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MG Midget and Sprite Technical - Engine back in.not OK?
| I just put the engine back in by 1500, had another thread yesterday 'no spark...don't know why' thanks to all those who helped out with that one, I now got it running. Reason I took it out was to replace crank bearing shells, also replaced oil pump, fuel pump, took off head, new valves and valve springs. However, things are not all smooth. I had it running for 10 minutes and this is the story..... Very very tappety. Not a problem, can fix that. Oil pressure gauge is reading a constant 20. Just constant no up or down as revs rise and fall, just sits on 20 Lots of white smoke from filler cap when I took it off. Engine is so hot to touch. I've never known anything like it. I tried to dip the oil but couldn't grab the dipstick it was so hot. Other than the above all is fine! I always worry, should I? |
| matthew stubbings |
| >>> Oil pressure gauge is reading a constant 20. Just constant no up or down as revs rise and fall, just sits on 20 <<< I wonder if the oil pressure relief valve is stuck open or something? That, or perhaps the oil pump isn't operating correctly. That might account for the excessive heat, if oil isn't being circulated properly, although I hesitate to think what that would do to the bearings and cylinder walls if this is the case. Best of luck getting it sorted! -:G:- |
| Gryf Ketcherside |
| Sounds like your oil isn't pumping round. Does the gauge drop to zero when you switch off? Did you prime the new oil pump before starting? (Don't know how to do this on a 1500, but somebody will) What's the water doing? Don't run it till some more experienced people than I have told you what steps to take! |
| Nick |
| I got to agree with the oil above...somekind of blockage You said...."""Lots of white smoke from filler cap when I took it off.""" a little more detail, what does that mean....... Im wondering if you dont have vapor lock,(part of the problem....being you got white smoke) aka large poocket of air in the cooling system....need to leave the rad cap off and let idle for 20 minutes....But only after you figure out the oil problem, agian ...did you prime the oil pump...if not Id say thats alot of it. Sorry...do you mean the white smoke is coming from the radiator filler cap, or the oil filler cap??? Prop |
| Prop |
| Hi all White smoke is from the oil filler. Water doesn't get time to geat up, besides which the heat is from the block, not the head. I did prime the pump and I have checked by turning over with the filter off and oil comes pumping out. I would not have been entirely surprised by the smoke from the oil as this could be condensation, the engine was out for a while and was cleaned down. The heat and oil pressure is my main concern, the white smoke is only a worry because of those other two things. I'm thinking maybe pressure relief valve stuck open? |
| matthew stubbings |
| Id say your barking up the correct tree...its got be blockage somewhere in the oil galleys system...Id try pulling the spring and stud on the oil relief and give it a good cleaning. see what happens...I wouldnt run it vary long with low oil pressure after all its just going to heat up...not good. another idea, would be to drain the oil and run "Parafin"(kereosene, K1, jet fuel) agian just up to normal temp then shut down, and maybe try agian after a complte cool down...agian look for the oil pressure last tought, when you put the new shells in, sometimes you have to "drill" a oil hole in the shells to line up with the crankshaft...I have no idea on the 1500, but would something like that be possiable. Prop |
| Prop |
| < Lots of white smoke from filler cap when I took it off > White smoke = steam: Head gasket? < Engine is so hot to touch > No coolant circulating/no coolant in block? < Very very tappety > Exhaust valves not sufficiently lashed = backup of hot gases = super-hot super-quick? Good luck! R |
| Richard 79 1500 with a Type 9 in the garage |
| sounds like you got a theory richard, whats your thinking? as to the problem. prop |
| Prop |
| Prop: If the oil is blowing out the filter housing while cranking the engine and the engine didn't seize after 10 minutes running time then it seems likely that the oil is circulating properly, but the oil pressure gauge reading needs to be sorted. No engine I've ever had had the same oil pressure reading at idle and revved up. I'd try a separate, external oil pressure gauge attached to the block, with a different pressure feed line to confirm or refute the steady 20 PSI reading on the other gauge. I'm betting the bulk of the problem (heat and steam) is a bad head gasket combined with insufficient valve lash. You will probably find oil in the coolant as well. R |
| Richard 79 1500 with a Type 9 in the garage |
