McMuttley Posted December 30, 2015 Report Share Posted December 30, 2015 Well the mongrel beasts are finally out. The underneath shows the effect off having an unsealed collector combined with running rich. Bob was correct, the throttle thin gamy was not properly connected, just nipped on by the nut - could this be a contributor to my woes ? The manifold has a very dark colouring, what is the cause of this, the exhaust smoke being recycled ? Exhaust extractor is also coming out to be replaced with a phoenix that is sealed ! In effect it is 3 'loose' pieces that sit in a forward facing open collector on the central pipe. Head inlet also very black - is that normal ? Quote Link to post Share on other sites
Don H. Posted December 30, 2015 Report Share Posted December 30, 2015 We're gonna have to think of a new name when you're done with this project, Austin. Olde Smokey ain't gonna cut it anymore. Quote Link to post Share on other sites
Peter Cobbold Posted December 30, 2015 Report Share Posted December 30, 2015 Looks to me as if the heat from the near-horizontal exhaust pipes has baked fuel in the adjacent inlet manifolds to carbon. A heat shield between the two would be a good idea. Or design the new exhaust manifold to turn away from the intakes. Or both. http://www.hemmings.com/mus/stories/2008/01/01/hmn_feature19.html Peter Quote Link to post Share on other sites
BlueTR3A-5EKT Posted December 31, 2015 Report Share Posted December 31, 2015 (edited) Is the bottom flange of the exhaust manifold touching the top face of the head block? That would hinder manifold sealing and often happens when the head has been shaved.. Blow back from the collector might indicate an exhaust system constriction. Peter W EDIT Thank you for the correction Mike Edited December 31, 2015 by BlueTR3A-5EKT Quote Link to post Share on other sites
mike3md Posted December 31, 2015 Report Share Posted December 31, 2015 Peter, think you mean the top face of the block? HNY Mike Quote Link to post Share on other sites
oldtuckunder Posted December 31, 2015 Report Share Posted December 31, 2015 From looking at the pics, I'd guess a lot of exhaust blow back past the inlet valves or a lot of oil vapour in through the carbs from the rocker breather (if you had one fitted). Thats a lot of burnt black oil for an inlet tract. Also intreagued by the blueing on the inlet valve stems, could be just burnt oil, but that colour looks almost like heat blueing. Others may correct me. Alan Quote Link to post Share on other sites
McMuttley Posted December 31, 2015 Author Report Share Posted December 31, 2015 Hi Peter et al, With the smoke stacks removed, the setback between block and head is visible. Will I have an issue fitting a phoenix extractor ? The generally sooty theme continues inside the exhaust port and manifold..... Finally, the smoke stacks themselves - the 1" of free pipe only into the collector indicates why so much was flowing back out into the engine bay and cockpit ! Something therapeutic cleaning the now exposed decades of gunk off the block and bay - even found what looks like a starter motor under there ! What does a rocker breather look like ? Quote Link to post Share on other sites
oldtuckunder Posted December 31, 2015 Report Share Posted December 31, 2015 What does a rocker breather look like ? Just to save time I looked at one of your earlier threads on the carbs with pictures, you don't have one! Quote Link to post Share on other sites
iain Posted January 3, 2016 Report Share Posted January 3, 2016 Will I have an issue fitting a phoenix extractor ? I don't think you will be able to answer that question Austin until you have the new manifold and see if it fouls the ribs on the block. If it does you will have to relieve these areas. Quote Link to post Share on other sites
Malcolm Tatton Posted January 3, 2016 Report Share Posted January 3, 2016 1" into the collector is about the same as 3 out of 4 of mine, the fourth has even less, but I don't get the same problems as you have had. When you say 'open collector' was it literally 4 pipes into an open funnel type thing or does the collector have a back plate with 4 holes? Quote Link to post Share on other sites
McMuttley Posted January 4, 2016 Author Report Share Posted January 4, 2016 Hi Malcolm I had thought it was open, but having crawled under there this morning, it is actually 4 pipes into 4 sleeves on the collector, which makes the back flow of exhaust fumes even more confusing. Before ordering a replacement phoenix system I will take it all off and check that there no blockages in the rest of the system, but as it 'pulses' out of the rear with some force, I suspect not. I would again try wrapping the collector, but as the previous attempt resulted in flames, I am slightly reluctant to do so. Maybe once the carbs are refurbished and we have a decent combustion process, the exhaust will be less noticeable ??? Now to find a box big enough for those carbs ! Quote Link to post Share on other sites
McMuttley Posted January 4, 2016 Author Report Share Posted January 4, 2016 ps having taken the rocker cover off at the weekend it seems the gasket wasn't particularly effective, or is this normal ? In addition, some milky sludge inside the cover, although only little in the breather cap. could this simply be a sign of a poor fitting rocker cover and limited running this year, or could it be a sign that the rings or valves need replacing ? Also, why are there odd little tabs / wires on the inside ends of the rocker cover lid, just visible above ?? Quote Link to post Share on other sites
oldtuckunder Posted January 4, 2016 Report Share Posted January 4, 2016 Hi Malcolm I had thought it was open, but having crawled under there this morning, it is actually 4 pipes into 4 sleeves on the collector, which makes the back flow of exhaust fumes even more confusing. Maybe once the carbs are refurbished and we have a decent combustion process, the exhaust will be less noticeable ??? Nope I think you will still have problems. Looking at the collector the real problem I think you have is that there is no clamping mechanism for the pipes into the collector, if you just slide them in with paste they will initially seal but the vibration/flexing will just crack it and the exhaust will just start blowing out again. An 1" inserted would make an OK seal if you can get a clamp around each, but it looks (from the picture) the 4 inlet pipes are butt welded to each other so I don't think you can get a clamp around them individually. From the picture I'm not sure how the original maker thought they would ever get a seal unless they were supposed to be welded into the collector. Which would be one option for you. I assume that there is a clamp joint at the back of the collector? if so try loosening that, reinsert all the header pipes again and then see if you can remove all 4 headers and the collector as a single unit. If you can then you could have the 4 pipes tack welded in place (so everything lines up) then remove and weld properly knowing that the whole assembley will refit as one piece. Alan Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 4, 2016 Report Share Posted January 4, 2016 (edited) hold all the pipes in with springs? Many years ago.....JanSpeed favoured that arrangement on their tubular manifolds where they fitted to collectors - Think 'A' series race tuning here Cheers Peter W Edited January 4, 2016 by BlueTR3A-5EKT Quote Link to post Share on other sites
