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Mark Anson
Prolific User
Username: bentleybloke

Post Number: 54
Registered: 11-2004
Posted on Saturday, 16 April, 2005 - 06:34:   Edit PostDelete PostView Post/Check IP

Hi All,
Nearly at the end of my slight restoration of B72DA and having a little tinker with the engine. I removed the rocker cover to set the tappets and found six, not the twelve I expected. Where are the other six? What is the best method for adjusting them and does anybody have the settings for the feeler blades? Do you have to set the tappets hot or cold? Many thanks Mark
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Robert Wort
Grand Master
Username: robert_wort

Post Number: 189
Registered: 12-2004
Posted on Saturday, 16 April, 2005 - 10:25:   Edit PostDelete PostView Post/Check IP

Hi Mark,
The engine is of an F Head configuration. No, I'm not being rude. . It simply means that the inlet valves are overhead and the exhausts are side-valve. The exhausts rarely need to be adjusted and you will need to purchase some new gaskets when you remove the covers. If they are not noisy and if you feel that the car is running okay, I'd probably leave them be. Tappets can be set cold but I can't remeber the clearances. Iv'e got a handbook somewhere so if I find it, I'll pass on the info.
I used to adjust them hot and without feeler guages (I can hear yelling now),But if you can't get the specs, you can adjust them down just to the point when they become silent. Not the best method, but certainly better than that annoying Tap Tap sound. This is for the overheads only. The exhausts are definitely done cold.
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Bill Coburn
Grand Master
Username: bill_coburn

Post Number: 386
Registered: 4-2003
Posted on Saturday, 16 April, 2005 - 14:45:   Edit PostDelete PostView Post/Check IP

Well now that I have finished slapping Robert around his F head and I am being rude, the clearances are a nominal .006" for the over head inlet and .012" for the side exhaust. Robert is right in that the side valves rarely need adjusting although this may change slightly with the use of unleaded fuel where the valves without the cocoon of lead from the fuel may quietly hammer their way into the cylinder block. Here there are no valve seat inserts although they may have been retrospectively inserted - not a job for the amateur or for that matter most professionals! If the car is to be used for a lot of high speed continuous running it is advisable to open the exhausts out to .014" which tends to save valves. They are adjusted cold and the best approach with Bentleys is to have yourself suspended by the ankles and lowered partially into the engine compartment. The Dawns are a little easier having removable valances. You should have in the car's tool kit (tool kit! tool kit he says???) a weird looking tool about 2 1/2" long one end of which is hook shaped to go around a valve tappet and the other is 'U' shaped to hold the tappet next to it while you make the adjustment. As to the overhead lot they are adjusted cold and are easily checked. Do not overtighten the lock nuts they are only half nuts and are not required to contain a nuclear explosion. And to Robert - you will write out 100 times I will mot adjust tappets by ear and have them on my desk by 9.00AM Monday!!
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Mark Anson
Prolific User
Username: bentleybloke

Post Number: 55
Registered: 11-2004
Posted on Saturday, 16 April, 2005 - 20:06:   Edit PostDelete PostView Post/Check IP

Thanks Guys,
I will check the inlet valves today. I cant get the gaskets for a week or so for the exhaust valves so they will have to wait.
You mentioned unleaded fuel. At the moment I am running it on lead replacement petrol sold at our local Salisbury's. I have heard they are thinking of stopping this soon and wondered if my car can run on unleaded without too much fuss anyway. Is there any adjustments or modifications needed for running on unleaded?
Many thanks
Mark
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Robert Wort
Grand Master
Username: robert_wort

Post Number: 191
Registered: 12-2004
Posted on Saturday, 16 April, 2005 - 22:39:   Edit PostDelete PostView Post/Check IP

Will 10.00 AM Monday Do Bill? I'm a slow writer.
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Bill Coburn
Grand Master
Username: bill_coburn

Post Number: 387
Registered: 4-2003
Posted on Saturday, 16 April, 2005 - 23:23:   Edit PostDelete PostView Post/Check IP

