I use a very good quality 10/50 (semi-competition) oil in my tuned '126'engine, and have had no problems with it. I will however concede that you 'enjoy' hotter temperatures, so yes, a 15/50 might be a better choice.
I think 10w30 is very thin but since you have it maybe you can mix it with the thicker one like 2:1 or less until you finish it. 15w40 for your case sounds better.
That also sounds very strange to me! I appreciate that oil quality and performance has improved massively over the last few years, but the recommendation for the '126' engine is a 15/40---so yes. a 10/30 sounds somewhat thin
yeah, it is a specific "classic" oil, targeted at old timers, but im still a bit hesitant...
Just to advise you---mixing different viscosity oils does NOT give you an oil "in-between"! Personally, I would look for a high quality 10/50 oil. Remember, oil is the life-blood of an engine, and even expensive oil is a LOT cheaper than a 'goosed' engine!
I used that for a while but now buy the cheaper and more easily obtainable Mobil 1, 4T Racing 15W50. I've said this before; being designed for motorcycle engines with wet clutches, it has more of the traditional, slippery lubricant additives and omits the modern compounds that replaced them.
I was advised many years ago that ALL oil, whether it is 'synthetic' or 'mineral' starts as "the black stuff in the ground". Modern 'synthetic' oil is so much better than 'old fashioned oil' that a classic competition engine can expect to gain up to 10% in power purely by going to a modern 'competition' oil. What make of oil can you obtain in The Netherlands? can you get Castrol, Morris, Valvoline? Let us know and we can then guide you in the right direction.
Valvoline, some store brands for the less exotic stuff, Kroon, Castrol, Liquimoli, eurol are some brands i can find easily.
Castrol do a 10/50 high performance oil, as do Valvoline. If you have a car accesory shop nearby, they should be able to supply these oils. If you get the opportunity, try and fit one of the aluminium 3-1/2 litre sumps---they definately help the engine to run cooler (more oil in sump). You won't need to change the dipstick--just use the original/standard dipstick.
Yes, the gearboxlevel/re-fillplug can be a bugger to undo. I have found the best way is to use a short 1/2in drive extension THE WRONG WAY ROUND (i.e put the 'female' over the plug) and then use a suitable socket and bar on the 'male' end of the extension. If your gearbox needs oil, the location of the plug makes it difficult to refill---the answer is to get a length of clear plastic tubing, small enough to just go into the 'level-plug-hole' and long enough to come up into the engine bay. Put a small funnel into the end of the tube in the engine bay and fill the gearbox through the tube. When oil starts coming back out of the level-plug hole, the gearbox oil level is correct. If you have a 126 gearbox in your car, a good quality 20/50 oil can be usedyeah, a 3.5L alu sump is deffinitely on the cards for later on, i also plan on getting exhaust wrap on the pipes from the head to the muffler, keep as much heat out of the engine bay and all.
Those are plans for later on though, it has been sat for 4 years, so just swapped the rear brake cylinders, have a pair of driveshaft boots to put on, and am currently struggling with the gearbox fill plug, it is some weird non standard thing (sliiiightly bigger then a 1/2" socket drive) and my 500 Nm impact has only succeeded in rounding the top of it off a bit.
Just took it for a 5 mile testrun, brakes take a bit long to engage, handbrake is useless, indicators arent home, alignment feels a tad sketchy, but the engine runs smoothly and its tons of fun, like a go-kart for big boys
You probably all ready know but caster and mineral oils don't mix, so a good flush and maybe some more advice from someone more clued up than me, as my knowledge was related to racing karts in the early1970s when using Castrol R oil.
One thing to keep in mind. Modern "fancy" oils typically dont have the zinc protection of a oil designed for a "classic" car specifically. What do i mean about this over the years, modern oils have gone away from zinc as the high pressure wear additive, and unfortunately modern oils still do not give the protection that flat tappet cams neat (our cars included).
Now you might ask why zinc was eliminated?. Simply "catalytic converters", as cats have become popular in all cars starting in the 80, with their performance and longevity improving over the years, they have become super sensitive to specific chemical exposures. Zinc being one of them, zinc in the oil can "poison" a catalytic converter and destroy them. Thus oil manufactures have cut down or completely remove zinc as one of the major wear additives in modern oils; that is unless you buy an oil specific for classic/high zinc use. Unfortunately like i mentioned above, the replacement wear additives have yet to meet the wear performance that zinc provided, with that said modern engines are designed with different geometry/contact faces especially on the high pressure contact points on the camshaft/lifters that modern low/no zinc oils perform properly.
Just run a regular quality 20/50 oil (the 2nd number is the most important as that's the at temp operating viscosity spec), and just add a zinc additive to the oil and you should be good to go.
Our cars have flat tappet cams, and they need high zinc oils to survive. I really wish there was a way to run roller lifters in our cars
As far as oil pressure goes. Ive installed a pressure and temp sender in my car and have been observing temp/pressure with 20/50 oil. on start up, the car gets darn near instant 65+psi of pressure (seems to be what the factory pressure relief is). and with oil temps in the 100c on a hot summer day, running pressure is around 50psi, with idle pressure being at around 15-20psi at full operating temp. So high temp viscosity is important.
