which oil

[doctee]

Hi All,
         I have just completed 5,000 miles on my rebuilt engine. I would like to start using a synthetic oil. Can anyone recommend one or is it better to keep using the Penrite 20/50 oil.
regards
doctee

[Mark Hammond]

These engines wern't designed to run on synthetic oils, I'd stick with 20/50 oil.

Mark

[heralddolly]

Hello Doctee.

Give the synthetics a complete swerve !! Mark is spot on.

I've used Millers Classic 20/50 for years in my Sunbeam Alpines and have never had a problem. I will also be using the oil in my newly acquired Vitesse Mk1 2LTR.

It's a  VERY GOOD / EXCELLENT quality mineral oil but incorporates modern cleaning agents so it suits 99% of all classic cars - unless yours is a raging bull with mega bhp / turbo etc !! ?? !!

Stockists are not plentiful, but worth driving those extra few miles to obtain.

It comes in 5LTR containers (bonus !!) and usual price is about £21.

I always change the oil & filter every 3K.

Hope that helps  ??

Thanks.

Richard.

[lordleonusa]

Note that these engines were also not designed to run with oils low is ZDDP.

If the oil you select has an API marking of SL or SM, then there will be insufficient ZDDP in it to protect your cam followers and other parts of your overhead valve engine.

Leon

[herald948]

http://www.canleyclassics.com/?xhtml=xhtml/infodatabase/oil.html&xsl=infodatabase.xsl ...FWIW!

[Slimboyfat]

That snippet of info was written up by John Kipping many years ago (20 plus) and simply copied across to our website from the old paper catalogues.

Advice is still good though, and I'm still using Mobil 1 when I can afford it! When I'm feeling less generous to my old motors I have found Halfords fully synthetic an excellent product. A couple of engines in particular have had spectacular life enhancement as a result. Our Chicane (2.5) is well on the way to half a million kilometers, and Ive never even had the head off.

I wouldn't use anything else other than a synthetic in Triumph's longer stroke engines, in particular 1500's. They seem particularly prone to chucking number three rod as a result of oil film break down on the bearing surface. I know there are other contributing factors to this phenomenon, but many years ago JK found that one cure was a decent quality synthetic (Mobil 1) and subsequently we never had this problem again with the 'works' Heralds.

[Paudman]

I ran religiously on Castrol GTX for twenty years, never used anything else, and it was only this year I tried a semi-synthetic for the first time. I've noticed that the pressure varies quite a bit - Castrol seemed much thicker and pressure on the gauge was higher; it's more inclined to drop lower with the semi-synthetic, especially at idle. I'm keeping a close eye on it to see how things go but at the moment it's running very well.

[Slimboyfat]

I used GTX when I was a lad for no other reason than having copied my Dad and his oil buying habits.

I found that after a long run down a motorway GTX would loose it's viscosity when returning to normal roads. It never seemed to recover after this sort of treatment either so regular changes were the order of the day back then.

Synthetics don't suffer this problem in my experiance.

[mikew]

Slimboyfat wrote:

Synthetics don't suffer this problem in my experiance.

Agreed, I have used fully synthetic in my Stag since the engine rebuild 6 years ago, and 25k miles later there's no noticeable difference in oil pressure from the values I got after running in on a cheap oil (save the bores getting glazed), but with pushrod engines check the synthetic oil has enough ZDP (zinc addative) to prevent cam and follower wear. I think Millers do a synthetic for classics now.

The Stag has managed several 8 hour thrashes to the south of France and back at French Motorway speeds and 35 degrees centigrade temperatures, with no difference in oil pressure before during and after the run, although I do tend to find it weeps past some of the seals more easily than a conventional oil

mike

[CharlieB]

Slimboyfat wrote:

I'm still using Mobil 1 when I can afford it! When I'm feeling less generous to my old motors I have found Halfords fully synthetic an excellent product. A couple of engines in particular have had spectacular life enhancement as a result. Our Chicane (2.5) is well on the way to half a million kilometers, and Ive never even had the head off.

So in your experience there's no need to worry about the often talked about lack ZDDP in modern oils?
What viscosity do you use, does it matter much?

[esxefi]

gotta give my car an oil change before clm and i'm toying with using mobil now,probably go for the 15w50 grade i found,same hot grade as mineral oil recomended by triumph.

i think i have millers semi synthetic in at the moment and yesterday my idle pressure went down to 10-15psi after a good blast in the heat. :-/

[herald948]

CharlieB wrote:

So in your experience there's no need to worry about the often talked about lack ZDDP in modern oils?
What viscosity do you use, does it matter much?

