GazaGt6 Posted February 16, 2011 Share Posted February 16, 2011 Hi guys,been having problems with cylinder number one. So i took the head of for inspection, gasket fine, got the head pressure tested and re-faced as there was a slight bow. So no problems there. however being the idiot that i am, i only did a dry compression test. :o was so eager to get the head of i forgot to do a wet test. is there anyway of testing the piston ring wear with the head out of situ??RegardsGarry Link to comment Share on other sites More sharing options...
herald948 Posted February 16, 2011 Share Posted February 16, 2011 When you did the "dry" test, what sort of numbers did you get? and how quickly did each cylinder come up to said numbers?I suppose you could try filling the #1 cylinder with a thin oil or even petrol and see if it disappears quickly (which might well indicate seriously worn or broken ring[s]?) and compare that with another cylinder or two.... Link to comment Share on other sites More sharing options...
GazaGt6 Posted February 16, 2011 Author Share Posted February 16, 2011 These are the readings:No.1 80No.2 180No.3 170No.4 170No.5 165No.6 170My pressure tester broke ages ago, so i got my local garage to do it when it was getting its MOT done. so cant really comment on how quickly it reached its readings.regardsGarry Link to comment Share on other sites More sharing options...
TimW Posted February 16, 2011 Share Posted February 16, 2011 herald948 wrote:When you did the "dry" test, what sort of numbers did you get? and how quickly did each cylinder come up to said numbers?I suppose you could try filling the #1 cylinder with a thin oil or even petrol and see if it disappears quickly (which might well indicate seriously worn or broken ring [s] ?) and compare that with another cylinder or two.... or maybe fill the inlet/exhaust tract in the head and see if it leaks out of the valves (i would use petrol or some other sort of spirit for this) This may show any issues in the valve not sealing correctly.You had better get a move on! Royvoy only a few weeks away!! ;) ;) ;)Tim Link to comment Share on other sites More sharing options...
GazaGt6 Posted February 16, 2011 Author Share Posted February 16, 2011 Hi Tim!Yeah Royvoy currently looking unlikely. Would never have thought to check the valves that way, will check tomorrow. I think the plan is to re-seat the valves (possibly a good clean as they are coked up!) and refit the head and ancillaries and do a compression test again (Wet and Dry). Then find out if it is the rings and take it all apart again! hahaha 8) Garry Link to comment Share on other sites More sharing options...
CHRIS211083 Posted February 16, 2011 Share Posted February 16, 2011 With these engines the bore/piston rings last well. Its usually valve and head related. It's also more likely that all the cylinders would be showing low if it were a high mileage and all the rings would be worn. It will be worn valve guides or badly seating valves due to carbon Etc.Chris. Link to comment Share on other sites More sharing options...
Hugh Posted February 16, 2011 Share Posted February 16, 2011 Hi Gaz I would agree with Tim as I have used the petrol test before it will point to valve seat/face/stem wear and piston ring wear really quickly use petrol. Pour the petrol into the top of the cylinder head to test it and top of the bores for the pistons.Just be careful you do'nt whant to do a Hugh now ;DGood Luck Hugh Link to comment Share on other sites More sharing options...
GazaGt6 Posted February 16, 2011 Author Share Posted February 16, 2011 Thanks Guys,This is promising stuff! 8) However, if you remember it all started with a cloud of oily smoke pouring into the cabin on route down to Cornwall. Which originated from oil being pushed up into then out of the top of the rocker cover. Could the valve seating cause something like this, especially so spontaneously?RegardsGarry Link to comment Share on other sites More sharing options...
Freebird Posted February 16, 2011 Share Posted February 16, 2011 Sounds a lot like rings to me. Those numbers are very similar to mine a few years back. No1 rings were all stuck in the grooves. The compression bypasses the fauly rings and pumps up the sump, the gasses and oil carried by them then go up the pushrod tubes and out of the rocker cover.You may find lots of oil leaks too where the pressure inside blows oil out thru the easiest path. The petrol test will tell for sure, part fill No 1 and 2 at the same time with them at the same height and see how fast they drain. This will dilute the oil in the sump with petrol, but you will be changing that anyway. Link to comment Share on other sites More sharing options...
MarkB Posted February 16, 2011 Share Posted February 16, 2011 Unfortunately the only time my Spitfires cabin instantly filled with smoke many years ago, was when I was test driving it on a saturday night down the A20 following a rolling road session I was racing at Snetterton the following day, my second race. It was running on twin 40's and as I was caning it the whole car filled with smoke in a split second. Pulled over, car was running a bit lumpy, so got a tow home. Cut a long story short, tested compression and was down on one cylinder. Its now about 6 in the evening, whipped the head and sump off found that the side of no.1 piston had melted due to running lean, Apparently crap rolling road operator. Anyway while i stripped the engine my mate drove to the other side of london to TLD place who was always very helpful and Knowledgable who sorted out a piston for me that evening. Anyway got it back together and running under torch light working out in the road by about 2am Sunday morning successfully finishing the race. So unfortunately it sounds to me like piston ring/piston cracked etc. Hopefully not.Blue Link to comment Share on other sites More sharing options...
GazaGt6 Posted March 1, 2011 Author Share Posted March 1, 2011 hey guys Bad news, head back on. Wet compression test shows its the rings. Might as well find a reconditioned short engine. Shame i have no money! :o Link to comment Share on other sites More sharing options...
don cook1 Posted March 1, 2011 Share Posted March 1, 2011 Can't you just take the sump off undo the big end caps and remove the piston out the top, fit new rings, replace piston and big end cap?? Just the price of new rings isn't it? Link to comment Share on other sites More sharing options...
