Which engine oil
Discussion
Hi,I thinking of changing the engine oil,the last owner said he used Castrol GTX.I thought I might try castrol 15/40 Magnatec,but wondered if this was any good and what more experienced people was using.I don't realy want to use fully synthectic oil as its to expensive for me.thanks Ken.
Check out this thread - v.long.
The consensus on the RV8 seems to be synthetic, high detergent, and fairly thick because of the type of oil pump - works on volume not pressure, and a thicker oil is easier for it to pump. Something like 10 or 15 / 40 or 50 is good. Having said that, I used Mobil 1 5-50 in the 400 for years without problems, although have now switched to Motul 300V 15/50- cheaper than Mobil 1 Motorsport (£25 4L by mail).
www.pistonheads.com/gassing/topic.asp?t=124184&f=13&h=0&hw=opieoilman
The consensus on the RV8 seems to be synthetic, high detergent, and fairly thick because of the type of oil pump - works on volume not pressure, and a thicker oil is easier for it to pump. Something like 10 or 15 / 40 or 50 is good. Having said that, I used Mobil 1 5-50 in the 400 for years without problems, although have now switched to Motul 300V 15/50- cheaper than Mobil 1 Motorsport (£25 4L by mail).
www.pistonheads.com/gassing/topic.asp?t=124184&f=13&h=0&hw=opieoilman
I have just changed the oil on mine and used Castrol Magnatec 15W40 for a few reasons as follows.
Seen too many people say that oil pressure was too low (even to the point of the red pressure warning light being on at idle) using 0Wwhatever.
Remember reading somewhere that the RV8 actually prefers a thicker oil.
Cost - Magnatec's $17/5l as opposed to $65 for Mobil 1 ($2.5 = 1GBP) allows me to change more often, use an oil flush and new filter each time and still some change to go down the pub.
With the climate here the W rating is academical anyway apart from the first two minutes from cold.
Have used Magnatec on other cars and it seems to work well as they are much quieter on start up and pressure builds quicker. Must be to do with some of it sticking and not draining into the sump. As I had been told the ticking / knocking that could be heard from mine was a liner I also wanted to see what effect magnatec would have and it has reduced the noise by 90%. Not sure what this tells me but I am leaning towards the ticking (I can't hear it knocking) being associated with the solid lifters.
Of course the above may be a load of b*@#~ks and I should be sticking Mobil 1 in but I'll take my chances (always wondered what good a fully synth lo visc oil would do in an 50000 mile 1989 engine that's run on 20W50 mineral oil all it's life anyway - is there an expert here who can sell some Mobil shares ?).
Just as an aside they are now selling oil designed for large bore street or competition engines here - not sure whether it's in the UK but it's a 25W75. There's also Castrol racing - "specially designed to aid cooling and friction in high revving engines" with a 10W60 but at $75/5l it's a bit pricey and not sure you would call the RV8 high revving.
Seen too many people say that oil pressure was too low (even to the point of the red pressure warning light being on at idle) using 0Wwhatever.
Remember reading somewhere that the RV8 actually prefers a thicker oil.
Cost - Magnatec's $17/5l as opposed to $65 for Mobil 1 ($2.5 = 1GBP) allows me to change more often, use an oil flush and new filter each time and still some change to go down the pub.
With the climate here the W rating is academical anyway apart from the first two minutes from cold.
Have used Magnatec on other cars and it seems to work well as they are much quieter on start up and pressure builds quicker. Must be to do with some of it sticking and not draining into the sump. As I had been told the ticking / knocking that could be heard from mine was a liner I also wanted to see what effect magnatec would have and it has reduced the noise by 90%. Not sure what this tells me but I am leaning towards the ticking (I can't hear it knocking) being associated with the solid lifters.
Of course the above may be a load of b*@#~ks and I should be sticking Mobil 1 in but I'll take my chances (always wondered what good a fully synth lo visc oil would do in an 50000 mile 1989 engine that's run on 20W50 mineral oil all it's life anyway - is there an expert here who can sell some Mobil shares ?).
Just as an aside they are now selling oil designed for large bore street or competition engines here - not sure whether it's in the UK but it's a 25W75. There's also Castrol racing - "specially designed to aid cooling and friction in high revving engines" with a 10W60 but at $75/5l it's a bit pricey and not sure you would call the RV8 high revving.
Don't you get a little more power (maybe about 5%) running a thinner oil than a standard 20-50? Though there might be a slight depression in oil pressure at lower revs. I would have thought that an oil pump would find it harder to pump a thicker oil.
Hmm - just thinking about it again, wouldn't the viscosity characteristics change with use over time and remperature?
>> Edited by firefox1712 on Wednesday 16th February 11:12
Hmm - just thinking about it again, wouldn't the viscosity characteristics change with use over time and remperature?
>> Edited by firefox1712 on Wednesday 16th February 11:12
firefox1712 said:
Don't you get a little more power (maybe about 5%) running a thinner oil than a standard 20-50?
