Roger Posted July 25, 2023 Author Report Share Posted July 25, 2023 16 hours ago, Stratton Jimmer said: Is there too much heat from the exhaust manifold adversely affecting the carbs? I'm fortunate to live on an island far away from the extreme heat waves we see on the news. Outdoor temp was about 65F / 18 C when the engine failed, I assume the air was cool enough. Air flow arrangement as on original cars. Link to comment Share on other sites More sharing options...
Roger Posted July 25, 2023 Author Report Share Posted July 25, 2023 11 hours ago, Iain T said: My £1 bet still stands, what's the Swedish conversion! Oops sorry Finnish. Interesting thread drift, natinality is confusing in my case. The Åland Island was part of Sweden for 800 years, now part of Finland but autonomous and we have our own goverment & flag. My first language is Swedish but I have a Finnish passport. In short, I'm a Swede with a Finnish passport.... Link to comment Share on other sites More sharing options...
Roger Posted July 25, 2023 Author Report Share Posted July 25, 2023 5 hours ago, Adrian said: replaced seals (obviously old and brittle), spindles etc, and......no discernable change once hot and continued to run fine I pray to God that I have the same root cause here, and not a crack in the cylinder head that opens up with heat. Sticky valves are next on the list to check after replacing gaskets. I will keep you posted... Link to comment Share on other sites More sharing options...
Roger Posted July 25, 2023 Author Report Share Posted July 25, 2023 11 hours ago, johny said: 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. Euro € is the local currency on the island, but you might be right regarding the valve stems! 🙂 Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 25, 2023 Report Share Posted July 25, 2023 what ever is failed it is compression pressure that are spitting out the carb no seal gasket or wild myth will cause the problem its pressures being fire back into the induction the test results show even even high psi that should eliminate the main mechanicals thinking out the box have check the valve guides are not moving and all are at a equal height personally i have never found a sticky valve ,most rattling good fit , seized rockers and bent pushrods plenty might be worth checking the dizzy cam splndle is not worn and wobbling the timing Pete Link to comment Share on other sites More sharing options...
Roger Posted July 25, 2023 Author Report Share Posted July 25, 2023 Interesting. It is very difficult to get a picture of it, but there is plenty of oil on top of inlet valve, cylinder 6. I guess it should not be there... Well as long as there are no cracks I'm good. Just another character building moment... Link to comment Share on other sites More sharing options...
johny Posted July 25, 2023 Report Share Posted July 25, 2023 I think that rocker cover is finally going to have to come off too... Link to comment Share on other sites More sharing options...
Iain T Posted July 25, 2023 Report Share Posted July 25, 2023 3 hours ago, Roger said: Interesting thread drift, natinality is confusing in my case. The Åland Island was part of Sweden for 800 years, now part of Finland but autonomous and we have our own goverment & flag. My first language is Swedish but I have a Finnish passport. In short, I'm a Swede with a Finnish passport... Sorry for the drift, Aland certainly has an interesting history. Iain Link to comment Share on other sites More sharing options...
Iain T Posted July 25, 2023 Report Share Posted July 25, 2023 56 minutes ago, Roger said: Interesting. It is very difficult to get a picture of it, but there is plenty of oil on top of inlet valve, cylinder 6. I guess it should not be there... Well as long as there are no cracks I'm good. Just another character building moment... Forgive me for saying but it might have been a good idea to check the valves with the engine running before taking the manifold off? Iain Link to comment Share on other sites More sharing options...
Roger Posted July 25, 2023 Author Report Share Posted July 25, 2023 22 minutes ago, Iain T said: Forgive me for saying but it might have been a good idea to check the valves with the engine running before taking the manifold off? In hindsight yes. However, I just assumed that in order to repair sticky valves, the cylinder head (and manifolds) have to come off anyway. So the end result would have been manifold off anyway. Is there a way to fix that valve without removing the cylinder head? Even if it is possible (?) I think I would prefer to look at all valves given the state of that inlet valve. I just pray that there are no cracks. Link to comment Share on other sites More sharing options...
johny Posted July 25, 2023 Report Share Posted July 25, 2023 Cracks are pretty unusual with the mk1 head. The most likely is between the larger valves of the later design... Link to comment Share on other sites More sharing options...
Iain T Posted July 25, 2023 Report Share Posted July 25, 2023 It's head off time I hope you had a good breakfast! I only said to check the valve operation as it may have given you a good indication as to the culprit of the blow back. Link to comment Share on other sites More sharing options...
johny Posted July 25, 2023 Report Share Posted July 25, 2023 The oil on the valve is strange almost like the guide is to big for the stem! Could back pressure (a lot) come from the rocker box through the vent pipe to the carbs? Link to comment Share on other sites More sharing options...
Iain T Posted July 25, 2023 Report Share Posted July 25, 2023 That's a lorra back pressure. Does the mk1 rocker vent to each carb or through a pcv to the inlet manifold a la mk2? Iain Link to comment Share on other sites More sharing options...
