-CJ heads, offenhauser 4" single
> plane intake, tube headers to a dual exhaust, topped off with a
> holley model 4780 800 cfm double pumper carb with mechanical
> secondaries. The carb was rebuilt recently, a 6.5" power valve put
> in, and jetted down to #69 jets in front and #82 jets in back.
> Vacuum at idle is about 14-15", and initial timing is 12 BTDC.
> Here's the where it gets confusing....the idle mixture screws on the
> primary metering block are BOTTOMED, and it is still idling rich.
> Those mixture screws should completely shut off the fuel flow at
> idle, right?? Any idea where the fuel is coming from? Thanks for
> any insight.
>
> John Z.
> 67 F-100 460/C-6
> +-------------- Ford Truck Enthusiasts - 1979 and Older
> +--------------+
> | Send posts to fordtrucks listservice.net,
> | | Send Unsubscribe requests to
> fordtrucks-request listservice.net | +-- Visit Our Web Site:
> http://www.ford-trucks.com/ --+
>
>

The swift of foot and slow of wit
have more off road experiences

- -- Gary --

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

Date: Sun, 7 Sep 1997 09:37:04 +0000
From: "Gary, 78 BBB"
Subject: Oooops!

Sent that instead of canceling, sorry, meant to send Tim a note about
the binary format :-)

The swift of foot and slow of wit
have more off road experiences

- -- Gary --

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

Date: Sun, 7 Sep 1997 07:10:44 -0700
From: "Mark Mech"
Subject: Re: Timing, vacs, my new 302

Dana wrote:
(snipped)
> just to be sure your not over advancing the engine 38-40 max. should be
> safe in my opinion ) If every thing is OK take it for spin ( talk about
> throttle response ) I am not suggesting that you normally drive that way
> just test for fun!
just to be sure your not over advancing the engine 38-40 max. should be
> safe in my opinion ) If every thing is OK take it for spin ( talk about
> throttle response ) I am not suggesting that you normally drive that way
> just test for fun!

I think you just proved the theory I was trying to explain in your last
sentence. I was told that 37deg. total advance is the optimal power setting
for the way
our American V-8s are designed. Therefore when driving in town where you
have stop and go traffic and are accelerating all the time, you want the
total advance as fast as you can get it because it translates into optimal
power. More power out of the same engine (without adding more fuel, bigger
carb etc.) equals more efficiency. I am not satisfied with 14 mpg. My first
302 in an F-100 was getting 19mpg with 130,000 miles on it and a stock 2
barrel to boot!
I have a friend that bought used 67 F-100 with the truck 6 cyl. and he was
getting 20mpg in town and 24 on the highway with a stock settup. I believe
our trucks (all cars for that matter) are capable of far more mileage than
the oil companies would like us to know about. I will be experimenting with
a device that eliminates restricive manifold vacuum and improves mileage.
I'll post my results.

Mark Mech
1913 E. El Parque
Tempe, Arizona 85282
aerofoam earthlink.net
http://www.ford-trucks.com//lc/lc.php?action=do&link=http://home.earthlink.net/~aerofoam/

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

Date: Sun, 7 Sep 1997 07:19:56 -0700
From: "Mark Mech"
Subject: 302 and clutch

I got my new 302 in last night and fired it up!
It seems to run well but at very low loading it is surging a bit and
running a little rough at low rpm.
This could be due to the timing tricks I posted earlier!
or it could be carb settings and the fact that the vacuum advance is
disabled. For some reason the new clutch wouldnt engage properly. I ran out
of adjustment on the rod and had to wedge a nut into the dimple on the fork
in order to get enough throw on the clutch. It is very stiff too. Are there
thinner pressure plates out there? Do I have to get a longer adjusting rod?
Or did they give me a screwed up clutch that is too thin. The only physical
explanation I can think of is that the 3 prongs on the P-plate arent
sticking out far enough. Anyone have some answers?


Mark Mech
1913 E. El Parque
Tempe, Arizona 85282
aerofoam earthlink.net
http://www.ford-trucks.com//lc/lc.php?action=do&link=http://home.earthlink.net/~aerofoam/

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

Date: Sun, 7 Sep 1997 08:37:30 -0600 (MDT)
From: Kelly Farough
Subject: Re: Split

Split the list. The benefits would be more significant for the pre-60
owners. Right now I have had to wade through 100+ messages and none
of them related to pre 60's trucks. If I need info for my 1977 then
I'll find it on the appropriate list. Nobody really loses anything
by the split other than a minor amount of time and effort.

