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Post by dave1800 on Apr 2, 2015 11:47:43 GMT
On MK1 cars and early Mk11 (sorry I don't know engine numbers) you did indeed have to remove the oil pump so a big job. On later engines you can remove the camshaft as Tommy has done (more than once!) regards David I would think, that apart from the distributor drive gear, it would be necessary to remove the oil pump. Am I wrong? Peter
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Post by dave1800 on Apr 2, 2015 12:22:06 GMT
Hi Tommy It does look as though there is something seriously wrong with the cam lobes.Do they look worn? I have read reports of them not having been ground accurately but never knowingly experienced it. The dwell vs gap issue to me also indicates that direction. Changes of points gap with vacuum suggest the plate may be distorted or worn and lifts or falls as it rotates. The big difference between static and idle running timing would point towards a weak spring or backlash in the timing gear /drive but I think the latter can be discounted given the work you have done. Definitely one for the distributor doctor to answer I believe. I am trying to understand what is happening with your tappet clearances and why you get differences when measuring using tdc and rule of nine methods. I need to do a bit of research but can you confirm if the rocker shaft has been replaced or if it may possibly have wear. Logically something must be flexing or have wear in a bearing / bush if you are getting different readings. This must be either the camshaft or much more likely the rocker shaft. The two methods will place different loads on an area of these two shafts. The problem is I do not know what is "normal" and if anyone else has done this comparison. The safe option is to ensure that you have a minumum of 0.015" for each tappet. The downside possibly more noise. I assume you have the appropriate shims under the rocker shaft pedestals. Regards David Now, for the rebuilt distributor... The symptoms, both before and after the head/ cam change, which I believe boils it down to the distributor itself: Jumping timing marks, setting the static timing at 9 degrees btdc gives more than 15 degrees at idle, correct points gap gives to little dwell. To set the dwell correct I can't get a 0.014 feeler gauge in, so points gap to small. I tried different points, all quality items. The four point gaps are different, and the point gap changes between vacuum applied and not (checked by turning the points plate. Seems to me he cam lobe has not been changed. I've tried another distributor with points and it doesn't behave like this, also the timing marks are steady and the dwell is correct. I think I'll contact distributordoctor and let him have a look at it, as I now run another distributor with the electronic setup. It's been totally reliable, but I always carry points and condenser in the boot.. Tommy
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Post by tommydp on Apr 2, 2015 15:29:25 GMT
The rocker shaft assembly has been used for a little while on a previous cylinder head, so should have very little, if any, wear. The shims are there.
I recall I noticed the same on the white car, and I have not been into those timing gears:-) On that engine, I set the clearances so they were no tighter than 0.015 at tdc or rule of nine measure. I suppose that's the most logic thing to do. It would be interesting to hear if others have compared the clearances this way and if they've found differences.
On MGB pages there are different opinions on what is the correct way to set the valve clearances, but it seems to boil down to the rule of nine as the correct. I guess the main thing is that they are no tighter than 0.015 at tdc or rule of nine
Tommy
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Post by Penguin45 on Apr 3, 2015 0:02:21 GMT
Good stuff, Tommy. David is almost certainly right in his comments, but I note that you say the gap at the points in the distributor varies as well as the valve gaps. Perhaps an issue there? The bottom bearing on a Lucas dizzy is known for developing wear, which allows the shaft to move around in the housing. Keep going, you'll get there. Chris.
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Post by dave1800 on Apr 3, 2015 0:36:54 GMT
Chris, agreed the distributor bottom bush wear will cause the gap to vary but unless I am mistaken this distributor has been rebuilt by an acknowledged expert. Tommy has so many apparent issues with it, he needs to understand the cause(s)and probably the best person to ask is the one who overhauled it. As the other electronic distributor is working well this seems to discount any timing train issues. Interesting.
regards
David
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Post by tommydp on Apr 3, 2015 8:42:26 GMT
Thanks for your replies! I will contact distributordoctor, who overhauled it, and let him have a look at it. It's obviously something strange with it, and I'm almost certain the cam lobe was not changed, as I remember it had variable points gaps on the four lobe peaks when I sent it in. As mentioned it still has. There seems to be no play in the shaft/ bush.
I think the timing, drive gear issues etc can be ruled out for good now, as the symptoms is not there when running another distributor. Both with points and electronic, as I run now, the timing marks are stable. Also the relation between points gap and dwell angle is correct on the other distributors I've tried, and a static timing of 9 degrees gives 12 at idle as supposed to, not 15-16 like the overhauled one.