RobH Posted January 4, 2016 Report Share Posted January 4, 2016 Some weeping from the rocker cover gasket is fairly normal Austin, being so flexible they can be awkward to line up and never seem to fit the cover properly. Re-use is not a good idea and the cork goes very flat. The gunk in the rocker cover is probably just condensation due to the engine not getting thoroughly warm for long enough. Quote Link to post Share on other sites
McMuttley Posted January 4, 2016 Author Report Share Posted January 4, 2016 Thanks Rob, Re pipes, a spring on only one extractor pipe, which I suspect was to (i) hopefully stop the collector going backwards with a rock and (ii) reduce the number of pipes at risk from said rock if its was a big one. The collector sits at the front of the long central pipe. I guess it could be tack welded to each pipe in place, then cut behind, then taken out and welded properly. My work would be whether all four extractors still sat cleanly on the manifold at the end of the process. I did try to seal the holes with JB weld high heat putty but that failed, as did wrapping in Nigrin exhaust bandage, as did wrapping in exhaust bandage, although the latter over the first two may have been why one of the first two became combustable !!!!! Quote Link to post Share on other sites
Malcolm Tatton Posted January 4, 2016 Report Share Posted January 4, 2016 Still don't get it. I was going to check my car before posting again, but mine has no clamps and I don't have the problems that you have had. What it does have is a stiff wire between the tag on the collector and the extractor pipe(s?) What I have had is the one pipe that only goes in to the collector a short distance has popped out a few times, (once coming off a ferry, once on a sleeping policeman and at least once on my steep drive at home). Seem to have sorted that with a jubilee clip around all 4 pipes, not to hold them in but to hold them together so that if one pops out , it remains lined up and pops back in again! It will be the weekend before I can take a photo. Maybe yours are just too slack a fit? (or maybe I do have the same issue but don't notice the exhaust gases because of the gear oil that drops on the exhaust and really stinks!) Quote Link to post Share on other sites
Peter Cobbold Posted January 4, 2016 Report Share Posted January 4, 2016 (edited) The air filter elements are oil-wetted? - could overdoing the oiling have caused the thick carbon crust on the intake manifolds: oil/fuel mixture cooked with exhaust heat.?? Edited January 4, 2016 by Peter Cobbold Quote Link to post Share on other sites
McMuttley Posted January 4, 2016 Author Report Share Posted January 4, 2016 Hi Peter, the filters were only (over!) oiled when I tried the recent carb clean-up, before that they were dry. The soot is not simply confined to the manifolds, after just a single run a noticeable black coating begins to appear on the inner wings and under-bonnet. I had always assumed it was the leaking exhaust collector, but it may also be oil leaking out from the rocker (or elsewhere) (or both being constantly re-cycled) However, one thing this car has is steady oil levels, never really drops - but could it be being topped up with water ! (no sign of moisture). All that said, last year we probably did no more than 1100 miles. One thought re the engine bay carbon coatings. It has a 3/4" doormat attached to the underside of the bonnet. It is unsightly and no doubt a fire hazard, but my temptation to 'shave it off' has been fettered by (i) the worry of the resulting appearance of stubble and glue and (ii) the fact that it may have been put there in the past due to the the abnormally hot bay and (iii) the result might be having to spray the bonnet both sides. However, could this doormat be collecting exhaust smoke and oily mist and then effectively releasing it as a powder coating of dry carbon rain Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 4, 2016 Report Share Posted January 4, 2016 Where the pipe goes through the cruciform of the chassis is there any support clamp/bracket/strap? The favoured method is to attach the pipe with the TR4 system to the gearbox mount, rather than the original TR2/3 system of clamping the pipe with a metal bracket to the chassis. Using the TR4 arrangement the exhaust will rock with the power unit. Connect the exhaust at the rear to the chassis usng the correct mount point. Cheers Peter W Quote Link to post Share on other sites
Malcolm Tatton Posted January 4, 2016 Report Share Posted January 4, 2016 Looks as if I was too smug! Been and taken a couple of photos from the sides: https://dl.dropboxusercontent.com/u/14101357/2016-01-04%2016.18.53.jpg https://dl.dropboxusercontent.com/u/14101357/2016-01-04%2016.21.08.jpg You can see the wire holding the pipe to the collector, but can also see carbon from the joint of one extractor in particular. However, it really doesn't present the problem that Austin seems to have. I did once have terrible problems with smoke/fumes in the car, it was when I first bought it in the 70's, but got much worse when the speedo approached 100mph. It was the engine breathing a 'bit heavy', but in those days I just wound down the windows.... Quote Link to post Share on other sites
RobH Posted January 4, 2016 Report Share Posted January 4, 2016 OK, the pipes don't make a good seal to the collector but the problem you describe makes me wonder whether the silencer is producing a lot of back-pressure Austin. Surely a decent straight-through system shouldn't allow much blow-back if it is clear ? I wonder whether the stuffing in the box has moved and blocked the flow? Quote Link to post Share on other sites
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