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

Date: Sun, 7 Sep 1997 10:28:03 -0400
From: Kevin Kemmerer
Subject: RE: carburation problem

is there a small hole drilled in the throttle plates? these holes allow
the main jets to dump fuel into the carb - usually helping idle adjustment.
did you check float level?
if your air cleaner top is too close to the vent tubes, it can create a
venturi that sucks out fuel also - though this usually happens at high rpm.
also there should be 4 idle screws on that carb i think (my holleys do) are
all 4 bottomed or only the primarys?
it is not too big a carb. that motor will easily take dominators.

sleddog

- ----------
From: SARHOG aol.com[SMTP:SARHOG aol.com]
Sent: Saturday, September 06, 1997 1:11 PM
To: fordtrucks ListService.net
Subject: carburation problem

My engine is running very rich, especially at idle, and I can't seem
to
solve it. I have a 460 with 429 non-CJ heads, offenhauser 4" single plane
intake, tube headers to a dual exhaust, topped off with a holley model 4780
800 cfm double pumper carb with mechanical secondaries. The carb was
rebuilt
recently, a 6.5" power valve put in, and jetted down to #69 jets in front
and
#82 jets in back. Vacuum at idle is about 14-15", and initial timing is 12
BTDC. Here's the where it gets confusing....the idle mixture screws on the
primary metering block are BOTTOMED, and it is still idling rich. Those
mixture screws should completely shut off the fuel flow at idle, right??
Any
idea where the fuel is coming from? Thanks for any insight.

John Z.
67 F-100 460/C-6






+-------------- Ford Truck Enthusiasts - 1979 and Older --------------+
| Send posts to fordtrucks listservice.net, |
| Send Unsubscribe requests to fordtrucks-request listservice.net |
+-- Visit Our Web Site: http://www.ford-trucks.com/ --+

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

Date: Sun, 7 Sep 1997 10:42:25 -0400
From: Kevin Kemmerer
Subject: RE: Timing, vacs and stuff

i'll buy that for a dollar!

>>Wooow! I think I spent three cents this time!
- ----------
From: danadeb pacbell.net[SMTP:danadeb pacbell.net]
Sent: Sunday, September 07, 1997 5:57 AM
To: Ford Folks
Subject: Re: Timing, vacs and stuff

THIS IS NOT A FLAME!
It is just my two cents worth.

The mechanical advance responds to engine SPEED only.

Vacuum advance responds to engine LOAD only.


Vacuum advance was an attempt to gain fuel mileage and reduce emissions,
it is a MECHANICAL computer trying to control the engine at various
loads and speeds. Way back when, there was no such thing as vacuum
advance, all dist. used only mechanical. Most high performance engines
still use mechanical only.


I have always seen ( stock from Ford and all other car makers ) the
vacuum canister connected to the carb port which gives a reverse vacuum
signal as compared to the manifold vac. Under hard acceleration, if you
hook the dist vacuum advance up to manifold vacuum you will loose vacuum
signal because manifold vacuum goes down under WOT thus causing the
dist. to reduce the amount of advance when you need it the most. ( you
need more advance, to a limit, to allow the engine to speed up. advance
your timing at idle and the engine RPM increases ) Now heavy load at low
engine speeds presents a different situation, too much advance then,
will result in ping. At low RPM ( under 2000 or so ) the mechanical
advance is less then its maximum. With the throttle open allot, like
when climbing a hill but going rather slow (30 MPH in high gear) you
would be lucky to see 2000 RPM but your vacuum advance is seeing high
vacuum because you have your throttle plates open quite wide ( (high
vacuum = more or max. vacuum advance) + (low RPM = less than max.
mechanical advance) = less then max. advance = no ping!) Effectively
this is sort of a retard of the total advance. "T" in a vacuum gauge on
the carb port and see what it does under various RPM and load
conditions. Put the gauge on the manifold and do the test again. Compare
the two.


