johny Posted July 23, 2023 Report Share Posted July 23, 2023 I think it has the potential to make the readings poorer but as theyre ok cant see in this case its going to change anything... Link to comment Share on other sites More sharing options...
Roger Posted July 23, 2023 Author Report Share Posted July 23, 2023 I had around 175 PSI on all six. Link to comment Share on other sites More sharing options...
Iain T Posted July 23, 2023 Report Share Posted July 23, 2023 That's excellent but there's obviously something wrong when the engine is warned up. Link to comment Share on other sites More sharing options...
johny Posted July 23, 2023 Report Share Posted July 23, 2023 How has this problem started? One trip out it was fine and the next it did this with nothing changed inbetween? Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 8 hours ago, johny said: How has this problem started? One trip out it was fine and the next it did this with nothing changed inbetween? The problem is that there has never been any trips with this engine. The car has been in my garage for about four years and I have only driven it very short distances basically "on my back yard". I bought the engine from a scrap yard in Sweden and it is used "as is". I have not take it apart, and I have not had a chance to drive it on a longer trip. Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 (edited) This is also one of the parts I suspect. I do have a spare one in my boxes. Just my opinion, but I think that design with "clamps and pivots" to attach the inlet / exhaust to the head on Mk I engines is one of the worst designs on a Triumph and also one of the main reasons that I want a Mk II engine in the future. I did notice that the bolts to these "clamps and pivots" was not tighten properly (always have the feeling that they will snap) so I think there is a possibility that I have massive leaks in between the cylinders around this gasket. Plan is to remove it for inspection. I will keep you posted... Thanks all for your feed-back and advice, much appreciated! Edited July 24, 2023 by Roger Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 24, 2023 Report Share Posted July 24, 2023 have you checked the valve clearances at 0.010" cold i never had any manifold or gasket problems on my 1600 same as mk1 2lt make sure the studs/bolts are not thread clogged Pete Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 4 minutes ago, Pete Lewis said: have you checked the valve clearances at 0.010" cold Yes, I did check that. It was ok, did not have to adjust it. Link to comment Share on other sites More sharing options...
johny Posted July 24, 2023 Report Share Posted July 24, 2023 Yes the exhaust arrangement isnt great and I had a few gasket failures but always from an exhaust to the exterior so you can see and hear the leak. The distance is much greater between the exhaust and intake ports so a failure there is much more unlikely and Ive certainly never seen that. However in the end the solution was simple - just keep the manifold fixings tight and since including that in my routine maintenance Ive never had any more porblems... Link to comment Share on other sites More sharing options...
Peter Truman Posted July 24, 2023 Report Share Posted July 24, 2023 (edited) 1 hour ago, Pete Lewis said: make sure the studs/bolts are not thread clogged Pete We had great issues with big valve flanges (600mm plus) which had full face gaskets the flange bolts got thread bound with the rubber gasket, which is why all my specs specified insertion gaskets only ie a narrow gasket which fitted between the flanges and inside the line of bolts. Mind you I've never had any issues with full face gaskets in a car environment. Edited July 24, 2023 by Peter Truman Link to comment Share on other sites More sharing options...
Iain T Posted July 24, 2023 Report Share Posted July 24, 2023 A now defunct Triumph specialist installed a new manifold gasket on my Mk2 engine. When I drove home I discovered the gasket blown due to the clamps not being tightened! Iain Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 24, 2023 Report Share Posted July 24, 2023 but a gasket leak/fail would not blow fuel back out the carb throat, thats indicative of a failed valve seat or head gasket crossover problem the fact its seems ok cold but spits when hot could well be a head crack opening up those comp figures of around 175 ( if PSI) are far too high for a std engine so i suspect the gauge is not reading well around 130ish is more normal (9 x 14,5) Pete Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 46 minutes ago, Pete Lewis said: i suspect the gauge is not reading well The gauge was very cheap, made in China so yes, it might not be correct. I will do a new test with throttles open. Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 1 hour ago, Pete Lewis said: the fact its seems ok cold but spits when hot could well be a head crack opening up Thats my main concern. I don't have another cylinder head, that is the only one I have! The nearest second hand cylinder head is 2000 miles away.... Link to comment Share on other sites More sharing options...
johny Posted July 24, 2023 Report Share Posted July 24, 2023 Check those valves first as it would have to be an enormous crack to blow back that much out of the carb😮 1 Link to comment Share on other sites More sharing options...