| Richard I tend to agree that the fact it hasn't seized up on me yet implies some circulation of oil. I believe the pump is working. There has been a slight development in that without any prompting from me, the pressure gauge is now moving, just reading very low. Sitting now at around 20 at cold idle, nudging up a fraction when revved slightly. I've not had it running for long so I don't know the long term results of this. Here's another piece of info which didn't seem relevant before but I'll slip it in now. I put a new axhaust on it which is very noisy. There is an intermittent 'popping' from the exhaust, like you get when it's running very rich. I planned to adjust the carbs when I got the other things fixed, but maybe this is another symptom of the same problem. I'm not sure what to do next. Prop - What's this kerosene idea. Run the kerosene where, in the oil system? Matthew |
| matthew stubbings |
| Take a step back Matt! Many times new engines or rebuilt engines do have a smokey start to life. When we mess about with them traces of oil are left all over the place and these burn up as we bring the engine to life. So that smoke may dissappear. Also the "breathing from the filler cap on the rocker cover again may be a number of things, but first is to sor out the oil pressure, it is the life blood of the engine. You need to confirm does the oil pressure gauge read ZERO when the enine is stopped? if it does then the gauge rising to 20 PSI when the engine starts is a good thing! If that is the case then it seems likely that the relief valve is not working correctly/at all. So remove it and make sure it is all there and operates freely. If the gauge is moving from ZERO to 20 PSI on start up then you are pretty safe to have the engine idling for a couple of minutes if the gauge is not moving at all then a different pproach must be taken. |
| Robert (Bob) Midget Turbo |
| yes, gauge reads zero when engine off. moves slowly up to 20ish when started |
| matthew stubbings |
| OK that is a good thing Matt and you must now have a go at the relief valve which appears to be stuck. |
| Robert (Bob) Midget Turbo |
| Just wanted to say thanks to all those who helped out with sugggestions. I am bereft of ideas so I'm going to pop the sump off and see if anything looks awry in there. Maybe I've done something wrong. I'll report back. |
| matthew stubbings |
| ehh have you checked the relief valve as mentioned? don't pull anything aapart until you have checked the smalthings first! |
| Onno Könemann |
| Sorry, meant to say, yes I put a new relief valve on and the same thing, no difference. I've got the sump off and noticed that there is play in the big end bearing caps. I can't physically tighten them any more but there is still play in them. Is this normal?? |
| matthew stubbings |
| Side to side play by the way, in the bearing caps |
| matthew stubbings |
| Big ends can have a little side ways play. |
| Alex G Matla |
| MMmmm, When you replaced the shells, did you check the old shells with a plasti-gauge....It tells you how much wear and if the old shells are over sized do to a previous crankshaft grind. Im wondering if you got the wrong size shells, also might try a micrometer on the thrust bearings as they wear commonly in the 1500s...they control the side to side play My guess is the shells are to big and to oil is just blowing past and not able to devolop oil pressure...just my personal opinion kereosen is what you call parafin, I was thinking some kind of sludge blockage in the oil galley tunnels, by replacing the engine oil, with kereosene, and running the engine 5-10 minutes it will clean everything out...not always advisable..I Cant recommend doing this at this point...you need to do more inspecting. My advice pull the old shells out of the trash, go to a good parts store or machine shop and get some plasti-gauge and and see what you come up with in specs. Prop |
| Prop |
| here is a website for what and how to use plasti-gauges...there are 100s of companys that make these things im sure you got them in the uk Prop http://www.plastigaugeusa.com/ |
| Prop |
| Okay I was nice long enough...I got to ask!! when you say there is play in the big end caps, and you cant tighten them up anymore. what exactly does that mean, as in how did you get to those conclusions. you are using a torque wrench for tightening the nuts down, correct? how is it you know that you got play in the big end bearing caps? how are you determining that? is it by look, feel, hearing, measuring tool? Prop |
| Prop |
| < gauge reads zero when engine off. moves slowly up to 20ish when started > Shouldn't it jump right up to twenty? The fact that it moves slowly up to 20ish to me indicates that it may be as simple as crud in the pressure feed line. I would definitely verify with a separate feed line and gauge that the pressure is in fact moving slowly to 20ish. R |
| Richard 79 1500 with a Type 9 in the garage |
