Dannypwills Posted May 17, 2022 Report Share Posted May 17, 2022 Hi all I wanted to introduce myself as I am the proud owner of a 1973 MKIII GT6 in midnight blue. I bought the car from a great bloke in Rotterdam who had bought from a Dutch guy who exported in 2003, and who had looked after her excellently ever since (and given her a huge overhaul). I'm struggling at the moment to try and get the right balance/mix through the SU HS6s which the previous owner installed, and seem to be running rich no matter what I do! I'm in North London and would like to take the car to someone who knows what they are doing to take a look at that issue and to give it a once over, and so any recommendations would be hugely appreciated! Looking forward to contributing on here! Thanks Danny Link to comment Share on other sites More sharing options...
Steve P Posted May 17, 2022 Report Share Posted May 17, 2022 Try Dale at Moordale motors in Potters Bar,40 years of Triumph experience. Steve Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 17, 2022 Report Share Posted May 17, 2022 most who fit HS6 SU run into problems there a few around locally that we have reverted to strombergs and the original spec and all is smooth and fine there is no triumph spec for 2ltr on HS6 so you can end up laying with needles and never get it Nice would you be able to check what needles are fitted ??? Pete Link to comment Share on other sites More sharing options...
NonMember Posted May 17, 2022 Report Share Posted May 17, 2022 Just to agree with both Steve and Pete - the HS6s are your problem, and Dale is the man. Link to comment Share on other sites More sharing options...
Stratton Jimmer Posted May 18, 2022 Report Share Posted May 18, 2022 My GT6 (Mk3) has HS4 which work well enough while my GT6 engined Spitfire had (past participle) nearly new HS6 which I was able to get to run with a neutral mix - not too rich or too weak. The HS6 however gave me lots of trouble when starting the car and would never run smoothly on choke leading to many backfires, stalls and kangarooing until the engine was fully warmed up. I reverted to a pair of second hand Stromberg 150 CDSE very recently and the starting problems are now behind me. The car runs sweetly and with a very good mixture. What may have caused the problems was that the adaptor plates for the SUs had steps in them - a 1.75 inch carb feeding into a 1.5 inch manifold. My reasoning for this thinking being that I have no problems with the GT6 and its HS4 which are 1.5 inch carbs. Overall, I much prefer Strombergs to SU carbs. I can have a look and find out which needles the HS6 had as they are lying in my spares box waiting for me to sell them to some unsuspecting idiot thoughtful purchaser. Link to comment Share on other sites More sharing options...
Mjit Posted May 18, 2022 Report Share Posted May 18, 2022 In NW London I'd say your local specialists are: As others have said Moordale motors in Potters Bar JY Classics just outside High Wycome Picton Sportscars in Waltham Cross Link to comment Share on other sites More sharing options...
Stratton Jimmer Posted May 18, 2022 Report Share Posted May 18, 2022 After a trip to the shed, the needles from the HS6 are BCM. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 18, 2022 Report Share Posted May 18, 2022 Edit this is 2.5 sorry the triumph tune manual shows HS6 on aGt6/vitesse as std BDB with KN +631 BDQ + staged head BDM + camshaft BBQ have no idea how these would work you can play with the needle taper on here www.mintylamb.co.uk/suneedle/ HS6 have a 1mm jet HS4 & std stroms are 0,9 all these small points cause headaches bdb is a tad richer off idle but the bcm is a good bit richer everywhere else Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 18, 2022 Report Share Posted May 18, 2022 2 hours ago, Stratton Jimmer said: problems are now behind me. there you go these bright ideas never seem to match what triumph tested and used pleased the swap worked Pete 1 Link to comment Share on other sites More sharing options...
dougbgt6 Posted May 18, 2022 Report Share Posted May 18, 2022 3 hours ago, Stratton Jimmer said: problems are now behind me TENA sell stuff for that. Sorry, I was thinking about SUs flooding. Another vote for Strombergs. Doug Link to comment Share on other sites More sharing options...
Clive Posted May 18, 2022 Report Share Posted May 18, 2022 1 hour ago, Pete Lewis said: the triumph tune manual shows HS6 on aGt6/vitesse as std BDB with KN +631 BDQ + staged head BDM + camshaft BBQ have no idea how these would work you can play with the needle taper on here www.mintylamb.co.uk/suneedle/ HS6 have a 1mm jet HS4 & std stroms are 0,9 all these small points cause headaches bdb is a tad richer off idle but the bcm is a good bit richer everywhere else I can guarantee the BDB will be miles too weak on a 2 litre with K+Ns or any decent filter. They are te std 2500S needle, really weak and my 2.5 would not rev beyond 3000rpm, purely down to mixture. BDQ were pretty good although a tad lean in the mid range on an otherwise standard 2500s engine in my vitesse. And the list you posted is for the 2.5 engines. for 2 litre the TT manual gives: BDM/BAM/BAE depending on state of tune. In reality this needs to be set up by a COMPETENT rolling road operator. All complicated by not knowing about the head/cam. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 18, 2022 Report Share Posted May 18, 2022 21 minutes ago, clive said: nd the list you posted is for pleased you spotted that page had turned over and i have been scratching head on Ashley Mills recent 2.5 high speed shed wich has a right old mix ans match Link to comment Share on other sites More sharing options...
Clive Posted May 18, 2022 Report Share Posted May 18, 2022 17 minutes ago, Pete Lewis said: pleased you spotted that page had turned over and i have been scratching head on Ashley Mills recent 2.5 high speed shed wich has a right old mix ans match Ah, the Damson Dog. Or Basildon Banger... That should be well screwed together, if rather workman-like. But the saloon airbox is always a challenge. Link to comment Share on other sites More sharing options...
Stratton Jimmer Posted May 18, 2022 Report Share Posted May 18, 2022 2 hours ago, clive said: In reality this needs to be set up by a COMPETENT rolling road operator. The Sixfire had been "rolling road" set up by the PO. Hence the BCM needles. 1 Link to comment Share on other sites More sharing options...
Dannypwills Posted May 26, 2022 Author Report Share Posted May 26, 2022 Thanks all - appreciate the help! Have booked in at Moordale Motors so they can have a good look at it and potentially put the CD 150s back on. In the meantime the dizzy has bust so looking everywhere for an Accuspark that i can install! Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 26, 2022 Report Share Posted May 26, 2022 dont forget you need the tacho cable drive version what broken on the failed unit ??? Pete Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now