Robert - Just this once. Mark. Rolls-Royce used very hard seated valves which rarely fail. They also used very hard valve seats except as I mentioned under the exhaust valves on the F head engines. As yet I have not heard of anyone having problems with valve seat regression with the exhaust valves so I would not really worry. If you really want to give the old girl a treat run her on premium fuel otherwise with straight unleaded which without the lead has no 'anti-knock' stuff in it you may get pinging which is cured by screwing the distributor advance adjustment back a bit. I am personally very very wary of fuel additives for this purpose as there have been frightening reports of fuel lines disintegrating!
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Robert Wort
Grand Master
Username: robert_wort

Post Number: 192
Registered: 12-2004
Posted on Sunday, 17 April, 2005 - 00:32:   Edit PostDelete PostView Post/Check IP

Bill,
As some of the older RR/Bs ran on the old Standard fuel anyway, would unleaded make a great deal of difference? Did Standard grade fuel have lead in it? I always thought that only Super did.
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rich cwik
New User
Username: lotusrich

Post Number: 8
Registered: 1-2004
Posted on Sunday, 17 April, 2005 - 00:48:   Edit PostDelete PostView Post/Check IP

Don't forget to tell him about growing a third, smallhand on your wrench holding arm as you need to hold two wrenches as well as the feeler gauge, and use the special tappet holding tool on the exhausts. whilst being suspended upside down in the slot between the body amd the engine. It's also easier if you remove the exhaust manifolds from the head( at least it is on my car.
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Mark Anson
Prolific User
Username: bentleybloke

Post Number: 56
Registered: 11-2004
Posted on Sunday, 17 April, 2005 - 02:00:   Edit PostDelete PostView Post/Check IP

Hi Folks,
Just come in out the garage excuse the oily hands on the keyboard. The inlet clearances were quite far out on three of the tappets. I will wait until later in the year to do the exhaust tappets.
I am about to check the ignition timing with a strobe light and read somewhere that you cant use the pulley for the markings as it moves. The little hole in the flywheel is useless to see the markings. Is there any other way to set the correct timing settings? What would they be for they unleaded settings?
Many thanks
Mark
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Bill Coburn
Grand Master
Username: bill_coburn

Post Number: 388
Registered: 4-2003
Posted on Sunday, 17 April, 2005 - 10:11:   Edit PostDelete PostView Post/Check IP

Robert/ The 'kerosine' fuels these cars ran on when they were made were leaded otherwise every time you threw a load on the engine it sounded like a crate of lemonade bottles was being manoeurved under the bonnet. And while I realise you are just trying to show how old I am, in those days there was petrol and petrol - non of this multi grades etc. For racing one inserted secret liquors into the tank but that is and was far beyond my ken.

And Rich, it is funny (when you are watching and not doing) recounting the travails of adjusting side valve clearances. I can remember as a kid watching men do this job on all manner of cars with engines up to a straight eight (the Packard Clipper - a beautiful car). And the best example was the Morris eight which had an engine slightly larger than the Mark VI starter motor. To get at those valves you had to remove a plate under the mudguard in the valance. Rolls-Royce finally did this but then promptly dispensed with side valves - there is a reason for everything I am told. Incidentally I believe that if you want to do much more than change the oil in the new GT360, the approach is to rip the engine out which reportedly is fairly 'simple' - if you have the gear!!!

And to Mark. Set the timing statically on the flywheel. Before doing that whip the distributor out and take it to your nearest tuning specialist and get him to synchronise the points and check the performance of the distributor. As to the setting try the standard 2 degress BTDC and knock it back a little if it pings. And don't make the mistake of doing the setting using the crank handle. Turn the engine in one direction only using the back wheel and the car in gear (plugs out) or lever the flywheel around with a screw driver.
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Mark Anson
Prolific User
Username: bentleybloke

Post Number: 57
Registered: 11-2004
Posted on Sunday, 17 April, 2005 - 18:26:   Edit PostDelete PostView Post/Check IP

Thanks Bill,
My only problem is I am fitting an electronic ignition module in the distributer (yes I know "shame on me" for not keeping it original!) Is it still possible to set the timing statically with this fitted? What method would you use?
Thanks Mark
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Bill Coburn
Grand Master
Username: bill_coburn

Post Number: 389
Registered: 4-2003
Posted on Sunday, 17 April, 2005 - 21:49:   Edit PostDelete PostView Post/Check IP