| Prop - Wrong size shells? I guess that is possible. I still have the old ones. When I say I can't tighten any more what I mean is that they are up to the correct torque, indeed they are now slightly over. The caps can be wiggled side to side Richard - Implication that the gauge is giving a faulty reading. I guess that is also a possibility. However going back to the start, the excess heat indicates that there is a problem, albeit the two things could be unconnected. I think what I'll do next is check the gauge. I'll borrow an accurate pressure gauge and line and see what reading that gives Assuming the pressure is proven to be low I'll move on to the assumption that the bearings I put in are wrong some how, either wrong part or I've done something wrong in the installation, and that the lack of oil pressure is causeing the heat. I really do appreciate all your comments. Thanks |
| matthew stubbings |
| Matthew, The more I think about it, the more I lean towards the wrong size shells. Id get the plasti-gauge stuff and do several of the new bearing shells and compare the findings to the haynes book referance and see if your inside the tolerances limits My theroy as to why, I say the bearings are to big... the oil is spraying past the shells???, thus not reaching its destination or capable of holding its oil pressure???, thus over heating???, the tappety sound is the crank banging into the shells???, you can move the shells back and forth and you have exceded the torque max on the nut caps and the shells are still loose just my opinion Prop |
| Prop |
| Prop, I think you're talking a lot of sense here. Another weekend up to my armpits in engine awaits me. |
| matthew stubbings |
| the size is usualy stamped in the back of the bearing and remember big and smal end bearings do not have to be the same over size (ask me how i know ) |
| Onno Könemann |
| A little update folks. Just to be sure I had covered everything I took the sump off, retorqued all the big end and main bearing caps and put it back together. Some of the main caps had worked loose!! Started up and pressure went up to 40 then slowly and steadily dropped down to 20, say over 10 seconds. Left it running, what is there to lose. 30 seconds later there's a little knocking noise. Left it running again, starting to lose the will to live, knocking got louder and louder. Seems to be coming from the front about half way up the block. Oil pressure slowly going down settles at around 10 after 2-3 minutes. Switched off. Drained oil. Removed sump. Checked all bolts for torque. Put back together, started and the same thing again, pressure up to 40, down to 20, down to 10. Knocking noise there 30 seconds or so after starting. Checked compression in cylinders, 3 are similar, around 120, but one has no compression at all, barely showing on the gauge. Piston slap? Crank rattling? Who knows....not me! Anyway, switched it off. Came inside. Had a shower and felt like pushing car off a cliff. Can anyone help me here, anything. I am as desperate as desperate can be, and I seem to be making it worse with everything I do. |
| matthew stubbings |
| I know the feeling, although I'd spare the desperation for my everyday car! Unless the midget IS your everyday car, in which case I sympathize. So then, no compression - you may have a holed piston, a burned or stuck valve, or similar. Keep us posted! -:G:- |
| Gryf Ketcherside |
| Shower good. Pushing car off cliff bad. Did you tap and clean the threads before installing the main cap bolts? Crud can alter bolt depth and torque accuracy (ask me how I know).If the main caps worked loose does it bring into question the accuracy of your torque wrench? Have you re-checked the shells for correct sizing? As to the lack of compression, did the valve guides get replaced when you did the headwork? Is there positive pressure either in the sump or the rocker cover when running? Is there oil in the coolant? Sorry to be all questions and no answers. You seem to have multiple issues. One of the most frustrating things is trying to wrap your mind around a fix for a problem when there might be 2 unrelated problems manifesting at the same time. Hang in there. R |
| Richard 79 1500 with a Type 9 in the garage |
| Matt, When its knocking - if it sounds like an 'end' do not run it. You need to find out were its coming from. When you changed the bearings did you check - same size replaced, also ensure the cap went back on the same rod and the same why round - similar for centre main ? If its been knocking and you strip the cap off it should show itself damaged scoured etc. The oil pressure should have been better than when you started so its leaking somewhere. The main coming loose is a worry - again do you have it fitted the way round it came off ? The lack of compression - have you checked the tappets on the dead cylinder ? Does sound like an engine out job - is there anybody local you can call for advise/support - it always good to talk when it seems a bit dark - i know ! Richard. |
| richard boobier |
