Hi John, I know very little about the type of bearings and clearances. I
had the engine built by a roadster guy who once owned the car. He and a
buddy who is a porshe mechanic built the engine for me. They used a machine
shop that builds race engines and the machinist was very maticulous. The
mechanic did mention loosening the cam bearings just enough to see if the
problem is in the upper engine area. Also I have removed starter,
distributor, alternator, fan belt etc. I have been turning the motor by
hand for some time now. Also had been rotating the oil pump w/ a hand held
drill a number of times. I have never had the engine turning over enough to
pressure up the oil pump and force oil in to the various bearings. I don't
imagine just rotating the oil pump would do this. Larry.
----- Original Message -----
From: "John F Sandhoff" <sandhoff@csus.edu>
To: "roadster68" <roadster68@shaw.ca>
Cc: <datsun-roadsters@autox.team.net>
Sent: Wednesday, September 21, 2005 12:50 AM
Subject: Re: Starter Problem - '68 - 2000???
>
>> ...Now it looks like the engine is totally bound up somewhere.
>
> Ouch. Sorry to hear that.
>
> If you used lots of assembly lube on the bearings, and they weren't
> too tight to begin with, I kinda doubt it's a seized bearing. However,
> one item that bit me once: Did you use oversize bearings, and if so,
> did the thrust bearing clearance get properly adjusted? (The thrust
> bearing is on the SIDE of a main bearing and rides against the crank
> journal. On an oversized set it will be thicker than std.)
>
> My gut feeling is that a piston is hanging up in a bore...
>
>> The mechanic suggested backing off the cam bolts to see if the
>> problem is there.
>
> Oooh, be very careful. The U20 is an interference engine, if the cam
> isn't keeping time with the crank you'll run into an open valve with
> a piston. I suppose you can loosen the cam bearings and let all the
> valves close... watch out for the followers and springs and lash
> pads all trying to get away... (note: don't intermix where each
> follower goes if the engine has run. Cam lobes and followers 'wear
> in' with each other and get really upset if they get moved later)
>
> Make sure it isn't something simple like a jammed oil pump. Pull the
> dizzy and drive gear. While you've got that apart, you can also cut
> the handle off a long flat screwdriver, chuck the shaft in a drill
> and use it to spin the oil pump COUNTER clockwise to build up oil
> pressure. In about 15 seconds you should have oil flowing all over
> the cam. Watch out for where that little dizzy oil line is :-)
>
> Pull the fan belt, too, if you haven't already.
>
> -- John
> John F Sandhoff sandhoff@csus.edu Sacramento, CA
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