| Author | Message | ||
     Maximillian G. Tresmond, Esq. Yet to post message Username: maximillian Post Number: 1 Registered: 6-2017 |
Why did Rolls Royce/Bentley use wet liners on the 6.75 engine? Wet liners are typically found on large industrial diesels that are designed to be rebuilt multiple times. Is this engine designed to be rebuilt many times back to stock specifications like an industrial engine? | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 1454 Registered: 5-2015 |
Wet are used because the cooling system is more uniform. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2336 Registered: 6-2009 |
I can't say whether the original engineers designed with the idea of rebuilding the engine in mind, but given the history of the Rolls-Royce and Bentley marques by the time this engine was designed it was apparent that these cars stayed on the road far longer than most. I know of someone in the US RROC that has a 1970 (I think, it's early 70s at latest) Bentley T with over 500K on it that runs like a top and has been fully rebuilt at least once. Brian | ||
| Maximillian G. Tresmond, Esq. New User Username: maximillian Post Number: 2 Registered: 6-2017 |
500k? Really! They do make replacement liners, right? If that is the case, how could you ever wear the block out to the point where it couldn't be rebuilt? | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1719 Registered: 5-2012 |
The big enemies are cracks and corrosion. This is why regular coolant changes are so advisable. | ||
| Maximillian G. Tresmond, Esq. New User Username: maximillian Post Number: 3 Registered: 6-2017 |
Are cracks/corrosion inevitable? | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2339 Registered: 6-2009 |
Yes, 500K plus at last contact, which was in 2007. The car was (maybe still is) owned by Carlen Colgett and she and her husband, George Colgett, own and operate Acme Car Service in the San Francisco Bay Area. Mason's black and an absolutely lovely example. For a car of that vintage 500K is indeed something. The vehicles in my household, with the exception of the Rolls-Royces, are all in the 6-digit mileage range. My '96 Buick Roadmaster is just short of 210K and the 2001 GMC 2500HD is around 270K and neither has been rebuilt nor shows any indication of needing to be rebuilt. It astounds me how many people still persist in the belief that 100K miles is "very high mileage" and that a car is not long for this world after that magic figure is met. This has not been true for a very long period of time now and is an old-time belief that just won't die. Brian | ||
| John Beech Grand Master Username: jbeech Post Number: 404 Registered: 10-2016 |
And the nice thing about that belief, Brian, is that some very nice used cars come available for purchase at good prices. -- John, who is always happy when someone else absorbs the largest chunk of the depreciation in value. | ||
| Maximillian G. Tresmond, Esq. New User Username: maximillian Post Number: 5 Registered: 6-2017 |
Thank you for the information! We have a 1989 Bentley Turbo R used as a daily driver with 60k on it. We would like to keep it going - permanently, if possible. Looking to meet other people in the RR community. Do you have the LT1 in your Roadmaster? | ||
| richard george yeaman Grand Master Username: richyrich Post Number: 759 Registered: 4-2012 |
Maximillian welcome to the forum the turbo R is a great car I have a 1997 example in racing green what colour is yours and how long have you had it. Richard | ||
| Michael Carr Experienced User Username: carsie Post Number: 29 Registered: 7-2016 |
I was in P&A Woods recently admiring a Silver Shadow with over 220K miles on it; ran beautifully I was informed. I had a Sierra Cosworth in the early nineties. I used to leave the house in Oxford at 6.00am and cruise into London at a steady high speed and do the same in the evening, a round trip of some 150 miles every day. Regular Mobil 1 oil changes and an occasional set of Pirelli P Zero's + pads and that car ran a sweet on the day I sold it at 135k miles as the day I bought from the showroom.- the secret I believe is to let them warm up and cool down gently, use them..constantly and to service them well..they'll purr for miles and miles. I'm now on my 3rd Volvo, still have my XJR and my Shadow and leaving them dormant just does them no favours at all - warm them up and then run them hard for some time - does the power of good. p.s memory jog!...we're talking about the car here Gents ;) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2341 Registered: 6-2009 |
To answer the side question: Yes, my Roadmaster Estate Wagon does have the LT1 engine in it. It's a far more sprightly behemoth than most people could ever imagine and has power that is, in the terminology long used by Crewe, "adequate." Brian P.S. to John Beech: Amen to that observation regarding becoming the second or later custodian of any car that has been driven and maintained reasonably for the duration. You can get some real bargains. | ||
| christopher carnley Unregistered guest Posted From: 86.130.236.179 |
Rolls-Royce had to use wet liners as they were unable to found, ie cast, cylinder blocks in iron, as light as the ones in the USA.That is why the engines are all alum(i)nium alloy. As I understand the situation,cast iron and founding techniques in the USA are still superior to the UK. (Message approved by david_gore) | ||
| Jonas TRACHSEL Prolific User Username: jonas_trachsel Post Number: 136 Registered: 2-2005 |
Back to the initial question by Maximillian. Yes, Christopher is right: The reason to have wet liners is that you must have a harder surface to run your pistons on than aluminium. You probably could have dry liners instead of wet liners, but I do not know how they would react on warm up, as alu has a much higher expansion rate than iron. Dry liners could get loose in the alu block. With wet liners this expansion difference is taken up by the O-rings at the foot of the liners. A more modern method would be to place a liner of silizium cabide foam (or something like that, I do not remember the correct material used) in the mould when casting the alu block. The molten alu then will penetrate the much higher melting si-carbide foam liners and lock them in the block. The si-carbide then provides a very hard wearing surface for the piston. At rebuild time you need not rebore the cylinders, only replace the pistons. If I am not mistaken it was BMW that introduced this technique about 30 years ago. When developing the R-R V8 this technique was not yet available, therefore the wet liner technique adopted by R-R, a well proven technique at that time. | ||
| Mark Luft Frequent User Username: bentleyman1993 Post Number: 85 Registered: 10-2016 |
I believe it was Chevrolet that pioneered that process with the Vega. I had one of those smoking bastards in 1973. At that time, it was a failure. But BMW did get it right. | ||
| gordon le feuvre Prolific User Username: triumph Post Number: 195 Registered: 7-2012 |
I know this is away from original question, but I live on "tax haven" island. When Shadow came out in '65/66, we had loads of hydraulic issues with cars just sitting around not being used. I remember speaking with the Factory regarding "lack" of reliability and Shadow development and was told all the prototypes had covered more than 100,000 miles without issues. Point being, these cars are happiest being used. That said, I have a 30,000 mile '73 Fixedhead Corniche that I actually did the dealer inspection on, and it runs as the day it was delivered to us. Time warps my head! | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 1457 Registered: 5-2015 |
We on this site get to hear of engine problems with Shadows etc, but I suspect the truth is that providing the car is used a bit and serviced the engine will easily last 250k miles. The real problem is the cosmetics, due to cost this doesnt get done and the car just gets worse. | ||
| Ben Curtis Frequent User Username: burgundyben Post Number: 74 Registered: 12-2015 |
My car ended up in bits due to overheating, doubtless caused through a lack of correct maintenance. The two engines I stripped in the quest for one good rebuild, left me thinking that it'd be unusual to wear one out, but many will die due to insufficient changes of oil and coolant. |
