18 years ago I had that problem with my TR6 too. For old tired engines
20W-50 is like a "walker". On the other hand, I rebuilt the engine
recently and spent a little time crafting the tolerances. I broke it in
(200 miles on 10W-30 mineral based) and then switched to Syntech 5W-50
synthetic. Oil pressure is now never lower than 45 lb. and never higher
than 70 lb.. Engine pulls well to 7000, I get better gas mileage and
more horsepower. Synthetic oil is great and for new/rebuilt engines, its
like dancing shoes.
>----------
>From: Robert J Carley[SMTP:rcarley@uoguelph.ca]
>Sent: Friday, November 22, 1996 9:19 AM
>To: Barry Schwartz
>Cc: triumphs@autox.team.net
>Subject: Re: Engine oil weight - TR3
>
>I agree with the 20W-50 weight for TR's. I changed oil soon after
>acquiring my TR6, used 10W-30, and wondered what had happened to my
>motor! The oil pressure had dropped considerably. The british car
>dealer/ restorer from whom I had purchased it told me to switch back to
>20W-50, as that was the original weight of oil recommended for these
>cars. I did, and have had excellent oil pressure since.
>
>Robert Carley
>73 TR6 CF5713U
>
>On Fri, 22 Nov 1996, Barry Schwartz wrote:
>
>> > using a multi-viscosity oil is superior to any straight weight. I would
>> > use either a 5w-30 or 5w-40. If you do decide to take it for a spin on
>> > one of those snow free days, the 5w will allow the engine to spin more
>> > freely.
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> While I agree with using the newer improved, multi-grade oils, I disagree
>> with the choice of weights. Remember when theese cars were built. The
>>only
>> oil available was of the single grade variety. The clearances built into
>> these engines were such as to accommodate these oils. Newer engines are
>> built and designed with much tighter/closer tolerances which take advantge
>> of these new and better oils as well as thinner grades. If you use the
>> thinner multi-grade oils, you will not have the proper oil pressure your
>> engine was designed for. There is nothing wrong with a good grade of
>>single
>> weight, but if you want to use the "better" multi-weight I would recommend
>>a
>> minimum 20w-50. 5w is much too thin - and I think you'll find in your
>> owners manual the viscosity for your car at whatever temp. Use a
>> multi-grade that falls within these ranges.
>>
>> Barry Schwartz
>> Bschwartz@encad.com (work)
>> Bschwart@pacbell.net (home)
>> (San Diego)
>> 70' Spitfire (under-going major surgery) , 72'-V6 Spitfire (daily driver)
>> 70'GT6+
>>
>>
>
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