philheys100 Posted July 28, 2014 Share Posted July 28, 2014 Hi Guys,Can you give me your opinion on the sound of this engine, a friend of mine said it sounds like it is miss-firing?I thought it sounded well!Please use the link below.http://youtu.be/qIMf7ducEXMThanks Phil Quote Link to comment Share on other sites More sharing options...
jondhm Posted July 28, 2014 Share Posted July 28, 2014 Nice sound if it was a lawnmower. Start simple, looking for leaks from inlet or exhaust. Connecting the breather pipe will help by eliminating that noise.Exhaust or inlet manifolds may be loose, causing sound when engine rocks.Are the spark plugs loose. Quote Link to comment Share on other sites More sharing options...
DougBGT6 Posted July 28, 2014 Share Posted July 28, 2014 Yeh... I thought lawnmower, but I didn't want to say. :B I also notice it wasn't keen to rev, you had to pull the cable 2 or 3 times to pursued it. So everything said above, then check the carb dashpots are moving freely and you've got oil in them. Then the usual suspects, timing, spark and mixture. Quote Link to comment Share on other sites More sharing options...
philheys100 Posted July 28, 2014 Author Share Posted July 28, 2014 Thanks guys,Whats the best way to check for vacuum leaks?Phil Quote Link to comment Share on other sites More sharing options...
lancepar Posted July 29, 2014 Share Posted July 29, 2014 When hot pull a plug lead off or turn off first, remove and restart, do one at a time and see if it makes the running worse. 8) Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted July 29, 2014 Share Posted July 29, 2014 Sounds like running on three.....or the timing is way out.....or the plug leads are wrong for firing order Quote Link to comment Share on other sites More sharing options...
smithy Posted July 31, 2014 Share Posted July 31, 2014 8401 wrote:Thanks guys,Whats the best way to check for vacuum leaks?PhilFor the inlet manifold, pour something in nice sensible SMALL quantites on it that you won't mind the engine ingesting, such as some light oil perhaps - and see if it disappears. For the exhaust manifold, get a feather on a stick or something. Or some talcum powder. Don't burn yourself or set fire to the thing, of course. It doesn't sound farty to me though, as if it's got inlet/exhaust problems. Nope.VR's just mentioned something I hadn't considered, the plug leads being out of order. I quite like that idea. Ditto lance, I suspect. Or it's the timing. Or you're running it on stale garbage petrol. It looks tidy though! Quote Link to comment Share on other sites More sharing options...
philheys100 Posted July 31, 2014 Author Share Posted July 31, 2014 Hi all, 1. I attached the breather pipe, still no different. 2. Checked the spark plugs, still no change 3. Vacumn leaks - none 4. Did the timing again, starts very well but still the miss-fire. 5. Compression test - Cy 4 = 150 PSI Cy 3 = 152 PSI CY 2 = 0 PSI CY 1 = 0 PSI I put a bit of oil down the spark plug holes and still 0 compression, does that mean the valves have gone? I am surprised and totally ruled this out because I got the head converted to unleaded it may be looking like he has not done the job right? Or could there be another explanation? Thanks Phil Quote Link to comment Share on other sites More sharing options...
Dogsbody47uk Posted July 31, 2014 Share Posted July 31, 2014 Head gasket failure between cylinders 1 and 2 ? Quote Link to comment Share on other sites More sharing options...
philheys100 Posted July 31, 2014 Author Share Posted July 31, 2014 Really!Its new, the all engine is a rebuild do you really think that it is head gasket failure? how will I be able to check this?Thanks Quote Link to comment Share on other sites More sharing options...