Stratton Jimmer Posted July 24, 2023 Report Share Posted July 24, 2023 Interesting thread - engine gets hot and carbs malfunction (spitting back). Is there too much heat from the exhaust manifold adversely affecting the carbs? Where do the carbs get their cold air from? Cold air has to be essential in being both dense as required for effective combustion and cold for helping to cool the carbs. I had an exhaust leak on a Kawasaki 4 cylinder bike that directed hot gasses straight at the float chamber of number 4 carb. It caused the engine to run very rough. Took the exhaust apart, refitted it with some exhaust paste on the joints and the problem was cured. Link to comment Share on other sites More sharing options...
Iain T Posted July 24, 2023 Report Share Posted July 24, 2023 I don't think the primary cause is manifold gasket. When mine went you could hear and feel the gas escaping. It made a racket but the car still ran with almost no loss of power. It did make an orrible black soot mark on the underside of my bonnet! My £1 bet is sticky valves. Iain 1 Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 (edited) New compression test, open throttles, cold engine. From cylinder 1 to 6: 190, 180, 175, 185, 180 and 190 PSI on number 6. Measured with this cheapo device: Edited July 24, 2023 by Roger Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 I also think manifold gasket is quite unlikely but I will change it tomorrow since I have one in the garage. The engine is kind of a "bitsa" with a mix of 2000 Mk I parts and parts from an early Vitesse HC engine. I have a vague memory that the inlet manifold from the HC engine did not fit very well. I think the exhaust manifold is from the 2000, they did not match so good. If new manifold gasked does not improve things then head will come of... Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 24, 2023 Report Share Posted July 24, 2023 all 1600 and mk 1 use the same gasket mk2 is very different whilst there are mix and match Mk1 manifold differences across the range in angles and stand off you cant mix mk1 and mk2 physically impossible pete 1 Link to comment Share on other sites More sharing options...
Iain T Posted July 24, 2023 Report Share Posted July 24, 2023 (edited) 1 hour ago, Roger said: New compression test, open throttles, cold engine. From cylinder 1 to 6: 190, 180, 175, 185, 180 and 190 PSI on number 6. Measured with this cheapo device Putting my head above the parapet just multiplying 14.7 by the CR isn't really accurate. A reading of about 180psi can equate to around 10:1 CR. Yes higher than standard but not too high. The main point is they are all relatively the same. Posts on the forum about CR/psi can get as heated as carburettor damper oil! Take a peak at the valves/rocker arms. Iain Edited July 24, 2023 by Iain T Link to comment Share on other sites More sharing options...
Roger Posted July 24, 2023 Author Report Share Posted July 24, 2023 3 minutes ago, Iain T said: Putting my head above the parapet just multiplying 14.7 by the CR isn't really accurate Yes, as I wrote above the device was very cheap and it has definitely not been calibrated. I don't trust those values either. But that cheapo device would at least indicate if the gasket had blown completely and lets say I had only 20 PSI on one or two cylinders. Link to comment Share on other sites More sharing options...
Iain T Posted July 24, 2023 Report Share Posted July 24, 2023 (edited) I have the same kit curtosy of Amazon! It's fine providing you don't want a guaranteed reading but just a comparison. My £1 bet still stands, what's the Swedish conversion! Oops sorry Finnish. Iain Edited July 24, 2023 by Iain T 1 Link to comment Share on other sites More sharing options...
johny Posted July 24, 2023 Report Share Posted July 24, 2023 I'll add a krona and say I think the engine has sat around a while so a valve(s) stem has corroded and now doesnt slide smoothly in its guide. The inlet valve(s) still moves but is sticky which gets worse as it heats up when it doesnt close fast enough so the compression stroke pushes a bit of gas back out, maybe... 2 Link to comment Share on other sites More sharing options...
Adrian Posted July 24, 2023 Report Share Posted July 24, 2023 (edited) Sounds exactly the same problem I had, fine when cold but once hot no power and failed to start, had to wait an hour or so for it to cool down and started again. Air leakage in the carbs. I replaced seals (obviously old and brittle), spindles etc, and......no discernable change once hot and continued to run fine. Adrian Edited July 24, 2023 by Adrian Link to comment Share on other sites More sharing options...
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