I've just done a thorough check on the valve clearances now. I re- torqued the head first, in case it had changed but they all were fine. I set all valves by the rule of nine, only minor adjustments to some were neccessary to make the 0.015 gauge slide in and have a slight drag. I only turned the engine in the running direction, no I haven't always done that Sir... After completing all by the rule of nine, I checked each cylinder at tdc firing. To my relief they were quite identical, the gauge would slide in on all. The only issue, which I don't think I'll be to concerned about was that the gap on the intake valve on cylinder 3 was larger, so the feeler gauge was quite a lose slide at tdc firing. Well, rather that than too tight. Of course I've "borrowed" that very rocker's ball screw for god knows what engine/ cylinder head, and put in a used one. Confirmed by not having a shiny nut like the seven others. I remember it know, and maybe that could cause it? Also, there is perhaps a bit more play sideways on that rocker.
I think I'll just live with that slightly more tappety valve or perhaps get a new ball screw.
Regards, Tommy
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Post by dave1800 on Apr 3, 2015 13:58:35 GMT
Well that just shows you should look for the simple answer first! Good exercise though trying to work out a plausible reason Now what's the simple answer to your distributor woes, I wonder? My brain hurts. Regards David I only turned the engine in the running direction, no I haven't always done that Sir... Regards, Tommy
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Post by tommydp on May 8, 2015 14:25:57 GMT
Hi all! A quick update. I've contacted distributordoctor about the overhauled dizzy, and I'm sending it back to him for a check. I'm still running an old distributor with a cheap ebay electronic ignition set. It seems to work very well, timing is exactly the same and the timing marks are steady. I've driven it a lot. Actually, I've only used the blue one since taking it out in March.
As I mentioned in another thread here, I suspected a fault with the fuel pump the other day. Driving from town it suddenly lost power up hills. It almost stopped, but I was able to creep off the highway and take rural roads home. At least I've learned something over the years: If there are sudden running problems, think if you've changed/ altered anything recently. In deed I had, the same day. I installed a brand new set of Lucas (at least marked Lucas...) HT leads which I got on ebay. I believe they are new, and therefore could be of suspect quality.
As i felt the whole engine missed and left me with virtually no power at all, I suspected the coil to distributor lead. I changed it for another lead, and yes, it once againg flew upp the hills!
So, when do I learn and quit buying Lucas stuff that's not old stock?? Perhaps it was just bad luck. The white one has the ssame leads and there are no problems.
Regards, Tommy
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Post by Penguin45 on May 8, 2015 15:58:49 GMT
If it's labelled Lucas in a green box, don't buy it........
Chris.
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Post by tommydp on May 8, 2015 23:35:53 GMT
In deed, Chris! Wasn't even in a box, just a plastic bag. LOL. I can't think of anything else causing it. Improved instantly when I fitted another lead. Been fine all day today.
Going back to homemade copper leads:-) I buy them off roll here, have decent NGK caps that screw on the lead end, but the therminals which plug into the cap and coil I can get here are crap. Of course I could order some decent ones, but the good stuff crimping tools are quite expensive imo.
I see there's a bloke advertising UK made copper leads made to order on ebay at a decent price. Listed for MGB, Mini etc in different colours. Perhaps a better go.
Regards, Tommy
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Post by Penguin45 on May 8, 2015 23:46:25 GMT
Eyup, Tommy. Eugenie runs these from MOSS EUROPE and have been no trouble at all. The Austin still has an ancient set of green Champion leads of which I have no idea of their age. They work, so I leave them alone! Chris.
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Post by dave1800 on May 9, 2015 0:55:41 GMT
Copper leads can play hell with radio reception and are not advised for use with some electronic ignitions as they can cause false triggering which can lead to unit failure. Having said that as long as you don't listen to MW and have points they should be the most relable.
David
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Post by tommydp on Jul 6, 2015 7:10:01 GMT
Hi all! About time I made an update:-)
Well, the blue car has its engine out again and it is returned to the rebuilders. To make a long story short, it has used oil ever since the rebuild, and it developed blue smoke after overrun. Surely strange after about 15 000 kms since the rebuild. They've stripped it and the cylinders are worn and glazed again. Also the rings are all worn. They can't explain what has happened, and neither can I. They assume it has to do with too much petrol, washing the cylinders. I can't see how this has happened. Also, I guess the 285 cam they installed incorrectly didn't do it good in the beginning. Anyway, I've now supplied them with another block for overhaul, and we'll find an agreement on the cost of this work. They are very helpful and keen to make up for it. I hope it will be ok this time. After all they have been around for 70 years and are one of Norway's top reputated engine reconditioner's.