Dogsbody47uk Posted July 31, 2014 Share Posted July 31, 2014 Who rebuilt the engine and did they Re- torque the head after initially warming up the engine? Also, according to my manual, the head should be re-torqued after 500 miles. Hope this helps. Quote Link to comment Share on other sites More sharing options...
philheys100 Posted July 31, 2014 Author Share Posted July 31, 2014 Hi,An engineer converted the head and checked the bottom end, I rebuilt everything and the head as been retorqued but only recently its not been running but I have had it started several times but certainly not 500 miles worth.Thanks Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted July 31, 2014 Share Posted July 31, 2014 and has the correct head gasket been fitted? Recessed head or notEither way the head has to come off .............at zero poundsNew pistons? or rings?Your `engineer` has certainly done something wrongAlso check for oil in water and vice verca Quote Link to comment Share on other sites More sharing options...
junkuser Posted August 1, 2014 Share Posted August 1, 2014 Check that the valves are behaving correctly prior to removing the head.Grasping at straws, but there are some possibilities. Quote Link to comment Share on other sites More sharing options...
ferny Posted August 1, 2014 Share Posted August 1, 2014 Yes, check those rockers first just in case!Other than that, was the head skimmed to make sure it's flat? Was the block checked to make sure it's flat? Is it possible there's something trapped in there, like a hose or a bit of crap? Even with a duff gasket I'd expect some pressure, that sounds and appears to be very much not sealing at all. Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted August 1, 2014 Share Posted August 1, 2014 junkuser wrote:Check that the valves are behaving correctly prior to removing the head.Grasping at straws, but there are some possibilities.However all the valves would have to be stuck open for it to give zero reading, which would be rareI would say head gasket or............not even tightened down...........or terribly bowed headWorse scenario.....and I have known it to happen....a snapped crank shaft Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted August 1, 2014 Share Posted August 1, 2014 Most odd. Check valve clearances on 1 & 2 though they'd need to be seriously tight to give 0 psi.Wonder if you have a flat head gasket installed on a recessed block - this would make a major blow between cylinders 1 & 2 very likely and the greater surprise would be the 150 psi on the other two!Nick Quote Link to comment Share on other sites More sharing options...
philheys100 Posted August 1, 2014 Author Share Posted August 1, 2014 Thanks guys,The head was skimmed and converted by a engineer, I have to trust him because it was a job I was unable to do. I will check the valve clearances but I am guessing I will have to remove the head.To confirm I have a 73 spitfire would I need a recessed gasket, I am sure I have this fitted anyway?Would I need the head skimming again, its onky been a couple of months?Phil Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted August 1, 2014 Share Posted August 1, 2014 Recessed gasket will have a tab on it which sticks out of the joint at the back of the engine.Wouldn't have thought the head would need skimming again but it is still a bit of a mystery as to what the problem is.....Stuck valve theory is worth persuing before taking the head off - though you might still have to take the head off to sort it properly.Good luck and please report back.....Nick Quote Link to comment Share on other sites More sharing options...
don cook1 Posted August 1, 2014 Share Posted August 1, 2014 Is No 1 and 2 compression test carried out on the firing stroke or exhaust stroke...well, you never know?? Quote Link to comment Share on other sites More sharing options...
philheys100 Posted August 2, 2014 Author Share Posted August 2, 2014 Hi all,It was a blown gasket between cyl 1 & 2, at bit annoying but it is cheaper than new valves or rings.Thanks for your helpPhil 8) Quote Link to comment Share on other sites More sharing options...
philheys100 Posted August 5, 2014 Author Share Posted August 5, 2014 Hi all,New gaket fitted and she starts and runs like a dream.Thanks allPhil Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted August 5, 2014 Share Posted August 5, 2014 Excellent :)Nick Quote Link to comment Share on other sites More sharing options...
WIMPUS Posted August 5, 2014 Share Posted August 5, 2014 Now make a new video for us to hear ! :P Quote Link to comment Share on other sites More sharing options...
Dogsbody47uk Posted August 6, 2014 Share Posted August 6, 2014 Glad I was right.. Bitter experience pays! Cheers, Dave (at least it's relatively cheap and simple to fix.) Happy motoring. Quote Link to comment Share on other sites More sharing options...
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