1977 MG-B recommended oil?

[newtoncd8]

Our 1977 MG-B with about 60,000 miles has been sitting in storage since 1992. In early January, we took it to a place that specializes in restoring MG's to get it in drivable condition.

After replacing about every part but the engine, radiator and transmission

, the shop owner called on Saturday and said it was done and it was ready to be driven home. It has passed emissions and he said it one of the stronger engines he has run across.

I think back when it was running (circa 1983-89), I used to use Pennzoil 10W30 (or perhaps it was 10W40? I used back then) with Fram filters. I am considering going with Pennzoil or Castrol GTX and Purolator filters and probably changing every 3-4 months especially since we will only probably drive it on weekends and not much during the Colorado winter.

What would you all recommend for this car? BITOG's thoughts? Would it make sense to run a maintenance dose of Auto-RX to help with the internal seals? Appreciate any other thoughts. Thanks.

 

[Doug Hillary]

Hi,
Curtis - When these cars were new 10w30 was the oil of choice by BMC. They will tolerate almost any oil. I did my Engineering training in the 1950s-60s with BMC in New Zealand and in England

I would not use any "conditioner" and would initially run an HDEO such as Shell Rotella T Multigrade 15w40 for three or four months. Then I would consider using the likes of Shell Rotella T 5w-40 synthetic. The oil pumps in A & B series engine do prefer a lighter viscosity at cold startup in any temperature

I fully rebuilt the engine in my '74 "B" and then ran Shell Helix Ultra 5w-40 synthetic in it after running it in on a 15w40 HDEO
Sadly I sold it some years ago and purchased a BMW Z3 2.8 - I still miss the "B"

 

[Ignatz]

I was a mechanic back in 77 at a MG-Triumph dealer and we used Castrol GTX 10-40 as the standard oil, but recomended D-A SpeedSport oil as a better alternative. The D-A was expensive and I sorta remember it was a non detergent oil. That stuff is long gone. We had a bunch of engines go south in the 70's and the owner of the shop blamed it on Kendell oil. At another shop I've worked at we had a lot of Chevy 350's go south using Kendell. Our shop uses Pennzoil 15w40 now and never sees an engine failure. Not sure if a lot of the engine failures back then were due too inferior metals used, but the Kendell was the oil used back then, probably because it was the cheapest bulk oil at the time.

 

[mechtech2]

I like Doug Hillary's advice for this MG.
This sounds like a good weather car, not a daily driver through winter.

 

[Johnny]

Sound advise from Doug Hillary. I miss the days of the MG's and Triumphs. Fun cars to drive.

 

[Saab9-3]

I have a 72 MG with 70,000 miles on the original engine. Always used Castrol GTX 20w50, always runs very smooth and good oil pressure.

I tried RP 20w50, but the engine ticking was quite loud in comparison to the GTX.

I think this summer I am going to try a 5w50 or 5w40.

EDIT: Not sure if there is a big difference from 77 to 72, but all my manuals call for 20w50 oil, not 10w30

 

[coffee]

I agree with the 5w40 but why go with 15w40 first? I thought the only difference between the two was the cold starting and synthetic versus dino. It would seem to me to be better to go with 5w40 right off the bat but I am interested in the reasoning.

 

[newtoncd8]

Thanks for all of the replies, appreciate all of the help.

 

[Pablo]

Good advice.......we'll see you in the transmission section!

 

[newtoncd8]

I hope you don't mean the transmission is going to go soon!!!!.....I am letting the rebuilder take care of the transmission fluid, but I like to change my own oil, thus the question.

 

[Doug Hillary]

Hi,
Curtis - the gearbox fluids used in this series of BMC-Leyland vehicles were primarily engine lubricants (or some GL3 fluids) of SAE30 viscosity. Many people used 20w-50 viscosity lubricants and/or 10w-40 viscosity lubricants in very cold weather

In NZ and England (at BMC) we used Castrolite 10w-40 (approx) or Castrol XL 20w-40 products

In my MGB I used a synthetic SAE50 lubricant especially designed for gearbox use. In my case it was Castrol Syndrive 50E. Mobiltrans SHC 50 is also an excellent product - most major Oil Companies make these synthetic fluids as they are used in Eaton-Fuller "RoadRanger" multispeed truck gearboxes. They perform very well in the MGB's manual gearbox and I strongly recommend them to you owing to the nature of the gearbox's structure

They are excellent fluids and I have run them out to 1m kms (620k miles) OCIs (using used oil analysis) in the 18 speed constant mesh gearboxes in my Heavy Trucks

 

[Pablo]

Originally Posted By: Curtis Newton
I hope you don't mean the transmission is going to go soon!!!!.....I am letting the rebuilder take care of the transmission fluid, but I like to change my own oil, thus the question.


Didn't mean imply soon, but please don't miss many shifts. Doug has some good recommendations. Please also let us know what the builder used.

Amsoil recommends several motor oils:
Amsoil AMO 10W-40

But the viscosity of MTG GL-4 is almost identical, the gear protection better, the correct FM's and it's easy on yellow metals.
Amsoil MTG 75W-90 GL-4 MT oil

 

[Doug Hillary]

Hi,
coffee - The reasoning for a 15w40 HDEO over a 5w-40 synthetic HDEO is to see what condition the engine's internals are in. It was not rebuilt and seal materials of that era may be prone to weeping in any event. The 15w40 HDEO lubricants have good seal conditioning additives

If all is well, move on to a synthetic

Curtis - Has the engine got an oil cooler fitted? Most here in NZ and OZ had them - they are a valuable tool in extending engine life although the last of the "B" Series engines were fairly bulletproof

I would avoid the GL4 Amsoil lubricant recommended above!

 

[coffee]

Thanks, Doug, that makes sense.

 

[wgtoys]

HDEOs are in my view the best bet now for older engines. They are most commonly sold as 15w40, but you can get 10w30 and 5W-40 versions as well. These oils tend to have higher additive levels which might be well suited to the simple valve trains of the older engines.

 

[dave1251]

Originally Posted By: wgtoys
HDEOs are in my view the best bet now for older engines. They are most commonly sold as 15w40, but you can get 10w30 and 5W-40 versions as well. These oils tend to have higher additive levels which might be well suited to the simple valve trains of the older engines.



I think today's addy levels are about the same. Just ZDDP has been replaced by Moly and other more "advanced" anti-wear additives.

 

[40ford]

I run 5w-40 Rotella in my 73 XKE V12 Jag. It has work well for me.

I run 60+ lbs oil pressure at road speeds and 20-25lbs. at hot idle.

I also run 15w40 syn. Amsoil in my 1968 250SL M-B.

On the next oil change on my other old car I am going to put it on HDEO also.

40ford

 

[Doug Hillary]

Hi,
40ford - OT - I hope you enjoy your 250SL - Rotella would work well in it too. I purchased a '65 230SL manual in 1972 - it had both soft and hardtops. My two eldest children were reared in it (well almost). It was written off in an accident in Auckland NZ after I sold it - about 1979

Great cars (I still hanker for a 190SL - a fully restored silver/red one sold here last week for $A90k)

 

[40ford]

Doug, This SL has both tops also. Light beige with dark brown interior. Only 50,000 miles. I have owned this car since 1989.

40ford