stephen cooper Posted February 6, 2007 Report Share Posted February 6, 2007 Ok, now I know this topic has cropped up quite a few times already! (I had a search through the archives). But, I couldn't find hardly any info on a manifold I've just bought that is to be fitted to a pretty standard 150 TR6pi (see attachment). I know the general consensus is to fit a 6-3-1 be it moss or phoenix though they are pretty dear! I was wondering if anyone has any experience/opinion on how this bunch of bananas will work? It might not be the same but looks pretty similar to what revington and racetorations are selling looks basically a 6-1 setup. Oh and the current manifold is the old TT 6-2-2 - I think the worst thing possible! Thoughts appreciated! Steve Quote Link to post Share on other sites
roulli Posted February 7, 2007 Report Share Posted February 7, 2007 Oh and the current manifold is the old TT 6-2-2 - I think the worst thing possible! Steve Steve, and anyone who wants to comment, Assuming that you're talking about the steel sports manifold in 2 parts with 2 exits, not the original cast manifold. Why is this one so bad? My Tr6 is fitted with this one and I planed actually to replace the original exhaust system by a 2 box system from Revington. Now according to you, if the 6-2-2 manifold is bad, my plan to build on it is not good either. Explaining your concerns, could help me to adapt my plans. Thanks in advance Cheers Patrick Quote Link to post Share on other sites
john.r.davies Posted February 7, 2007 Report Share Posted February 7, 2007 (edited) Steve, Patrick, If you have read previous threads, you will be aware of the theory that a 6-3-1 allows the impulses from cylinders that fire on alternate rotations (eg 6/1, 5/2, 4/3) to 'interfere' or 'resonate' and so improve extraction from each other. Once this arrangement is in place, the length of the primaries determines at what engine speed the interference optimises. Like an organ pipe, a long tube produces a deeper note, a lower frequency and will resonate at a slower engine speed. The practical optimum seems to be about 15". A 6-2-1 connects the cylinders in the wrong way for this to happen. The impulses from, say, 4-5-6 will arive at the junction at the wrong moment for them to assist extraction from their adjacent cylinders. A four cylinder engine, that has no pairs of alternating cylinders, cannot have an interference manifold but can achieve resonance at much higher revs with a manifold with much longer primaries . Triumph sixes cannot achieve the higher revs, 7K+, that a four can without extensive and expensive mods. The manifold you show is designed, I suspect, for a full race engine by someone striving for resonance at very high revs. I doubt if a road engine will gain any benefit from it. John PS if you want a manifold for very, very high revs, see: http://www.jagclub.ru/triumph_tun.html Edited February 7, 2007 by john.r.davies Quote Link to post Share on other sites
CONCRETE24 Posted February 7, 2007 Report Share Posted February 7, 2007 (edited) Anybody any idea where to get the Phoenix manifold (and single pipe exhaust)? I thought TRGB sold it but their catalogue states 6-1, same as Revington, which I understand will give little benefit in my (sub-standard ) road engine. All the previous threads point to Phoenix being the best supplier of 6-3-1 and as my current stainless exhaust seems to have had most of the baffles blown out and the standard manifold likes to separate from the rest of the system, I feel an upgrade coming on! Thanks, Michael. Edited February 7, 2007 by CONCRETE24 Quote Link to post Share on other sites
Tom Fremont Posted February 7, 2007 Report Share Posted February 7, 2007 Steve, What you depict is similar to the Racetorations / Phoenix 6-2-1 ( as I call it - 2x [3-into-1] again into 1 via Y ). The "dissed" type seem to be the short-runner type which join about mid-way up the block. Since you've bought it I suggest sending the picture to Racetorations for their comments. You'll get a straight answer on that , plus what benefits you can expect for your state of tune. Spare yourself some potential grief and ensure your starter is good at time of installation of the headers - some interfere with removal/replacement Quote Link to post Share on other sites
stephen cooper Posted February 7, 2007 Author Report Share Posted February 7, 2007 (edited) Thanks for the comments guys, Patrick it's my understanding the 6-2-2 which you and I have is the worst, because as John points out the cylinders on the triumph 6 pot are paired up. On a 6-2 where 1-3 and 4-6 are joined together the system at no point joins up as 1 so in effect you have have a system which is working like two 3 cylinder engines! This doesn't give the system a chance to pulse or scavenge/interference which is what a good extractor should do, hence you probably lose a lot of torque over even the standard cast iron manifold. Tom I'm not sure Phoenix have made anything other than the well known 6-3-1 they offer so to avoid confusion I'd call the manifold in my picture the racetorations/revington style 6-1 I think it is technically a 6-3-2-1 however the secondaries are that short that it's basically a 6-1 is it similar to what you have fitted? If so how do you find it? I will email racetorations by the way thanks for that. I'm a bit worried that it'll be all for the top end as John states however at least this one going into one pipe should scavenge and give an improvement over a 6-2-2 I'd hope!? Cheers Steve Edited February 7, 2007 by stephen cooper Quote Link to post Share on other sites