| Hey folks Lots of questions here's some answers Gryf - Not my everyday car so it could be worse. Not sure how people coped with this technology as regular transport back in the day! Richard 1 - Tap and clean bolts? No Accuracy of torque wrnech - debatable. Old and budget Rechecked size of shells - no I haven't Valve guides replaced - no positive pressure in sump / rocker cover? - I never particularly checked for any but I do not recall any, thinking back at it. So I'll say no, no pressure Richard 2 - Does it sound like an 'end' - I don't know the difference between the sound of different knocking noises I'm afraid. When it started I just thought that there was not much else could go wrong so just leave it running. Check bearing size - When I changed bearings I did not check sizes, I just bought new ones and trusted it was correct Bearing caps - 100% these are in the correct location and the right way round oil pressure - is definately worse now than when I started. tappets - I don't understand what to check. Can you advise? In summary - I'm thinking that all I can do is take the engine out again, and this time do things slightly different. I will get someone to check the crank size before assuming I have the right bearing shells. I will replace piston rings. I will replace other stuff. Can anyone suggest what should be done, or any last gasp ideas before I pull the whole thing apart again |
| matthew stubbings |
| my personal guess for the dead cly. is a a blown head gasket or a craked head most likely between the valves...this may have occoured when the engine ran so hot that you could not touch the dip stick. I agree with richard at this point, your going to be money, time, and aggervation ahead pulling the engine and breaking it down....luckly it sounds worse then it is, or find another 1500 engine in good shape and install that one >>>>>>>>>>Left it running, what is there to lose. 30 seconds later there's a little knocking noise. Left it running again, starting to lose the will to live, knocking got louder and louder. <<<<<<<<<<<<<< That seems to be a popular frame of thought....unfortantly its just not true, when it starts to go south shut it down, bad problems rarely trun around and get better The great news is you got alot of good options 1500s are plentiful and parts are cheap ...just be glad its not a modernday car. Prop |
| Prop |
| Matt, The bearing sizes are stamped into the back of the shells i.e +10 etc if you have the old ones check they are the same size as the new ones. Check as I said that you have set all the tappets / valve clearances correctly - also turn the engine over by hand and check the dead cylinder valves are going up and down and not stuck partly open etc - should be obvious from checking the valve clearances. Richard. |
| richard boobier |
| Im almost certian its the shells....even if you where off by 25 ftlbs. you shouldnt have the bearing shells move around at will as your indecating like richard says look at the size stamped on bearing shell. if there standard size, then the crank was most likely reground...you said you still have the old shells, check if there are any markings ...probably wont be, but worth a look, Agian, Go to a parts store and get some plasi-gauges as I made mention above, I think a pack of 10 is like 12 dollars, super easy to use, extremely accurate For no more then grade 8 hardware cost, it might be worth getting new hardware for the caps and mains...at the vary least new nuts and washers....(Do NOT USE off the shelve every day hardware....it MUST be grade 8 minume) Prop |
| Prop |
| Update. I've got the old shells out of the bin. Writing on them reads : Main shells - 010 / 149082 at one end 010 / 5106 at the oher end big end shells - s2022sa / 010 u/s t/b The original problem was the main bearings, which were worn through to copper. big ends OK. The haynes book tells me that a knocking which is there at tick over but disappears with revs is big end failure. That is what I have? |
| matthew stubbings |
| Matt, The shells appear to be minus 10 thou i.e the crank has been already ground - therefore the ones you put in should match - are they ? Did you take them to the bearing supplier when you bought the new ones to check ? Do you have the packaging for the new ones - it is marked on the boxes or take them out and check. Richard. |
| richard boobier |
| The ones I put in were standard. However if the crank is ground you put oversize bearings on, not undersize? Simplest thing is I'll give the existing bearings to the supplier to check and buy some to match. Then I'll replace the whole lot again. While I'm about it I'll do the rings on the piston where there is no compression. |
| matthew stubbings |
| Matt, Can be confusing, but crankshafts start at standard, then only get smaller by grinding when reconditioned. Hence a 10 thou grind requires shells to fit - yes the inside dia of the 10 thou ground shells is smaller to suit the ground shaft - the recon shop normally supplies the correct shells to suit. Good idea taking them to the supplier to check if unsure. Check if the crank surfaces are smooth etc before buying more shells - or get someone who knows what they are looking at to check - it might be better to consider regrinding - but this is obviously a bigger job. Or drive this summer and do a rebuilt later. Pistons only get bigger when rebored - so if you do decide to buy new rings make sure you get the correct size - this is marked on the piston top i.e. +20 etc. Best of luck. Richard. |
