Optimal Oil Temperatures

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I have a 1970 MGB which, like all North American models of this vintage, has a factory oil cooler. The oil in it now started out as Castrol GTX 20W-50, but in the past year has been topped up with VR-1 20W-50, Penzoil 20W-50, and even some convenient store 10W-40(when you're on the road and need oil, you take what you can get). I will be pulling the engine in the next few weeks, and after doing that will refill with VR1 20W-50. I've been told, although I don't know how true it is, that BMC/BL assumed that a lot of US cars would get 10W-30 and they wanted to be sure the oil pressure was sufficient. In any case, I've been concerned for a little while about my oil temperature reaching their optimum level. Since buying a IR thermometer, I've become a bit more concerned. I'm running a 195º thermostat and, with the exception of very hot days crawling in traffic, the temperature gauge stays put right in the center. I typically measure 200-205º right above the thermostat immediately after a drive. The oil, however, is a different story. I'm getting temperatures in the 160-165º range at the block right above the oil pump on the hose that goes to the cooler, and about 140º coming out of the cooler and into the oil filter. Sump temperatures seem to run in the 130-135º range. My most recent numbers are from last night after about 2h of "spirited" back road driving, but they were in line with these. It's been my understanding from reading here that optimum temperatures oil temperature are somewhere in the 200º range for the additives to be most effective. I'm wondering if I should be doing something to keep the temperature up. As I see it, it looks like I have a couple of options. The first, and least expensive, is to just wire some cardboard in front of the oil cooler. I did this most of last winter, although I never actually measured temperatures. I do know that it seemed to help the engine come up to temperature faster. If I wanted to be a bit neater on this, there is an aluminum blanking plate available that's designed to "snap" around the cooler(apparently a dealer option when new, although someone is making them now). The second would be to eliminate the cooler entirely. While the engine is out, it would be very simple to run a straight pipe from the oil pump to the bottom of the filter. I think the major parts dealers stock these, as many post '75 engines didn't have a cooler at all, nor did the UK market ever have them as standard. The third-and most expensive option-is to install an oil thermostat. These run $400 for the good ones(and I've heard bad reports of the less expensive ones). Any thoughts on any of the above?
 
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I would think an electric cooling fan installation would help stabilize engine temps without reducing the overall cooling capacity which the old British cars, because of the mild British climate, seemed to be designed for. Motor oil has gotten a lot better since 1970 though.
 

bunnspecial

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Originally Posted By: HerrStig
I would think an electric cooling fan installation would help stabilize engine temps without reducing the overall cooling capacity which the old British cars, because of the mild British climate, seemed to be designed for. Motor oil has gotten a lot better since 1970 though.
Trust me, the electric cooling fan is something I've very much considered. I think BL started using them in 76 or 77-the US ones had two fans while everywhere else had one. Most of the refit kits have one big fan. I think all of them are one speed, but that's fine. They're appealing since they kick on and move air in situations like idling in traffic where a mechanical fan move very little air and you have virtually no ram air. At the same time, at 4K RPMs on the interstate, there's enough ram air to keep the car cool without needing a fan, and you avoid the parasitic drag of the mechanical fan at those speeds. I will say, though, that even in 90º+ weather with 80% or better relative humidity, I've never seen the temperature gauge get anywhere near the danger zone. The highest I've ever seen it is halfway between "N" and "H". In any case, though, the oil cooler is well forward of the radiator and off to the side, so most of its cooling comes from ram air and not the engine fan. US market MGs do very much have a reputation for being overcooled. A lot of that-I think-comes from the fact that BL didn't know whether the car was going to Arizona or Manitoba. It would be nice, though, if a company in a country that has a reputation for raining all the time could have figured out how to weather equipment smile. I have an aftermarket Robbins top("hood" in the UK) on my car which has some feature the OEM tops lack and my installer uprated a lot of the weather seals. Amazingly enough, my car is tight in the rain, but I can't get around the fact that it takes 10 minutes along with a lot of futzing and making sure you fold everything just right to get the top down(without scratching the window) and about 5 minutes to put it up-assuming it's not so cold that you're putting all your weight on it to stretch the vinyl.
 
