oil thermostat

[Pluscat]

Hi guys,

Just did a splendit run over my beloved winding road in my XI. Back home I discoverd an oilleak. It was the oilthermostat (again).
The thermostat is a separate unit which is placed in the oillines to the oilcooler.
My XI has an A-series engine. An adapter is bolted in the oilfilterholder from which oillines go to the thermostat and from there to the oilcooler.

I know there is also an adapter on the market with an internal thermostat. But I can't find it on the internet.....
Anyone knows where to find such an adapter?

[erictharg]

Personally I reckon oil thermostat's are more trouble than they are worth. They are a potential for leaks (as you've found out) and are not usually fail safe. It's not as if we start our engines from cold and thrash them straight away. Ditch the thermostat and run a good synthetic oil (that still has an SAE50 weight when hot) and the oil will be nice and thin from cold anyway. In fact on a road car you could run synthetic oil and probably ditch the oil cooler too, assuming you had decent cooling for the water side of things.

[Westfield 129]

I agree. Get rid of the thermostat.

Here in Sunny California, I would never get rid of the oil cooler, but I don't worry about oil temp, as it seems to warm quickly enough.

In colder climes, you can just block the oil cooler.

I do disagree about the oil weight. Flow is what lubricates the engine, and I use 20/50 dinosaur based Valvoline Racing, but 10/40 also works just fine, as does 10/30. I have yet to put synthetics into my A series, instead relying on the ZDP enriched racing oils. So far, I have yet to wear out an engine (or even grind a crank) on that stuff, and the cams do just fine.

[Pluscat]

Got rid of the thermostat and bought new hoses, a quick fix.
Did another splendit fast run, reving up to 7500 rpm: no oilleaks....
The oiltemp did rise to OK level.
I use a 20W60 Classic,(20W50 is no longer available) and it works well.

[erictharg]

Jan - agreed you need flow. And also viscosity. That's why a 5W-50 synthetic is better than a 20W-50 mineral oil. It stay in range over a wider temp band, for longer. And as a racing oil it also has the usual selection of additives you'd expect. Plus only needs changing once per season...and at £25 for 5 litres of the Total Quartz Racing oil, as its subsidised for the Formula Renault guys, why wouldn't you?
I've heard all the nay sayers telling you shouldn't use synthetic in an A Series but never any facts. Omega recommend synthectics unreservedly for longevity of their pistons.

[adamwilkinson]

We run fully synthetic too, Millers

[jonclancy]

erictharg wrote:
> ...and at £25 for 5 litres of the Total Quartz Racing oil, as its
> subsidised for the Formula Renault guys, why wouldn't you?

Is this oil readily available please, Charles?

[Westfield 129]

The best thing to run in the A series with the flat tappets is an oil that contains ZDDP. You can run synthetics, but there is no advantage, other than higher cost.

Viscosity is highly overrated, as F1 engines run 10w oil, and most of the NASCAR engines run nothing thicker than 20W.

I have run Valvoline in my road engines, the most mileage accumulated beint 350,000 miles on my Alfa. The crank was removed for the rebuild (it was using a quart/1000 miles at that mileage) and found to be at normal tolerances. It was polished and balanced, then reinstalled into the new 1750 race engine with standard sized bearings. While the cylinder walls showed minor wear, there was nothing that demanded using a synthetic oil, and no excessive wear, anywhere.

My Mercedes C280 has had a strict diet of dinosaur oil as well. Only 117,000 miles, but no oil consumption at all. I don't run synthetic in it as it takes 9 quarts per change, which is about $100 USD. Mineral oil costs about half, or less. Since the engine is doing quite well, thank you... I will continue to use the same Valvoline race oils that I have used in this engine for the last 18 years.

My Mustang's 5 liter V8 had over 8000 track miles and 120,000 miles total. It never did burn anymore than a pint/1000, and is still circulating race tracks on our East Coast. It ran on Mobil 1 15/50 Racing, which I received for free as part of the sponsorship deal. While this speaks well for the Mobil 1, the engine would have lasted on any oil that I would have chosen.

My Renault R5Turbo 2 uses synthetic, but only after the first 10 years of ownership. Synthetics do save turbos, and make them last much longer, provided that the turbo is not abused during engine shut down. The turbo is still working fine after 28 years, a tribute to the two minute spool down time I always adhere to prior to shutting down the engine.

The fact is that if you change the oil regularly, and don't abuse the engine while the oil is warming, the engine may last indefinitely. My own 1380 has over 18,000 miles on it, and still burns the same pint per 1000 as it always has. That engine, in all the time it was in existence, ran on mineral oil. When I went to rebuild it to 1380, the crank was fine. Journal finish was at standard specs, as were the measurements. I had the journals polished, the crank balance and the oiling improved, then put it back into the block with standard sized bearings.

While there are good reasons to use Synthetic Oils, longevity of our little A series engines is not really one of them, nor is "reduced wear". If you want reduced wear, change the oil regularly, and take it easy on start up and warming up.

I have been screwing around with this stuff for about 46 years, and have yet to have an engine expire due to failure of the oil. I have yet to have an engine that needed anything more than polishing of the crank journals prior to rebuild. Have you actually seen a lubrication failure that didn't follow some massive failure immediately prior?

While I do use synthetics on all of the new cars (especially with the extended oil changes) and in my turbo car, I find that in the old ones, the dinosaur oil works just fine.

[erictharg]

Jon - call Fluids in Motorsport, or check out their website. You will see the Total Quartz. They have a lot of other suitable oils, including the Miller that Adam runs. But the Total wins it on price. As Jan so eloquently points out, the A Series is not that fussy as long as it's a 50 weight or better oil when hot. Mineral oil is absolutely fine, but you'll need to change it more often.
The fact that F1 engines use thin oils has no relevance to our engines! Quite a different world. Different materials & coatings, different tolerances, different application.

[Westfield 129]

No, not exactly. The stresses on an F1 engine are far higher than anything that even a racing A series might meet, but the A will work fine on 30W, and may not even need an oil cooler in most instances. I would still run a multi viscosity with a 40 or 50 rating, but the reality is that it is overkill, and it may very well be possible that better lubrication can be had with a 30w. The trend, even in racing, is to run lighter oils.

It might even make more power with lighter oil.