Dear fellow listers;
Just to keep you updated on my progress, I am the originator of the Gas in Oil
question that has been discussed on the list lately.
Background: After a carb rebuild, my car (1973 TR6):
1. Was getting raw gas in the cylinders due to a rich mixture (replaced jets
with new Grose jets and replaced all gaskets and seals that come with TRF ZS
2. I was unable to start the car, until I removed the carbs again and cleaned
out the cold start valve, adjusted the center screw out 7.5 turns (was at 3
turns), and I also lowered the floats another 1/16" in the bowls (5/8" from
the bowl rim to highest point of float, measured with carb turned upside
down.) The standard height is 11/16".
3. Adjusted the small washers on the needles in the carbs to be flush with the
bottom of the air valve.
4. The car started, but was still rich.
5. I drove the car around the block, it seemed to lack a little power
(probably from the wrong air/fuel mix at the carbs) and I then noticed a
troubling sight, my oil pressure was "0 psig"?
6. I checked the oil level, OK
7. I checked the oil pressure sender tube at the engine, OK
8. I started the engine the next day, the oil pressure went up to about 60
psig when cold, then slowly dropped to about 0 psig when engine reached
operating temp. Revving the engine did not have any effect on raising the oil
9. I was told with all the rich gas the cylinders have been seeing, I might
have gas contamination in the oil which would cause the low oil pressure. The
pump has a harder time pumping the thinned out oil.
10. I drained the engine "cold". Dropped the oil pan and cleaned out a layer
of silver grey muck that had settled over the past 15 years (10 of those years
11. I removed the oil filter and I also removed and inspected the oil pump.
12. The oil pump center gear had small scratches on the surface of each lobe,
but all measurements were within .010" spec (all about .008") so I primed pump
with cam lube and oil and remounted to engine.
13. I also checked end play to see how much my thrust washers were worn. The
end play wasn't as bad as I had originally thought, about .008" to .009" :)
so I decided to just put the the oil pan back on and try new oil and see what
I get for oil pressure.
That is where I am at today, I am waiting for some parts to come in, and then
I will be pouring new Castrol GTX 20/50 oil in and mounting a new Fram oil
filter. I plan to turn the engine over w/o plugs installed to get the oil
pressure up before I fire up the engine. I hope the oil pressure stays around
20 psig with engine at operating temp the way it use to be before this whole
carb rebuild mess.
I have balanced the suction on the ZS carbs before I dropped the pan, but I
would like to adjust the air/fuel mix ASAP before I contaminate the new oil.
Does anyone have any advice for adjusting the mix, I think I am running
"rich", when I lift the air valve approx. 1/8", my idle would start to die
out. I read that this was an indication of a rich mix?
Wayne from Massachusetts