Stern Tube / Gearbox / Engine Maladies Part 4

[RLWP]

<snip>

Now, now, Richard...

 

I'm not sure if it's bad karma or not, but it's certainly bad luck. I think we've been quite nice to the engine recently too, if you include its gearbox, and all the cleaning. Love and attention and look how we get repaid.

 

Any idea what the oil pressure gauge take-off union is going to be in thread terms? Looked a bit like an adaptor union from the 2-3mm-ish pipe, to maybe 3/8" BSP? Be useful to take a gauge down next time and at least try cranking it by hand to see if we get any pressure at all.

 

PC

 

I've seen the movies. It's always the same when you try to raise the dead

 

Richard

 

1/8"BSP is about that size. BSP (British Standard Pipe is based on the pipe size)

Edited May 17, 2010 by RLWP

[gazza]

Ta, MP!

 

Yup, that's why I was getting confused - and the parts list even for the SL3 further enhanced my confusion for not showing the right (for an SR3) quantities of bearings!

 

Currently in a can-I-be-bothered-to-take-engine-out quandry.

 

I think I'll go with what I was just thinking, which is to pull the heads and cylinders with pistons off, and see both what state those shells are in, and what the crank feels like. Then make a call from there as to what needs doing next.

 

Unless anyone's got any further thoughts on direction?

 

I'm going to want to be sitting down again, when I hear the prices of these shells aren't I? And if the oil pump is shagged, then I guess it needs overhaul? Can't be that costly????????????? Can it???????????

 

If it's all broken, then we'll have to look at just swapping it out - we're waaaaaay too short on time to take it into a hundred pieces. Having spent a lot of effort reconditioning the reduction, finding (and paying for) a starter, just about sorting the reversing, and finding a LH prop, it'll have to be the same again and we'd swap our working ancillaries onto it.

 

Thinking ahead, if we found an SR3 with a manual box, does our hydraulic one just fit on? Please tell me yes... Same question with an ST2, which would be an alternative, again, if we could find one.

 

PC

 

paul, last time i played with an SR 3, it had a set of rings and a hone, new big ends and a general clean and sort. when reassembling and setting the squish clearance we discovered that the rod was slightly bent. a quick call to BRYCO in daventry revaled a con rod for 180 quid. this was 7 odd years ago. no doubt prices have kept pace with everything else.

 

we went down the route of bushing the little end and boring off centre. motor runs sweet as any SR. the rod must have been bent for a very long time as this was the first time the motor had had any love since the boat was purchased in the mid 80's.

 

as is often with projects like this your budget looks like its going to go over. a call to baldock may be a good idea. its sometimes more cost effective to replace with an exchange unit than rebuild a shagged one. especially when you factor time into it.

 

for an idea of what i am getting at. dad had a recon BMC 1500 from calcut boats. he supplied an old MOWOG motor to them. it needed injection gear too. the only bit that didnt get replaced or worked on was the camshaft. it had the following: -

 

block bored and liners pressed in, then bores to suit pistons. set of 4 piston and rings

 

crank regrind, shells to suit.

 

cyl head skim, guides seats.

 

timing chain, water pump, oil pump.

 

exchange injector pump and injectors, new lift pump, new filter housing

 

spin on oil filter housing

 

full gasket set

 

etc etc etc.

 

cost? 1650 quids.

 

eldest brother rebuilt a perky 4107 and spent over a 1200 on bits and machining. the calcutt rebuild was a bargin, especially when you consider a 9.9hp outboard will set you back more than the cost of the rebuilt BMC

 

bummer the motors poorly BTW.

Edited May 17, 2010 by gazza

[paulcatchpole]

I've seen the movies. It's always the same when you try to raise the dead

 

Richard

 

1/8"BSP is about that size. BSP (British Standard Pipe is based on the pipe size)

 

Aye, I know the BSP bit, but this has an OD that's within an eyeball of the 3/8" BSP coupling that was in my hand at the time - definitely not small...

 

PC

 

paul, last time i played with an SR 3, it had a set of rings and a hone, new big ends and a general clean and sort. when reassembling and setting the squish clearance we discovered that the rod was slightly bent. a quick call to BRYCO in daventry revaled a con rod for 180 quid. this was 7 odd years ago. no doubt prices have kept pace with everything else.

