Engine running roughly

Went to see an old friend of mine to borrow an old imperial micrometer. John used to run a small garage( a large shed) and is from the old school. John is now retired and the shed stands locked and forlorn.. Amazingly as well as loaning me the micrometre John was able to fix me up with shims, as his father used to own a couple of p6's years ago .However I believe, as John does, that some of the shims may have been ground to length..is this acceptable , hardness or case hardening etc. I am amazed that I was able to find these so close to home, but if they are unsuitable I don't really want to use them. John doesn't believe it will be a problem, but as I said earlier, he is from the old school.....georgecook
 
Practise has shown that the use of grounded shims to size is perfectly acceptable if you don't have access to the correct size.

Just take your measurements correctly and you will be fine.
 
Valve clearances are now spot on and the engine is running more smoothly, but still not in my view as it should be. Carried out another compression test with and without oil. Number one cylinder. 120psi and 225psi.....number 2 cylinder 185psi and 225psi ...number3 cylinder 185psi and210psi and number4.cylinder175 psi and 180psi............engine out ?.......georgecook
 
The rings can be replaced without removing the engine, and if you could find someone with a portable boring bar you could even get it rebored in-situ if that was required. I wouldn't be removing the engine unless it was absolutely necessary. With those type of figures I would have expected some other symptoms in addition to the poor running, such as oil burning, and oil smoke from the exhaust.
 
I did believe that after completion of the welding and the car being more or less 'solid' once more, that I would be able to take her out on the road and enjoy a few months of summer motoring. For some reason I just didn't expect to have what I perceive to be major engine problems. Is there light at the end of this tunnel? ......I suppose if it was easy, then everyone would do it.......georgecook
 
Head is now off and am now removing the valves. Have ran my finger around the cylinder bores and found no obvious scoring. Number one cylinder combustion area on the head appears different from the others. The valves seem ok but the head appears to be porous and flaky. Have only removed number one cylinder valves and there appears to be a hole in the head casting behind the inlet valve seat Will need to check it further and have taken some pictures but not sure how to get them onto the forum
 
georgecook said:
Yes I know... clutching at straws perhaps. georgecook
Click to expand...

That won't get you anywhere. You could have tested the valves before removing them. You can do the same to the rings now the head is off, and prove which is the problem.
 
I intend testing the cylinders by pouring a measured quantity of oil in the bores and timing how quickly it runs through. . What I did find however were the marks on the number one cylinder head. That's why I removed the number one cylinder valves to determine whether there was further damage inside behind the valves, and this does appear to be the case. Whether this is the cause of my problems or a contributory factor, I just don't know..... Also, the top of number one piston is rally clean compared with the sooty carbon deposits on the other pistons. Could this be cracked or leaking water jacket in the cylinder head..... Is pouring the oil in the cylinders, the best method of testing the cylinder bores/pistons? ...Harveyp6, I really appreciate your guidance on this, I have never gone so deep into an engine before.....georgecook
 
The clean piston could be an indication that water is getting in there, but you made no mention of coolant loss in your initial description IIRC. You normally get lots of pinking when water gets in the cylinder. The heads do corrode around the water passageways, and then coolant can get under the head gasket. Were the head bolts loose?

I'd use paraffin rather than oil. I would have tipped it down all the ports with the valves closed and seen what (if anything) leaked through, and I'd put a measured amount into each bore to see how fast that disappeared as well.
 
Have just got the head back from the local motor engineers. The head is cracked around the number one cylinder exhaust valve... head is kaput. I never thought about doing that head test with the oil . Could have saved me forty two quid..... Will carry out the cylinder paraffin test at the weekend... Will advertise for a replacement head on the forum......georgecook
 
georgecook said:
Have just got the head back from the local motor engineers. The head is cracked around the number one cylinder exhaust valve... head is kaput.
Click to expand...

Normally the valve seat would have fallen out and wrecked the head, and possibly broken the valve damaging the piston and bore, so even though you may not think it, you've probably had a lucky escape.
 
Just to clarify some points regarding the engine diagnosis... I bought the car in November 14. The previous owner delivered the car, drove it into my garage where it has remained ever since.... Until the last couple of weeks my time was spent doing bodywork repair. During this time I ran the engine for a few minutes say every five or six weeks. The engine sounded roughish but I thought some "tinkering" would resolve that, in any event, with the bodywork required I had bigger fish to fry.... I have never driven the car...georgecook
 
RESULTS OF PARAFFIN BORE TEST.....I poured half a pint of paraffin into each bore. The timing began as soon as I poured, and ended when the bore was empty of paraffin less that remaining inside the concave of the piston crown.
Cylinder one... two hours and fifteen minutes to drain through
Cylinder two..one hour and 12 minutes
Cylinder three... two hours and forty minutes
Cylinder four... two hours and forty five minutes

Are these figures, good, bad, or indifferent? Bearing in mind my concern regarding the cylinder head crack near the valve on number one cylinder it does appear that no damage has been done to the bore.... More advice please.....georgecook
 
Cylinder 2 lost the paraffin in half the time (approximately) of the next quickest cylinder, and a lot quicker than the other two.

If it was me, seeing as the head is off already, I'd remove the pistons, and if the bores and pistons look OK, I'd hone the bores and fit new rings. Removing the sump is no problem, you just need to take care with the timing chain when turning the engine over. While the sump was off, I'd have a look at the lower mains as well......
 
I would agree one hundred percent with Harvey's recommendation.

I got my Rover 2000 TC motor back to good health without removing it. A few tips I would give are:
- use a ridge reamer prior to removing the pistons. That way the rings will not catch, and they will come out easily. I did not use a ridge reamer, and had to replace some pistons as a result.
- I used Hastings piston rings.The Hastings part number is 6777. Deves also have a set, their part number is 1257.
- if you do have to replace the pistons, try to get new old stock pistons if you can. There has been a problem reported with the ones made by JP pistons in Adelaide. If you end up using them do a search here for more information. There is a clearance issue with these, but the can be made to work ok.
- take your radiator out and get it flow checked. A blocked radiator may be why there are engine problems. Check the thermostat as well.
- I would replace the big end and main bearings while you are in there. It is not that hard to do. Here are some photos of how to do them:
viewtopic.php?f=2&t=5768&start=30
Where are you? If you are in the US, then I have a 2000 TC head which I believe is serviceable.
Make sure you adjust the valve clearances properly. Search here for assistance. I have a spreadsheet which will assist with the calculations.

Your first engine overhaul is bit daunting, but it is not that hard to do, and it feels good once you get it back on the road.

James.
 
Pistons are out... to be honest they came out quite easily( should I be worried about that) am now checking the internet for replacement rings and big end bearings.... There are scuffing marks on each of the four pistons. These marks are around an inch wide and are at ninety degrees to the gudgeon pin (little end) running vertically from the ring grooves to the bottom of the piston skirt. I know it makes sense to replace the main bearings while everything is stripped down, but am just about starting to panic as there are so many bits and pieces lying around and am not convinced that I remember how to put them back together. It is so good to know that there are people out there who have completed this job successfully and are prepared to share their experience. georgecook
 
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