Sorry to hear about the recent break Hardy. I've noticed that the repro
pumps have very sharp inner edges at the drive slot. Perhaps that is part
of the problem. I'm running with an electromotive and have eliminated the
distributor and blanked the pedestal opening. The shaft and drive gear are
cut down and centered in the blanking plate with a bronze "top hat" type
bushing. No problems with that installation yet.
Why couldn't you cut a piece of 1/2" shaft as a small shim between the roll
pin and the top of the existing shaft?
Good luck at Portland, my next stop is the Glen on the 12th, work-load
permitting.
Chip
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From: Catpusher@aol.com[SMTP:Catpusher@aol.com]
Sent: Monday, June 30, 1997 1:25 PM
To: fot@autox.team.net
Subject: oil pump drive ear failure
Hi FOT
every so often I have broken the ears off the top of the oil pump shaft.
previously the failure occured in pre race sessions. It happens with
the oil fully warmed at racing RPM.
Yesterday it hit two laps from
the end of the Laguna Seca Nat. when I was trying to catch the leading
elva courier mk IV T with IRS (I think a total of 13-17 were ever built!).
I decided against a "Prolong" test, but the redline oil more than likely
saved the bottom end, as I shut off the motor as quickly as one can
at 6800! The only consulation was that the miata was a no show,
and the points lead is still ours.
I have to change the gearing, fix the motor, do several days of routine
checking, and leave for the Portland Double Natl. this Wednesday.
Has anyone tried to hold the oil pump drive shaft down, as it can
move up quite some distance before hitting the drive gear roll pin?
Thanks in advance for any ideas Hardy
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