foster461 Posted August 15, 2008 Report Share Posted August 15, 2008 There is a third leg to the crankcase ventlation and catch tank topic when considering the Weber conversion and that is the Anti Run On mechanism that is part of the Stromberg system. The later model TR6 has an anti-run on valve that is engaged when the oil pressure is is above zero and the ignition is off (ie you have just turned off the engine). At that time the AR Valve opens and lowers the pressure in the Stombergs to cut off the fuel supply. With the Weber conversion, that capability is lost along with the other items we have discussed at some length already. I and according to the traffic on the 6pack list today apparently several other Weber users are having issues with run on. Roger Williams describes a nifty solution using an ex Rover part that T's into the servo hose and opens up when the ignition is turned off. No suckee, no runee !. It is described as part number ADU9535 but it no longer seems to exsist, at least I cant find it. There is an old one on the UK eBay but that is the closest I have come to seeing one. Anyone know of a source for this part or an alternative to it that is still available ?. Stan Quote Link to post Share on other sites
Bald Rick Posted August 15, 2008 Report Share Posted August 15, 2008 Hi Stan This is listed in the Moss Europe catalogue: ARO Valve Found it under MGB/C Hope this helps Tony Quote Link to post Share on other sites
foster461 Posted August 15, 2008 Author Report Share Posted August 15, 2008 Hi Stan This is listed in the Moss Europe catalogue: ARO Valve Found it under MGB/C Hope this helps Tony Thanks Tony, just what I was lookmg for. Stan Quote Link to post Share on other sites
TR6 Poor Posted August 16, 2008 Report Share Posted August 16, 2008 There is a third leg to the crankcase ventlation and catch tank topic when considering the Weber conversion and that is the Anti Run On mechanism that is part of the Stromberg system. The later model TR6 has an anti-run on valve that is engaged when the oil pressure is is above zero and the ignition is off (ie you have just turned off the engine). At that time the AR Valve opens and lowers the pressure in the Stombergs to cut off the fuel supply. With the Weber conversion, that capability is lost along with the other items we have discussed at some length already. I and according to the traffic on the 6pack list today apparently several other Weber users are having issues with run on. Roger Williams describes a nifty solution using an ex Rover part that T's into the servo hose and opens up when the ignition is turned off. No suckee, no runee !. It is described as part number ADU9535 but it no longer seems to exsist, at least I cant find it. There is an old one on the UK eBay but that is the closest I have come to seeing one. Anyone know of a source for this part or an alternative to it that is still available ?. Stan BPNW, and or, TRF, had them new when I restored my car 3 or so yrs. ago, I had a new one, and sold it as it turned out my old one worked fine. Also, my car will still run on with cheap gas, and if the timing is to far advanced, look out. Quote Link to post Share on other sites
foster461 Posted August 16, 2008 Author Report Share Posted August 16, 2008 BPNW, and or, TRF, had them new when I restored my car 3 or so yrs. ago, I had a new one, and sold it as it turned out my old one worked fine. Also, my car will still run on with cheap gas, and if the timing is to far advanced, look out. I still have the original ARO valve and it works but only with the Strombergs. The valve I mentioned in my earlier post is used on some other BL cars and can be T'd into the servo hose to bring the inlet manifold up to atmosphere when you shut off the motor and so will work with the Weber conversion. Agreed about the contributing factors... gas octane, idle speed, plugs, timing all can play a role in this new engine and I'm going to try and sort them out before I resort to the brute force of a valve. Stan Quote Link to post Share on other sites
Quark Posted August 26, 2008 Report Share Posted August 26, 2008 I still have the original ARO valve and it works but only with the Strombergs. The valve I mentioned in my earlier post is used on some other BL cars and can be T'd into the servo hose to bring the inlet manifold up to atmosphere when you shut off the motor and so will work with the Weber conversion. Agreed about the contributing factors... gas octane, idle speed, plugs, timing all can play a role in this new engine and I'm going to try and sort them out before I resort to the brute force of a valve. Stan Does anyone have a diagram/pictures to illustrate fitting this conversion (apparently mistakenly I thought I could adapt the Stomberg version). Quote Link to post Share on other sites