I've been wondering about this myself...thinking it might end up being a bit like the whole unleaded fuel thing. So far, over 35,000 not-too-gentle miles on an original 1147cc Herald engine has convinced me there's no problem at all with using unleaded. My experience so far with the lower levels of ZDDP in either Castrol GTX or GTX High-Mileage (usually 20W-50) has given me no cause for worry, either! But we'll see....

[lordleonusa]

Actually Castrol GTX High Mileage 20W/50 mineral oil is a good choice over the normal GTX as it does contain higher levels of ZDDP.

This is the link to the best information about oils I have found on the web:

http://www.lnengineering.com/oil.html

L

[Slimboyfat]

CharlieB wrote:

So in your experience there's no need to worry about the often talked about lack ZDDP in modern oils?
What viscosity do you use, does it matter much?

I wasn't worried until someone gave me something to worry about!

My experience is limited to the two oil's I mentioned over a twenty year period, and many hundreds of thousands of miles in a wide range of Triumph engines. Take that as you would, it's just my experiance, may contain nuts.

I have always tried to use 5W-40.

[thescrapman]

esxefi wrote:

i think i have millers semi synthetic in at the moment and yesterday my idle pressure went down to 10-15psi after a good blast in the heat. :-/

I don't see that as a problem, 15psi at idle with very hot oil is OK.

As long as it climbs rapidly and you have full pressure by about 2000rpm, not an issue.

If like me you get the 10-15psi at 2000rpm , and still have it at 3000rpm you have a big problem.... :-(

Cheers

Colin

[sparky_spit]

I've been using Millers Classic Sport, a semi-synthetic 20/50, on the recommendation of a few fellow CT'ers and found it very good. In hot weather and extreme use (Spain/Andorra to Beziers on last year's 10CR) I was dropping to quite a bit less than 20psi on idle, but it soon recovered once the revs got up. When very hot, the oil still looks very viscous on the dipstick, whereas I believe a mineral oil would have looked like water under the same circumstances.

When hot, the oil has an odd characteristic which mineral oil does not; it looks and feels as though it has "skin" on it and feels a bit like "runny silicone" - difficult to explain but if you see it/feel it you will understand what I mean. Certainly different, and better, than my experiences with mineral oils (admittedly much cheaper ones..) in the past under very hot conditions.

[Tim Bancroft]

On the recommendation of Dale B I have been using VALVOLINE VR1 MOTOR RACING OIL SAE 20W50 5LTR for sometime and have found it to be perfect for use in my old cars.

Lovely stuff.

Can be found on e-bay for £23 for 5L.

Just been trying Miller 20/50, not so impressed.

[andy thompson]

Recently changed from Mobil 1 to Penrite HPR30 which is 20W/60 and fortified in ZDDP. It certainly is less prone to leaks.

Change it every 6months ( or 1000miles in my Race car anyway )

I think my Stag still has Mobil 1 in it - they are a bit more leakproof

http://www.penriteoil.com/uk/nextpage.php?navlink=products

[doctee]

Hi,
     Thanks for the swift replies. I used to work on Triumph motorcycle in the mid 90's and Triumph told us we had to put Mobill 1 in from new which we did and the bikes started to burn oil, Triumph later revised this and told us to put Mobil 1 in after the bikes had covered 5,000 miles as the oil was that good it wouldn't allow the pistons to bed in with the bores,
So I will probable go with Mobil 1.
Thanks for the info, by the way my oil pressure reads 70 psi at tickover rising to about 90 psi on the motorway at 70 mph does this sound right as I bought the smiths gauge second hand. the engine was a rebuilt unit from "Jigsaw" and covered just over 5,000 miles.
regards Doctee

[heralddolly]

That sounds a tad too high on both counts to me  :o!!

Taking away any possible blockage, 2x obvious points are: gauge could be defective or the oil pressure relief valve may be not working properly.

I would expect about 15 / 20psi @ tickover and between 50 / 60 on a run; especially as your engine only has 5K under its belt.

I think you need to check the pressure with a known accurate gauge and would be worth cleaning the relief valve and reseating it. Any doubts, get a new one.

Cheers.

Richard.

[esxefi]

agree,

not to mention wasting power creating that much pressure,also too high a pressure causes the oil to heat up quicker because of the friction and will put undue stress on the shear pin in the dog drive. :-/