Re: Tom's V8

[tsm1@domain.elided (Tom Mandera)]

>I swear I've read every digest, but I somehow missed how
>Tom M. fixed his plug fouling problem.  Please repost.

Well, per my wheelin' this weekend, I most definitely have *NOT* cured the
fouling plugs!

The "fix" thus far has been to keep my foot out of the throttle.... (yeah,
it's killin' me).. 

In town, it works fine.  Get it on the highway and push too hard, and I feel
the motor start missing... that's usually when I take my foot out of the
throttle and start going slower... this happens in 4th gear on the flats
when pushing 75+ for any period of time, or when climbing the pass... 8%
grade, it'll start missing in 3rd if I try to accelerate at all, or maintain
more than 45mph.  (close T19, 4.09, 33s)

On the trail Sunday, I kept fouling plugs while trying to power up hills n'
such.  I think part of it was the float too high (center hung, rear
float)... it was loading up badly on hills, which may have contributed to
both #5 & #6 fouling, and a very sharp, staccato exhaust bark... not to
mention, low power. ;)

Lowering the float substantially (it was set too high when I parked on "the
level" (hey, we were on a trail), so it was lowered a good deal) helped, but
it didn't cure anything until after I *also* yanked #5 & #6 to clean the plugs.

We didn't do any additional long-climbs after I cleaned the plugs and set
the float and changed one (all of which, brand new) plug wire around, so I
can't say it was "fixed" or not... but it sure did run better after that.  

Well, we did do a few sustained climbs.  

My guess now is that I'd fouled #5 & #6 on the highway run to the trailhead,
and I only suspected #6 at first... so it wasn't until both got cleaned out
that the motor finally picked up.

Yesterday I had an idea that maybe my big problem was that float setting,
and the motor flooding... liquid fuel right into #5/6, causing the cold
fouling.  Most of the times it fouls is when I'm climbing... either
off-road, or mountain passes on pavement... 

Too bad when I tested that theory last night, I couldn't hold 75 w/o it
starting to miss...  on a flat. :-(

So I'm still not sure what the culprit is.

A former Scouter, following me all day in his Early Bronco, suggested I need
to throw some Chevy umbrella valve stem seals in... his observation was
no-smoke when I was on the gas, but smoke when I took my foot out of it.
It's possible the valve stem seals are letting oil past and fouling the
plugs or just making the mixture unburnable....

but, OTOH, it's all carbon on those plugs.  I had my passenger cleaning and
re-gapping the dirty plugs... I had a few spares w/ me. ;)  I could rub most
of the carbon off the plug with my fingers very easily.

It's just puzzling that it's 5&6, directly below the intake, on opposite
sides of the motor... the 6 other plugs look fine.  

Running the motor faster doesn't pull through the miss, it makes it worse.

I need to hook the timing light up and confirm the mechanical and vacuum
advance is working properly.

I'm also running 16deg BTDC.. I may back off some, it's difficult to start
cold... starting involves taking your pick on the choke (it hasn't seemed to
help yet...), cranking it, and mashing the throttle... it'll generally run
for a second (w/ the starter) then die when I release.  Try this once or
three or five times, and it'll run for a second, slow down, then catch again
and life is good.  

Oh, and that great aftermarket magnetic pickup kit installed in my '72
Holley points distributor?  Big A and even my good friends at NAPA couldn't
find a new rotor for me.... so I guess a Pertronix is closer in my future
than I thought (I could install points and a condensor... and figure out how
the wiring was modified to accomodate this magnetic pickup)..j

I grabbed the distributor shaft (where the rotor mounts) yesterday when I
took the rotor in to find a new one.  There is play on the shaft, but
nothing I'd call excessive.  It moves, but I think it's more just the
necessary bearing slop than any particular wear.  The distributor cap
doesnt' show any signs of a wobble (which was one theory on why 2 cylinders
foul at high load/rpm)

Other suggestions I've received is a restricted exhaust port... 

My biggest problem with the situation is, 2 years ago, I drove this motor
daily... and when I would take a trip to Missoula, we would run it near
redline, and cruise 85mph (3.73/31) the entire way to Missoula.  I never had
a plug fouling problem, and I would get 12-15mpg on the highway.

