| Author | Message | ||
     Martin Cutler Frequent User Username: martin Post Number: 20 Registered: 10-2004 |
Great website Ashley! One question, did the 4.5 litre engines suffer from the bore wear issue as well as the 4 1/4 litre engines? I keep mine to 60 mph, but am not sure if this is a problem for my big bore Mk VI. Thanks Marty | ||
| Ashley James Unregistered guest Posted From: 84.92.55.251 |
They all had the short liners till the arrival of the S1, hence they all suffer with the problems. I have seen engines where broken rings have damaged four cylinders. I think people kept on replacing pistons but not addressing the real problem. Both my cars have full length liners and Norman's 3.424 to 1 rear axles so I can cruise at about 70 Incidentally I have fitted a slightly modified version of the R type Continental exhaust to my 4.25L car and its performance is indistinguishable from the 4.5L but I've managed to find a Continental head for the bigger engine to redress the balance! | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 516 Registered: 4-2003 |
Ashley, That is indeed a fine site. It may be of note that most, if not all, Australian-delivered MkVI and R-Type cars have the 12/41 rear axle. They also have stiffer springs, dual foglamps, heavy export bumpers, oil bath air cleaners, high speed fans and more. Almost all cars had automatic transmission from its introduction as an option on the Home market. You would be hard pressed to find a motor with short liners as the word was out by 1960. I think that the harsher usage and comparatively higher value at the time downunder meant that most cars were overhauled early by UK standards. We were always shocked at the comparatively low resale prices in the UK until the 1980s, and many R-R/B cars, MkVI to Silver Shadow alike, were imported secondhand. Nowadays, many of the best examples are being re-exported to the UK and fetching premium prices. Silver Dawns, originally export-only, are also less rare in Australia. There should be no practical limit to the cruising speeds of these cars. The legal limit of 110km/h (69mph) is a breeze. On high demand, they only shift to top gear at that speed with automatic transmission (third is 1.45:1). With manual transmission, they are good for 75mph at less than the 4250RPM limit in third (1.34:1) as the third gear is taller; with a close-coupled transmission they will wind out further to around 83mph in third (1.22:1). As a student, I drove Sydney-Canberra (300km each way) most weekends in my R-Type Automatic at speeds far above these before the radars were so prolific. I had only one very nasty speeding ticket. I won't admit to the speed at which I was clocked for 10 km by an unmarked police car along Lake George, but I only kept my driver's licence and avoided a court hearing because I have a driving licence and registration from another state. The cop was also cranky because I was wearing thongs. Today I would be gaoled. A 4 1/4 or 4 1/2 with full length liners is unbreakable, as of course are the S1 and Continental 4.9s. My car had done over 400,000 miles by 1992 and never suffered decent use. Sadly, it is mostly parked since then, but I shall drive it next weekend when I next visit Canberra. I pulled a few of the last remaining motors with Brichrome inserts down in the 1970s and 1980s, my own included. In every single case, at least the top rings were broken. Needless to say, the first step was to fit full-length liners. The attraction of whipping off the head and sump, a quick hone, and bunging in new pistons was unfortunately compelling to many, especially on a car for sale. I hope that the present value of the cars entices people to do a proper full-length insert job as you have. | ||
| John Dare Frequent User Username: jgdare Post Number: 23 Registered: 12-2004 |
Full length liners or not, I will go with Martin C and keep my J.Vawser rebuilt engine at around 100/110kph (in top)in deference to these patrician and noble cars which in my opinion have ALWAYS deserved to be treated with respect and driven with some degree of aplomb. Speed limits aside, I am never tempted, nor do I encourage other owners to "see" what these older cars, will, or should, "do" in each gear. As Ashley points out in his web, you need to drive according to conditions leaving more than the usual space behind those in front, being mindful of stopping distances, manoeuvrability and general handling of a 50 y.o motor car. After all, what R-R/B owner ever is (or was) in a genuine life or death "hurry"?. If however, I feel a sudden rev.or "speed need" coming on, I start out in the 911S or the Eaton (force fed) Ranger. Even the Shadow is driven sedately lest I be viewed as putting on a show (of my driving "abilities") or worse, as a person in possession of a stolen car! | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 518 Registered: 4-2003 |
