OK, time to make the plea to the FOT list, since I've tried everywhere
else...
I've got this 1147 GP Spit you see. It's gotten into this habit of
eating #3 rod bearings. Like 4 out 5 times. (once was a stupid move on
my part, then #4 went...) I usually catch it before it goes boom, but
last fall @ Watkins Glen, it went Boom in a big way, punching a rod
through the oil pan and all that good stuff. Not the first time, but
perhaps it's last in my care.
There are only 3 engine components common to all 5 motors, the cam, the
head (and all it's assorted bits), and the owner. I've been through
three engine builders, three blocks, five cranks (besides myself!). The
failure mode seems to be a pounded out # 3 rod bearing which is bright
blue. Engine temps are not unreasonable before it goes ( 195-215 h2o,
215-230 oil). Oil pressure was good ( start @ 80-100 lbs hot, down to
40lbs at speed, hot). I've not been seriously anal about rod clearances
(1.5 - 2 thou) but having the same journal go four out of five times
kinda has me puzzled. Typical lifetime is 30-50 minutes.
There have been a number of theories as to what is going on. Oil
starvation was one, put in an accusump and deep oil pickup. Overheating
- put in electric fan, then serious air ducting and huge oil cooler, oil
temps dove, still lost it. Lack of oil to 2/3 journals - opened up oil
passages to #2 main and cross drilled crank - oil pressure dropped
overall (to 40 lbs hot) and engine lasted one race plus 3 hard laps @
the Glen. Detonation - changed to Electromotive crankfire ignition
examined very carefully - one race.
I'm out of options. I'm not really in a position where I can spend $K on
having some one else build me a motor (did that once before, it lasted
18 minutes). The spouse has decided to get rid of the car, but I'm not
wholeheartedly convinced of that. (though I have bought another car (a
FV)...albeit sans motor) When last @ the Glen, I had an offer for it,
but it was alot less than I wanted. I'm going to have to put an engine
in it before I get rid of it, so something has to be done. I've got a
block/crank @ the machine shop now, but once that is done, I'll have a
dillema. Put it together and try to keep it, or just dump it.
Can any of you 1147 wizards offer any opinions/options?
Bob
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