| richard boobier |
| Matt, Since it sounds like you put standard bearings on a ground crank, that is your oil pressure and knocking problem. Now you need to see if you damaged the crankshaft with the error. Also, I suspect you should have your rod big ends checked for roundness, and resized if need be. While you are at it, the small ends should be checked if they are the bushed type. None of this explains the zero compression in one cylinder. I would not do the rings on just one piston. I would suggest doing all of them at the least. If a cylinder ridge exists, that will need to be cut out or it will probably break the new rings. Have the bores and pistons measured while it is apart. In fact, I would suggest pulling the entire engine down and check or rebuild everything at one time. Otherwise, I suspect you will end up doing a full rebuild one part at a time, and that is more work and money than doing it all at once. Charley |
| C R Huff |
| Matthew The rings are "NOT" the problem for the dead cly, you said the engine ran well before you put the new shells in, meaning the cly was working fine...the damage to the cly. occured after the fact (durig the installtion period of installing the shells) Like I said above and for the reason I stated above, Its a blown head gasket or a craked head. If you want to install new rings you have to do all 4 AND you MUST hone the clys. or have them rebored, before installing new rings or bad things will happen agian Am I good or what, I was the 1st to call the wrong size shells...Arrogence definatly suits me.....LOL Prop |
| Prop |
| Matthew, Any update on your engine trouble. I'm restarting a stalled engine rebuild and your story is giving me some worries. |
| tm wainwright |
| Before rebuild the engine had no compression on 2 and 3 cylinders. I hoped it was HG so took off the head and replaced gasket. This fixed 3 but not 2 The bearing and oil pressure issue was a different one altogether As a general update it is going very badly. I'm not sure how much more time and money I should keep throwing at this car. After all this, the head or block may well be cracked or damaged, who knows the history and how often it's overheated. |
| matthew stubbings |
| eBay item number: 160345498369, but there are others. |
| f pollock |
| I saw this on there yesterday. This looks the way I am heading. |
| matthew stubbings |
| Matthew, You said, <Before rebuild the engine had no compression on 2 and 3 cylinders.> Are you saying that this is a recently rebuilt engine? Charley |
| C R Huff |
| Charley - Misleading use of words on my part. I meant before I did any of this work to it. |
| matthew stubbings |
| Matthew, Speaking of the history of your engine, what do you know about the history? Did you buy this car with problems, or have you been driving it for years and then ran into problems? Also, exactly what did you do when you put the new valves and springs in? Did you take it to a machine shop to have it checked for cracks and warpage, and did you have a full valve job done with all valves and seats ground? Any chance you put the head gasket on the wrong way or didn't torque it properly? I kind of doubt that the overheating was related to the bearings. If the rest of the car is pretty good, then you aren't throwing money at it, you are investing it, but only if you do it properly. Charley |
| C R Huff |
| Charley I bought the car with engine problems. It had no compression on 2 cylinders, it had characteristics of HG failure such as heavy milky deposits in the oil, lots of pressure in the rocker cover and white smoke fom oil filler cap, it had very low oil pressure being shown in the region of 20 or less, and it had a very evident rumble from the crank. To repair the rumble I replaced the main bearings. The old ones were very worn. I also replaced the big end bearings while in there. I replaced the oil pump also. I hope the compression and HG problem were the same problem. I took off the head, the valves were very badly pitted to the rear so I put new ones in which I properly ground into place on old seats. I also replaced the valve springs as one had broken altogether, so I replaced them all. I did not have the head skimmed, machined, checked or anything. I rebuit it and put it back on. The rest of the car is good, surprisingly good, which is why I bought it. The situation I have is that I have thrown money and time at the car to repair two issues. Thus far those issues have not been repaired, and it remains no more than a series of guesses to find out what is wrong. I could now spend more time and money doing more things, which ultimately don't work. For example, if I read all the latest advice on here I will need to remove engine