bluelighttaxidriver Posted February 6, 2017 Report Share Posted February 6, 2017 Just aquired a 2.5ltr bare engine, code MM. Will the CD150'S from my existing 2ltr be sufficient (obviously with needles), or the set of HS6's sitting in my shed? It's for a mk3 gt6 by the way. I know there are clearance issues, so can I just get short dashpots, springs & dampers..? Thanks. Link to comment Share on other sites More sharing options...
TomL Posted February 6, 2017 Report Share Posted February 6, 2017 Hi, I think most people associate the bigger, HS6's with the 2.5, and the smaller, HS4's or CD150's, with the 2-litre. I have HS6's on my 2.5-litre Vitesse and I use a 2500"S" manifold (which has been machined to compensate for the approx. 7 degree cant of the big saloons' engine). I believe it is possible to fit the CD150's to the 2.5 but it is far less common. Tom Link to comment Share on other sites More sharing options...
dougbgt6 Posted February 6, 2017 Report Share Posted February 6, 2017 American TR6s with 2.5s use the larger 175CD Strombergs http://www.buckeyetriumphs.org/technical/technical.htm Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 6, 2017 Report Share Posted February 6, 2017 not looked but i would think finding compatible needles for 150 stroms on a 2500cc would be a bit hard to please there was an australian spec 2500 with CD3 150 used needle B5DG but UK was HS6 needle BDU spring specs are not in the Triumph WSM Pete Link to comment Share on other sites More sharing options...
bluelighttaxidriver Posted February 6, 2017 Author Report Share Posted February 6, 2017 That's really good, thank you people. Tom, I have the manifold for the SU's too, so will look into machining. Happy days..! 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted February 6, 2017 Report Share Posted February 6, 2017 The 2.5 carb Saloon needles are BDB and springs yellow. A bit weak on K & N's SAH/Triumph Tune recommend BDQ. More importantly the Standard SU's and 2500 manifold will not fit under the bonnet of a GT6. Your have to fit adaptor plates, Triumph Tune, to the GT6 manifold and used short dashpot SU's from a Dolomite Sprint. Or as the 2500 inlet manifold is angled up, the problem, modify it take out the angle. A job for a specialist. As a temp measure you can use the CD150's. But,as you would suspect with smaller throat carbs lots of low down torque but less willing to rev from mid to top range. Pete, BDU is the OZ spec for the 2500, as per the Triumph WM and SU notes. You have to turn BDU needles upside down to get them to work in the UK! Dave Link to comment Share on other sites More sharing options...
Clive Posted February 6, 2017 Report Share Posted February 6, 2017 The BDQ needles are a pretty good match to a 2.5 in one of our cars. My vitesse used the std vitesse manifold initially with adapter plates, later I slotted the carb mounting holes. Also need to open up the manifold to the bigger opening (i used a cone shaped drill rasp type thing, took 10 mins) Re air filters, I used the std airbox cut open to suit the carbs, and used K+N elements siliconed into place. Don't need cleaning too often! Use GT6 sump with some dents added to clear N01 and 2 crank journals. 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted February 6, 2017 Report Share Posted February 6, 2017 Clive - Yes did the same on the wife's GT6 Convertible she had 20 years ago. Ended up with a skimmed S head and Mk2 Cam. BAE needles and green springs. The Rotoflex couplers put up with the torque OK which surprised me. 160 flb torque and around 130 BHP. It used to make drivers of more powerful sports cars wonder what was going on. You been there you know what I mean! Dave Link to comment Share on other sites More sharing options...
Clive Posted February 6, 2017 Report Share Posted February 6, 2017 That vitesse was my everyday car for many years (13 or 14 I think) and was brilliant fun. I blew a few 3.27 diffs though......and it used quite a bit of fuel owing to my enthusiastic driving on the morning commute! Laster had a TR6 short engine and piper cam, but in all honesty I preferred the std cam, much smoother. nowdays I intend getting rather more power and torque out of 4 cylinder engine, but it ain't a triumph lump. It is already bolted in the spitfire though, just all the little bits to sort. Ready for Santa Pod! 1 Link to comment Share on other sites More sharing options...
Steve P Posted February 6, 2017 Report Share Posted February 6, 2017 I thought the angle of the engine on the 2.5 came from the front plate mountings,i didn`t modify the long `S` manifold on my Vitesse 2.5 but it does have short dashpots from a Sprint. Not sure if that`s relevant to a GT6 though. S Link to comment Share on other sites More sharing options...
bluelighttaxidriver Posted February 6, 2017 Author Report Share Posted February 6, 2017 Can't see any sprint HS6's anywhere. However have seen some CD175's that came off a TR6. Would they be suitable..? Shouldn't be any clearance issues either.. Link to comment Share on other sites More sharing options...
Steve P Posted February 7, 2017 Report Share Posted February 7, 2017 Cd 175`s will work but there wont be as many needle options for Strombergs. Steve Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 7, 2017 Report Share Posted February 7, 2017 there will be std needles available both have limited clearance with the turret and need a thin airbox and tubed filter on the saloons dont know how that stacks up on a GT6 as soon as you use orrible pancakes you need needle or spring options to compensate for the lower intake depression. Link to comment Share on other sites More sharing options...
dave.vitesse Posted February 7, 2017 Report Share Posted February 7, 2017 You can't use the 2500 inlet manifold under the GT6 bonnet. CD 175 will fit using adaptor plates on the existing GT6 manifold. However, I agree with Steve the lack of suitable needles is a problem. Steve, The angle is also on the 2500 inlet manifold. It just fits under the bonnet of a Vitesse. But not under a GT6 bonnet. Dave Link to comment Share on other sites More sharing options...
Clive Posted February 7, 2017 Report Share Posted February 7, 2017 Can't see any sprint HS6's anywhere. However have seen some CD175's that came off a TR6. Would they be suitable..? Shouldn't be any clearance issues either.. I have a pair I was going to take to stoneleigh..... 1 Link to comment Share on other sites More sharing options...
bluelighttaxidriver Posted February 7, 2017 Author Report Share Posted February 7, 2017 Clive I have sent you a message. Many thanks..! Link to comment Share on other sites More sharing options...
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