I agree. Sedate driving is always advisable. At 3750 RPM, this is easy cruising. It can do 4,500rpm in top mind you. 270 klicks are quite comfortable thank you.  | ||
| Martin Cutler Frequent User Username: martin Post Number: 21 Registered: 10-2004 |
Hi Guys, My car was home market big bore Mk VI, driven in England, (and rust out), then shipped to Signapore, then shipped to Sydney. When the chassis was too rusty to drive, the original owner sold it to the second owner who pulled it apart, and did some of the restoration, and then I came along and put it back together. The car had 99,000 miles on it, I have done another 15,000, and I have no service records for the first 99,000 miles. I can then only assume that no work has ever been done to my engine. On a brighter note, the filter in the top radiator hose is working well, collecting a fair amount of crud out of the system. Marty | ||
| Michael Unregistered guest Posted From: 80.219.133.144 |
An R-R/B looking ponderous is not a happy sight. | ||
| David Gore Moderator Username: david_gore Post Number: 353 Registered: 4-2003 |
Hi Richard, Memories flooded back when you mentioned Lake George and irate cops - I had a similar experience in a Falcon XY 351 one night except I "lost" the pursuer by turning down a side road and having a sleep for a few hours - fortunately when I passed him at speed, he didn't have time to get the number plate so there was no follow-up but other friends weren't so lucky - he was an unforgiving, cranky so-and-so. Loved the picture of the speedo on the autobahn - this is exactly what our cars were designed for - equally at home transporting maiden aunts at a sedate pace around town or high-speed long-distance touring. I will make one observation to those who think high-speed driving is reprehensible; you only ever drive at a speed where your stopping distance is less than the viewable distance in front of you. Having driven many miles in the days of no absolute limits as well as today's limits; my alertness and concentration at 100MPH is intense and not affected by the "highway hypnosis" which occurs when travelling at 100KPH - I see too many instances today of drivers creating problems through lack of concentration/awareness caused by boredom from travelling at a relatively constant speed on high-standard roads. I will not get into the topic of licensing standards either as these are reprehensible and our traffic laws reflect the lowest-common-denominator standards applied - why should an experienced driver in a high-performance car have to conform to the same limits as a novice driver in a 4WD or passenger van which has unsafe handling characteristics? Restrictions should be based on both the experience/ability of the driver and the performance/handling characteristics of the vehicle being driven. I would never drive my 4WD at the speed I would drive the Corniche on the same stretch of road given the vast difference in the handling and braking performance of these vehicles. | ||
| John Dare Frequent User Username: jgdare Post Number: 26 Registered: 12-2004 |
The first question which appeared under this particular thread evolved (originally) from Ashley James new dedicated web site for Mk6/R-type cars. The concern was in relation to bore wear (and by inference "wear" generally)and whether keeping to 60 mph (approx)IN A Mk6/R-TYPE was perhaps preferable (safer) or even ideal in terms of engine longevity etc. I have spoken to many owners who talk of the so-called "sweet spot" (most older engines seem to possess this "feature") which in Mk6/R types seems to be around 65-70mph. Hardly "slow" nor ponderous (a la Volvo) and I might add,comparatively relaxing for driver (and passengers alike) unless you are trying to prove something, which today is largely a waste of time given that much of what comes out of Japan (R34s etc) will see off anything that has come out of Crewe. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 519 Registered: 4-2003 |
Yes, indeed, back to the topic. Remember, the close cousin, the R-Type Continental was hailed as a 115mph car and driven accordingly. The early ones only had a 7.2:1 compression ratio, changed gearbox and final drive ratios, and a big bore exhaust, compared to the standard chassis. A standard saloon is easily driven Gently Bentley quite comfortably at over 90mph all day. Remember, the Mk VI high-lift camshaft was dropped in 1947 because they wore out in France when driven at constant speeds of over 90mph. That was even with ancient lubricants and primitive post-war fuel. A less-efficient, overlap-profile camshaft replaced it to preserve power and reduce lobe wear. Modern fuel and synthetic oil make that all irrelevant. In a proper state, the piston rings are the last thing to worry about. I fitted a microprocessor cruise control 20 years ago so I can potter down the Hume at a paltry 70mph with both feet on the dashboard. | ||