foster461 Posted August 26, 2008 Author Report Share Posted August 26, 2008 Does anyone have a diagram/pictures to illustrate fitting this conversion (apparently mistakenly I thought I could adapt the Stomberg version). I think it it something like this: http://mgaguru.com/mgtech/engine/ro202.htm It just connects into the servo hose and when activated by shutting off the engine it just vents to atmosphere. I would verify that you need this and make it a last resort rather than assume it will be required. I put some higher octance gas in the tank and that seems to have greatly diminished my run on problem. Stan Quote Link to post Share on other sites
88V8 Posted August 26, 2008 Report Share Posted August 26, 2008 Despite harder plugs, I still get run-on with my PI engine, although only if the temp has crept up due to idling before shut-off. A chap at the weekend gave me a tip which worked twice, so I pass it on FWIW - as you turn off the ignition, open the accelerator wide. Not so as to vroooom the engine, I mean at the same moment as you turn it off, so it doesn't vrooom at all. The alleged effect of the open throttle(s) is to admit a wadge of cold air and so cool down whatever hot component is causing the run-on. Folklore? You decide.... Ivor Quote Link to post Share on other sites
stuart Posted August 26, 2008 Report Share Posted August 26, 2008 Despite harder plugs, I still get run-on with my PI engine, although only if the temp has crept up due to idling before shut-off. A chap at the weekend gave me a tip which worked twice, so I pass it on FWIW - as you turn off the ignition, open the accelerator wide. Not so as to vroooom the engine, I mean at the same moment as you turn it off, so it doesn't vrooom at all. The alleged effect of the open throttle(s) is to admit a wadge of cold air and so cool down whatever hot component is causing the run-on. Folklore? You decide.... Ivor Ivor that in effect works the same as an anti run on valve would do, just means you havent got to fit one! Stuart. Quote Link to post Share on other sites
foster461 Posted August 26, 2008 Author Report Share Posted August 26, 2008 Ivor that in effect works the same as an anti run on valve would do, just means you havent got to fit one! Stuart. I wonder if this works when you have carbs with accelerator pumps ?. The Webers shoot a lot of gas into the chokes when you open the throttles wide quickly and if the engine is still turning it is still sucking.. Stan Quote Link to post Share on other sites
Guest ntc Posted August 26, 2008 Report Share Posted August 26, 2008 (edited) I wonder if this works when you have carbs with accelerator pumps ?. The Webers shoot a lot of gas into the chokes when you open the throttles wide quickly and if the engine is still turning it is still sucking.. Stan Stan No it does not work you can have quite a spectacular backfire and goodbye air filters. Running on is not a problem over here maybe down to fuel, main cause the timing is to advanced or the tickover to high Edited August 26, 2008 by ntc Quote Link to post Share on other sites
foster461 Posted August 26, 2008 Author Report Share Posted August 26, 2008 StanNo it does not work you can have quite a spectacular backfire and goodbye air filters. Running on is not a problem over here maybe down to fuel, main cause the timing is to advanced or the tickover to high A buddy of mine with a racing TR6 has dcoe's on it and he didnt realise it but one time he had a fire in one of them and it MELTED the insides of the auxillliary venturis. These things can act like flame throwers when the conditions are right. I learned early on that where there are three big Webers there is a lot of petrol around and they are inches from the exhaust pipe so it is best to keep the fire extinguisher handy!. Stan Quote Link to post Share on other sites
TR6 Poor Posted August 26, 2008 Report Share Posted August 26, 2008 The only way mine will run on is with the timing advanced too far, or if I run regular grade fuel. Cheers Quote Link to post Share on other sites
foster461 Posted August 26, 2008 Author Report Share Posted August 26, 2008 The only way mine will run on is with the timing advanced too far, or if I run regular grade fuel. Cheers Just curious, what do you have your static timing set to ?. In fact have you mentioned what your full engine configuration is ? Stan Quote Link to post Share on other sites
stuart Posted August 27, 2008 Report Share Posted August 27, 2008 A buddy of mine with a racing TR6 has dcoe's on it and he didnt realise it but one time he had a fire in one of them and it MELTED the insides of the auxillliary venturis. These things can act like flame throwers when the conditions are right. I learned early on that where there are three big Webers there is a lot of petrol around and they are inches from the exhaust pipe so it is best to keep the fire extinguisher handy!. Stan I bought a 3a that had had a similar fire in one, not a pretty sight and expensive to sort out! Stuart. Quote Link to post Share on other sites
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