Xander Posted May 29, 2006 Report Share Posted May 29, 2006 Hi New to this so here goes. I purchased a TR6 CR 1974 which has been converted from a PI. It is starving of fuel if I put my foot down. I have been told that someone has put on TR4 SU carbs (H6 I think) and that I will never get a TR six to work with them as they have fixed needles and I will have to puchase a new or second hand set of HS6's with the correct BAG floating needles. Someone else told me that that is not necessary as I can keep the H6 carbs, buy BAG needles and knock off the top hats (whatever they are). Will this work ? Or, would it just be better to go to a rolling road, suffer the 200 pounds and have it sorted. or even a set of new HS6's 309 pounds plus vat. Thanks Alex Quote Link to post Share on other sites
Cinnobar Posted May 29, 2006 Report Share Posted May 29, 2006 Hi New to this so here goes. I purchased a TR6 CR 1974 which has been converted from a PI. It is starving of fuel if I put my foot down. I have been told that someone has put on TR4 SU carbs (H6 I think) and that I will never get a TR six to work with them as they have fixed needles and I will have to puchase a new or second hand set of HS6's with the correct BAG floating needles. Someone else told me that that is not necessary as I can keep the H6 carbs, buy BAG needles and knock off the top hats (whatever they are). Will this work ? Or, would it just be better to go to a rolling road, suffer the 200 pounds and have it sorted. or even a set of new HS6's 309 pounds plus vat. Thanks Alex No problem with fixed needles you just need the right ones! Be worth a ring to Burlen services as they maybe able to get closer or yes invest in a session on the rollers! Quote Link to post Share on other sites
boxer Posted May 29, 2006 Report Share Posted May 29, 2006 No problem with fixed needles you just need the right ones!Be worth a ring to Burlen services as they maybe able to get closer or yes invest in a session on the rollers! phone burlens they will put you on the right track.i converted my hs6,s and run on bag needles but i think i may change to bae as it does run a bit rich . a good site to visit is www.mintylamb.co.uk/sunneedle/ it has a brilliant needle comparison chart Quote Link to post Share on other sites
marvmul Posted May 29, 2006 Report Share Posted May 29, 2006 TR4A have HS6 SU's with fixed needles, so not all HS carbs have spring loaded needles, but I think that all H carbs have fixed needles. Spring loaded needles can be recognised by a collar on the upper end. I don't think you need a rolling road to choose the right needle, the Triumphtune Manual is very useful to choose the right needles (the jet's need to be 0.100, TR4A cars have SU's with 0.090 jets). For a TR6 I suppose HS6 carbs only can be used, the H carbs have a long tract towards the inlet manifold (used on TR2-TR3A and also TR4 cars). I suppose all HS6 carburettors with a 0.100 jet can be used, with BAE needles to start with, and BAE are often the best choice. Quote Link to post Share on other sites
marvmul Posted May 29, 2006 Report Share Posted May 29, 2006 'TR4A cars have HS6 carbs with 0.090 jets' : I meant US TR4A's : those cars have SU's with 0.090 jets while the european TR4A's have 0.100 jets. Quote Link to post Share on other sites
reg brg Posted May 30, 2006 Report Share Posted May 30, 2006 Alex There is another good site called WINSU151 I have found this brilliant If you type in winsu it will let you down load to compere at your leasure Reg Quote Link to post Share on other sites
Xander Posted May 30, 2006 Author Report Share Posted May 30, 2006 Hmmm. Thanks for all that. Not sure now whether I have H6's or HS6's. What did TR4's have ? If I have TR4 carbs (I assume H6's although not sure) would BAG's or BAE's suffice ? More importantlly is it worth me trying to find the correct needles or will TR4 SU carbs never work correctly with a TR6 as Southern Triumph Sevices have told me and I therefore have to get some new HS6's with floating needles. Arrghhh ! Quote Link to post Share on other sites