| John Dare Frequent User Username: jgdare Post Number: 28 Registered: 12-2004 |
Yes.. the topic and original question. Whether travelling at 60mph had any merit or was for whatever reason inappropriate (possibly damaging etc) in a 54 y.o motor car. It was obvious (at least to me) that the correspondent was perhaps fearful of higher speed driving given the age of the car in question. Perhaps he had read from an AUTHORITIVE source (such as the respected UK Bentley Drivers Club) about valve seat recession occasioned by sustained high speed operation and/or was concerned about overall engine/drive line or general mechanical stresses in such an ageing car. No one is seriously interested in what the cars "could do" when new or what others can "Do" in them today or did in days or yore; "80 in third" wasnt it?. I guess to "slip into top" (in a manual) one would need to remove at least one leg from the dashboard for a vintage "boy racer" gear change with a poor old "auto" changing at that speed, being another matter. Either way ,such a yawn, best left to the WRX boys and assorted cafe racers. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 520 Registered: 4-2003 |
My goodness, JGD. You make our cars sound like war veterans in a nursing home. One big difference: you can buy better-than-new spare parts. Remember that the cars originally had exhaust valve seats ground into the cast iron blocks and ran on low-grade fuel, using oil which was as good as sandpaper. They should all have, by now, austenitic steel inlet and exhaust valve seats, modern pistons, full length liners, 98 octane fuel and synthetic oil. Not to mention better tyres and radiators with multiples of the original heat transfer capacity. The list goes on. Maybe even magnets on the exhaust pipe. With all this progress, our 50+-year-old cars are safer and longer-lived under any duty cycle and speed. Oh, and if you drive on motorways, it's nice to keep up with the lorries at least. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 194 Registered: 9-2004 |
Richard how right you are. My old English, Italian bodied 1951 car is used as modern on long continetal trips and the like, speeds of 80+ mph. I must confess the heads and valve seats are cast iron still. I have been testing the valve clearence for valve recession and so far have had none. Run exhaust clearance more,has the effect to give more cooling on the valve seat! 5000 + miles. U/L was reformulated here some time ago after early probs. Oils are most important[semi and fully sythetic are a must. Good modern type tyres are a must for the high speed and loading.  | ||
| David Gore Moderator Username: david_gore Post Number: 356 Registered: 4-2003 |
Pat, what a magnificent car and one which deserves to be driven in the manner for which it was designed and built. I acknowledge the importance of reconciling the problems of those around us with our own lifestyle/activities as raised by other contributors to this forum however one of the unique abilities of the human species is our ability to multi-task where we can care for others in our own individual ways often without drawing attention to our benevolence whilst also enjoying our life in whatever way we choose to do so hopefully without impinging on the rights of others. | ||
| Robert Chapman Grand Master Username: shadow Post Number: 138 Registered: 5-2003 |
As a person who has a (some may say) morbid interest in road transport accidents I would suggest those of us that would contemplate driving a MK6 at 60MPH and over should recall Newton first law of motion. This is a very ridged vehicle with a full chassis,no energy absorbing crumple zone or other passive safty devices,nothing to speak of in the way of active safety ,most still not fitted with belts and the driver sits behind a 5 foot long harpoon more commonly known as the steering column. At 60MPH the average driver (70kg) if forced to stop in 1 metre (as in running into something stationary or another vehicle of the same weight traveling at the same speed) will now weigh 2800kg (YES THATS 2.8 TONES)FORTY TIMES HIS BODY WEIGHT . And this will be aplied to the very unforgiving steering wheel ,steering shaft ,wooden dash, interior vision mirror and then a sheet of glass. To hit a stationary immovable object at 60MPH is the equivalent impact of free falling a vehicle 119ft off a building onto the concrete. As they say its not speed that kills its the sudden stop,and ten seconds after that type of impact you are just another statistic holding up trafic. And traveling at 240kph you are covering more than 100ft per second every second,since it takes the average driver 1 to 2 seconds to look down at the speedo,take in the infomation and refocus on the road this means 100 to 200 ft has been travelled (at 240kph) without the driver looking at the road or trafic in front of him. Scary to think that a vehicle at this speed could be coming towards you and your family travalling at the legal speed limit or closing in from behind. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 197 Registered: 9-2004 |