What I have found with my own testing, reading books and gaining info
from you folks on line, is that for most driving needs, 8-10 deg's
initial, 10-15 deg's mechanical ( all in by 2000 RPM) and 15-20 deg's
vacuum ( taken from the carb port ) results in a well mannered, tire
burning, load hauling, good enough gas mileage ( we are talking V8's in
non aerodynamic trucks here, if you can't afford gas at 8-15 miles to
the gallon go get a Ford Escort ) truck. Some of the newer vacuum
advance cans allow too much advance, 30 deg's or so, added to initial
and mechanical and you get 50 deg's or more ( major ping, stumble,
backfire etc. ) I know, I was there just a few weeks ago! Right now I
am at 8 deg's initial, 10 deg's mechanical, and 20 deg's vacuum. Put the
peddle to the floor and you GO! Clime a steep hill at slow speeds on a
very hot day ( 95 deg's ) and then give it more gas without downshifting
and you GO! ( slight Ping! on 87 octane, NO ping on 89 octane )

Here is an example out of my Ford Shop Manual:

Vacuum Advance Mechanical Advance
Inches of Mercury Advance RPM Advance
5 0-1 500 0-1
10 5-8 750 1-3
15 8-11 1000 3-6
20 11-12 1500 6-8
2000 8-10

Max. advance would be initial plus 22. assume 10 initial and you get 32,
a little low for hotrodders, but quite livable for the rest of us!


Just for kicks:
If you want a kick in the butt, try setting your initial advance to 20
deg's advanced ( a bit hard to crank so don't turn off the engine until
you get back home ) Disconnect your vacuum advance. ( Check the dist.
advance on the the damper to the highest RPM you feel comfortable with,
just to be sure your not over advancing the engine 38-40 max. should be
safe in my opinion ) If every thing is OK take it for spin ( talk about
throttle response ) I am not suggesting that you normally drive that way
just test for fun!







Wooow! I think I spent three cents this time!

Dana





+-------------- Ford Truck Enthusiasts - 1979 and Older --------------+
| Send posts to fordtrucks listservice.net, |
| Send Unsubscribe requests to fordtrucks-request listservice.net |
+-- Visit Our Web Site: http://www.ford-trucks.com/ --+

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

Date: Sun, 7 Sep 1997 10:48:54 -0400
From: Kevin Kemmerer
Subject: RE: Timing, vacs, my new 302

- ----------
From: Mark Mech[SMTP:aerofoam earthlink.net]
Sent: Sunday, September 07, 1997 10:10 AM
To: fordtrucks ListService.net
Subject: Re: Timing, vacs, my new 302

>>>editted for content

I will be experimenting with
a device that eliminates restricive manifold vacuum and improves mileage.
I'll post my results.


remove restrictive manifold vacuum? would that be a really tall tunnel ram
intake with 2 1100cfm holleys with race ported large valved alum. heads and
a bumpstick as big as mt everest? or would it be more along the lines of a
supercharger pushing 15 pounds boost? ;-)

sleddog

Mark Mech
1913 E. El Parque
Tempe, Arizona 85282
aerofoam earthlink.net
http://www.ford-trucks.com//lc/lc.php?action=do&link=http://home.earthlink.net/~aerofoam/









+-------------- Ford Truck Enthusiasts - 1979 and Older --------------+
| Send posts to fordtrucks listservice.net, |
| Send Unsubscribe requests to fordtrucks-request listservice.net |
+-- Visit Our Web Site: http://www.ford-trucks.com/ --+

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

Date: Sun, 7 Sep 1997 11:22:55 +0000
From: "Gary, 78 BBB"
Subject: Re: Timing, vacs and stuff

> From: danadeb pacbell.net
> Date: Sun, 07 Sep 1997 02:57:05 -0700
> Subject: Re: Timing, vacs and stuff

> THIS IS NOT A FLAME!
> It is just my two cents worth.
>
> The mechanical advance responds to engine SPEED only.
>
> Vacuum advance responds to engine LOAD only.

