[TR] Vacuum Advance of a delco remy

[Bud Rolofson]

Thanks,
It's 1969 stock deco remy distributor with a vacuum advance with ported vacuum so there's no vacuum until the throttle plate opens.  When it opens it makes the distributor timing advance via the vac unit.
It's a 69 so no clutch fan.
Thanks
Bud
Sent from my Commodore 64

> On Jan 11, 2021, at 6:01 PM, John Innis <jdinnis at gmail.com> wrote:
> 
> That does not sound right to me, normally you expect vacuum to be HIGHEST at idle and fall off as RPM's increase.  Do you know which model of the Delco distributor you have?  IIRC there was one that had a vacuum retard, instead of advance.  
> WRT your overheating, check your fan clutch.  That sounds like it is not getting enough air.  
> 
> 
>> On Mon, Jan 11, 2021 at 2:03 PM Bud Rolofson <levilevi at comcast.net> wrote:
>> I’m using dual 1 1/4” SU carbs. The front carb has a vacuum connection right at the butterfly that pulls no vacuum at idle but 9 psi at > 2000 rpm when the butterfly opens.
>> 
>> 
>>> On Jan 11, 2021, at 12:03 PM, John Innis <jdinnis at gmail.com> wrote:
>>> 
>>> What carb are you using and where on the carb is the vacuum line connected?  DGV's are notorious for this, because carb vacuum line is NOT a manifold vacuum source, it is a venturi vacuum source.  
>>> 
>>>> On Mon, Jan 11, 2021 at 12:34 PM Bud Rolofson <levilevi at comcast.net> wrote:
>>>> Listerati,
>>>> 
>>>> I’m trouble shooting a overheating problem at highway speeds (65-70mph) with my 69 Spitfire. Temp gage goes to red at higher speeds but then immediately cools off when idling.
>>>> 
>>>> I suspect I have a bad or weaken vacuum advance on my Spitfire’s delco remy (friggin spell check made me type that over and over) distributor. I tested the vacuum line from the carb and it gets to 9 psi where the line connects to the vacuum advance when the engine is at 2500-3000 RPM.
>>>> 
>>>> The problem is there is no movement to advance the timing that I can see by watching the vernier advance knob, it does not move at 2500-3000 rpm.
>>>> 
>>>> Two questions:
>>>> 
>>>> Should 9 psi be enough for the vacuum advance to work properly?  I couldn’t find specs for vacuum advances.
>>>> 
>>>> If the vernier knob isn’t moving then is the vacuum advance not working or the centrifugal weights not moving? Or maybe both?
>>>> 
>>>> Thanks
>>>> Bud 
>>>> 
>>>> Extreme Parts Racing (more than just a haircut)
>>>> 
>>>> 71TR6 CC57365 (Good 6)
>>>> 71 Spitfire MK IV Race Car #3
>>>> 69 Spitfire MK III (back up FE engine/dinghy car)
>>>> 93 Minnie Winnie Race Support Vehicle 
>>>> 77 Z-50A Hardly Davidson Honda Mini-Trail Bike (Triumph Pit Bike)
>>>> 
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>>> -- 
>>> =================================
>>> = Never offend people with style when you   =
>>> = can offend with substance --- Sam Brown  =
>>> =================================
>> 
>> Bud Rolofson
>> 
>> Extreme Parts Racing (more than just a haircut)
>> 
>> 71TR6 CC57365 (Good 6)
>> 71 Spitfire MK IV Race Car #3
>> 69 Spitfire MK III (back up FE engine/dinghy car)
>> 93 Minnie Winnie Race Support Vehicle 
>> 77 Z-50A Hardly Davidson Honda Mini-Trail Bike (Triumph Pit Bike)
> 
> 
> -- 
> =================================
> = Never offend people with style when you   =
> = can offend with substance --- Sam Brown  =
> =================================
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