Mike:
We (my son was driving the car at drivers school) spun my #2 rod bearing
exactly the same way in our first outing this year. Car was running well
Friday and Saturday, Sunday morning as I was preparing the car for the first
session I noticed a very slight oil sheen in the top of the radiator while
checking fluid levels. Checked the dipstick, capture tank, and popped the
valve cover off to check for any evidence of water. Finding none, I sent
him out with the idea I would re-torque the head as a precaution when he
returned. Needless to say the car didn't finish the session.
It appears, in our case, that the #2 bearing spun, allowing the piston to
slightly tap the head causing it to break the seal on the steel shim head
gasket. On the next down stroke it sucked a slug of water and on the
upstroke compressed the water and blew out the side of the liner
What I don't know is whether the bearing spun (1) due water contamination
in the oil, (2) lack of lubrication to the # 2 rod bearing for some reason,
or (3) faulty bearing(s).
I too, was running a non-hardened stock crank, Carrillo rods, and
Tri-metal bearings which I had purchased from BPNW. Same engine block with
different crank suffered the same #2 rod bearing failure by previous owner.
Same
rod from previous failure had been reconditioned by Carrillo, pronounced
good and reused. Block had been line bored and cleaned prior to reassembly.
On tear down remaining bearings (Main and rod) showed either no damage or
slight evidence on galling (probably due to water contamination of oil
after the failure). #2 rod bearing was completely wiped out. Surprisingly
little (but enough) damage was done to the crank journal. Cam bearings looked
perfect. No other damage was noted. There was no blueing of the crank or
any other indication that the bearing/journal was running hot.
I am about to begin building two new engines this winter. I'm curious to
know what bearings you used in your engine, and more importantly, anything
else you may have noticed during both teardowns regardless of whether you
think it was a factor in the failure or not.
Cheers!
Mark A. Eden
62 DP TR4 #357
64 HP Spitfire #42
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