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I have a Triumph Spitfire that has been fitted with an oil temperature gauge. I have never seen oil temps over 200f even thought I often drive quite hard. Still, the parts catalogues strongly promote oil coolers for my car duh I would get rid of the oil cooler, or better still, consider fitting an oil/coolant heat exchanger (as found on many modern cars. VW's have a nice one) BTW MG did list an oil cooler cover as optional equipment. Have you considered using a 15w-40 like Rotella or Delvac. I have had good results with them.
 
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Quote: It would be nice, though, if a company in a country that has a reputation for raining all the time could have figured out how to weather equipment .  You are American, you do not understand, it is all about 'Building character' The first Triumph I had, the car heater was an optional extra (presumably for Whimps)
 
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Originally Posted By: expat
I have a Triumph Spitfire that has been fitted with an oil temperature gauge. I have never seen oil temps over 200f even thought I often drive quite hard. Still, the parts catalogues strongly promote oil coolers for my car duh I would get rid of the oil cooler, or better still, consider fitting an oil/coolant heat exchanger (as found on many modern cars. VW's have a nice one) BTW MG did list an oil cooler cover as optional equipment. Have you considered using a 15w-40 like Rotella or Delvac. I have had good results with them.
Many owners of Toyota Camry I 4s don't realize that the I4 engine from 96 forward has an oil to water cooler as standard equipment. I have used T6 in mine for many years.
 
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I had an air to oil cooler and took it off. Even with a thermostat in the oil cooler adapter when the weather was cold it never went over 160F (the oil cooler adapter t-stat rated temp). I took that off and fitted a coolant to oil heat exchanger on the filter mount. This worked great. Kept the oil temp a little over the coolant. Took that off due to being too complex and with no track time anymore no real need. The filter selection was very limited too. Now with no oil cooling I find the oil temp to be under 210F all the time, usually in the 190s. This with a 180F t-stat.
 
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If my memory is accurate I recall the Wheel/Dealer mechanic, Ed China, relocating the cooler on a later "US bumper" MGB to right in front of the radiator.
 
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Originally Posted By: HerrStig
Joseph Lucas....because gentlemen don't drive at night.
The Prince of Darkness (Triumph Motorcycle, 1970's right side shift). Get bike, handled like a dream, went really well. Has intermittent electrical issues ...
 
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Originally Posted By: SHOZ
I had an air to oil cooler and took it off. Even with a thermostat in the oil cooler adapter when the weather was cold it never went over 160F (the oil cooler adapter t-stat rated temp). I took that off and fitted a coolant to oil heat exchanger on the filter mount. This worked great. Kept the oil temp a little over the coolant. Took that off due to being too complex and with no track time anymore no real need. The filter selection was very limited too. Now with no oil cooling I find the oil temp to be under 210F all the time, usually in the 190s. This with a 180F t-stat.
Sounds like the perfect solution smile
 
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Originally Posted By: expat
Quote: It would be nice, though, if a company in a country that has a reputation for raining all the time could have figured out how to weather equipment .  You are American, you do not understand, it is all about 'Building character' The first Triumph I had, the car heater was an optional extra (presumably for Whimps)
I had a 1966 MK II Cortina without the heater option. I remember one very cold winter where I had to drive down the highway with thermal lined winter motorcycle gloves.
 

SR5

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Originally Posted By: Ducman
Originally Posted By: expat
Quote: It would be nice, though, if a company in a country that has a reputation for raining all the time could have figured out how to weather equipment .  You are American, you do not understand, it is all about 'Building character' The first Triumph I had, the car heater was an optional extra (presumably for Whimps)
I had a 1966 MK II Cortina without the heater option. I remember one very cold winter where I had to drive down the highway with thermal lined winter motorcycle gloves.
I was riding motorcycles for 5 years before I got my first car. Staying dry in the rain was a new experience for me. On a bike, winter meant 20% of your weight was cloths, and summer meant 5% of your weight was lost in sweat. Back then any car was a palace to me.
 