I was younger n' less experienced then, and I'd bought this new 2300 2bbl,
and paid to have it installed (after I unsuccessfully rebuilt the carb 2,
and the shop told me the base was cracked anyhow).  That shop tuned the
carb, and set the timing to 16BTDC, and I drove it for a year.  (the carb
went on about 2 weeks after I bought the Scout... :-(  )

In fact, I recently found a box in the garage, containing Autolite 303s
(why?)... the box was a Champ RJ12YC box, labeled "Scout plugs" with each
Autolite plug labeled 1through8 (though I doubt I knew which cylinder was
which... I did number them in *some* order)... they all looked equally dirty
(it was running rich due to the cracked base).

The motor sat for a year... at that S.O.B. body man's shop... I finally got
it home....

I drained the oil (needed changed), looked at the fuel filter, etc... and
fired it up.  It ran fine in the driveway under no-load.  I even moved the
Scout forward and backwards a few times (before I cannibalized a hub, both
driveshafts, a rear axle shaft, transfer case, and then the motor.).

You may recall that I was concerned it smoked white so badly.  It had always
puffed at startup... but it was running white continously.

I yanked the plugs, checked compression... 145 or so in #1/3, with 150-165
in the other 6, including 5&6.

Drained the oil *again*, drained the coolant, yanked the motor.

W/ the motor out, I changed the rear main, and oil pan gasket.  Put 8 new
Champion RJ12YC plugs in, gapped to .030 (changing plugs on a motor dangling
from an engine hoist, with no accessories is easy!)

Drop the motor in, damaging the starter and oil filter in the process.  :-)
Changed those out.

Filled radiator with water (test for leaks) and put 3 quarts of oil in (all
I had handy of the right stuff)... 

Got the motor running, clack clack clak of lifters (Hmm, low on oil?)...
limped to the corner gas station, which didn't have what I wanted... so I
had to take a short jaunt to the right gas station... put 2 or 3 quarts in,
and waited... didn't stop clacking for quite a while... but it eventually did.

Caught some sleep (it was 4am when I finally fired it up), went to work at 8
(no hood, no power steering, with a glasspack shoved onto the end of the
manifold pipe on the driver's side, stock 4cyl exhaust on the passenger
side)... 

Put the hood on, fixed the p/s, installed a new exhaust (Thrush Turbos on
both sides now), and adjusted the throttle linkage, etc.

Then I went for a drive on the highway and fouled two plugs.  So much for my
mighty V8.

I've been fighting it ever since.  Tearing the carb down and rejetting from
61 to 58 has made the fouling less severe.  I also ran a quart of ATF in the
oil for a little bit in an effort to clean any varnished lifters... 

I tried changing 5 & 6 to RJ14YC, one stage hotter... still fouled.

I replaced all of the spark plug wires, and the coil high-tension wire, with
new 7mm Napa lifetime wires.  

Still didn't fix it. ;)

Oh, when I put the 304 into the '77, with fresh fuel in the tank, the white
smoke disappeared... I assume it was from water in the gas, or just bad
gas.... I was smart enough to fill the tank on the '72 before I parked it
1.5 years ago. ;)


So... where do I go from here?....

I want to check the timing and advance mechanisms... maybe I need to retard
the timing a bit... it shouldn't hurt, anyhow.

I need to get some time to use a friend's shop (w/ a "real" compressor vs.
my on-board air)... yank the valve covers, push on the valve springs to see
if 5/6 are any weaker than the others.  If I'm going in, I might as well put
the compressed air to the spark plug hole, change the valve stem seals (any
idea on cost?) and yank the lifters to inspect / clean them (or replace w/
new.. $4 I think).  Eliminate the valve train as the culprit... or determine
that it *is* n' fix it.

The carb may also get properly overhauled still... with a new power valve
gasket, new base gasket, etc.

If none of that helps.... I either a) use an MSD with a hot coil, and *make*
those plugs fire, or b) take more apart.

The upsetting part of all of this is it *was* a good running motor.  It was
a "known good", which is why I yanked it.  the motor has 64k miles on it.  I
knew there was nothing wrong with it, and thus I knew I could yank it from
one truck and drop it in the other, no problems.

So whatever's happened to this engine has happened through 1) sitting for
over a year... something varnish up?  Corrosion?  or 2) malicious acts by a
disreputable body man / mechanic that is either so ignorant he believes his
own lies, or has no problems lying under oath.

In any manner, it's not like I was driving it for years n' years and it just
started failing... or that I subjected the motor to any particular
catastrophic act... 

Which is what makes this all the more puzzling.

So... it still fouls the plugs!  And I still ain't happy 'bout it.

So.. here's some food for the digest for today.  *smile*

-Tom Mandera, Helena MT
http://www.tmcom.com/~tsm1/scout
'77 Scout II, with a '72 304A that fouls 2 plugs