TimW Posted March 1, 2011 Share Posted March 1, 2011 read your text! i have a 2000 mk2 engine that you can use. domed pistons and crap cam i think so down on power but at least it's a good runner Link to comment Share on other sites More sharing options...
alex4wwl Posted March 1, 2011 Share Posted March 1, 2011 Hiyou can't rering a worn engine, thwe rings will break and not seal,the only fix is to reboresorryAlex Link to comment Share on other sites More sharing options...
don cook1 Posted March 1, 2011 Share Posted March 1, 2011 Of course a re-bore is a permanent fix but if the rings are broken they can be replaced on their own, as long as the bore isn't damaged or worn (i.e. not within tolerance). If you were going to re-bore then you might as well do the crankshaft, change the oil pump.... Link to comment Share on other sites More sharing options...
Clive Posted March 1, 2011 Share Posted March 1, 2011 Amazing what a hone and re-ring can achieve, done it a few times.If the bore is bad it should be obvious, scored or a ring around the top that can be felt with a fingernail. Saying that nhewark engines had some pretty cheap short engines on the bay recently, cheaper than getting the work done on yours IF you decided on a rebore/crank grind.OR use Tims engine. May even be viable to use you head and swap the pistons over, hone the bores, new rings and ta-da, nicely refreshed engine :) Again, done that more than once, and will soon be doing it again. Link to comment Share on other sites More sharing options...
Hugh Posted March 1, 2011 Share Posted March 1, 2011 With the engine Tim has at least you should be back on the road quickly and then when you have some spare cash and time have your engine rebuilt. Gotta be the way to go for you mate if your strapped for cash at the moment ;) Link to comment Share on other sites More sharing options...
piman Posted March 1, 2011 Share Posted March 1, 2011 Hello Alex, I have to disagree with your statement "you can't rering a worn engine, thwe rings will break and not seal,the only fix is to rebore"It is necessary to 'glaze bust' the cylinder either with a hone or emery cloth (much harder) Replacement rings have the top ring relieved so as to clear any step that may be on the bore.It isn't necessarily an answer, that can only be judged by assessing the piston (Ring lands not too worn for instance) and is there any scoring in the bore?Alec Link to comment Share on other sites More sharing options...
ghr630 Posted March 1, 2011 Share Posted March 1, 2011 If you fit new rings to a worn engine, you need to either remove the wear ridge at the top of the bore with a scraper or such - or - use a stepped top ring. Link to comment Share on other sites More sharing options...
GazaGt6 Posted March 1, 2011 Author Share Posted March 1, 2011 The walls are fine, no scoring and no lip. Its really strange that its occurred in the first cylinder especially as its the coolest being at the front. :-/ Surely if i was to bore out and re-ring the engine, you would have to do crankshaft. by the time ive done that it would cost me just as much as buying a recon engine or taking Tims as i dont have the facilities to do something like that. Tim -when you say 2000 mk2, you mean the saloon, not at 2ltr GT6 mk2? :) I shall get back to you on that offer. could be a quick fix until i sort my current block sorted out. Oh and by the way, thanks for all the responses, its given me a lot to think about.regardsGarry Link to comment Share on other sites More sharing options...
rhodes Posted March 2, 2011 Share Posted March 2, 2011 Where do you get stepped rings from? Or do you step them yourself? Link to comment Share on other sites More sharing options...
TimW Posted March 2, 2011 Share Posted March 2, 2011 gazagt6 wrote:The walls are fine, no scoring and no lip. Its really strange that its occurred in the first cylinder especially as its the coolest being at the front. :-/ Surely if i was to bore out and re-ring the engine, you would have to do crankshaft. by the time ive done that it would cost me just as much as buying a recon engine or taking Tims as i dont have the facilities to do something like that. Tim -when you say 2000 mk2, you mean the saloon, not at 2ltr GT6 mk2? :) I shall get back to you on that offer. could be a quick fix until i sort my current block sorted out. Oh and by the way, thanks for all the responses, its given me a lot to think about.regardsGarryYes Garry it's a 2000 saloon. I will have the engine tommorrow after removing it from Ted Taylors saloon. I also have an engine hoist so if you need a hand putting it in i'm sure we can arrange it. Link to comment Share on other sites More sharing options...
ghr630 Posted March 2, 2011 Share Posted March 2, 2011 rhodes wrote:Where do you get stepped rings from? Or do you step them yourself?Some replacement rings intended for reringing should have this step. But not all!! And I bet our so called expert suppliers will not be able to confirm. If buying, make them open the packet!! Link to comment Share on other sites More sharing options...
sparky_spit Posted March 2, 2011 Share Posted March 2, 2011 ghr630 wrote:Some replacement rings intended for reringing should have this step. But not all!! And I bet our so called expert suppliers will not be able to confirm. If buying, make them open the packet!!I've been asking around regarding this, and I think it will be more and more difficult to get stepped rings these days. I'd love to be proved wrong though.You could always go for a set of Cords Rings if you are desperate - available on eBay all the time. They usually have a stepped top ring in the pack. I did smile when I saw somewhere (maybe on here?) them being described as "a rebore in a packet" !!! ;D Link to comment Share on other sites More sharing options...
GazaGt6 Posted March 3, 2011 Author Share Posted March 3, 2011 339 wrote:Yes Garry it's a 2000 saloon. I will have the engine tommorrow after removing it from Ted Taylors saloon. I also have an engine hoist so if you need a hand putting it in i'm sure we can arrange it. Thanks Tim, I think im going to ask around at stoneleigh, A recon short engine is the first point of call. If i cant find one at a reasonable price, i shall take you up on that offer 8)RegardsGarry Link to comment Share on other sites More sharing options...
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