Another Lister D

Rings ordered from Thorntons, sure this had the wrong oil ring in, and with the gaps on the rings headng for 1/4" or so I have doubts about all of them.

Looking at it and my wanting to do things properly I have decided while its apart it may as well come apart just a little more , no point in half a job, so dropped the timing assy off and given that a clean of all the oily mess. Now I can give the bore a good de-glazing, clean the crankcase right out of any debris and build back up again.

The studs were a swine to get out, but I got them out all in one piece, I have some studs I purchased for my other D so they will be going back. Head gasket ordered as the old one fell apart.

So I shall sneak off to the workshop over a nice long weekend and get the the bottom end rebuilt, piston rings to fit and file - not done that for a while.

Geoff

biomed32uk wrote:Rings ordered from Thorntons, sure this had the wrong oil ring in, and with the gaps on the rings headng for 1/4" or so I have doubts about all of them.

Looking at it and my wanting to do things properly I have decided while its apart it may as well come apart just a little more , no point in half a job, so dropped the timing assy off and given that a clean of all the oily mess. Now I can give the bore a good de-glazing, clean the crankcase right out of any debris and build back up again.

The studs were a swine to get out, but I got them out all in one piece, I have some studs I purchased for my other D so they will be going back. Head gasket ordered as the old one fell apart.

So I shall sneak off to the workshop over a nice long weekend and get the the bottom end rebuilt, piston rings to fit and file - not done that for a while.

Geoff

Just back in time to wish you well on the second engine job Geoff, Nice that you have it sorted and on the way.

I'll be following,
Cheers, John.

Looks like Geoff has his Easter weekend sorted, good luck and hope all goes well with the rebuild.

Stu.

Well, I did have the weekend planned out, and got to play with the D on friday afternoon, put the new rings into the bore, made sure the gaps were OK and fitted the rings onto the piston, compression ones fine, the oil ring shattered into four using the proper pliers , so that bought that to a swift halt, the most I managed with it was to fit the timing case back on, and some cosmetic jobs with the rest of it while it's in bits.

Ordered another ring tues,and turned up today. Gapped it and it runs through the bore nicely, infact it can be encourged out the bottom. Onto the piston - job sorted so I think. Piston fitted into a well lubed bore, piston binds up tight about three quarters down on the oil ring, removed the compression ones to prove it.

So the ring clears the bore with a gap and no piston, the bores standard and so is the piston, but it appears the ring is nipping the piston by bottoming out in the groove, which is totally clean.

The groove depth on the piston is 130thou, the ring is is 136thou, so when the ring is bottomed out the diameter is 12thou over, in engine terms lots, even though there is some wear it's not this much. How it clears the unworn 3" at the top i dont know, but it goes in, but did take some gentle encouragement.

Anyone have any theories as to whats up, other then the ring is incorrect - came from Thorntons.

They have probably allowed a bit extra knowing its going back into a worn engine. Obviously yours is not that worn! Looks like you will need another ring.

Well the oil ring from SEP turned up today, which was no dearer than Thorntons, but this one is only .120 deep compared to .136, result - onto the piston during my lunh hour, slipped into the bore and moving nicely. Crank assy back in so bottom end done.

Get the head put back, carb etc etc and see what she runs like. Hopefully less smoke this time.

Are there any guide lines for head nut torque, I know the engines not that fussy about such things but its alien to me not to torque them down evenly.

Also are there any guide lines setting for the air valve in the carb, there's quite a lot of spring tension on this one even to get it to lift.

Geoff

I always torque head bolts down, usually just go for 10 ft/lb as it's the lowest my torque wrench will go to & feels pretty tight on an old engine (remembering the leverage as most torque wrenches are pretty long). Sometimes I go up in increments of 5, but the main thing is to get them tightened down evenly & to the same figure. Like you I just don't like using guess work when it comes to head fixings.

Start in the middle and work out when tightening head bolts. As for the setting I'm sure there will be 1 but I tend just to torque to about 30lbs/ft and that seems ok to me. If you haven't a torque wrench try to tighten down evenly with the final pull on the spanner matching the others for tightness.

Stu.

I would concur with that Stu, 10ft/lbs just felt too loose, went up to 30 and that feels nice and about the right level of tight. Condsidering I had a 2' breaker bar to get them undone, with the engine following me around while leaning on it I think thats right.

Well it all went back together yesterday morning, without trouble and old smokey as its become known smokes no more, gave it a run for a couple of hours, the odd small puff every now again, especially towards the end of the run when it was getting hot right through. Beforehand - by that point the shed would have been disappearing in clouds of smoke billowing from it. Sure when the rings bed in it'll be even better, but that's plenty good enough for for me at the moment.

Weather starting to improve so I can get in with the other one, done some bits chipping away at it.

Torque figures sound about right. They all depend on the size of the stud involved (there are standard figures for standard size studs in standard materials, but I don't know what they are). The studs on my Kohler are quite a lot smaller than Lister D ones (they take a 1/2" AF spanner), 30 Ft/Lb would be far too much for them & probably strip the threads (one of them started feeling a bit iffy at 15!) So I usually start low & work my way up to whatever "feels" comfortable. If anyone reading this doesn't have that feel for things like this, then probably best to ask or seek out the correct figure.

At least now I know what to do the Lister D ones up to when I eventually get round to doing it.

I will have to look up some standard torque figures, they must be available. Today I wanted to gap some new piston rings for an engine I'm restoring for someone else. After some searching I found a basic "rule of thumb" figure of .004" gap for each inch of piston diameter for the top ring, going up to .005" per inch for the 2nd ring (or thereabouts). I added a little bit for the fact it's not a car engine, but it was handy to have a ballpark figure to work to.

Now I've bought myself a laminating machine & large stock of pouches (for my engine log sheets & reproduction period adverts/literature) I suppose I should print off some of these different charts & put them up in the workshop.

P.S. if I do find a torque chart I will put it up in the reference section.

Nuts the figure of 30lbs/ft was just for the D sized studs, and as you say if you haven't that feel for knowing when things are tight or not best not to guess. You also have the problem that some people are stronger then others so even the nip up would be different. So if you can get the correct settings and even hire a torque wrench it would be best. If you over tighten your facing an unknown world of stripped threads, snapped bolts so take care when tightening any nut/bolt more so on an old engine.

Stu.