[TR] [EXTERNAL] Re: Ideas, anyone?

[andrew uprichard]

If you spin an oil pump with a long screwdriver bit on a drill, you will get
oil pressure, but no feed to the head, which makes me think the rear cam
bearing is just responsible for the latter.  But I could be wrong. 

 

Andrew Uprichard

Jackson, Michigan

 

From: Reihing, Randall S. <Randall.Reihing at utoledo.edu> 
Sent: Friday, May 15, 2020 10:08 PM
To: andrew uprichard <auprichard at uprichard.net>; 'Alex & Janet Thomson'
<aljlthomson at charter.net>; triumphs at autox.team.net
Subject: Re: [EXTERNAL] Re: [TR] Ideas, anyone?

 

Don't know for sure on TR4's but some engines source their oil pressure from
the rear cam bearing, not the oil pump, mains or rod bearings. Where does
the TR4 source it's oil pressure? If it comes from the rear cam bearing and
if that clearance is excessive it could result in a very low pressure at
idle with hot oil. Oil pumps are volumetric flow pumps not necessarily
pressure pumps, so you might be fine if the oil pressure gauge senses it's
pressure indication from the rear cam bearing. Just a thought. 

 

Randall Reihing

1959 TR3A 

  _____  

From: Triumphs <triumphs-bounces at autox.team.net
<mailto:triumphs-bounces at autox.team.net> > on behalf of andrew uprichard
<auprichard at uprichard.net <mailto:auprichard at uprichard.net> >
Sent: Wednesday, May 13, 2020 7:34 AM
To: 'Alex & Janet Thomson' <aljlthomson at charter.net
<mailto:aljlthomson at charter.net> >; triumphs at autox.team.net
<mailto:triumphs at autox.team.net>  <triumphs at autox.team.net
<mailto:triumphs at autox.team.net> >
Subject: [EXTERNAL] Re: [TR] Ideas, anyone? 

 

Thanks for al the suggestions.  Gauge is good, have tried a new oil pump.
I think the next step is to plastigauge the bearings and check the rocker
shaft, as suggested.  Then I guess the engine will have to come out. Sigh...

 

From: Alex & Janet Thomson <aljlthomson at charter.net
<mailto:aljlthomson at charter.net> > 
Sent: Wednesday, May 13, 2020 5:58 AM
To: 'andrew uprichard' <auprichard at uprichard.net
<mailto:auprichard at uprichard.net> >; triumphs at autox.team.net
<mailto:triumphs at autox.team.net> 
Subject: RE: [TR] Ideas, anyone?

 

Was the crankshaft cut down by a previous owner for use with undersize
bearing shells? I saw this happen in a Nuffield tractor once. Great oil
pressure at startup but diminishing quickly as the oil thinned out.

 

Alex Thomson

 

From: Triumphs [mailto:triumphs-bounces at autox.team.net] On Behalf Of andrew
uprichard
Sent: Tuesday, May 12, 2020 5:54 PM
To: triumphs at autox.team.net <mailto:triumphs at autox.team.net> 
Subject: [TR] Ideas, anyone?

 

Having (I think) sorted out the problem with the TR4, I took a
recently-finished TR3B out for its second inaugural drive.

 

The first inaugural drive went pretty well, but once the engine temp came
up, the oil pressure fell like a stone - and here we are talking around
40psi at 3000rpm and almost nothing at (what was hot) idle. Adjusting the
pressure with the screw on the oil filter head did nothing.

 

I checked everything over, even pulled the oil pan and checked all the
bearings (one main and 4 rods) - all perfect.  I really didn't find
anything, and the specs on the oil pump looked good, but I ordered a new
pump as well as a new spring for the Purolator oil filter head (the valve
itself is no longer obtainable).

 

So today when I first took it out, the pressure was almost too high - around
90 at 3000 rpm.  But as soon as the engine warmed up, it again dropped to
scary levels. No leaks, no oil in water or vice versa.

 

I am running out of ideas here.  Could it be a bad oil filter head?
Anything else?

 

Andrew Uprichard

Jackson, Michigan

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