Rolls-Royce and Bentley Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
Dear All,

My 1976 SS1 has been getting more and more gutless lately. Engine starts and idles nice and smoothly but lacks mid range and top end woooosh. Hills becoming a problem too. Rang up a Lucas specialist here in the UK. Very helpful and a good source for quality caps and arms : http://www.distributordoctor.com/ which I duly replaced along with the plugs and leads. Always a good starting point.

The good doctor reckoned that this type of Dizzi is prone to a sticky advance and retard vacum unit. Having only recently acquired the car I do not have a good manual (any recommendations?) and the online manuals I have seen are a bit sketchy in this area. I need to check to see if the unit is advancing fully. Trying to find the timing marks, I can see a mark on the crank pully but not sure what I am looking at, TDC, the idle advance mark , full advance mark or what :?:

So firstly if somebody could please help me work out which mark is which I'd be grateful,

and secondly I need to know what total advance I should be looking for once the vacum (and weights if there are any) is all in, at what RPM, and if there is a total advance mark to check that against.

many thanks.....
 

·
Registered
Joined
·
1,558 Posts
Take the vac pipe of and fit a temp pipe remove dizzy cap and suck on pipe you should see the base plate moving
As for timing you need to go on line and get a pick so you can see the markings
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #4 ·
going to try the suck method tonight and will look at those manuals on the link

Many thanks for your help
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #5 ·
That link gives the idle advance setting but no clue as to what it should give fully advanced at high rpm. Doesn't show the timing marks either - like I wonder if there is a mark for fully advanced like my nasty german car!!!
 

·
Registered
Joined
·
668 Posts
Keith,

On the SSII there's a pointer attached to the block and a scale on the crankshaft damper reading every 5° up to 25°.

On the SSII you're looking for 25° at 1300 RPM and 11° at 650 RPM, both read with the hose off and blanked. (That should test the advance cam and linkage, and the suck-test will test the diaphram. Between them you should have full coverage of all the working parts.)

You're on your own to translate to SSI. ;)

Jeff.

BTW: have you checked that there is oil in your carb dashpots and that the carb pistons go up and down? If they're stuck (or even sticky) that could lead to lack of power at open throttle.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #8 ·
Dear all,

Thanks for your help. Have located the marks and compared the advance with my friend's Corniche 1 which has similar marks. Vac pipe off, the bob weights on mine give the same total advance as the Corniche so that proves they are not stuck. Vac pipe reconnected and engine reved to give full advance my SS1 is deffo lacking in total advance. Going to pull the dizzi so I can get the part number off it to order the correct vac advance unit.

But then I will need to time it. However the SS1 and Corniche 1 just have 2 plain marks without the number of degrees against them. Question still is what do they represent :?: I assume one is TDC and one is the vac line off advance mark but not 100% sure. The other mark could be a 5 degree mark or something. None of it ties in with the SS2 marks kindly provided by Jeff and Michael.

http://www.rrtechnical.info/ page M13 tells you where to set the timing - 15 degrees @ 1200 rpm (as my car is late '76 so 2218 on) but not which mark relates to that setting. Furthermore page M13 does not state that 15 degrees @ 1200 is read with the vac pipe disconnected. My mates snap on strobe allows me to set TDC on the light and then read off total advance on the dial on the back of the light but I do not know if the first mark is a TDC mark or a 5 degree mark.
 

·
Registered
Joined
·
221 Posts
ss1 suspect vacuum advance

The line next to tdc is the line you need to use, always clamp on the hose on the vacuum advance when checking, presunably the timing has been altered for unleaded this varied according to age of car if memory serves me right that was 2-4 degrees retarded on your model, start at 2 degrees if it isn't 'pinking' then that is ok otherwise go to 4 degrees
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #10 ·
Looks as if the vac unit is not advancing up so have just received a new unit in the post. Going to pull the dizzi to fit new unit.

Going to ask a really daft question now. Need to turn the motor to get it into no 1 firing for removal and refit of the dizzi. Only ever worked on manual box cars where it is easy to rock it too and fro in gear to get the right position. Would use the crank pulley but that looks buried to the point where adequate leverage would be a problem with plugs in. Is it ok to rock it backwards and forwards on the air conpump pulley to get the final position without straining anything:?:
 

·
Registered
Joined
·
221 Posts
ss1 suspect vacuum advance

Ideally if you can get under car remove the small plate by the ring gear by gearbox and use a large screwdriver to turn engine over
 
1 - 11 of 11 Posts
Top