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My tale of woe and possibly intrigue


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;) Stan

I hope your tale of woe ends soon as I am sure it will, while you are changing the oil pump just check the main bearing's

the oil you are using is to high in viscosity that is why they tell you to pre heat it

 

Regard's

ntc

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;) Stan

I hope your tale of woe ends soon as I am sure it will, while you are changing the oil pump just check the main bearing's

the oil you are using is to high in viscosity that is why they tell you to pre heat it

 

Regard's

ntc

 

 

This engine is cursed. The latest tragedy is that while repairing the drive dog the gear fractured so now I have to track down another one. I sent an SOS to the 6pack and my local club list so hopefully I will have a replacement soon. sigh.

 

Stan

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This engine is cursed. The latest tragedy is that while repairing the drive dog the gear fractured so now I have to track down another one.

 

Hi Stan, could be a blessing in disguise, it may have been hairline fractured and would have failed with potentially disastrous results at some point in the near future, look for the positives!

Edited by jonlar
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I think I have found the source of the current oil pressure problem. The shaft in the dizzy drive dog that drives the oil pump is rotating in the gear. The pin probably sheared when the oil pump died. Oh well, back to the machine shop.

 

Stan

 

Something had to give - I was befuddled as to how the dizzy went round without the oil pump turning :unsure: but now it's plain <_<

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Here's the latest news. A fellow New England Triumph member donated a drive dog from his spare engine and after about 15 seconds of cranking on the starter I got a steady 75lbs of oil pressure. So far so good. I didnt see obvious signs of oil pouring out of the rockers but I'm not quite sure what I should be looking for. I have the dash apart AGAIN tracking down a short in the green circuit (see related topic) and the weather is **** today (torrential rain) so I expect to have a go at starting it either later tomorrow or Weds when the weather is better (it is reversed into the garage so I cant start it in situ without gassing the Mrs and need to get it outside onto the driveway).

 

I think that most if not all of my recent problems were related to a drive dog that had a broken pin in the distant past and had been "repaired" by trying to weld the shaft to the gear. The sticking oil pump with the alu fragment was enough to overwhelm the tenuous weld and so the shaft was rotating free in the gear. A normal drive dog would have had enough torque to force the pump to eat that small piece of alu I think. While the shaft was rotating in the gear it did occasionally bind giving the appearance that we were getting oil pressure some of the time, further obscuring the root cause.

 

 

Hope to report a running engine tomorrow.

 

Stan

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Something had to give - I was befuddled as to how the dizzy went round without the oil pump turning :unsure: but now it's plain <_<

If the pin, locating the driven gear to the shaft, has sheared, I suppose not only the drive for the oilpump will be lost but also the drive for the distributor at the same time?

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If the pin, locating the driven gear to the shaft, has sheared, I suppose not only the drive for the oilpump will be lost but also the drive for the distributor at the same time?

 

The gear is driven directly by the cam so even with the pin sheared the dizzy continues to rotate and the engine continues to run but with no oil pressure. Pretty bad falure mode but hopefully not a common one.

 

Stan

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Here's the latest news. A fellow New England Triumph member donated a drive dog from his spare engine and after about 15 seconds of cranking on the starter I got a steady 75lbs of oil pressure. So far so good. I didnt see obvious signs of oil pouring out of the rockers but I'm not quite sure what I should be looking for. I have the dash apart AGAIN tracking down a short in the green circuit (see related topic) and the weather is **** today (torrential rain) so I expect to have a go at starting it either later tomorrow or Weds when the weather is better (it is reversed into the garage so I cant start it in situ without gassing the Mrs and need to get it outside onto the driveway).

 

I think that most if not all of my recent problems were related to a drive dog that had a broken pin in the distant past and had been "repaired" by trying to weld the shaft to the gear. The sticking oil pump with the alu fragment was enough to overwhelm the tenuous weld and so the shaft was rotating free in the gear. A normal drive dog would have had enough torque to force the pump to eat that small piece of alu I think. While the shaft was rotating in the gear it did occasionally bind giving the appearance that we were getting oil pressure some of the time, further obscuring the root cause.

 

 

Hope to report a running engine tomorrow.

 

Stan

Hi Stan, you're gonna hate me for saying this, but if you want any reasonable life expectancy from this engine then you are going to have to strip it down completely and find and clean out all the metal shards that have been created by the numpty who tried to weld the shaft and drive cog together. Most of the bits should end up in the oil filter, but not all, some will end up embedded in the white metal of the main and big ends and get a good ol' grind going on. It'll run like this for a fair old while but never be the engine it should be. Sorry, but it's time to get dunking all the components in cleaning fluid again.