 

we went down the route of bushing the little end and boring off centre. motor runs sweet as any SR. the rod must have been bent for a very long time as this was the first time the motor had had any love since the boat was purchased in the mid 80's.

...

bummer the motors poorly BTW.

 

Aye, it's a fair point Gazza...

 

I suspect rings and even big end shells can be found at sensible prices, but taking it apart far enough to get to the mains is probably beyond my enthusiasm... If we can get it running with a rumble, then that'll have to do.

 

I've sent a few feelers out for engines too...

 

PC

[RLWP]

Aye, I know the BSP bit, but this has an OD that's within an eyeball of the 3/8" BSP coupling that was in my hand at the time - definitely not small...

 

PC

 

Yebbut... a 2-3mm pipe sounds like a 1/8" pipe. An 1/8" pipe goes in a 1/8"BSP fitting, which has a thread diameter of about 3/8", or 10mm ish if you prefer

 

Richard

[paulcatchpole]

Yebbut... a 2-3mm pipe sounds like a 1/8" pipe. An 1/8" pipe goes in a 1/8"BSP fitting, which has a thread diameter of about 3/8", or 10mm ish if you prefer

 

Richard

 

Aye, but the coupling I was holding was a compression 3/8" (for OD 3/8" pipe) to 3/8" BSP male, and was the same size - about 15mm or a bit less?

 

PC

[RLWP]

<snip>

Any idea what the oil pressure gauge take-off union is going to be in thread terms? Looked a bit like an adaptor union from the 2-3mm-ish pipe, to maybe 3/8" BSP? Be useful to take a gauge down next time and at least try cranking it by hand to see if we get any pressure at all.

 

PC

 

What's that bit in red all about then.

 

Although I think I'm being involved in an autopsy here rather than surgery

 

Richard

 

Or perhaps necromancy

[paulcatchpole]

What's that bit in red all about then.

 

Although I think I'm being involved in an autopsy here rather than surgery

 

Richard

 

Or perhaps necromancy

 

:lol:

 

Been trying to find a piccy of what it looks like, from Google but failing so far.

 

The fuel flexies we've got on that engine are 1/4" standpipes with union nuts and olives. The oil pressure one looks the same size fitting as the union nuts but with a 1/8" pipe coming out of it...

 

PC

[paulcatchpole]

:lol:

 

Been trying to find a piccy of what it looks like, from Google but failing so far.

 

The fuel flexies we've got on that engine are 1/4" standpipes with union nuts and olives. The oil pressure one looks the same size fitting as the union nuts but with a 1/8" pipe coming out of it...

 

PC

 

Alright, I'm prepared to accept, on face of global evidence, that they seem to universally be 1/8" BSP, in which case you are right and I am wrong... There, I've said it...

 

Mind you, if I take a 1/8" gauge and hose down there and it doesn't fit...

 

 

PC

[paulcatchpole]

Whilst reading another (!) forum, I came across this description of smooth running...

 

Feels like spinning a hot ear of corn on a stick of butter.

 

I like that...

 

Can I have an engine that does that, please?

 

PC

[creamcheese]

Alright, I'm prepared to accept, on face of global evidence, that they seem to universally be 1/8" BSP, in which case you are right and I am wrong... There, I've said it...

 

Mind you, if I take a 1/8" gauge and hose down there and it doesn't fit...

 

 

PC

 

Oh my lord, I've been waiting for him to say that for years, about many many things. Now here it is in writing! Marvellous

[WotEver]

Whilst reading another (!) forum, I came across this description of smooth running...

 

 

 

I like that...

 

Can I have an engine that does that, please?

 

PC

You need one of these:

 

Tony

[Guest User]

Alright, I'm prepared to accept, on face of global evidence, that they seem to universally be 1/8" BSP, in which case you are right and I am wrong... There, I've said it...

 

Mind you, if I take a 1/8" gauge and hose down there and it doesn't fit...

 

PC

 

Oh my lord, I've been waiting for him to say that for years, about many many things. Now here it is in writing! Marvellous

 

Not the the last bit then ?

