took the CCKW with 12V conversion for its road test today,
and it did prove to be a test.
Firstly the truck starts well now, at least for the last 2 days
a dozen times, no real trouble.
There still seems to be a fuel problem, needs choke to rev,
and tends to stall, backfires under load...maybe lean??
well anyway, we went down a local track, so i could have
my mate drive it about while i listened and looked for
noises and binding etc....its is dirt, with a large cul-desac
and bush, but very steep...the road is about as steep as a regular
road is allowed to be, a 1st or maybe 2nd gear road in a standard
car. On the way back, the GMC started to splutter, backfire and then died.
No fuel was evident at throttle pump, tank was 10-20% full, so
we surmised that more fuel would be good...to the servo, 20 litres
in a jerry can, she starts and we get home,Does the fueltank pickup
have problems at steep inclinations and low fuel tank?
Power is low and backfire is evident.
Fuel is leaking out the carbie, so this would also probably
make it more lean.
I will soon put on a Stromberg that is on another GMC, I believe it has
adjustable mixture needle.
My gear changes are atrocious, but i did seem to need to engage low range
to negotiate the steep hill...which brings me to TM9-801, page 19,which
states "maximum grade in High range 3.5*(3 1/2).....Low range 65*
* GVM 19500. Is this a misprint?..What does the figure shown
for High range represent?. Do they mean 31.5 gradient?
I would have thought the truck should easily
pull a grade like that( estimate 35%) in 1st, with no load?
Also, whilst stalled on the steep hill, we noticed oil trickling out
from what appeared to be the rear main oil seal, it stopped when parked
on a level..lost about 1/2 litre, engine was probably 1-2 litres overfull
how hard is it to change the rear main oil seal?
would i need to? or can an overfull crankcase flow a little out?
Can it be done with the engine still in, by using a little jigger tool
to sneak it in like on Chevys or Jags.
I presume the seal has hardend due to lack of use, over the years.
12V certainly seems the go, spins the starter really well.
Does anyone on the list have a dumper GMC?
I am curious also about Hercules engines, I looked them up om Net search
engines, but could find little, to my surprise.
What i understood is they are large 6 cyl petrol engines, developed from
stationary engines. Are they side valve?...a GM product?
If some knowlegable lister would point to a website etc, that would be good
with regard to the electric fuel pump, one lister did point out
the problem of overpressure on the needle/seat causing flooding.
I think i remember reading a article describing an adjustable fuel pressure
regulator, i think it had a screw type fitting, and went down to 2 PSI
Does anyone know of these?
Maybe i should just mount up a set of injectors into the underside of the
manifold, add extractors, injector computer,HP pump, electric fan,
electronic dizzie, cell phone and be done with it.
regards tony
This archive was generated by hypermail 2b29 : Thu Jul 05 2001 - 00:40:38 PDT