Knotshaw Posted June 6, 2021 Report Share Posted June 6, 2021 Can I use a triple Weber manifold from a TR6 on my Vitesse Mk2? Thanks Link to comment Share on other sites More sharing options...
johny Posted June 7, 2021 Report Share Posted June 7, 2021 Physically I cant see any reason why not as they are pretty much the same engine. Believe the exhaust manifold is different as the TR comes out in two pipes and the Vitesse one but that shouldnt affect the inlet. The main problem is over carburation and presuming you can adjust the jet size they might still end up working poorly at lower revs and need some serious gas flow work on the head and exhaust... 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 7, 2021 Report Share Posted June 7, 2021 what do you hope to gain ,,certainly not any economy and lots of intake roar setting up 3 can be another headache in terms of carbs more can often be ...less especially if used as a road car Pete 1 Link to comment Share on other sites More sharing options...
Clive Posted June 7, 2021 Report Share Posted June 7, 2021 The GT6 needs a special stepped manifold to clear the bonnet. My old TriumphTune manual suggests the stepped manifold IS required on a vitesse. So unless you get specific info, tread carefully. (setup is no issue, I have a pair of dellorto DHLA on a spit 1300, drives beautifully and economical on a longer run when driven with a light foot) 2 Link to comment Share on other sites More sharing options...
Knotshaw Posted June 7, 2021 Author Report Share Posted June 7, 2021 Thanks for the replies guys. Sorry, I should've said I'm considering an EFI installation and weighing up DCOE type bodies against converted Lucas bodies. Running a mildly worked head and TH5 cam - I think the cam will be too hot for a plenum and single body. 6-3-1 manifold and straight through single box 2" system sort out the other side. I realise that although I'll avoid most of the pitfalls you've all mentioned relating to triple carbs, I'll still be up against it when it comes to progression at small openings... does anyone know the approximate effective bore size of each of the two Lucas PI bodies. Link to comment Share on other sites More sharing options...
Clive Posted June 8, 2021 Report Share Posted June 8, 2021 PI bodies are big. In theory far too big for a 2L. However, having seen a MK1 2000 on them they do work. Nick on here has a VERY well sorted EFI setup on his vitesse, plenium, decent cam etc. That car goes rather well, he may be along, or find him on te sideways forum where you are likely to find more EFI Triumphs. (I cheated, fitted a ford engine, but GSXR throttle bodies so understand the issues involved) 1 Link to comment Share on other sites More sharing options...
Nick Jones Posted June 8, 2021 Report Share Posted June 8, 2021 Lucas TBs are 46mm each….. Big. Makes part throttle mapping fussy to say the least. I run a single 54mm on a plenum. Cam is from Newman, a hybrid of their PH3 on the inlet (300 degree) and PH2 (280 degree) on exhaust. It’s on the ragged edge for a plenum manifold, just a bit of hitchiness at low rpm/very light throttle. Slightly irritating in traffic queues, otherwise fine. About 140 bhp with a stomping midrange. Have an ITB inlet based on BMW K1100 parts in the works but motivation is low as the plenum does the job pretty well and is already there! Nick 1 Link to comment Share on other sites More sharing options...
Knotshaw Posted June 9, 2021 Author Report Share Posted June 9, 2021 On 08/06/2021 at 06:52, Nick Jones said: Lucas TBs are 46mm each….. Big. Makes part throttle mapping fussy to say the least. I run a single 54mm on a plenum. Cam is from Newman, a hybrid of their PH3 on the inlet (300 degree) and PH2 (280 degree) on exhaust. It’s on the ragged edge for a plenum manifold, just a bit of hitchiness at low rpm/very light throttle. Slightly irritating in traffic queues, otherwise fine. About 140 bhp with a stomping midrange. Have an ITB inlet based on BMW K1100 parts in the works but motivation is low as the plenum does the job pretty well and is already there! Nick That's great info Nick, food for thought, thanks. Those PI bodies are huge then, don't think they'll be the thing to achieve what I'm aiming for - was already thinking 40mm bodies were a bit on the large size for the job! Sounds like I might just about get away with a single body (the TH5 is 280 in and out) - did you modify PI runners and plenum? I've considered bike sourced ITBs but have concerns over linkages - opening progression and balancing. Link to comment Share on other sites More sharing options...
Nick Jones Posted June 9, 2021 Report Share Posted June 9, 2021 My Vitesse has a homebrewed manifold made from exhaust tube and 1.6mm sheet. How I did it (very out of date!!) http://www.tengaston.plus.com/Megasquirt1.htm A PI I did a few years later using the original manifolds but with a single TB. The PI stuff fits under the bonnet on a big saloon and looks at home. That made just under 150bhp and >160lb/ft from 1800 - 5200 rpm with the standard cam (TR6 twin downpipe manifold and some headwork) The Vitesse ITB project..... awaiting the will to take a working car apart to see how much it misses fitting by! BMW K1100 ITBs are 34mm and modular. I got 3 sets for <£100 total. I've made some proper rails since the pic was taken. The throttle linkage will be a bit fiddly..... If looking for bike ITBs, ignore the sports bikes, even the small capacity ones - mostly too big. The bigger touring stuff is more about torque and has better sizes - though often not prices! Nick Link to comment Share on other sites More sharing options...
Knotshaw Posted June 12, 2021 Author Report Share Posted June 12, 2021 Thanks for taking the time to post Nick, the plenum set up looks very neat and at home - it's easy to see why, when it's working reasonably well, you wouldn't be too anxious to get on with changing it. Is the plenum just an empty box, or have you got airflow separators of some nature? The ITBs look promising - the length of the runners looks quite erm.. ambitious 😀, way to go. Will you fit injector bosses right up close to the head again? Link to comment Share on other sites More sharing options...
Nick Jones Posted June 13, 2021 Report Share Posted June 13, 2021 The plenum is an empty box, but the entrances to the runners are well radius’d. If I were doing it again I’d try tapering it. A little wider than it is now at the front with the TB set more outboard and a little narrower at the back. There is no evidence of distribution problems though, plug colours very even. I’d also reduce the angle of the runners a bit to move the plenum back as the air filter is a very snug fit! Yes, the ITB runners are a touch long and may get trimmed a little, though we’ve made them tapered….. Tape measure says they’ll fit but the airbox will have to be compact! injector pockets will be next to the head and may lay them down a bit further to point more at the back of the valve. Nick 1 Link to comment Share on other sites More sharing options...
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