Like I said, I'm wearing the suit :-) I went to Oak Shade last nite
to watch the bombers, sportsmen and sprint cars and have been
thinking about all this continuously since posting those comments
Saturday. I'm going to throw out more food for thought. Don't
assume I know what I'm talking about but this is how it's beginning
to look to me:

I (and many others) have alluded to the fact that mechanical is
performance only and vac is for economy but may have missed the
reason for this. Since racing is at or near WOT at all times the vac
would never come into play so they just leave it off to eliminate
another potential failure point. (IMHO :-)) They also use high
octane fuel, either gasoline with 104 - 108 octane or methanol so
there is no detonation, ever. They also allow more mechanical range
to obtain the ideal "compromise" for best high rpm power without
grenading the engine which everyone seems to agree is about 38 max
total and about 10 - 12 initial but a stock Ford distributor can't
give you that much so many go with MSD etc. which probably does,
don't know, haven't checked into it. Maybe someone out there knows
for sure, maybe in the spec sheet for your MSD or Mallory etc.? I'd
be interested it that info :-)

Anyway, I agree with much of the comments on this so far but believe
that the anomoly you mentioned (others have said this too) about
needing more advance to make the engine go faster isn't quite right.
(remember, this is just my opinion) More volumetric efficiency and
access to more fuel mix is what makes it go faster, the advance
allows it to burn more efficiently, utilizing more of the mixture
within the cylinder before the exhaust valve opens so when you
increased the advance at idle, it already had sufficient, very lean
fuel and volume for the rpm range but wasn't utilizing it very well
due to leaness so the additional advance improves that causing more
rpm etc.

Since the vac has a limited amount of advance built in it can only
make up for so much of this and if you advance the initial so it has
the highest idle speed at any given throttle setting you will find
yourself around 40 - 50 degrees which would not work if it stayed
there under load. If you have manifold vac to the distibutor and you
adjust idle, initial timing with the vac hooked up you may get close
to the ideal but not likely even then.

If you advance the timing before the volumetric efficiency level and
richness (or leaness) mitagated by rpm (burn time available) demands
it you will get ping so you need to improve the volumetric efficiency
(open the throttle more to raise manifold pressure) and mixture
availability (more open venturi) to increase rpm and add advance as
rpm climbs but since this condition actually calls for less advance
initially the vac retards the spark momentarily for best power etc.
in a touring engine. In a racing engine it never drops below the
torque peak so timing can stay up near max all the time with no ill
effects.

Simple rule of thumb as I see it is run without the vac on a dyno at
all rpm ranges and at WOT to develope the mechanical curve. This
means loading the engine so it stays at a specific rpm while at WOT
long enough to adjust the timing for best torque reading. Do this
every 500 rpm or so through the total range the engine is expected to
run and you have absolutely the best curve for that engine under full
load conditions.

Now put the vac on and play with part throttle loads at various rpms
and you can find a good compromise for cruising for best economy.

Since the factory has already done the dyno testing on the mechanical
curve, it's going to be hard to beat in a stock or near stock engine
but since the vac, as many have said is contorted to get best
emmisions (unfortunately the cam is too in most cases) there is a
place you can probably get some improvement and I've found that to be
the case in my testing so far but it's still all a big compromise for
a touring engine. If you're going to pull sleds or mud bogg or drag
race the problem becomes much simpler (ducking here!!!) since you're
only trying to get one thing to happen.

Us old farts that want our cake and eat it too want to blow everyone
in the weeds and get Festiva economy in the process so it gets more
complicated. All I'm trying to do here is energize all the minds out
there so I can selfishly pick up some new ideas. Please don't assume
I'm being argumentative just to aggrivate anyone or show anyone up.
It's my sincere hope that arguments I stirr up will help others to
see ways to improve as well and make some old dogs rethink their
strategys where it may be needed. I know the two lists have really
opened up my eyes to some wrong notions I've been hanging on to and
REALLY appreciate all the new ideas. :-) :-) :-)

Now I've got some ideas on how the cam affects timing .......... :-)



The swift of foot and slow of wit
have more off road experiences

- -- Gary --

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

Date: Sun, 7 Sep 1997 11:33:10 +0000
From: "Gary, 78 BBB"
Subject: Re: timning, advance, etc.

> From: Kevin Kemmerer
> Subject: timning, advance, etc.
> Date: Sat, 6 Sep 1997 15:44:38 -0400

> i'll steer away from the theoretical for now, and just tell you
> about one of my engines. i ran a '68 460 with stock manifolds,
> 11.5:1 compression, stock heads, 600 holley, and a good street cam
> for 2 years. the timing was a ford destr. with the vacuum unhooked
> and as far as i know stock springs-weights. i ran any gas, with
> very few ping or detination problems.