Been there once or twice, it's a PITA, but at least you know everything fits!!

Cheers, Rob

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Hi Stan, you're gonna hate me for saying this, but if you want any reasonable life expectancy from this engine then you are going to have to strip it down completely and find and clean out all the metal shards that have been created by the numpty who tried to weld the shaft and drive cog together. Most of the bits should end up in the oil filter, but not all, some will end up embedded in the white metal of the main and big ends and get a good ol' grind going on. It'll run like this for a fair old while but never be the engine it should be. Sorry, but it's time to get dunking all the components in cleaning fluid again.

Been there once or twice, it's a PITA, but at least you know everything fits!!

Cheers, Rob

 

Rob, I dont think it is quite that catastrophic. The welded drive gear has been in this car for at least the 27 years that we have owned it and based on the condition of the bottom end it has not been shedding bits. The inside of the hole in the top of the hear was always rough and if I tried hard I could pry chunks off the weld but they were largish chunks and none of them eneded up in the motor (I collected them all and still have them !). I stripped the oil pump and cleaned up the casting of any other bits of alu that might fall off so I'm going to cross my fingers and go for it. The next time I have the sump off though I'll check the bearings just to see if anything bad is going on.

 

Stan

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Rob, I dont think it is quite that catastrophic. The welded drive gear has been in this car for at least the 27 years that we have owned it and based on the condition of the bottom end it has not been shedding bits. The inside of the hole in the top of the hear was always rough and if I tried hard I could pry chunks off the weld but they were largish chunks and none of them eneded up in the motor (I collected them all and still have them !). I stripped the oil pump and cleaned up the casting of any other bits of alu that might fall off so I'm going to cross my fingers and go for it. The next time I have the sump off though I'll check the bearings just to see if anything bad is going on.

 

Stan

 

;)

Hello Stan because the engine has been run already what is done is done but i think and hope you just might be alright

Good Luck go for it ;)

 

Regards

Neil

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and the distributor ( ignition ) is keyed into the offset slot in the gear, so no pin drive.

Agree I was wrong about the layout of the distributor/oil pump drive. Maybe because PI and carb engines are different : the Moss catalogue is showing 2 gears : is it possible that the PI models have a second gear for dizzy and metering unit on the same shaft, located by a pin or key?

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First the good news. The engine runs, I have oil pressure and it is spitting oil out of the rocker cover hole when the cap is removed so we are getting oil to the top of the engine. Ran it for 20 mins at 2K rpm for the initial cam break in, water temp gauge rises to about half way end then the newly installed electric fan kicked in and cooled it back down to 1/4. Bit of noise from the valve train, carbs not balanced etc but it ran steadily through the 20 min session.

 

Now the bad news. I have a significant oil leak at the lower to middle front, not sure where yet, seems to be origiating on the alternator side of the engine. Hopefully the timing cover or sump and not the front plate. Bugger.

 

Edited to add link to commemorative video clip (low quality, shot from phone..)

 

http://s38.photobucket.com/albums/e119/fos...irststartup.flv

 

Stan

Edited by foster461
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;)

Stan it's alive ;) Don't forget you are running low viscosity oil these engine's are comeing up to 40 year's old now.I would change the oil for 20/50 and run a while.

 

Ps your distributor is one place out the advance knurl should face 3 stroke 4 o'clock

It sounds ok

 

Regard's

Neil

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;)

Stan it's alive ;) Don't forget you are running low viscosity oil these engine's are comeing up to 40 year's old now.I would change the oil for 20/50 and run a while.

 

Ps your distributor is one place out the advance knurl should face 3 stroke 4 o'clock

It sounds ok

 

Regard's

Neil

 

Neil, I will be changing the oil this afternoon for some Valvoline VR1 20-50 racing oil and a bottle of zddp for the next phase of the break in. I'm not optimistic that will change anything about the leak as I think that was an assembly error. Since it is not gushing out I think I will move on to something else for a day or two and come back to it.

 

I positioned the dizzy for the best configuration for the tach cable. I think if I rotate it in either direction the cable will get tortured.

 

Stan

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Are you sure you want to be putting proper oil in just yet - an amount of wear is needed to allow the rings to bed in adequately so if you take out the running in oil too soon the chances of this happening are increased.

This is even more important with chrome rings.

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Are you sure you want to be putting proper oil in just yet - an amount of wear is needed to allow the rings to bed in adequately so if you take out the running in oil too soon the chances of this happening are increased.

This is even more important with chrome rings.

