OK... so I have finished fighting with my carbs for a while...
acceleration is good but the plugs are >black<... if I lean any the
exhaust note gets harsher and I lose throttle response. I'm running on
premium now with the timing advanced... pickup is pretty good.
Howsomever...
Weeks ago when I was first starting to fight the carbs, I accidently
started the car in gear one time. Immediately thereafter I experienced a
20 lb reduction in oil pressure in all modes... which has persisted ever
since...
The first things I tried were 1) new oil pressure relief valve 2) new oil
filter 3) playing with the crankcase ventilation 4) making sure the oil
is topped up (oil consumption has gone up, it was bad before but is about
double now) and 5) CD-2 "engine restorer" goop snake oil.
It leaks a bit from the timing chain cover, and through the oil filler
cap. There is quite a bit of blow-by.
A mechanic friend of mine and I dropped the oil pan and inspected... The
oil pump and strainer are in great shape, and there is very little
sludge, no hunks of metal either. The main and big-end bearings were
shot... we replaced all big-end bearings and all but the rear main
bearing (5 main engine). We didn't have time or energy to pull the
engine or tranny so couldn't get at the rear bearing. He said the thrust
washers looked OK.
His quote: "I haven't seen bearings this bad except in engines with
catastrophic failure".
I realise I have to do a top overhaul to get the oil consumption down and
reduce the blow-by... plus compression isn't that great (though not bad
at ca. 120).
"Bad oil consumption" means was 1 qt/ 150 miles and is now closer to 1
qt/80 miles.
Before After
Cold Idle 60 40
Cold 3000 70 50
Warm Idle 35 10-15
Warm 3000 60 35
My questions: 1) Is it because we didn't do the rear bearing that there
has been no change from the bottom end work, or 2) Is there something
else to check I have overlooked? 3) Is this a >bad thing< and I should
stop driving the car, or can I limp along until I can afford the top and
getting the last bearing replaced? I need to put my other car in the
shop for a heater core replacement and misc. sundries... time consuming
stuff.
I know these figures are still close to spec, but I get very concerned
with the warm numbers.... and they dropped SUDDENLY.
Help?
John M. Trindle | jtrindle@tsquare.com | Tidewater Sports Car Club
'73 MGB E Stock | '69 Spitfire E Stock | '88 RX-7 C Stock
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