Swings and roundabouts. The thinner oil will give less hydrodynamic friction but will put more areas into boundary lubrication, with higher friction and higher wear. What power you gain in one area could be lost in the other. I'm not sure about power improvements, although I would doubt you'd get more than 1 percent. Data from the industry shows moving from a 15W40 non friction modified oil to a 5W20 non friction modified will get you about 2.5% better fuel economy. So, not a lot, and 5W20 is as thin a Fosters lager !
chunder said:
I have just changed the oil on mine and used Castrol Magnatec 15W40 for a few reasons as follows.
I took my 1989 TVR 400 SE down to Mark Adams to get the engine set up properly on a rollong road. Without going into the gory and expensive details, both Mark and the guys who ran the rolling road said that the RV8 and Magnetec should never meet.
It is to thin and I was recommended to change to Castrol RS, 10-60 I think. As this is now difficult to get hold of I use Valvoline Racing 20-50.
Kenneth.
KJR said:
I have just changed the oil on mine and used Castrol Magnatec 15W40 for a few reasons as follows.
I took my 1989 TVR 400 SE down to Mark Adams to get the engine set up properly on a rollong road. Without going into the gory and expensive details, both Mark and the guys who ran the rolling road said that the RV8 and Magnetec should never meet.
It is to thin and I was recommended to change to Castrol RS, 10-60 I think. As this is now difficult to get hold of I use Valvoline Racing 20-50.
Kenneth.
If Magnatec's too thin at 15W40 then what about Mobil 1 and other lo visc synths - oils of choice for many RV8 owners and recommended by many specialists !
I especially wanted to see what Magnatec would do for the knocking noise otherwise I would have used a 20/50 or 60.
Also goes to show the difference in advice you can get on this subject. Your RR said Magnatec and RV8 shouldn't meet yet two months ago (in Sprint I think) you have the guys at TVR Power saying the biggest engine killer is high revs before warming up the oil. Surely then an oil that provides a magnetised coating to protect at start up should be embraced.
IMHO the more expensive synths are a waste of money on all bar highly developed low tolerance turbo screamers. Otherwise a decent 20/50 (Castrol GTX, GTX 2) changed every 3000 or less is both better for the engine and cheaper.
jmorgan said:
Bob, anyone? Question.
"biggest engine killer is high revs before warming up the oil."
I thought it was also to warm up the components to operating tollerance not just the oil?
I never go above 2000 rpm until warm.
I'm no expert at all but I imagine yes also to warm up internals. I also take it easy until hot which means that the W viscocity rating for any oil is pretty immaterial anyway. Why pay more for a 0W40 over a 15W40 when the only time the engine is stressed the oil will be at the 40 rating.
Maybe someone who knows what they're talking about can add to this.
Fully synthetic is better at coping with the higher temps that TVR's experience. Minerals are cheaper but sludge quicker and need changing frequently. Apart from that every story that says using such and such will prevent the engine from dissolving also has an equivalent my engine turned to jelly using such and such.... There I've said it. Got to go hide from the oil police now 
Most important things are not to rev when cold and check the oil frequently.
Steve
www.tvrbooks.co.uk
Most important things are not to rev when cold and check the oil frequently.
Steve
www.tvrbooks.co.uk
Just to add my 2p worth. If you are doing a low mileage (unless track days) then you may as well use mineral, or semi-synthetic and change it at regular time intervals. I have run several vehicles with RV8 engines and never had a mechanical problem. I followed the two rules below:
Don't thrash it until properly warm
Change the oil every 3,000 miles.
Highest miles I have personally seen on a RV8 was 247,000 in a R/Rover used to tow a car trailer for it's living. It had one top end overhaul at 180,000 and was run on mineral 20/50 (GTX) changed every 3,000 miles.
Don't thrash it until properly warm
Change the oil every 3,000 miles.
Highest miles I have personally seen on a RV8 was 247,000 in a R/Rover used to tow a car trailer for it's living. It had one top end overhaul at 180,000 and was run on mineral 20/50 (GTX) changed every 3,000 miles.
Anything below 15W is probably a bit thin for the pre-serp. RV8 (not sure how the later cars deal with thinner oils as the pump is different). Ignoring the years that the factory / dealers pushed Mobil 1, for which I'm sure there were conmmercial reasons, the only advantage of a thinner oil is that it will circluate that much quicker when cold. Unless you do your motoring in sub-zero temps., this is pretty much irrelevant, and if you do, then a pre-heater would be a worthwhile investment. Some of the Wedges had factory/dealer windscreen stickers advisng that 2,500 rpm should not be exceeded until the engine was warm, to help avoid cold start wear problems.
Interesting opinions, perhaps these may help or dare I say add to the confusion 
www.pistonheads.com/gassing/topic.asp?t=123654&f=66&h=0
www.pistonheads.com/gassing/topic.asp?t=121715&f=23&h=0&hw=Oil
www.pistonheads.com/gassing/topic.asp?t=123654&f=66&h=0
www.pistonheads.com/gassing/topic.asp?t=121715&f=23&h=0&hw=Oil
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