I'll have them time the camshaft this time, to make sure it's ok:-) Just hope the cam, which is standard, is ok to them. If not I'll have to get a new standard MGB cam. I actally bought a new Piper 270 cam at an autojumble the other day. I'm having doubts about fitting it to the "new" engine, in case it messes up something and doesn't go well with the carburettor and distributor. It was only £35, so I had to buy it though:-)
The reconditioned distributor has been returned to distributordoctor, as there's obviously something wrong with it as described earlier.
So, sadly no blue 1800 driving this summer:-( Luckily the white one is running like a dream and is very reliable. I've given him a set of new tyres, Barum Brilliantis. They appear to be very good and I'm releaved they dont' wear. I'm also doing some upgrades to the interior and some paint here and there.
Hope you're all fine:-)
Tommy
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Post by indianajones on Jul 6, 2015 8:00:09 GMT
Hi Tommy,
Hopefully this time round it gets sorted, bit of a bugger though!
-Andrew
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Post by dave1800 on Jul 6, 2015 12:52:12 GMT
Sorry to hear of your woes, Tommy. You certainly do seem to get your fair share of baffling issues, sadly. It's very difficult to understand how there could be that much wear after such a low mileage. Certainly lack of oil either due to excessive cylinder washing or a defective oil pump / oilway partial blockage could account for this, but I would have thought it would have shown up as black smoke from the exhaust if the mixture was excessively rich. You would have noticed this when you tuned the car or looked at the tail pipe. The blue smoke on the overrun is normally a sign of worn valve guides which would occur if there had been some oil starvation causing wear or the guides were old. Maybe worth checking the inlet valve to guide clearances in case this is one of the main factors. The fact that it used oil after the rebuild does possibly point to an error in the reboring or pistons and rings when it was rebuilt. When you have the engine back, if it's not with you already, it would be worth taking some measurements of each of the bores, the piston rings: bore and the piston ring gaps. Is the issue the same across all 4 cylinders? Have a look at the crank and the bearings to see if there is any evidence of possible oil starvation. I think it would be good to bottom out the cause just in case the rebuilder is doing something wrong; but these engines are so simple I can't imagine what. I can't recall when you had the 285 cam fitted if you changed the carb needle to suit. If not I would hazard a guess that it could severely upset the mixture across the range. Setting the mixture right at idle would not have guaranteed it was appropriate. If you have a good standard cam you may wish to go with it rather than introduce additional complications. Regards David Hi all! About time I made an update:-) Well, the blue car has its engine out again and it is returned to the rebuilders. To make a long story short, it has used oil ever since the rebuild, and it developed blue smoke after overrun. Surely strange after about 15 000 kms since the rebuild. They've stripped it and the cylinders are worn and glazed again. Also the rings are all worn. They can't explain what has happened, and neither can I. They assume it has to do with too much petrol, washing the cylinders. I can't see how this has happened. Also, I guess the 285 cam they installed incorrectly didn't do it good in the beginning. Anyway, I've now supplied them with another block for overhaul, and we'll find an agreement on the cost of this work. They are very helpful and keen to make up for it. I hope it will be ok this time. After all they have been around for 70 years and are one of Norway's top reputated engine reconditioner's. I'll have them time the camshaft this time, to make sure it's ok:-) Just hope the cam, which is standard, is ok to them. If not I'll have to get a new standard MGB cam. I actally bought a new Piper 270 cam at an autojumble the other day. I'm having doubts about fitting it to the "new" engine, in case it messes up something and doesn't go well with the carburettor and distributor. It was only £35, so I had to buy it though:-) The reconditioned distributor has been returned to distributordoctor, as there's obviously something wrong with it as described earlier. So, sadly no blue 1800 driving this summer:-( Luckily the white one is running like a dream and is very reliable. I've given him a set of new tyres, Barum Brilliantis. They appear to be very good and I'm releaved they dont' wear. I'm also doing some upgrades to the interior and some paint here and there. Hope you're all fine:-) Tommy
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