Author |
Message |
Geoff Wootton
Grand Master Username: dounraey
Post Number: 985 Registered: 5-2012
| Posted on Thursday, 15 October, 2015 - 08:15: | |
When starting my car from cold, I notice the engine is slightly noisy until it warms up. I'd put this down to a 40 year old engine that will need to be reconditioned at some time in the future. However, I was reading a contemporary article on a "new" RR Silver Shadow with just 30k miles on the clock in which it was stated "It is inaudible when idling; after the initial clatter of the hydraulic tappets has died down from a cold start." When my car starts from cold, I certainly don't get a "clatter of the hydraulic tappets", but it is noticeably noisier than when the engine has warmed up. Is this normal and to be expected on these older cars? Have any other owners found this? The article can be found here: http://www.motorsportmagazine.com/archive/article/may-1968/59/long-weekend-rolls-royce-silver-shadow Geoff |
Brian Vogel
Grand Master Username: guyslp
Post Number: 1703 Registered: 6-2009
| Posted on Thursday, 15 October, 2015 - 09:00: | |
Geoff, SRH33576 has always been "noisier" when cold started than after it warms up. My noises are mostly of a clicking/light tapping type. I have yet to be around a Shadow that's "inaudible when idling," particularly if you're outside the car. It is quite quiet inside the car. I've actually been shocked at how truly inaudible some of the pre-war cars are even when you're standing a couple of feet from them when they're running. Brian |
Robert Noel Reddington
Grand Master Username: bob_uk
Post Number: 603 Registered: 5-2015
| Posted on Thursday, 15 October, 2015 - 11:00: | |
The clatter is normal even on a new engine woth hydraulic tappets. When stationary valves will be open and the valve springs are pushing on the hydraulic tappets which because they have no oil pressure causes the tappits to drain. Once started and warm the clatter goes. Mine clatters for 2 mins then goes quiet and after 5 miles quieter still. Another source of cold noise is piston slap. The RR V8 does suffer only when cold. Mine has no slap that I can hear over the tappets. Again once warm it goes. I can just about hear the engine at idle once warm. Which doesn't take long. Noisy drive belts can be silenced with engine oil. |
Geoff Wootton
Grand Master Username: dounraey
Post Number: 986 Registered: 5-2012
| Posted on Thursday, 15 October, 2015 - 11:43: | |
Brian and Bob_uk Thanks for your replies. I'd kinda guessed that my car was ok, but it's nice to have it confirmed. The quietest engine I ever heard was a sleeve valve Daimler. It was astonishingly quiet. Standing by the side of it I just could not hear the engine running, much to the amusement of the owner, a friend of mine from the SP250 (Daimler Dart) club. I guess there is a little of the RR myth about how these cars glide along in complete silence, broken only by the ticking of the clock. Geoff |
michael vass
Experienced User Username: mikebentleyturbo2
Post Number: 40 Registered: 7-2015
| Posted on Thursday, 15 October, 2015 - 18:22: | |
Hi All I think these engines would be quieter without the enormous mechanical fan, has anybody replaced it with an electric one? Mike |
richard george yeaman
Grand Master Username: richyrich
Post Number: 372 Registered: 4-2012
| Posted on Thursday, 15 October, 2015 - 22:19: | |
There was a thread or two on fitting electric fans in these pages the main man in favour for fitting them was Michael Hicks (Bentleyman22) if I remember correctly there was a lot of opposition. I would be of the opinion that the use of an electric fan would be beneficial. (here we go again) |
Jean-Pierre 'JP' Hilbert
Prolific User Username: jphilbert
Post Number: 133 Registered: 9-2013
| Posted on Thursday, 15 October, 2015 - 22:24: | |
Noisy tappets: drain about one litre engine oil, add same amount of Dexron II (yes, the stuff for the gearbox and/or power steering), drive 1000 km, perform a complete oil change. Your tappets will be quiet! |
Robert Noel Reddington
Grand Master Username: bob_uk
Post Number: 607 Registered: 5-2015
| Posted on Friday, 16 October, 2015 - 05:43: | |
