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MG TD TF 1500 - What Oil Weight Do You Use In Your T?

Just curious to know what weight and type of oil drivers are using in their T series.

I've been using Castrol 20W50 since the engine was rebuilt in 2000. The car was at the shop for another issue, and the mechanic checked the oil pressure. He said it was 38 psi, which he said was a bit low. Wondering if a different viscosity would raise the oil pressure?

Erick
1952 MG TDC
2008 BMW 3281, last of the inline 6 cylinder engines
EB Blackwelder

Castrol 20W50 is what I have been using in all my MGs in the last 35 years. I don't think 38 psi should be considered low, but it depends upon the engine temperature and RPMs. If the engine is at idle and cold, it might be slightly low, but more dependent on the wear - bearings and rocker shaft bushings.
Volume of oil is more important than pressure.
Lew3

Where did he take the oil pressure reading? If at the banjo bolt on the head the reading will be different than at the banjo bolt on the block. For 35 years my gauge was connected at the top. Finally learned that was wrong, changed it and gained 15 lbs of indicated pressure on the dash gauge with Castrol 20W50.
John Quilter

Erick, check the archives. This has been a very popular issue for quite some time. You'll probably find that 20W50 is the most popular weight. Bud
Bud Krueger

And also that Castrol reduced its zddp levels several years ago. I use 20W-50 oil with minimum 1200ppm zinc. Currently that's Valvoline VR-1 non-synthetic.

I agree that 38 is a bit low, but it isn't too low. As a general rule, 10PSI per 1000RPM is ok.
Steve Simmons

Any time an oil thread starts I like to get out the popcorn. Having said that I've been running Rotella T 15-45 in pretty much everything, tractors, backhoe, trucks, my Commando in the fall but not summer, and, at present, in my MG. I may change like I do the Commando but I do that because it's air-cooled and the heavy weight is OK in summer. When it's cool I've twice blown seals when cold as the oil pressure will peg an 80 PSI gauge when cold; gotta be patient and let it warm up.

Popcorn is on the stove.
JE Carroll

I use Brad Penn 20w-50. Tons of zddp. 1500 ppm zinc & 1340 to 1400 phosphorus. It's a blend and runs about $5.00 to $6.00 a qt. on the Internet.
John Mitchell

Valvoline VR-1 20/50 in the TF, PJ
Paul161

Kendall GT-1 20-50. Oil pressure- what was engine temp and what RPM?
George Butz

I run 20W50 in my Lycoming aircraft engine in my Cessna because it is air cooled. Some old-timers run straight 80W in their Lycomings and Continentals.
EB Blackwelder

I'm using Brad Penn 20W50 because the salesman convinced me that it had all the ZDDP and other stuff that an old flat tappet motor requires. I have only about 1,000 miles on it but it seems OK and I have 40-50lb/inch^2 once the motor is warm. 60lb/inch^2 when it real cold and the motor has not reached full operating temp. Jud
J. K. Chapin

When the mechanic at the shop tested my oil pressure he got 38 psi at 2500 rpm. He said that is a bit low. What would be an acceptable minimum oil pressure at 2500 rpm?
EB Blackwelder

VR 1 20/50 in the TD and my B. Both have used this oil since their last rebuild. Not an issue one.
Bruce TD4139 Cunha

I use Castrol HD-30 or HD-40. Still has the Zddp in it, plus I use the additive just to be sure.
Rich King TD 8732

I fitted a spin on oil filter adaptor, the original filter was as new only done a few miles, when I put the adaptor and new filter on (Ryco Z71) my oil pressure went up on the gauge by 8 lbs psi.

regards

George
G Mills

"salesman convinced me that it had all the ZDDP"

More ZDDP is not necessarily better for your engine. Increased ZDDP does not protect your engine better, it protects it longer. ZDDP is used up during metal to metal contact within the engine. Problems only occur when oil is not changed on schedule or your engine is in poor mechanical condition.

Salesmen love the 3-bearing "test" you see on TV because it makes it appear that more ZDDP is better to ill informed owners. Real oil companies run engines for millions of miles under varying driving conditions and build additive packages that produce the lowest overall engine wear.

Too much ZDDP can increase combustion chamber deposits, and this is a major reason ZDDP has been reduced (along with better engine construction and CATs).