again, remove the crank and have it reground. I will need to remove head again and have it checked, machined and returned to me. I will need to replace piston rings and potentially have repairs to the block where the cylinders are damaged. It all then needs to go back together with new gaskets, seals, bolts, bearings, etc etc. If I do all of this work myself except the specialist engineering stuff it's going to be looking at costing £300? at best. And then it might still not work because at any stage the head might be shown to be beyond repair, or the block might be beyond repair, or the crank could be so badly damaged it is beyond repair, or the fault could be something else altogether. So yes you could be right I may have made a mistake. I may not have torqued the head bolts enough. I may have the HG on upside down. I may have done all manner of things wrong but what? I don't know. I'm no mechanic, I'm just a guy with a load of tools, a manual and a bit of common sense. I follow instructions and that's all, I take (un)educated guesses at the rest of it. I have stripped/repaired many engines over the years, modern and old ones, but never been quite so downhearted and more to the point completely lost for which way to turn as I am with this one. Do you see my problem here. There has to come a point where you say enough is enough, so unless I am happy in myself that there is a particular cause to a problem, so I can do a particular item of work and it will repair it, I don't want to do it. I would rather find a way to spend that £300 on something I know will work. |
| matthew stubbings |
| Can I just add aswell that I understand a lot of the advice people are offering is with the best intentions and I really do appreciate it. I don't want to be the odd one out here but I don't actually enjoy working on engines that much. So the thought of continually doing this, then that, then the other is not filling me with joy. Stripping an engine down is bit like making love to a beautiful woman, a bit of an adventure first time round, but not so much fun after that... |
| matthew stubbings |
| Hang in in there matthew, welcome to the land of the midgets, all i can say, once you have it running, it will be worth every once of heart ach your experiancing. belive it or not your almost out of the woods, I know its hard to see, but you have your bearing situation worked out, the bearings are to big, so you can check that one off...the dead cly is a result of the head area what is that 2 sqft...its ither the head gasket didnt take, or its upside down, a cracked (most likely between the valves, or a warped head....trust me to go from where you where 10 days ago...that aint bad. all fairly easy to fix and not an excessive amount of money involved So here is what My Best recommendation is!! repost a new thread titled "Please help me, I need an experianced hand to guild my out of rebuild hell" then state where you live, and that you got a 1500, and need someone to look over my work...do I have a craked head, a blown gasket, and bearing issues...tell them your will to buy a tuck load of hot beer, and lots of cold fish and chips ( do you brits really like your food that way) any way...you dont want someone thats going to get there hands dirty, but can show you the little idiocitys you may not be aware of, that can put a straight edge on the head to see if its straight, that knows a good well priced machine shop to have the work done...this way you can be focased on where the problem is and get back to even trust me...eveyone here is more then willing to help if they can, and for the most part the brit side of the pound have no shortages of hang out pubs for the Mg crowd... trust me a little pride swallod will pay huge dividends who knows 5 years down the road, there maybe your reincarnation asking for the same help, seriously you wouldnt turn the down would you...I wish I lived with in 2 hours of you, id love to come by and try and screw it up...Imean help you out...Im to the point of almost bored waiting on mine in the machine shop. Prop |
| Prop |
| Matthew You owe Me buddy, I emailed a good friend that I have alot of respect for, She is vary busy right now, with work on several race engines, Im not sure what the 2 of you can work out, but you can trust her...she will be around with in the next several days provided she got my message...but she ill know what to do and how to do it. diz her at your own peril, as to me, Ill just sit and laugh as she takes you apart like a fish Prop |
| Prop |
| Matthew, You can't really put a price on the repair until you know what is wrong with it. You can't really know what is wrong with it without taking it apart. The good news is that it doesn't cost anything to take it apart. So, you could do that and then decide if it is worth your time and money to fix it. Charley |
| C R Huff |
This thread was discussed between 30/06/2009 and 08/07/2009
MG Midget and Sprite Technical index
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