Tom Fremont Posted February 7, 2007 Report Share Posted February 7, 2007 Tom I'm not sure Phoenix have made anything other than the well known 6-3-1 they offer so to avoid confusion I'd call the manifold in my picture the racetorations/revington style 6-1 I think it is technically a 6-3-2-1 however the secondaries are that short that it's basically a 6-1 is it similar to what you have fitted? If so how do you find it? I will email racetorations by the way thanks for that. Steve, I think my Racetorations-supplied system is by Phoenix ( they didn't deny it when I referred to it as such ) but it may be available only through them. Again, very similar to what you show though the two sets of (3) are better nested down low on mine. I have only known Racetorations to use a single-bore exhaust in conjunction therewith. I love mine which has done ~ 35000 miles. I don't know precisely what it does for performance because I fitted a Racetorations head at the same time! The combination cut at least 1 second off the 1/4 mile time, however. I'll be using the same system on my current project, with a new twin-outlet muffler on the large single-bore exhaust Not a highly modded engine, I don't go over 5500 rpm. It's got the early P.I. cam and triple Webers besides the exhaust and head, but std c/r. I got my 1st set ceramic coated, and will do the same on the current project. Quote Link to post Share on other sites
boxer Posted February 8, 2007 Report Share Posted February 8, 2007 phoenix manifold and single big bore available from robsport 01763262263. the fixing kit is a must about £400+gordons beer money of course. works and sounds great with head and cam work Quote Link to post Share on other sites
CONCRETE24 Posted February 20, 2007 Report Share Posted February 20, 2007 phoenix manifold and single big bore available from robsport 01763262263. the fixing kit is a must about £400+gordons beer money of course. works and sounds great with head and cam work Thanks for the tip off - yep they managed to find one when everybody else was offering a vague 'several weeks, not in production at the moment etc....' I'm having some clutch, gearbox and starter repairs at the moment, so the garage doing the work are going to fit the exhaust while I go mountain biking across the Atlas mountains in Morocco! Can't wait to get back and see/hear it all in one piece now! (er..if I make it back). Michael. Quote Link to post Share on other sites
oily Posted February 20, 2007 Report Share Posted February 20, 2007 (edited) This is a full race tubular manifold for a TR6. A bit different to the road going versions. But the thing of interest is that it runs 6 3 1. The 1 being a collector that isnt shown. Final exhaust size 64mm ID. This would seem to support the theory. Noel PS This is going on my 6. God help us when it gets to Malvern this year. I will make sure that i do not arrive at night an wake up all the happy campers. Edited February 20, 2007 by oily Quote Link to post Share on other sites
stephen cooper Posted February 20, 2007 Author Report Share Posted February 20, 2007 As sold by TRE that one I think? How much did that one set you back? I've since picked up a phoenix 6-3-1 so I think i'll be using this over the "bananas" for now at least. Thanks Quote Link to post Share on other sites
oily Posted February 20, 2007 Report Share Posted February 20, 2007 Old sharp eyes. Quite right. TRE are building the engine complete so it would seem to make sense to get the system from them. Manifold and exhaust is 7-800 nicker. However i am replacing the exhaust with a copy in stainless steel. Ceramic coating another 250-300. Noel Quote Link to post Share on other sites
john.r.davies Posted February 20, 2007 Report Share Posted February 20, 2007 Old sharp eyes. Quite right. TRE are building the engine complete so it would seem to make sense to get the system from them. Manifold and exhaust is 7-800 nicker. However i am replacing the exhaust with a copy in stainless steel. Ceramic coating another 250-300.Noel TRE? As in "Triumph for the Environment" and vapourware about re-using the Triumph marque name? Surely not!? John Quote Link to post Share on other sites
grmills Posted February 21, 2007 Report Share Posted February 21, 2007 This is a full race tubular manifold for a TR6. A bit different to the road going versions. But the thing of interest is that it runs 6 3 1. The 1 being a collector that isnt shown. Final exhaust size 64mm ID. This would seem to support the theory. I had one of these, or something remarkably similar; it rotted through in about five years... Quote Link to post Share on other sites
oily Posted February 21, 2007 Report Share Posted February 21, 2007 Did you have it ceramic coated. The one thing i dislike about stainless steel manifolds is the noise they produce. Mild steel is a lot quiter. The exhaust on the otherhand needs to be stainless for the very reason you mention. Which is why its being rebuilt in 316. Quote Link to post Share on other sites
grmills Posted February 21, 2007 Report Share Posted February 21, 2007 Did you have it ceramic coated. The one thing i dislike about stainless steel manifolds is the noise they produce. Mild steel is a lot quiter. The exhaust on the otherhand needs to be stainless for the very reason you mention. Which is why its being rebuilt in 316. Not ceramic quoted, but it was wrapped (which may have been a factor with the rot). Regards the noise, my suspicion is that the increased tinniness and volume with SS has more to do with reduced wall thickness than the resonant qualities of the material. Consequently if I were going down this road again I'd avoid off-the-shelf items (and associated fitting problems) by having it custom-built by a specialist, using a greater wall-thickness. Quote Link to post Share on other sites
oily Posted February 21, 2007 Report Share Posted February 21, 2007 Back to this old thing about materials. It seems to me that systems are made from 304. Salt will make this rust. Few pounds more for 316 and it would last forever. I beleive that stainless will resonate more regardless of thickness. But then adding thickness to dampen sound isnt what the racing boys want. So for the road car there has had to be a compromise. Manifold in mild and triple ceramic coated. Mild steel exhaust used as a pattern for a 316 copy at 1.6mm t. Quote Link to post Share on other sites
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