Conradski Posted February 18 Report Share Posted February 18 Hi Forum, I have just finished a range of changes and upgrades to my 72 TR6 standard Lucas PI car. New exhaust, new manifold 6-2-1, new throttle linkage, throttle rods, and new running gear - prop, drive shafts, UJs, O need to adjust the tick over and butterflies - any tips? Do I need an "airflow balancer" tool? Thanks Quote Link to post Share on other sites
Jonny TR6 Posted February 19 Report Share Posted February 19 Welcome to borrow my airflow balancer. Used it on mine and it works well. I'm in Heswall, so pop me a PM. Funnily enough, I've just done my throttle linkage, but have a couple of other tweaks before I get everything fully set up. Looks like you have the same throttle linkage as me as well, Fred Millturn with the ball bearing upgrade. Cheers Jonny Quote Link to post Share on other sites
JohnC Posted February 19 Report Share Posted February 19 As far as tips go, please use the search function. Or, better still, use a Google search but add "site:www.tr-register.co.uk" at the end. You may have luck including the term "fag paper"... JC Quote Link to post Share on other sites
Mk2 Chopper Posted February 19 Report Share Posted February 19 Get all the butterflies set as fully closed as possible without them gauging into the throttle body. Next find a means to prop open the throttle to a fast idle speed, and use the airflow balancer to check what the flow is in each throttle body. You want to open the lowest reading one to match as close as you can to the highest reading one (you can't reduce the higher one because of where you set the butterflies earlier), so that they are all quite similar. Then put the throttle back to fully closed, before using the air bypass valve to set the final idle speed to somewhere between 750 - 850 rpm. Gareth Quote Link to post Share on other sites
Andy Moltu Posted February 20 Report Share Posted February 20 I find the easiest way is to get a idle of say 1200-1500 rpm by tightening the throttle cable and shutting down the air bleed valve. Then adjust the throttles using a air flow meter until balanced. Once balanced, slacken off the throttle cable and open up the air bleed valve so that sets tick over. Simples (ish) unless you have a CR linkage in which case you fiddle around for ages and buy an after market one from the likes of Revington etc. (Which you seem to have done) The fag paper trick is really only for TR5 set ups that were not modified in the day to use the bleed valve. Quote Link to post Share on other sites
Waldi Posted February 20 Report Share Posted February 20 1 hour ago, Andy Moltu said: I find the easiest way is to get a idle of saw 1200-1500 rpmby tightening the throttle cable and shutting down the air bleed valve. Thanks Andy, Closing the air bleed valve while balancing the trhottle bodies is a very good tip (for me at least): it will eliminate the influence of the bleed air on the balancing of the butterflies. I will certainly do that next time I’m on it. Waldi Quote Link to post Share on other sites
michaelfinnis Posted February 27 Report Share Posted February 27 On 2/20/2024 at 9:46 AM, Waldi said: Thanks Andy, Closing the air bleed valve while balancing the trhottle bodies is a very good tip (for me at least): it will eliminate the influence of the bleed air on the balancing of the butterflies. I will certainly do that next time I’m on it. Waldi When driving the car the air bleed valve would not be closed off, it would be open, so wouldn’t you want to to set the butterflies up in that condition? Quote Link to post Share on other sites
Waldi Posted February 27 Report Share Posted February 27 That’s a good thought Michael, the purpose of balancing is to set the butter-flies and with the idle air valve open there is some influence of that on the adjustment. That is assuming the air provided to all 6 inlets by the air idle valve is equal, more or less. I will follow Andy’s method next time. Waldi Quote Link to post Share on other sites
Andy Moltu Posted February 27 Report Share Posted February 27 In theory the 3 manifolds are linked by balance pipes so all 3 sets get air via the bleed valve when the throttles are closed. When the throttles are open, the small amount of air entering through the bleed valve becomes less significant. Even on modern efi cars with multiple throttle bodies the throttles are balanced before the air bleed valve is made operational. Quote Link to post Share on other sites
Conradski Posted March 4 Author Report Share Posted March 4 On 2/19/2024 at 10:13 PM, Mk2 Chopper said: Get all the butterflies set as fully closed as possible without them gauging into the throttle body. Next find a means to prop open the throttle to a fast idle speed, and use the airflow balancer to check what the flow is in each throttle body. You want to open the lowest reading one to match as close as you can to the highest reading one (you can't reduce the higher one because of where you set the butterflies earlier), so that they are all quite similar. Then put the throttle back to fully closed, before using the air bypass valve to set the final idle speed to somewhere between 750 - 850 rpm. Gareth Thanks Gareth, that's really helpful. Quote Link to post Share on other sites
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