[creamcheese]

Not the the last bit then ?

 

*creamcheese says nowt*

[RLWP]

Meawhile, back in the workshop...

 

I didn't like the look of the wobbly, loose pin screwed into the sterntube, so I drilled it out and turned a stepped plug. The small diameter stops the sterntube bearing rotating, the next diameter is to fill the hole drilled in the sterntube, and the flange is to stop the peg dropping in while it is being silver soldered. I then pressed the peg into the tube.

 

 

This is the peg being silver soldered into the stern tube:

 

 

Here is the whole lot silver soldered up:

 

 

And after the flange was filed off:

 

 

So, that's the first part done.

 

Richard

 

Chief Necromancer

Edited May 23, 2010 by RLWP

[paulcatchpole]

Meawhile, back in the workshop...

 

I didn't like the look of the wobbly, loose pin screwed into the sterntube, so I drilled it out and turned a stepped plug. The small diameter stops the sterntube bearing rotating, the next diameter is to fill the hole drilled in the sterntube, and the flange is to stop the peg dropping in while it is being silver soldered. I then pressed the peg into the tube.

 

<snip>

 

This is the peg being silver soldered into the stern tube:

 

<snip>

 

Here is the whole lot silver soldered up:

 

<snip>

 

And after the flange was filed off:

 

<snip>

 

So, that's the first part done.

 

Richard

 

Chief Necromancer

 

 

B*gger me, Richard, that's excellent work!

 

I may even forgive you for sandbagging me with the wire wheels...

 

But serious, that's really, really impressive - thanks for the incredibly neat work!

 

:lol: ;)

 

PC

[paulcatchpole]

Righty, ennin not so good.

 

Bit of a lengthy update from Saturday's engine diagnosis - with (for me) an unbelievable outcome, to whet your appetite.

 

PS, we're having a day off today, mainly to get over the results of yesterday, and partly 'cause it's far too warm to finish the welding or flowcoat the roof! Sorry, gods of boat work, it's tough...

 

Anyhow...

 

Plan started with connecting up an oil pressure gauge to see if we were getting anything at all whilst cranking, to see if a complete lack was behind all of the engine problems - to try and gauge the scope of the problem...

 

Gauge connected (pic taken after further disassembly!) :

 

 

I connected the gauge, drained the fuel filter to try and make sure it wouldn't run, and cranked it over. Low and behold, it starts so easily, it fired up and ran perfectly (if loudly) until the fuel ran out. Pressure was about 30psi on our dodgy Ebay gauge, and bounced a lot between 100psi and b*gger all.

 

We were so encouraged by this, and the lack of orrible noises (did I say it was still loud?), we ran it for another ten mins with some bleeding...

 

Youtube vid up here, of it running okay:

 

 

Twas about now that we wandered inside the boat with it running, and thought, blimey, this really is louder than our ST2, by a huge amount - maybe it isn't just diesel ignition we're hearing... But more of that later.

 

It ran for 15 mins then died to a slow halt, a bit like last weekend, and although it would restart, it was obviously overloaded and smoky, partially seized, and with only 5psi oil pressure or so...

 

Sooooooooo.........................

 

Time to take it apart a bit more.

 

I took the manifolds off, rocker covers off, injectors out and then pulled the head for cylinder 1 (well, nearest to gear end).

 

First thing found was a broken top compression ring on that piston, but not too much signs of skirt wear, and the bores looked okay. Also, there wasn't a lot of carbon on the piston top, which was a bit surprising.

 

The next head came off okay, piston looking in better condition again.

 

The third head came off in love with its cylinder and didn't want to be parted, but again, the piston and bore wear looked fine.

 

Buuuuuuuutttttttttttt................

 

A little pulling up and down of the pistons showed that 3 and 2 had no detectable play - a good sign, as surely this is a case of "if you can feel it, it's too much"? 3 thou new clearance on the big end, with 10thou about the limit?

 

But, No.1 had, and I'm not joking here, between 1/8" and 1/4" of up-down play in the big end... !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Hmm!

 

Here's an amusing youtube of this play:

 

 

Apologies for Kate videoing me cleaning it up - the scary bit is towards the end...

