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Barry Brears
Frequent User
Username: turney_2009

Post Number: 81
Registered: 8-2009
Posted on Tuesday, 07 December, 2010 - 07:12 am:   Edit PostDelete PostView Post/Check IP

Bentley T1 SBH 17291.In previous threads I've often been asked to check vaccuum leaks,I have checked all over the engine bay and checked against workshop manual and for the life of me cannott find any pipes etc,would it be suffice to say I'm without vaccuum.I have fitted new NGK Iridium plugs and now the engine runs smoother,but the engine at idle and low revs increases its revs then after about 1 minute dies back down to lower revs,also the exhaust note changes at the same time when the revs change,has this got something to do with the weakening device which on my car has been disconnected.The automatic choke system has also been disconnected as mentioned in previous threads can this be detrimental to the engine the choke stove pipes have been disconnected and the connection on the butter fly housing has not been blanked off should it be?.The cost of reconnecting these devices is expensive and if they are not detrimental to the engines performance then the status quo is preffered.The final problem I have is the carb on the A bank doesn't seem to respond to adjustment therefore I cannott tell whether its running rich or weak can someone help?

Regards to all and the compliments of the season

Barry
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Jan Forrest
Prolific User
Username: got_one

Post Number: 169
Registered: 1-2008
Posted on Tuesday, 07 December, 2010 - 09:03 am:   Edit PostDelete PostView Post/Check IP

Sorry to say this Barry, but it sounds like your car's carburation setup has been well and truly buggered up. Before you can even consider checking the mixtures on each carb you must check that everything is as it should be. Although there are several individual components which can be dispensed with without any immediate negative consequences, due to the factory employing a full 'belts and braces' approach, so many have been lost from your system that it's a wonder the car runs at all - as I believe I said before. This starts with each and every component of the throttle linkage and continues with the individual butterflies and their associated spindles and bushings. If any of these are excessively sloppy (particularly the butterfly spindles & bushes) then you'll never get a good mixture. I've never liked all those individual bars, stops, screws, etc which can only add slop to the system and would dearly love to eliminate them by using bowden cables to synchronise the carbs. However I'm more worried about your failure to find any small pipes on the 'vacuum side' (inlet manifold) of the carbs. There should be several and a leak in any of them or just their removal will automatically result in a weak mixture - as will a leak in the main air trunking from the air filter in the right hand front wing. The lack of an air cleaner or the wrong one will do the same.
I have no doubt that many would advise overhauling the carbs with a full overhaul kit. I'm considering the same for The Old Girl but the only ones I can find are over 100 (GBP) per side. That's a bit rich for my pocket at the moment. Fortunately I should be a bit better off, financially speaking, from next March so I'll be considering it again then.
At least the Iridium plugs are a step in the right direction. I fitted a set, along with a new set of leads, earlier this year and the engine immediately ran a lot smoother.
I assume that you're aware that each carb doesn't feed all the cylinders on the bank on that side, but actually feed 2 on each side. This means that if you 'lose' one of them the car continues to run as a V4. It also smooths out any slight differences between the carbs.

In short there are no short cuts to achieving or maintaining a properly running Rolls or Bentley of any era when it comes to carburation. If you can't or won't do it The Factory Way then you may have to completely redesign the whole system from scratch, buying, modifying and fitting a whole range of non-standard parts which would end up costing a hell of a lot more than just returning everything back to the way it should be!
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Barry Brears
Frequent User
Username: turney_2009

Post Number: 82
Registered: 8-2009
Posted on Tuesday, 07 December, 2010 - 10:33 am:   Edit PostDelete PostView Post/Check IP

Thanks Jan for your imput,I really think I'm throwing good money after bad so does anyone want to buy a stuffed up Bentley T1 with a back to bare metal respray clean and tidy interior a car thats had $22000 dollars spent on it.I'm serious this car has been the most unreliable car I've ever owned and it it keeps on asking for more money to be spent,now the starter motor has jammed I'm just about ready to slash my wrists.
Barry
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Mark Aldridge
Experienced User
Username: mark_aldridge

Post Number: 25
Registered: 10-2008
Posted on Tuesday, 07 December, 2010 - 08:12 pm:   Edit PostDelete PostView Post/Check IP

Barry, a thought; Vitally you only need the vacuum ignition advance/retard( I presume this works ok) and the air intake temperature flap although this could be wedged to supply cold air.If you have a manual choke then with the above exceptions you could blank off the other vacuum supplies temporarily.
You could then obtain the services of someone with the old type Sun or equivalent engine analyser and comparing cylinder efficiencies set up ignition and carburretion to the best compromise. I have found these old type analysers invaluable and they can now be purchase from garage clearance sales quite cheaply.Best of luck freeing the starter;check that the relay is not corroded,this one gave me hours of fun and finally failed on holiday one year.
Mark

(Message edited by mark aldridge on 07 December 2010)
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Jan Forrest
Prolific User
Username: got_one

Post Number: 171
Registered: 1-2008
Posted on Wednesday, 08 December, 2010 - 02:34 am:   Edit PostDelete PostView Post/Check IP

Barry: I'm sorry to hear that you're considering giving up on this T1. Many of us consider these ongoing 'failures to proceed' (usually at the most inopportune moment) to be just the price we have to pay for running cars (un)comfortably over 35 years old. The more masochistic of us even see it almost as one of the ... joys ... of running an older Rolls Royce or Bentley. The Old Girl has let me down more times than I care to think about, but I would much rather live on baked beans on toast for a month than part with her for the sake of a little more TLC. When I slide into the driver's seat and she fires up and then settles down to a *purr* not too dissimilar to a lion gently goading one of its cubs all is forgiven
If you read some of the Tee-One Topics there are several stories of people who will spend $hundreds on paint, leather, etc while ignoring the 'dirty bits' with the obvious consequences. It seems to me that your T has passed through a few hands with a similar ethos. Frankly I think that you're close to having a good Bentley which could outlast you and be passed on to your children, grandchildren and beyond. Do it right, please, and don't let the ba**ards grind you down!

Ps. If I was living on Oz and I'd got the cash to spare I'd be the first in the queue to snatch your hand off!
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Jeff Young
Experienced User
Username: jeyjey

Post Number: 25
Registered: 10-2010
Posted on Wednesday, 08 December, 2010 - 05:48 am:   Edit PostDelete PostView Post/Check IP

Barry,

I've got the other side of the coin: a nicely running T2, but in need of a bit of bodywork and a bare-metal respray. Personally, I'd rather be in your shoes: the engine bits can be done a little at a time, whereas the bodywork is pretty much one huge, monolithic project.

Anyway, good luck, whichever course you take.

Jeff.
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Omar M. Shams
Prolific User
Username: omar

Post Number: 179
Registered: 4-2009
Posted on Thursday, 09 December, 2010 - 03:49 am:   Edit PostDelete PostView Post/Check IP

Dear Barry,
If I lived in Australia, I would make plans to visit you to help you overhaul the carbs on your car and replace your starter motor. we would then put it all back according to the book. I would want to welcome you into the community that helps one another out in the hope that you don't give up on what must be a fine motor car.
It is not too hard to resolve mechanical issues with these cars. All you need is patience.
I am sure a kind member in your neck of the woods will be happy to swing by and help you a little.
May I wish you good luck in advance.
All the best.
Omar

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