Robert you are correct of course, however in a heavy solid non crumple type old car or 4+4 off roader with the wearing seat belts a must,you will come off far far better in the impact than the many moderns due to the to the crumple zone taking most of the force,of course as the c/zone has deminished with the monocoque weakness and the pasenger compartment next even with modern seat pre tensioners and air bags in most cases driver passengers in a moderns are far more likly to have more serious injurys. Of course i will aim for the softer part of a hedge and not the tree as traveling at speed i am far more alert to do so! Ashley. Great job on your car, love the web site. I feel a very under rated car as i have missed that one over the years. | ||
| John Dare Prolific User Username: jgdare Post Number: 34 Registered: 12-2004 |
Its all about "I" and "ME". "I" am alert (statement of OPINION only!) as "I" do this and "I" do that on the public road/s etc. How dare these cavalier pleasure (?) seeking, egotists ASSUME that ALL other road users are equally alert. Or perhaps I should say, as alert as they "believe" that THEY are. If anyone continues to be afflicted by RYS (Repressed Youth Syndrome) they ought to invest in a Play Station and load up "Gone in 60 Seconds" on a nightly basis. At least that way some of our roads might be a little safer. | ||
| Robert Chapman Grand Master Username: shadow Post Number: 139 Registered: 5-2003 |
Patrick, Yes there is know doubt that you would be better off in an older car or 4X4 as you say, IF you run into a smaller modern car,disastrous for the people in the small car of course, but you would be ok. But that weight and rigidity all starts to work against you with the catastrophic results I outlined in my previous post,when you run into something heavier or more ridged like the back of a truck or as you have mentioned a tree. Then all the Kinetic energy you have accumulated will apply its force to your body as you rattle around inside your very ridged safety cage(occupant space) ,whilst sharp engine parts enter your zone accompanied by scalding coolant and oil as the body shears off its mounting and concertinas its way to the front of that very ridged chassis. There is no doubt that you have a far greater chance of survival in a modern car(up to a point ) than in an older car with no active or passive safety features. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 208 Registered: 9-2004 |
Robert. Hummmmm yes. The wearing of seat belts a must,I will take my chances and enjoy the true delight and pure enjoyment of my cherrished motor cars driven when permitted in the sprightly manor of which they are acustomed. On return to the motor house i will pamper them with enthusiastic care. Do the police have 4+4 persuit vehicles in Oz for there own saftey? | ||
| Martin Cutler Frequent User Username: martin Post Number: 22 Registered: 10-2004 |
Hi Patrick, To answer your question regarding 4 x 4 police vehicles, they use them quite extensively, usually Toyota Landcruisers, "troop carriers", for outback/alpine regions, although I don't think you would call them a pursuit vehicle. The West Australian police prefer straight 8 Bentleys for their pursuits, well, at least in the 1930's. | ||
| Roy M Tilley Unregistered guest Posted From: 222.152.145.90 |
Whilst on many occasions in my wild youth I have succumbed to the lead-boot syndrome, and felt that I was in perfect control of both myself and my car, since becoming a professional driving instructor nearly 17 years ago, I have become aware that other less-experienced drivers often cannot comprehend the speed of on-coming vehicles and how much time and distance it can take to stop. Therefore I urge all who consider themselves perfectly safe at 150 km/h or whatever, to bear in mind the novices who have recently passed their tests or the elderly whose reactions have slowed, and who, in an emergency could adopt the 'rabbit-frozen-in-the-headlights' syndrome. | ||
| Ashley James Unregistered guest Posted From: 84.92.55.251 |
I have never seen any non RR&B engine conversions to MKVI/Rs etc. but I believe John Clough of the RREC has fitted a Turbo R engine to a MKVI special. Also a Scandanavian Club member is running a military B60 in one and Larry Ross is fitting a B80 to a Silver Wraith. The site has just been unpdated in anyone is interested. www.kda132.com |