There are noises and there are other noises. Clattering tappets are not a nice noise but the whoosh of the fan is not loud or unpleasant. At idle the fan should be quiet because its not doing much work. However in certain hot regions .maybe an electric fan would be better. But do bear in mind when engines tend to overheat it usually means something is wrong not just the fan. The main reason for electric fans on cars is because the engine is traverse not north to south thus making an engine driven fan difficult. Peugeot 304 had a drive belt that went round corners. Weird but reliable. |
Geoff Wootton
Grand Master Username: dounraey
Post Number: 987 Registered: 5-2012
| Posted on Friday, 16 October, 2015 - 06:29: | |
However in certain hot regions .maybe an electric fan would be better. I've lived in a hot regions (Las Vegas and currently Tampa, Florida) and have never had a problem with overheating, other than when the viscous coupling on my car needed replacing. The cooling system on these cars is more than adequate. As for the sound, a lot of the time the fan is freewheeling anyway. When "engaged", I have never found the whoosh from it to be in any way intrusive. It seems to me fitting an electric fan would be an unnecessary expense for no gain. Geoff |
Randy Roberson
Grand Master Username: wascator
Post Number: 532 Registered: 5-2009
| Posted on Tuesday, 20 October, 2015 - 05:34: | |
I ran across an item this weekend, in which the writer discussed the merits of synthetic vs conventional oils. He stated that engines, especially used ones in Cars as ours with a few years on them, might be a little noiser and leak a little more with synthetics, even of the same viscosity, because of the synthetic's easier flowability. My is not as quiet as, say, the flathead V-8 in a 1940 Cadillac I heard this weekend; but it is reasonably quiet at idle for a modern V-8 with accessories all over, a huge fan, and a higher idle speed. the cooling system on the Silver Shadow is more than adequate for all conditions, IF it is in proper condition. Deterioration of cooling systems, including radiators and water pumps, not to mention fan clutches, is rampant amongst the collector car world and can be difficult for the hobbyist to find. |
Robert Noel Reddington
Grand Master Username: bob_uk
Post Number: 626 Registered: 5-2015
| Posted on Tuesday, 20 October, 2015 - 08:37: | |
Randy. Exactly right. Rolls-Royce tested the snot out of the shadow cooling system because they sell to any country like the Middle East and Australia. 40 years on the main culprits for overheating are the coupling the radiator and sediment in the system. The coupling can be drilled and refilled with Toyota coupling silicon. See Tee one topics. Electric fans are over rated at their ability to shift air. The Shadow fan at hot idle moves a fair amount of air and as soon as the revs pick up even more. The coupling stops the fan from going too fast and consuming too much power and damaging the drive belts. Some think that 90c is hot. Well it ain't boiling so not too hot. Sythentic Oil. Leaking has been the main complaint about synthetics. The main comment is its like water. Its as if the gaskets on the engine can't hold back water which is plainly wrong. Myths about engine oil are numerous. However some oils are good at cleaning the engine out. And maybe the sludge was stopping the leaks. The same varnish and crude around the pistons and rins could also be cleaned off and results are piston slap and oil smoke. My advice is that if the engine is in good condition with healthy compression and runs like a sowing machine then fit synthetic. If the engine is a dog which should be put down by the Vet then use mineral oil with low detergent and never flush and keep fingers crossed. When new synthetic and mineral oil are about equal in performance. As miles build the mineral oil gets thinner. Synthetic stay the same until next oil change. I use Mobil 1 stuff. Its a waste really because I change at 6000 and a modern mineral oil like GTX will easily do 6000. Semi synthetic is a good compromise. 6000 miles is subject to conditions of use though. All turbos use only synthetic. My car is 41 years old and minerals oils contemporary to 1974 are not as good as modern minerals. Modern GTX isn't the same as the original GTX. Castrol have vastly improved the oil. The same with other oil companies. Check bob the oil guy on the web. He explains the details. |