Revolution Posted March 2, 2015 Report Share Posted March 2, 2015 Hi Everyone I've had the usual occasional, leaky float chambers on my TR4A HS6's for some while and have done the usual floats, jets replacements etc., But I notice that the Float Chamber bodies are a good 5 degrees off level ,sloping away from the manifold This could be causing uneven pressure on the float as the chamber fills up with fuel and hence causing an intermittant shutting off of the fuel supply and therefore creating the flooding Is it usual to have sloping Float Chambers or do you think they should be level? Appreciate any views even if it's to say I barking up the wrong tree (or barking mad!!!) Regards, Nick Quote Link to post Share on other sites
Peter Cobbold Posted March 3, 2015 Report Share Posted March 3, 2015 (edited) Nick, The f/c float floats up to close off the petrol flow into the carb. So I'm not sure how it shutting off the fuel supply can create flooding. Is the engine flooding over-rich? or is fuel coming out of the f/c overflow or between the lid and bowl? Not having a 4A I dont know for certain. But the angle of the float chamber vertical axis compared with the jet and main body can be set on HS carbs by using the correct adaptor - item 10 here: http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29129 There are several adaptor designs - for a wide variety of engines - that set different f/c to body angles. Maybe you have the wrong adaptor for the 4A ? The fc valve would I think work best if the fc is vertical to the ground, I try to set mine like that. Peter Edited March 3, 2015 by Peter Cobbold Quote Link to post Share on other sites
ctc77965o Posted March 3, 2015 Report Share Posted March 3, 2015 If 5 degree were important we'd never tackle hills. also, think of the vibration on your engine, I bet even if they 0 degree they'd be sloshing +/- 5 degree as u drive.... Quote Link to post Share on other sites
Revolution Posted March 3, 2015 Author Report Share Posted March 3, 2015 Hi Pete Thanks for your comments.....fuel is coming out of the f/c overflow I just had the feeling that maybe the carbs were from another car and the f/cs had been set up differently Dave, point taken.....guess I'm grasping at straws ........may be it's as simple as the occasional bit of dirt preventing the valve working properly 100% of the time Perhaps I'm just resisting the need to flush out the fuel tank! Cheers, Nick Quote Link to post Share on other sites
RogerH Posted March 3, 2015 Report Share Posted March 3, 2015 Hi Nick, here is another view of the adaptor - item 10. http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/fuel-system-induction-controls/carburettors-manifolds/carburettors-air-cleaners-hs6-su.html The FC is attached by a big bolt that passes through the carb body. However the adaptor is pegged in place. As Dave pointed out 5 degrees isn't a lot. Have you fitted new valves. 'Gross jets' are almost foolproof and worth fitting (always carry a spare). Roger Quote Link to post Share on other sites
Graham Harris Posted March 3, 2015 Report Share Posted March 3, 2015 Check the float to make sure it's floating? Graham Quote Link to post Share on other sites
Peter Cobbold Posted March 3, 2015 Report Share Posted March 3, 2015 Both f/cs overflowing? - fuel pressure too high? Quote Link to post Share on other sites
Revolution Posted March 3, 2015 Author Report Share Posted March 3, 2015 Hi Peter Have just checked the fuel pressure with a guage by cranking the engine over....it's around 5 - 6 lbs/sq in That's a bit high isn't it ? Nick Quote Link to post Share on other sites
Fireman049 Posted March 3, 2015 Report Share Posted March 3, 2015 I agree with Roger ~ I fitted both my TR3A and 'E'-type Jaguar with Grose jets and have never had any trouble since. Remove both floats and give them a shake and listen for any fuel inside them (if they're brass then they can easily be repaired by soldering ~ if plastic then replace). Tom. Quote Link to post Share on other sites
MRG1965 Posted March 3, 2015 Report Share Posted March 3, 2015 Hi Peter Have just checked the fuel pressure with a guage by cranking the engine over....it's around 5 - 6 lbs/sq in That's a bit high isn't it ? Nick HI Nick, I have just been playing with the carbs on my TR4 (put some grose values in too) and my fuel pressure with the mechanical pump, at idle (running on the contents of the float chambers) was 3psi. I think 5 or 6 is quite high, can you be sure the gauge is accurate?. I recall from my research recently that it should be around 1.5 to 3 psi. Mark Quote Link to post Share on other sites
Peter Cobbold Posted March 3, 2015 Report Share Posted March 3, 2015 Hi Peter Have just checked the fuel pressure with a guage by cranking the engine over....it's around 5 - 6 lbs/sq in That's a bit high isn't it ? Nick Nick, For SUs I think it is. I use 3psi, set with one of these in the hose to the f/cs: http://sucarb.co.uk/media/catalog/product/cache/3/image/9df78eab33525d08d6e5fb8d27136e95/s/u/su_image-2859_original.jpg Peter Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 3, 2015 Report Share Posted March 3, 2015 Once upon a Time.... There were cheap SU HS6 carbs sold to TR Register members through the spares scheme by messrs Cox & Buckles. These carbs often had the float chamber at the wrong angle, being I think ex Volvo items. (what do you want for £12.50 the pair!) To correct you could either BUY the correct rubber adaptor (item 10 on Roger's link above) or FILE the fitted aluminium adaptor to get the float chamber level. (this assumed you had the aluminium spacer fitted) My own car is fitted with such items and filed aluminium adaptors. For my money the fc should at least start level, to give the thing a fighting chance. Cheers Peter W Quote Link to post Share on other sites
Revolution Posted March 3, 2015 Author Report Share Posted March 3, 2015 Peter W .....that's interesting and I wonder if my carbs were out of a Volvo then Anyway, I 've filed the aluminium adaptor so that both f/cs are level and with fingers and toes crossed I started her up and ran it for 20 minutes.........no leaks!! Time will tell but as you say, it gives her a fighting chance If the problem returns, I think my next plan will be to reduce the fuel pressure but will double check with a guage before I start and then consider the Pro Flow suggested by Peter C Thanks all for your advice as usual Nick Quote Link to post Share on other sites
Lebro Posted March 4, 2015 Report Share Posted March 4, 2015 Once upon a time I have said pair of HS6's from Cox & Buckles purchased in the 70's. The ID tag on mine show them to be from an Alegro "sport", but re-needled for TR. The float chamber angles are correct in my case, & have given no trouble in all that time. Bob Quote Link to post Share on other sites
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