Mark you are now talking Swahili as far as I am concerned. Whoever is fitting the electronics - and I heartily endorse the idea and will be most interested in the result - he/she should advise you. I would think that you could time it empirically by getting the firing point at the static mark. This will get you to a dyno tune where they will time the car on meters. The only bad word I have had incidentally on electronic ignitions is that when it goes you are stuffed! With points you can usually file something and get home - but that is progress.
Come to think of it why not simply use your stobe, jack the car up and time it on the flywheel. 500 years ago I have done this. The engine if idling correctly at about 400 rpm will have no centrifugal advance so you will not be far out.
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 704
Registered: 4-2003
Posted on Sunday, 17 April, 2005 - 22:28:   Edit PostDelete PostView Post/Check IP

Although my newer cars have non-adjustable digital gizwhat ignitions integrated into the elecric mirror control and window lift ECUs, I still like the dual points on the R-Type. Why change them ? At least they are not programmed to stop if you forget your yearly donation to the Salvos.

Timing ? Gave up doing that by measurement decades ago as it's a waste of time and useless. Use the strobe to synchronise the points if you haven't flushed them. Put some low octane unleaded in and tune the motor so it starts to pink on full load, low RPM, then back it of until it just stops pinking. Filler' up with higher octane. Bingo. Dave's Dyno is expensive.

Shoot me now.

RT.
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Gordon Norris
Prolific User
Username: crewes_missile

Post Number: 149
Registered: 2-2005
Posted on Sunday, 17 April, 2005 - 23:00:   Edit PostDelete PostView Post/Check IP

Mark,
Although Richard's words sound like heresay, and I know some that WOULD shoot him, he is right. Setting the timing to specification is a waste of time in this case unless you are using the same fuel as when the car left the factory. As that is plainly not possible, the factory specs are no longer relevant other than as a ball-park figure.

Set it roughly right as suggested by Bill with the strobe, and then the fine tuning as per Richard's description either with the original points, or with the electronic replacement.

Electronics theoretically won't need touching/adjusting once right, but if they breakdown it's a ride home on a flatbed truck. On the other hand, standard points are fixable but will need adjusting more often &/or in accordance with Murphy's law, will choose to close up and stop on a wet cold night when you have no umbrella, flat torch batteries, and the essential screwdriver from the toolkit will be sitting at home on the bench. Pick your preferred scenario....6 of one, half a dozen of the other....

GN.
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Bill Coburn
Grand Master
Username: bill_coburn

Post Number: 390
Registered: 4-2003
Posted on Monday, 18 April, 2005 - 09:46:   Edit PostDelete PostView Post/Check IP

Which raises a concern that has been niggling me. The Spur obviously has the -Gizwat ignition constructed by Mr Lucas I believe. I had a Shadow some years ago with the setup and the whole thing failed. Going to get a new one from the local agents - was told that they had two on the shelf but don't sell them there is a fault. And so relating to Gordon's prophesy I am wondering should I fit or have fitted a new ignition for prophylaxis and if so what sort as there seems to be a number of options. The car has done a little over 100K.
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Robert Wort
Grand Master
Username: robert_wort

Post Number: 193
Registered: 12-2004
Posted on Monday, 18 April, 2005 - 14:32:   Edit PostDelete PostView Post/Check IP

I recently had a Pirhana system fitted as a replacement on my Spur. Much cheaper than OEM and they have a good track record. In answer to Mark's question about fitting electronic ignition to B72DA, you can purchase a solid state system that fits neatly into where your points were without too many modifications and if it does fail (and if you've kept your old set of points in the boot), you can simply re-instal the points to get you home. A friend of mine did that with his Silver Cloud. You can try this link to lumenition who also manufacture systems to suit RR/B http://www.holleycarbs.com.au/lumenition.html
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Mark Anson
Prolific User
Username: bentleybloke

Post Number: 58
Registered: 11-2004
Posted on Tuesday, 19 April, 2005 - 05:10:   Edit PostDelete PostView Post/Check IP

I bought a purpose made unit from http://www.classicheads.com/Homex.html they make all sorts of other items for classic cars. They supplied a higher power coil to go with the unit. It all fits in the distributer cap with only two wires to connect. I have not fitted it yet, I am waiting until after my first wedding (30.4.05( before I start messing with it.