 

Hence, next we took the crankcase door off, and had a look to confirm this was in the big end, even though it couldn't be anywhere else...

 

 

This chunk of metal was sitting on the lip of the crankcase door:

 

 

Hmm, definitely the big end then...

 

Blimey, it's amazing it ran at all, and that explains the knocking!

 

Oddly, the other two big ends felt fine, and the bore/piston/rings seemed good too - I reckon it's been overhauled not that long ago. No detectable main bearing play either, although it'd be hard to feel without taking it apart some more.

 

Next plan was to take the big end cap off and see what state the shells were in...

 

Kate supported the piston whilst I undid and removed the cap, and you know what we found?

 

There aren't any shells in No.1 big end!!!!!!!!!!!!!!!!!!!!!!!!!!1

 

Yup, no bearing at all...

 

Eh?????????????????????????/

 

The only thing I can think is that someone's put the shells in the cap and conrod, lowered the conrod in, and somehow had the con-rod side shell fall out without them spotting it, leaving only one shell. Might feel okay when back together by hand, but then destroyed itself in five minutes running? I dunno, can't imagine anyone 'forgetting' to put the shells in??????

 

Anyhow, understandably, this hasn't had a good effect on the crank and conrod...

 

 

The crank ain't any better either!

 

So, whadda'ya reckon? I've not measured it, but I expect the crank journal to be undersize by more than the maximum allowed? What can you get OS bearings in for this? Max +60 or even +80? Nothing going in +1/4"?

 

We reckon this writes the crank off, and hence the engine too. Plan is to try and find a good second hand one (oh okay, Casper.... ) and swap our gearbox onto it.

 

By the way, the Gearbox has cheered up even more and now reverse works as well - so a fully working gearbox but no engine!!!!!!!

 

Ah, these things are sent to try us!

 

Hope this keeps you all amused...

 

Amazing it ran at all eh?

 

PC

[Athy]

Amused, Paul? It makes me feel very tired - and, of course, sympathetic.

[RLWP]

I doubt that the shells were forgotten. My guess is that the engine has totally destroyed them. Have a furtle about in the sump and see what you find. You have already shown us the first shard from the crankcase door.

 

Richard

 

Not up for more necromancy then?

 

 

A word to the wise. Don't do engineering wearing a ring. If you are lucky, you'll wreck the ring. If you are unlucky you'll catch it on something and it tears through the skin of your finger meaning stitches. I've seen the result and it wasn't at all nice and that was from someone using only hand tools.

Edited May 23, 2010 by RLWP

[BEngo]

I doubt that the shells were forgotten. My guess is that the engine has totally destroyed them. Have a furtle about in the sump and see what you find. You have already shown us the first shard from the crankcase door.

 

Richard

 

Not up for more necromancy then?

 

 

A word to the wise. Don't do engineering wearing a ring. If you are lucky, you'll wreck the ring. If you are unlucky you'll catch it on something and it tears through the skin of your finger meaning stitches. I've seen the result and it wasn't at all nice and that was from someone using only hand tools.

 

 

I have seen the resulting injury to the man who caught his wedding ring on the door gutter of a Wasp helicopter, just as he stepped down (about 2ft). Bones might have thought it would make a replacement avatar but the maintainer won't do it again because there's nowt left to do it to. De-gloving injuries are very nasty- the end result of this was even worse than the ones sustained by the chap who accidentally put his hand up into the rotor disk!

N

[paulcatchpole]

I doubt that the shells were forgotten. My guess is that the engine has totally destroyed them. Have a furtle about in the sump and see what you find. You have already shown us the first shard from the crankcase door.

 

Richard

 

Not up for more necromancy then?

 

I agree, I can't imagine the shells being forgotten either, but the other two big ends have no 'feelable' play, the bores are good too, and the mains although a little rumbly aren't horrible. If it did have a pair of new shells in there, how did they have enough clearance to disintegrate? The engine was still making good oil pressure, so I'm not convinced on the oil starvation front, unless someone managed to put them in and get the oil holes misaligned, is that even possible with 'tabbed' shells?

