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#21 Thermostatic Vacuum Valve, Retard Unit and overheating
Posted: Tue Apr 04, 2017 5:46 pm
Finally got it running pretty well. Cooling system stripped out and found loads of old Bars Leaks cork plugs. Ignition replaced and with coil relocated to outer wing area for cool. operation Multiblade cooling fans fitted. Carburettor temperature control valves were making car run weak so they were stripped and calibrated on the later opening 60 deg C setting. Mixtures adjusted with colour tunes as it was set too weak and really affecting the hot running. Anti pop off valves adjusted to kick in at much higher vacuum and virtually inoperative. Top grade fully synthetic Castrol Edge 10 60 oil used. Retard unit retained as it is inoperative once mobile and helps with nicer tickover. Thermostatic valve bypassed and ignored and flaps in air filter trumpets taken out of service to only give cold air. BP5ES plugs used for better burn.
Cooling fans modified with additional switch and warning light to enable kick in earlier and later. Goes really well now. Using best fuel available.
#22 Re: Thermostatic Vacuum Valve and Retard Unit
Posted: Tue Apr 11, 2017 9:04 am
"Mixtures adjusted with colour tunes as it was set too weak and really affecting the hot running."
If you have mounted a different "sport exhaust" system, the motor is running leaner at half or full throttle, also you have adjusted the mixture at iddle correct. If air-filter or exhaust have a higher gas flow, the mixture is becomming leaner. To compensate this, the motor needs a different needle profile.
I never have tested with my lamba-measuring system at half or full throttle, how the mixture of a original EV12 is. This wopuld be interessting to know. I started to test the mixture, after I have mounted a free flow silencer and realised, that the car had flat spots.
Regards Wolfang Gatza
#23 Re: Thermostatic Vacuum Valve and Retard Unit
Posted: Wed Apr 12, 2017 7:07 pm
All of my car is standard UK spec with PJ Langford SS exhaust. I'm sure it can always be improved but with the torque it runs great at last with no flat spots. I'm sure lamba information would improve it but you'd be amazed how using an air flow meter on the carburettors highlights imbalance when setting up on tick over, Essential tool and 4 colourtunes and mixture setting tool.
#24 Re: Thermostatic Vacuum Valve and Retard Unit
Posted: Wed Aug 30, 2017 5:05 pm
Hi...i am a new user here. As per my knowledge what you need to do is use your gauge to measure 1/ manifold vacuum at various throttle openings; 2/ ported vacuum at the place where the later ZS carbs had their EGR connected at various throttle openings and finally 3/ vacuum from the LH rear carburettor which is where the oem retard unit was connected at various throttle openings.