My 460 seems to be very tolerant of timing and fuel too so I
attribute this more to the wedge head design but whatdoiknow :-)

> sometimes things just plain work right, even if they seem like they
> shouldn't. sure, more mileage would be possible, but 10 ain't bad.
> i could go 4 wheeling all day on a tank sometimes.

Again, as I've said, you can't argue with success :-)

> say the 9" is a strong unit! mileage is slao worse with the 3000
> stall converter, bigger carb, etc.)

The converter allows the engine to stay near or above it's torque
peak so all in is the right solution probably in this case?? :-)
Probaly should use 90 wt oil for lube instead of pure murcury for
traction :-) Guy at the races last night said he watched a Dodge
truck outpull Fords and Chevies at a truck pull and I suggested the
above may be the case :-)

The swift of foot and slow of wit
have more off road experiences

- -- Gary --

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

Date: Sun, 7 Sep 1997 11:44:18 +0000
From: "Gary, 78 BBB"
Subject: Re: carburation problem

> From: SARHOG aol.com
> Date: Sat, 6 Sep 1997 17:11:01 -0400 (EDT)
> Subject: carburation problem

You didn't mention idle speed in rpm so I'll guess you have a fairly
radical cam, huge carb and probably 800 -1100 rpm idle with no vac
advance.

My guess is the screws are not being looked at due to slighly open
secondaries and transfer port interaction but someone could have
tightened the screws too tighly and mangled the seats causing them to
leak so there is no way to calibrate them. I'm not familiar with the
4780 but if it's modular the metering block may be wrong for your
application since there are several hundred interchangeable versions
to satisfy varying engine sizes and emissions requirements, don't
know. Mains should not have ANY effect on idle since it has it's own
passages but transition port timing could and the secondaries don't
have an idle circuit so would be richer if open even slightly.

Also any gasket leaks including (if it's a top loader) the screws and
seals around the top cover assy. or between the metering block and
main body etc..

> My engine is running very rich, especially at idle, and I can't
> seem to
> solve it. I have a 460 with 429 non-CJ heads, offenhauser 4" single
> plane intake, tube headers to a dual exhaust, topped off with a
> holley model 4780 800 cfm double pumper carb with mechanical
> secondaries. The carb was rebuilt recently, a 6.5" power valve put
> in, and jetted down to #69 jets in front and #82 jets in back.
> Vacuum at idle is about 14-15", and initial timing is 12 BTDC.
> Here's the where it gets confusing....the idle mixture screws on the
> primary metering block are BOTTOMED, and it is still idling rich.
> Those mixture screws should completely shut off the fuel flow at
> idle, right?? Any idea where the fuel is coming from? Thanks for
> any insight.

The swift of foot and slow of wit
have more off road experiences

- -- Gary --

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

Date: Sun, 7 Sep 1997 11:55:29 +0000
From: "Gary, 78 BBB"
Subject: Re: 302 and clutch

> From: "Mark Mech"
> Subject: 302 and clutch
> Date: Sun, 7 Sep 1997 07:19:56 -0700

> disabled. For some reason the new clutch wouldnt engage properly. I
> ran out of adjustment on the rod and had to wedge a nut into the
> dimple on the fork in order to get enough throw on the clutch. It is
> very stiff too. Are there thinner pressure plates out there? Do I

I don't mean to be silly but is it possible the throwout bearing is
on backward? I haven't looked at a three pronger in a while but if
the plate is new and the disk is new it would seem to me the linkeage
would be near full length since as the clutch wears you have to
shorten the linkeage to keep the free pedal? Sorry, I'm not much
help on this one :-(

The swift of foot and slow of wit
have more off road experiences

- -- Gary --

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

Date: Sun, 7 Sep 1997 11:26:08 -0700
From: "art l"
Subject: Timing

About a month ago I posted that I was having problems with spark
knock. I took the suggestons messed with the timing, no luck. I took it
to a mech. here in Vegas, he had it for 2 weeks, he never toched it. So
now with all this talk about timing recently, I am going to try it again.
Just for information, I use to have a Mallory dual point manual advance on
the engine, same problems, went back to the electronic vac. advance. Okay
78 F-250, 400M, Carter 4v, Edelbrok performer. Under normal driving it
runs fine, but when It is under a load like going up a hill or towing it....

---

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