Steves_TR6 Posted May 25, 2013 Report Share Posted May 25, 2013 Hi guys Reading the 'how to improve' volume yet again I am interested in the suggestion of fitting a second air bleed valve to smooth the idle. My car is a CR but the 'bespoke' engine has CP throttle bodies with the associated single air bypass and radiator end mounted air bleed. I'm awaiting a new set of injectors, from the excellent Neil, and was wondering if its worthwhile to fit the second air bleed valve at the driver end of the engine whilst I'm in the vicinity next week. Has anyone actually done this modification, and how positive where the results? My linkages are all pretty good, the at runs great but the idle does vary especially when sitting in traffic for any length of time, which I'm thinking is due to cylinders 5 and 6 running short of air. Also, is the throttle body already threaded or will I need to tap it? Steve Quote Link to post Share on other sites
TR NIALL Posted May 25, 2013 Report Share Posted May 25, 2013 I've looked at this also and am considering,also on my list is to increase the diameter of the plenum chamber by 1inch. Don't think you need to tap the throttle body just Drill as the Bleed Screw is just a Tapered Push In. Quote Link to post Share on other sites
ianhoward Posted May 25, 2013 Report Share Posted May 25, 2013 (edited) I shall get a inferiority complex...my car doesn't even have one air bleed!!! Cheers Ian Edited May 25, 2013 by ianhoward Quote Link to post Share on other sites
Steves_TR6 Posted May 25, 2013 Author Report Share Posted May 25, 2013 I've just seen the 'air bleed valve' thread in the tr6 forum from April Think I will try this modification, as several forumites report smoother idle with the second valve. So, where do I find a second valve? Steve Quote Link to post Share on other sites
Steves_TR6 Posted May 25, 2013 Author Report Share Posted May 25, 2013 Ps, Niall I also think a larger plenum would be advantageous. Of course the two mods do different things, the air bleed valves are for idle mix adjustment and the plenum size increase works at the other end of the spectrum. Steve Quote Link to post Share on other sites
TR NIALL Posted May 25, 2013 Report Share Posted May 25, 2013 Yes Steve your right,but both worth a try. Think eBay for a Throttle Body but you will find it difficult to get just the one. Quote Link to post Share on other sites
Ade_TR6 Posted May 25, 2013 Report Share Posted May 25, 2013 I had a look at this - both the TR Shop and Revingtons will sell you a bleed valve and both were circa £40... Quote Link to post Share on other sites
Steves_TR6 Posted May 25, 2013 Author Report Share Posted May 25, 2013 Thanks guys, will have a chat with the TR shop in the week. Quote Link to post Share on other sites
stuart Posted May 25, 2013 Report Share Posted May 25, 2013 If you do a forum search you will find a thread on increasing the size of the plenum. Ian dont worry about it, if you havent got it then its one less thing to fiddle with Stuart. Quote Link to post Share on other sites
John Harvey Posted May 25, 2013 Report Share Posted May 25, 2013 A friend of mine did this mod and swears his car runs better. I rang a well known TR parts supplier to try and get a second hand air valve they asked me had I lost mine when I told them why I wanted one I was told not to do it as this would upset the air mix and that they once had a car in their workshops with this mod and took it off straightaway. So that left me even more confused than normal. Quote Link to post Share on other sites
Davidw Posted May 26, 2013 Report Share Posted May 26, 2013 Please don't drill the end of the rearmost throttle body, Steve. There is just a blanking plug. Get a piec of steel bar ( I used an old hacksaw) with a crank in it to miss the middle throttle body, insert and give it a gentle tap. Then just Araldite the new bleed screw into place. Quote Link to post Share on other sites
mike3739 Posted May 27, 2013 Report Share Posted May 27, 2013 Hi Steve Four Inch plenum works a treat well worth the time & effort, along with four inch flexible hose which draws air from the middle of the Grille with a huge K& N filter on the end. Have now had this running for three years with several trips to France. Jersey Royal also has the same set up. Can't comment on extra bleed valve not required on my car smooth idle & always runs on six cylinder's. Cheers Mike Quote Link to post Share on other sites
Steves_TR6 Posted May 27, 2013 Author Report Share Posted May 27, 2013 Thanks for the comments/suggestions I shall definitely try the second air bleed, and probably have a larger plenum made when the opportunity arises. Steve Quote Link to post Share on other sites
Keith Winston Posted May 27, 2013 Report Share Posted May 27, 2013 A friend of mine did this mod and swears his car runs better. I rang a well known TR parts supplier to try and get a second hand air valve they asked me had I lost mine when I told them why I wanted one I was told not to do it as this would upset the air mix and that they once had a car in their workshops with this mod and took it off straightaway. So that left me even more confused than normal. I MUST SAY SHE DOESNT LOOK CHEAP, BUT I WOULD PUT MY WHEEL BALANCEING OUT OF SITE. Quote Link to post Share on other sites
TR674 Posted May 28, 2013 Report Share Posted May 28, 2013 I got as far as post #10 then forgot what the question was......................... Quote Link to post Share on other sites
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