marvmul Posted May 30, 2006 Report Share Posted May 30, 2006 Hmmm. Thanks for all that. Not sure now whether I have H6's or HS6's. What did TR4's have ?If I have TR4 carbs (I assume H6's although not sure) would BAG's or BAE's suffice ? More importantlly is it worth me trying to find the correct needles or will TR4 SU carbs never work correctly with a TR6 as Southern Triumph Sevices have told me and I therefore have to get some new HS6's with floating needles. Arrghhh ! HS6 carbs are not much longer than the piston housing, H6 carbs are twice that length because the tract of this carb to the inlet manifold is about 3" long. H carbs are fitted to the sidescreen cars and part of the TR4 cars. Only HS6 can be fitted to a TR6, either with fixed (no collar) are with spring beased needles. Fixed needles need to be checked after fitting if they move freely in the jet opening without touching the jet. Spring loaded needles are supposed to touch the inside of the jet in order to get a constant shape of the area between needle and jet. Hope this helps. So you have to find HS6 carburettors, and fit them with BAE needles, spring biased. Don't know if HS6 are different in order to accept fixed or spring needles. Quote Link to post Share on other sites
pauls Posted May 30, 2006 Report Share Posted May 30, 2006 The HS6 SUs with fixed needles will stay longer in tune than the ones with the later spring loaded or floating needle. The spring loaded ones wear the needle and needle guide down faster that the ones that are fixed. When I converted my 78 MGB over to dual HS4 SUs I had them modified to use the earlier fixed needles because of the wear issues and the fixed type also had a larger selection of needle sizes. Also check the throttle valve (disc) and if yours has a small spring loaded valve on it then soldier it closed or convert it to an earlier solid type disc. If you live in the US give Joe Curto http://www.joecurto.com/categories.php?op=newindex&catid=10 a call, tell him what you have and he will fix you up. You do not need to buy different carbs to get your 6 running right,just call Joe. Paul Quote Link to post Share on other sites
marvmul Posted May 30, 2006 Report Share Posted May 30, 2006 Xander if your HS6 have fixed needles, I will find out which (fixed) needles you need. I suppose most HS6 and all new HS6 have spring loaded biased needles. Quote Link to post Share on other sites
Rex Wyer Posted May 31, 2006 Report Share Posted May 31, 2006 Alex, Ring Andrew Turner 01572 767665, He is nr Grantham and specializes in SU Carbs. Also look at his website www.su-carbs.co.uk He has probably forgotten more about them than we will ever know. Ususally attends all the shows and is very helpful. Quote Link to post Share on other sites
Xander Posted June 3, 2006 Author Report Share Posted June 3, 2006 Xander if your HS6 have fixed needles, I will find out which (fixed) needles you need.I suppose most HS6 and all new HS6 have spring loaded biased needles. Marvmul I don't think I have got HS6 carbs. I think I have got H6 carbs and you said that TR6's will only take HS6 carbs because of the length. Is that the case ? Cheers Alex Quote Link to post Share on other sites
marvmul Posted June 3, 2006 Report Share Posted June 3, 2006 Marvmul I don't think I have got HS6 carbs. I think I have got H6 carbs and you said that TR6's will only take HS6 carbs because of the length. Is that the case ? Cheers Alex The deep (about 3") K&N filters on the HS6 carbs of my TR6 almost touch the inner wing : about 8mm - 1/3" clearance. An H6 carb is at least 1" longer than an HS6 one, so it would definitely touch the inner wing on my car. I'm not sure about the length of the respective inlet manifolds though, but I wouldn't fit a HS6 on a TR4 or earlier manifold, because from TR4A on, the manifolds are a much better design, and perhaps the early manifolds are as long as the later one's. I've never seen a TR6 with H6 carbs either. Xander, from piston chamber to manifold flange, a H6 carb has a tract of about 2", on a HS6 carb, this tract is only 1 " I guess. Quote Link to post Share on other sites
marvmul Posted June 3, 2006 Report Share Posted June 3, 2006 I've screwed up things in my former post : only a 6 cyl inlet manifold can be used of course, not a 4 cyl manifold. So I suppose H6 carbs can't be fitted in a TR6. Quote Link to post Share on other sites
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