bunnspecial

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Originally Posted By: expat
Quote: You are American, you do not understand, it is all about 'Building character' The first Triumph I had, the car heater was an optional extra (presumably for Whimps)
I suppose I have at least had some "character building" moments smile . When I bought the car, the hood(or top over here) was in poor condition and wasn't even mounted on the car. The guy who drove me up to pick up the car carried it back in his van-it sat in my office for another 6 weeks or so. For a VERY long time, I only used the tonneau to cover it when parked. On the day I bought it, I drove straight to work. About 4:00 that day, my mom called me and said "It looks like there's a bad storm coming in-you might want to get your MG under cover and drive your other car back to work." I took the surface streets back home, and was fine before until I got into downtown Louisville and was met with a torrential downpour. Having prepared somewhat for driving in the rain, I at least had the passenger side tonneau in place. None the less, as I said I got caught in torrential rain and didn't quite know what to do. It was at that point that I realized the windscreen wipers were of indetermenant age and that two of them were only rubber strips without the blade. The third lost its blade on the trip home. I found myself looking over the top of the windscreen just to be able to see what was ahead. Second, my uncorrected vision is bad enough that I can't legally drive without glasses(or contacts, if I wore them). Despite this, with the rain I absolutely couldn't see out of my glasses and drove the rest of the way home without them on. Third, a lack of familiarity with the car along with 20 year old hard-as-a-rock rubber tires allowed me to turn the car sideways in a 90º turn-fortunately there was no one around me. I got in, changed clothes, and returned to work. My co-worker asked me if I'd taken a shower while I was at home smile I had a few more of those experiences. I managed to locate blade refills so at least was able to get functional windscreen wipers. I did finally install the hood, but it was really only good to give a little more protection when parked. New tires and more experience improved the wet handling, but I still got in a few more of those torrential downpours. The first was the most memorable, however. It wasn't until I had a functional hood fitted early this summer that I got to experience actual rain driving. The hood at least keeps me more-or-less dry, although rain at very much of an angle will still leak through the weather seals at the top of the windows. Fortunately, the B also has the unprecedented luxury(at least for its 1962 design) of roll up windows as opposed to side curtains smile The heater might as well be optional on the B for all the good it does. The heater valve that was on the car when I bought it was stuck open, which unfortunately made for very uncomfortable driving on hot days-moving still forces air over the heater core and out the floor vents even with the blower off. Replacing the valve allowed me to to shut the heat off, but even on it still doesn't put out much when you want it. The 195º Tstat did help with that. I currently don't even have the cable hooked up to the heater valve(the cable is broken, and I haven't ventured behind the dash to replace it) so when I need the heater I have to manually open the valve. Opening it all the way(the stock set-up only opens it about halfway) does get some more heat flowing.
 

bunnspecial

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Originally Posted By: CATERHAM
Don't know why you've started a new thread when you could have continued with the last one below? http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3928126/1 The minimum oil temp's you want is about 180F. As has been suggested ditch the oil cooler. Run the lightest oil that allows you maintain 50 psi oil pressure at high rev's when the oil is fully hot.
I apologize for violating unspoken forum rules. In all honesty, I'd forgotten that my previous thread from 6 months ago ventured into discussions of oil temperature. Aside from that, on most of the fora of which I'm a member, it's considered poor etiquette to bump a 6 month old thread. I'll bear that in mind for the future. In any case, I appreciate the variety of helpful responses I've received here. I'm going to call my parts guy and see if he can point me toward the pipe for earlier engines that bypasses the oil cooler-I can't see it on the Moss website, and honestly I'd be happy to get rid of one point of failure. Assuming I can get it in time, it seems prudent to install while the engine is out. Also, in the time sense I've had reason to cast some doubt on my oil pressure gauge. When I get "a round tuit" I have a mechanical oil pressure gauge and all the correct fittings to install it. The mechanical Smith's oil pressure gauge is externally identical to the one I have now(aside, of course, from it having a compression fitting on the back for the oil pipe rather than a plug in for the sender). Also, being British Leyland, they never actually bothered to eliminate the tube routing for the mechanical gauge, something that was no doubt beneficial when they reverted to using it in '72. If I hadn't had bigger fish to fry on the car this weekend, it would have been a good time to do the job-I always end up looking like I had a fight with a cat any time I do any kind of gauge or other behind the dash work.
 
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I'd just cover the cooler...I remember the British trucks used to use a canvas cover over the grill, domed back for warmer weather. You should be able to find the non oil cooler pipes easily enough, 99.9% of B Blocks didn't use an oil cooler, it was only used on MG's...unless they used them on Morris Oxfords for desert use.
 

bunnspecial

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Originally Posted By: BrocLuno
Good plan. Even with the "new" thread (OK by me), you got a bunch of interest and responses. So all is good smile
I agree, this turned into a great thread. Thanks again for your input and everyone else's.
 
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