Roger Posted July 27, 2023 Author Report Share Posted July 27, 2023 On 24/07/2023 at 12:25, Roger said: Thats my main concern. I don't have another cylinder head, that is the only one I have! I might have to correct myself: The cylinder head from my original early Vitesse HC engine looks very similar to the 2000 Mk I head. I know the crankshaft and many other things differ, have not had a chance to put them next to each other for comparison yet. Anyone know if they are interchangable? Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 27, 2023 Report Share Posted July 27, 2023 think youre about right the real changes came with mk2 ?? when the standardised the heads and gave pistons a domed top to compensate the CR ratio across the ranges Im hoping you just have a failed inlet valve /seat but the comp tests dont suggest that Pete Link to comment Share on other sites More sharing options...
Roger Posted July 29, 2023 Author Report Share Posted July 29, 2023 (edited) On 25/07/2023 at 09:31, Pete Lewis said: might be worth checking the dizzy cam splndle is not worn and wobbling the timing There IS something weird with the timing! I checked the static timing with a light bulb, and it was at least 20 or 25 degrees BTDC, far away from the 10 degrees according to WSM. Only had a few minutes for the test, will look closer at it on Monday. The high compression results confuse me, I want to elininate every possible root cause before removing the head. My old HC engine has a 22D dizzy and this engine has a 25D. Anyone know if they are interchangable? I would like to test with another distributor Edited July 29, 2023 by Roger Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 29, 2023 Report Share Posted July 29, 2023 both dizzy should work enough to prove ok , many prefer the lucas and the timing marks are on the pulley harmonic damper ring the bonding cam loose its adhesion and the ring can move round on the pulley johnD has a engine rig to test this , the bonding breakdown its not uncommon , plays havoc with your timing marks you must check the piston tdc matches the damper marks on my 1600 you could turn the ring with some ease it wont come off but may rotate a lot Pete Link to comment Share on other sites More sharing options...
Roger Posted August 4, 2023 Author Report Share Posted August 4, 2023 (edited) Short update.... The head is till on the engine block since I do not have anything to replace it with at the moment. I'm currently cleaning up my HC cylinder head which might replace the current one in case of a crack. Electrical issues should be eliminated by now, the only thing I have not replaced is the coil. Currently running the engine with a 123 ignition dizzy + Bosch blue coil, and timing is adjusted and correct. Seems to work fine when checked with timing lamp so coil also assumed to be ok. But as soon as the engine gets warm (ish) it looses power and finally stalls. One thing that confuses me is the fact that compression test shows really good results for both cold and warm engine. If there is a crack in the head that opens up with heat and the crack is big enough to make the engine stop, then how come compresion test is perfect also on warm engine??? This makes me thinkt that the leak (if there is one?) is "outside" cylinder compression, so valves are also eliminated as root cause. I also re-checked and adjusted valve clearance so it is not too tight which might cause the valves not to close properly when warm. Thoughts? Inlet manifold leak? I usually don't use any sealant or glue when assembling these things but I did add some this time in case that was the leak. No improvement... Edited August 4, 2023 by Roger Link to comment Share on other sites More sharing options...
Roger Posted August 4, 2023 Author Report Share Posted August 4, 2023 And here is another reason I want a Mk II engine in the future... Do I have to add heat in order to remove that dowel so I get access to the cylinder head bolt? Link to comment Share on other sites More sharing options...
68vitesse Posted August 4, 2023 Report Share Posted August 4, 2023 Never been a problem on my 2L Mk1, the dowel on my engine is only to locate the inlet manifold. Perhaps yours has been replaced with one which is to long or not fully seated, if mine I would be tempted to shorten it. Regards Paul. Link to comment Share on other sites More sharing options...
Puglet1 Posted August 4, 2023 Report Share Posted August 4, 2023 Is that definitely oil in the inlet port? It looks like green anti freeze. I had a similar problem. I also removed the carbs and thought I’d cleaned them but I eventually found a tiny slither of rubber sitting in the front carburettor needle valve. With that amount of “oil” in the port I would expect a massive misfire on one cylinder only and lots of smoke coming out of the exhaust. From personal experience, I’d go back to the carburettor before removing the cylinder head. Link to comment Share on other sites More sharing options...
Roger Posted August 4, 2023 Author Report Share Posted August 4, 2023 43 minutes ago, Puglet1 said: Is that definitely oil in the inlet port? It looks like green anti freeze. Definitely not anti freeze since I have 100% water in the cooling system for now. It looked and smelled like engine oil. No misfiring or smoke from exhaust. I have had the carbs apart so many times now that I can clean them, and assemble them blindfolded in ten minutes... I also suspected those rubber slivers (i have changed all hoses) so I have flushed the pipes and hoses with clean petrol. If it where carbs then I guess it would run roughly also as cold not only a problem when warm? But it runs ok as long as it is cold. Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 4, 2023 Report Share Posted August 4, 2023 for that level of oil spill on the head of the valve i feel there is a valve guide problem here {Pete Link to comment Share on other sites More sharing options...
Puglet1 Posted August 4, 2023 Report Share Posted August 4, 2023 “If it where carbs then I guess it would run roughly also as cold not only a problem when warm? But it runs ok as long as it is cold” My car ran ok when cold but I guess the fuel bowls were full at that point- it seemed to loose power but after stopping for a while it would start and run again for another few miles. Can you isolate the misfire to a particular cylinder by pulling the plug leads off with the engine running? Is the number 6 spark plug drenched with oil? I’ve never known an engine die after 10 minutes of running due to an isolated 1 cylinder misfire? Link to comment Share on other sites More sharing options...
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