Cheers Mark
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Mark Anson
Prolific User
Username: bentleybloke

Post Number: 65
Registered: 11-2004
Posted on Tuesday, 12 July, 2005 - 09:59:   Edit PostDelete PostView Post/Check IP

I bet you all thought I had "popped off". Sorry for the delay in replying.
I fitted my electronic ignition without any problems. I stripped too much of the dizzy down originally but it made the points removal easy. It also gave me a chance to clean all the gunk out of the base plate.
Anyway, after altering the end of my coils main HT lead because the new coil has a modern connector (push fit) I switched on the ignition.
I had only pressed the button for what seemed like half a second and the car burst into life. In fact so well the uneven tickover had nearly disappeared. On a road test the power was unbelievable and the acceleration much better. Usually the car would turn over a couple of revolutions before firing. The spark at the plugs is so bright now you have to wear shades!!

I would highly recommend this kit.
Cheers Mark
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John Richardson
Unregistered guest
Posted From: 210.84.192.26
Posted on Tuesday, 12 July, 2005 - 21:49:   Edit PostDelete PostView Post/Check IP

Interesting and beneficial thread taken into consideration when having B.20.RT prepared for
relocation/reuse.

Like to second Mark Anson's post.

R-type B.20.RT has been fitted with Electronic Ignition, Bosch GT40 Coils (Painted Black), Magnacore leads and the largest Optima yellow
Top Battery that would fit, which alone gives
fast cranking - result is per Mark's report except there was no uneven tickover. The original points, coils, spare distributor cap and spare rotor are in the trunk if ever needed. Test refit conducted and points did not need any adjustment -even a klutz like me can do it. Relocation run of some 507 miles over almost 10 hours with appropriate stops and sustained legal speeds of 60 MPH and 70 MPH did not produce any problems. Newly manufactured exhaust headers also appear beneficial. B.20.RT is certainly quicker to start.

Thanks to those who provided input/info.

Johnny
B.20.RT







(Message approved by david_gore)
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Bill Vatter
Frequent User
Username: bill_vatter

Post Number: 13
Registered: 9-2004
Posted on Monday, 15 August, 2005 - 13:00:   Edit PostDelete PostView Post/Check IP

Mark,

Did you get your valves to operate silently?

One problem that will interfere with correct adjustment is wear on the end of the rocker arms. The end of the rocker arm develops a dished place where it rubs on the valve stem. When you use a feeler gage you don't get an accurate measurement because the feeler gage does not measure to the bottom of the dished place, only to the unworn area along side of the dish.

As a result, you set the valves to what you think is .006 but is really something more, and maybe much more, so the valves are still noisy. The fix is to remove the dish on the end of the rocker arms. (5 nuts on the pedistal tops hold the rack full of arms; be careful not to loose the special spherical washers.)

With the rockers off, carefully grind the end of the rocker to remove the dished place; don't remove any more material than necessary to make an even surface. Retain the original curved contour.

Now you can make an accurate adjustment.

I am of the old school regarding points. I have heard, not experienced, the advance adjustment with the solid-state gizmo is different than with the points; sometimes enough different the car will hardly run without the spark being re-timed. That's more than I want to set myself up for in an emergency situation.

Also, this new-found smooth running and power increase of which I read here and other places is more of a testimonial to the poor condition you started with rather than the virtues of the solid-state ignition. This solid-state stuff is only a different method of interrupting the primary current in the coil, and in itself offers no advantage, excepting that possibly the coil has more dwell time, which could give stronger spark at high rpm, say 4000 rpm and above. I think it is unlikely you drive your car at that engine speed.

Those super hot coils make a hot spark for sure, but I have a good friend who put a super hot coil in his Sprite and was doing really well until one night (it's always in the dark or rain these things happen) the hot spark burned a hole through the distributor cap, shorting out the secondary and stopping him cold. (stopped cold by a hot spark ) He needed to call his buddies and we installed new parts by the side of the road with flashlights. We also told him we weren't comming the next time it happens so he should go back to the regular coil.

Also consider this: these cars ran really well when they were new. Wealthy people are usually not stupid and generally don't put down big $ (or ) for cars that don't run well.

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