 

Good question. The instructions that came with the cam said to dump the oil and filter after 20 mins @2k rpm so that part is clear. Now as to what to fill it with, I guess I could do another 5 quarts of the break in oil and run that for a few hundred miles. I was reading various opinions on how to break in a new engine this morning and I'm more confused than ever although I smiled at the "drive it like you stole it" strategy.

 

Stan

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Good question. The instructions that came with the cam said to dump the oil and filter after 20 mins @2k rpm so that part is clear. Now as to what to fill it with, I guess I could do another 5 quarts of the break in oil and run that for a few hundred miles. I was reading various opinions on how to break in a new engine this morning and I'm more confused than ever although I smiled at the "drive it like you stole it" strategy.

 

Stan

The "Drive it like you stole it" one is a modern version of advice that was given to me years ago. Although then it was phrased as "Drive it as you mean to go on" i.e. if your going to thrash it then do it from the start! (wouldnt like to say wether that was good advice but the bloke was a race engineer for Brabham!)

Stuart.

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Hi Stan, whatever you do, don't run it at a constant engine speed - it may end up smooth as silk at that one speed, but cr*p elsewhere - run it up to 2500/3000 for the first 100 miles or upto 3000/3500, then upto 3500/4500, change oil and re-torque head back down in the correct order - upto the 1000 miles milestone vary and increase max. revs, then once again re-torque head in correct order, if any head fastenings move more than 1/2 a flat, re-check at 1500 miles. My take on it and how we used to break-in 2.5s, resulting in super smooth, long-lifed engines.

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Hi Stan, whatever you do, don't run it at a constant engine speed - it may end up smooth as silk at that one speed, but cr*p elsewhere - run it up to 2500/3000 for the first 100 miles or upto 3000/3500, then upto 3500/4500, change oil and re-torque head back down in the correct order - upto the 1000 miles milestone vary and increase max. revs, then once again re-torque head in correct order, if any head fastenings move more than 1/2 a flat, re-check at 1500 miles. My take on it and how we used to break-in 2.5s, resulting in super smooth, long-lifed engines.

Only thing I'd add to that is to find a nice long hill - get up near to Jon's rev limit and floor it. Back off once you get to the limit (the hill helps prolong the time at full throttle). Apparently this helps the rings bed in, whereas small throttle openings (even at highish revs) can lead to glazed bores. That bit of advice came from several professionals when I rebuilt my engine a few years ago; I followed it and I'm pleased with the result. Incidentally I would like to know why it helps, if indeed it does...

Cheers,

John

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Only thing I'd add to that is to find a nice long hill - get up near to Jon's rev limit and floor it. Back off once you get to the limit (the hill helps prolong the time at full throttle). Apparently this helps the rings bed in, whereas small throttle openings (even at highish revs) can lead to glazed bores. That bit of advice came from several professionals when I rebuilt my engine a few years ago; I followed it and I'm pleased with the result. Incidentally I would like to know why it helps, if indeed it does...

Cheers,

John

 

Thanks guys for all the great advice. To John C's question, the rings get bedded in by the pressure from the combustion process pushing them against the bores. You would get the biggest bang at the higher throttle openings so I guess finding a hill keeps the rpm's down but allows you to get the max combustion pressures. Just a guess..

 

Stan

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Few years ago I was at an evening glider club where they launched with a big V8-powered winch - ooh my stomach - :( then recovered the half-mile of winch cable with a V8 Range Rover. The old Rangie had an easy life, but its oil consumption rose steadily.

 

It was deduced that the bores might be glazing, so it was harnessed to a couple of old aircraft tyres and set to drag them around the field for a while. Result - oil consumption back to normal.

 

So I guess the hillclimb advice may have been good.

 

Ivor

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A word of waring for people who remove the plugs and use the starter to get oil pressure on a newly rebuilt engine. You may not realize it, but you may be damaging your camshaft/lifters by doing this, as there is not any oil being splashed up on the cam and lifters at the low starter rpms. This could cause an early camshaft/lifter failure. It would in my opinion be better to prime with the drill in the distributor hole. There are alot of early camshaft/lifter failures over here nowadays.

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I think many of the premature cam follower/cam failures are down to poor quality reproduction followers which were circulating for a number of years.

The original chilled iron ones were great and after these ran out the initial repro ones were fine then the rot set about 12 or so years ago. There seem to be some better quality ones around these days but I guess there are pleanty of the crappy ones around still.

 

Anyone fitting a new cam should ideally fit one ground from a new blank rather than a reprofile and make sure they get quality followers. If the supplier doesn't know that better ones exist buy your cam elsewhere.

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