Kevin.payne.15 Posted August 17, 2015 Report Share Posted August 17, 2015 Hi last week I took the GT6 to a rolling road setup but didn't get that far because it turned out that I had inadvertently created a problem replacing the vacuum advance pipe to the distributer which was causing too much advance (45 deg) when it should be about 33 deg max As a way forward he disconnected the pipe and blocked it to get the engine running smoother if rather uninspiring The recommended way forward was to fit a 123 distributer or equivalent. I've looked them up but they look like they only replace Lucas units where mine is a delco remy unit General timing was difficult as the rotor was very worn. Any suggestions how to resolve ? Kevin Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 18, 2015 Report Share Posted August 18, 2015 yes max mechanical advance is around 29/31 deg at 3000 rpm, you add to this the vac unit which if its lucas will have the deg advance on its canister, you add this to the dynamic and if the vac gives 15 then 45 is correct if it gives 7 then 45 is too much, delco dont mark the canister you need to look in the WSM data . the vac unit is controlled by the spring inside ,if its failed you get too much vac advance when cruising at full throttle it does not advance any extra at all. if the Lucas centrifugal is excessive a set of new springs will correct it cheaply, if its a Delco unui they are not diy repairable...only to destruction just some clues before you jump Pete Link to comment Share on other sites More sharing options...
AidanT Posted August 18, 2015 Report Share Posted August 18, 2015 If you want to get your original rebuilt I can recommend H&H they did Delco-Remy as it was in quite poor condition - Not had any issues since - Does take them a couple of weeks to turn it around though http://www.h-h-ignitionsolutions.co.uk/ Aidan Link to comment Share on other sites More sharing options...
Eddie Posted August 18, 2015 Report Share Posted August 18, 2015 I had my distributor rebuilt by the Distributor Doctor. Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 18, 2015 Report Share Posted August 18, 2015 Dont forget club shop sell new or recon your own Believe they use H &H as a supplier pete Link to comment Share on other sites More sharing options...
Kevin.payne.15 Posted August 18, 2015 Author Report Share Posted August 18, 2015 Thanks for this. How do I determine what the advance retard curve will be from a rebuilt distributer. My concern is that I'll go to that expense and it still won't suit the car setup. I think that was why he was suggesting the 123 distributer alternative since you could then program it to suit the car Kevin Link to comment Share on other sites More sharing options...
Kevin.payne.15 Posted August 18, 2015 Author Report Share Posted August 18, 2015 The alternative question is is the Lucas mount the same as the delco remy one such that I could fit the 123 as a replacement? Kevin Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 19, 2015 Report Share Posted August 19, 2015 A recon shoulds match the oe spec if your cars modified and needs something away form normal then a progamable one is a way to go why was connecting the vac unit a mistake ,????? These are purely a economy device that advances at low load partial throttle running , like cruising, they have no effect on acceleration as they dont advance with wide throttle opening, and are not driven by manifold vacuum, but a small port which the airflow across the throttle plates vortex makes a vacuum the gain is around 4mpg If you run a std car on road then surelyn just use the triumph specs pete Link to comment Share on other sites More sharing options...
Kevin.payne.15 Posted August 20, 2015 Author Report Share Posted August 20, 2015 Pete. It's almost standard. I had to do an engine rebuild and it's got a piper cam but just their road one but I'm just nervous to get a rebuild and then find out it's not matched to the car. Hence my desire to find out what advance it will provide then I was going to ask the engine tuner if it will match I didn't really understand your first post could you please explain. The worn distributed delivered 45 to 47 and that was too much. And removing the vac advance restricted this to 33 ish but then at Tickover it ran rough. So much for a six cylinder. Kevin Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 21, 2015 Report Share Posted August 21, 2015 33deg At 3000 rpm with the vac off is close /about spot on. But tired springs may make the curve rather steeper than specified but with the same max as this is limited by the bob weight carrier inside the vac unit will advance extra on top of the static/dynamic while reving a light no load engine on a rolling dyno it should applyy enough load to enable wide throttle opening and the vac unit would behave as on the road, at full power it should add nothing as the vac that operates it is down to nil the vac works most at medium to light openings for max advantages when cruising not accelerating If they measured high vacuum advance under load then something is wrong, the vac spring has probably failed, the vac unit adds to the centrifugal , delco dont put the data on the canister if you have the delco numbers off the side of the vac unit it can be identified what advance it should give let me know will try to look it up and compare with what they found Link to comment Share on other sites More sharing options...
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