Subject: [TR] Oil pressure in my TR6

From: Joe DeMuth <[email-masked]>
Date: Thu, 23 May 2013 17:35:34 -0500

Help. Just bought a '73 TR6 after selling the TR3 I owned for thirty years.
Everything looked good about this car, but I soon became concerned with the
oil pressure reading. At idle, running 20-50 oil, all heated up, the pressure
dropped to what looked like about 10 lbs or less on the gauge. At highway
speed it read about 40. I dropped the pan and used Plastigauge to check
clearance in the mains. I checked the back three and all where in the 2
thousandth range, which I assume is good, can't find a spec for that. All
bearings had oil. I didn't do the front one because I didn't have a new timing
chain gasket, but assumed three are good the other is probably OK. I checked
one rod bearing and it was well within spec. The rocker train appears to be
lubed its full lenght. Pulled the oil pump and found it to be just over the
high end of the various specs. Put in a new one, checking clearances before
installation. Pulled the oil relief valve and found that the previous owner
had replaced the standard spring with the slightly longer one sold by Moss.

I put it all back together. Now I have about 6o lbs at highway speed, but only
about 12 at idle. I checked the gauge by hooking up an after market gauge in
the oil pressure warning sender hole. The gauges read about the same across
the whole range of rpm

So, can I get by with this? Do I need to look further, if so, where?

** [email-masked] **

Archive: http://www.team.net/archive

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From: <[email-masked]>
Date: Fri, 24 May 2013 12:29:53 +0000

I agree with what Dave said. While the numbers are lower than you will see for a fresh motor, or even a well worn one in good nick, I have driven many motors many miles with similar numbers and nothing has blown up.  There is an old adage about 10 psi per 1000 rpm being adequate.  In addition to a new oil pump a new rocker shaft and or new rod bearing can bolster up the pressure short of a pull the engine rebuild.

Greg Lemon

---- Dave Massey <[email-masked]> wrote: 
>  That sounds a little low but no terminally so.  You may have excess
> clearances in the oil pump and a fresh pump may improve things significantly.
> Camshaft clearances also help determine oil pressure but that is a bit more
> work to address.
> 
> Keep in mind that the TR6 does typically run lower pressure than the old
> TRactor motor typically does so don't expect to see those pressures on an
> engine with a lot of miles.
> 
> And if that kind of oil pressure scares you stay away from a TR8.  Those
> things run in the single digits at warm idle.
> 
> 
> 
> Dave Massey
> 
> 
> 
> 
> 
> 
> -----Original Message-----
> From: Joe DeMuth <[email-masked]>
> 
> 
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From: <[email-masked]>
Date: Fri, 24 May 2013 7:31:39 -0500

Greg Lemon

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From: Chris Kantarjiev <[email-masked]>
Date: Fri, 24 May 2013 09:51:14 -0700

Those pressures seem totally reasonable; my target is usually 10PSI/1000rpm. 
Too high an oil pressure is just robbing power from the engine.

One thing you didn't look at, and is not an uncommon problem, is a worn rocker 
shaft; check the underside for wear. You can lose a lot of oil pressure there.