 

A word to the wise. Don't do engineering wearing a ring. If you are lucky, you'll wreck the ring. If you are unlucky you'll catch it on something and it tears through the skin of your finger meaning stitches. I've seen the result and it wasn't at all nice and that was from someone using only hand tools.

 

Kate's the ring wearer, not me, no doubt she'll take it onboard. I was doing most of the near-engine stuff, all the same.

 

PC

[RLWP]

I agree, I can't imagine the shells being forgotten either, but the other two big ends have no 'feelable' play, the bores are good too, and the mains although a little rumbly aren't horrible. If it did have a pair of new shells in there, how did they have enough clearance to disintegrate? The engine was still making good oil pressure, so I'm not convinced on the oil starvation front, unless someone managed to put them in and get the oil holes misaligned, is that even possible with 'tabbed' shells?

 

 

 

Kate's the ring wearer, not me, no doubt she'll take it onboard. I was doing most of the near-engine stuff, all the same.

 

PC

 

Dunno why on the shells, but I'm still pretty sure that they are shagged out and sitting in the sump

 

Incidentally, I know it's all horrible, but you'll only really know about crankshaft if you measure it. It may not be quite as bad as you think. Even so, looks like a replacement will be cheaper.

 

Richard

 

I thought that ring did look a bit feminine, even for you...

[paulcatchpole]

Dunno why on the shells, but I'm still pretty sure that they are shagged out and sitting in the sump

 

Incidentally, I know it's all horrible, but you'll only really know about crankshaft if you measure it. It may not be quite as bad as you think. Even so, looks like a replacement will be cheaper.

 

Richard

 

I thought that ring did look a bit feminine, even for you...

 

It's a good mystery, the missing/disappeared bearing. I still can't believe it ran as well as it did.

 

I've got a very sensible price on grinding, polishing and oversize shells - but I've no idea on how available good cranks are with no usable exchange unit! The crank big end journal is pretty horrible though, worse galling than the pics of the conrod above. Finish like sandpaper etc...

 

I'd need your big measury-thingy to measure it, don't think my callipers are up to it, and I've only got a small one. Micrometer, that is.

 

First things first, I'm going to ring Casper's contact regarding a sensibly priced second hand identical unit. The price of that isn't far off the regrind, shells, rings and gaskets needed to rebuild this one, and that's without a 'new' crank.

 

PC

 

PS: *My* rings are far more, let's say, in my own inimitable style... :lol:

[RLWP]

<snip>

PC

 

PS: *My* rings are far more, let's say, in my own inimitable style... :lol:

 

Richard

[springy]

Glad to hear that the gearbox has decided to behave properly, shame about the

big end though. As has already been suggested you will probably find the rest of

it in the sump, and only proper measuring will determine if the crank and/or

conrod are recoverable, and then you can decide whether its economically

best to rebuild or replace, though dont forget to include a factor for an engine

which you know is "all good" 'cos you rebuilt it as against an engine picked up

second hand as "all good" or even "running ok when removed", even though

you'll have a big pile of spares to chuck at it.

 

springy

[paulcatchpole]

Glad to hear that the gearbox has decided to behave properly, shame about the

big end though. As has already been suggested you will probably find the rest of

it in the sump, and only proper measuring will determine if the crank and/or

conrod are recoverable, and then you can decide whether its economically

best to rebuild or replace, though dont forget to include a factor for an engine

which you know is "all good" 'cos you rebuilt it as against an engine picked up

second hand as "all good" or even "running ok when removed", even though

you'll have a big pile of spares to chuck at it.

 

springy

 

Aye, it's good news on the gearbox front, even though it's taken some of the fun out of troubleshooting. Ta for your help, and to everyone else who helped out in getting it this far.

 

It's a very fair point about a known good unit, after rebuilding it. It's something I've been trying to convince Creamcheese of, but she's a bit more fond of the drop-in-replacement idea. I wonder if it'd be worth at least re-ringing any given replacement as a matter of course...?

 

And Richard, Men's evil manners live in brass; their virtues we write in water...

 

The new, extra long, shaft, is on the way, and should be here early this week. Not a lot of point in doing much with it, I guess, until the engine situation is sorted, in case the mounting point changes!

 

PC