Oil is cheap. Simply change you oil and you have a new supply of ZDDP and other extreme pressure lubricants.
WHTroyer

Eric - a safe minimum rule of thumb is 10 pounds oil pressure per 1000 RPM. 38 pounds oil pressure running is on the low side; 38 at idle is just fine.

You have a Mark II, and don't want to destroy the engine with no oil pressure!

Tom Lange
MGT Repair
t lange

Tom Lange, the 38 psi was measured at 2,500 rpm.

John Hambleton gave me a tip that I follow when I start the car. I pull the starter in 3-4 second bursts with the ignition switch OFF until the oil pressure needle on the gauge rises. Then I turn the ignition switch ON and start the engine as usual.

Erick
EB Blackwelder

Erik,

What's the purpose of the 3-4 second burst instead of cranking and turning the ignition on when the needle starts to move?

Jim
JE Carroll

Quote;
I run 20W50 in my Lycoming aircraft engine in my Cessna because it is air cooled. Some old-timers run straight 80W in their Lycomings and Continentals.

Curious, I've been in aviation over 60 years, how does your reply relate to the question on an an MGT engine? PJ
Paul161

Not a "T" engine but close.

Back around 1963 I had a 58/59 Bugeye Sprite. I lived on the top of a wind blown hill in Beverly MA.
It started to loose oil pressure. My next door neighbor worked for North East Airlines (Long gone now.)
He would bring me 5 gallon cans of 80 weight Aircraft oil. (NE Still ran DC-3's).
That cured the oil pressure problem until Winter came.

Then the oil was so thick I had trouble starting. I would add 1 Quart of Kerosene to the oil just before shut down at night and let the engine run about 30 seconds to mix it up. Start up was much easier in the AM after the long cold overnight soak.
In the AM I would let the car warm up good before the 1 hour treck down 128. The warm up was to evaporate the Kerosene.

I later found out the bolts holding the snorkel, in the sump, were loose. Breaking the vacuum needed to suck oil into the pump.

Jim B.
JA Benjamin

Modern cars with higher revving, higher internal pressures don't even turn on the low oil pressure light until approx 11psi...how is 38psi "low" in a much slower turning engine with lower internal pressures? unless you are stage tuning your engine there is no need to worry about ZDDP levels in your oil either. Every reputable trade publication that is not trying to sell ZDDP oils and additives reads the same. ZDDP was not even invented when this engine technology was developed pre-war. A multi-viscosity 50wt oil is great. Something like 20-50 is a good wt.
Regards, tom
tm peterson

Hi Eric,
If I were operating my TD in the southern states, there is no doubt there would be a 20/50 wt oil in the sump. However, I am driving my TD in the region of 52 degrees North of the equator in a much cooler climate. I use a 10/30 wt oil and it does the job. My point is, a lot has to do with where you drive your car. There is not one oil wt that will be the correct one for all regions. How you drive your car is another factor to consider.

George
George Raham

Am I missing something I was led to believe multi grade oils were designed to operate under varying ambient temperature conditions. Maybe the disparity between southern and northern US temperatures are too great for a multi grade oil to deal with?
G Evans

Can't resist a follow - on to Jim Benjamin, 5 above. Some aircraft engines actually had oil dilution systems. In cold climates, before shut down, you'd feed fuel into the oil to dilute it and reduce the viscosity enough to start in the morning. The fuel would evaporate off thru the vents as it warmed up.

I know that bush pilots would actually drain all the oil from their engine on the last landing of the day and heat it in a kerosene tin on a wood stove the next morning, to get the viscosity down for the first start. Probably not recommended for T Types.

David
DavePro

I know of several street rod crate engines and machine shop rebuilds where the owners did not believe ZDDP was an issue to be concerned with and just used modern off the shelf oils. That is until they got to do the engine a second time. Some of these engines had less than 300 miles before the cam and lifters ate each other. Play it safe, good oil with ZDDP noes not cost anymore than oil without it. On the subject of racing oil like VR1 which I used in my 350 Chevy for years which is a very good oil but is a high detergent oil it turns black much sooner than Brad Penn which I have switched to.
F. Driver

"I am driving my TD in the region of 52 degrees North of the equator ..."

That's the same latitude as Abingdon!
R G Everitt

The same latitude as Abington? I did not mention that my 52 degrees North, is at 4500 ft in elevation in The Canadian Rocky Mountains. This does affect our climate and my choice of oil.

George
George Raham

This thread was discussed between 22/02/2016 and 05/03/2016

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