Post by slingy1052 on Sept 9, 2014 23:35:44 GMT
Hi Gents,
This follows on from my scavenge pump thread, and bare with me as this will be a bit long winded, but the more info the better i think.
So i am having issues with smoke on start up, oil in the exhaust etc which has been going in since February. I must have had the turbo off and on 12 times now and done more experimenting and testing than i care to mention.
So for those that don't know, my basic system is as follows.
1052cc slabby motor
TD04-13T mounted below oil level, rebuilt with genuine Mitsubishi parts
Alloy sump under turbo ( sized to allow capture of post run drain back)
VDO 12V pump returning oil back to nere fill point above engine oil level.
So with a stainless braided brake line looped above oil level and 1mm restrictor feeding the turbo when i first built the system i had no issues with smoking at any point. Very happy with it all.
My only issue was , on the side stand it was all good, but if i started it on the paddock stand, with the bike level, the supply oil gallery stays submerged and even with the supply line looped up it would siphon oil after shut down and fill the turbo housing. Once i worked this out i was just careful not to leave it on the paddock stand after running the engine.
This was the case until February this year when i fitted the VFR end cans, fired it up to listen and then got distracted and forgot to take it off the stand. I came back to it a week later, wheeled it out , fired it up and holy shit , oil came out everywhere, filled the exhaust, filled the intercooler and plenum , the works DOH!!!!
So after a long strip and flush of all contaminated components (apart from the VFR cans as too baffled to do too much with), i swore to remedy this issue . So started looking into it . I remember reading on the old forum about a guy using a FPR as a check valve and flow regulator on his turbo bike and it had done several years of service with out any issues, so i dug out a spare GPZ FPR did a quick check with it rigged up to oil gallery, and perfect. Oil flow while running, turned off motor and stopped . No drips nothing. Great, so made a fitting to mount it as nere the turbo as possible and retested. All good when the engine was cold but when it warmed up the flow at idle stopped , give it a blip of throttle and it would flow again, back to idle and it would stop. So i opened up the FPR and reduced the spring pressure until the oil stayed flowing at all times, but it would still stop any leaking after shut down.
After all this it also ended up with a 1.5mm restrictor rather than the original 1mm one.
But at this point i was getting alot of white smoke on start up. I noticed when cold, with the exhaust removed , there would be a small amount of oil coming out of the turbo on initial start up. This would stop after a few seconds but the smoke would continue. When the engine is warmed up, there is no smoke at idle , but if you give it a big rev, it smokes on the wind down.
It never did any of this before, so i convinced myself it was the oil contamination in the VFR cans causing the issue and that it may take some days of riding to clear.
So, just to clarify,
Full exhaust on = Lots of white smoke for 3-5Min's on start up.
straight out of turbo = Some smoke on start up for 2 Min's, but not as dense
Turbo removed but rest of exhaust in place= Some smoke on start up for 2 Min's, but not as dense
To do the last test i pulled the bearing center out of the exhaust housing and machined up a blanking plate to seal the housing.
I then had the turbo sitting on a box with the oil lines attached and used compressed air to spin the turbo while the engine was running to simulate it in use to see if any oil was leaking past the seals. None leaked, all good , even when not spinning, no oil leaked.
Another interesting thing i observed from this test was , with no oil pressure to the turbo, you could spin it and it would run on for several seconds, probably as we have all tried while playing with our turbos, but with the engine running and oil pressure applied, it added quite a bit of resistance to the turbine where a good hard spin would only yield maybe 1 extra rotation from when my finger left it.
I tried this a number of times and it was the same each time, engine off really free spinning, engine on and not so free spinning. I suppose this goes to show where the advantage of BB turbo's is. So put all back together and put it back in the shed.
So 2 days later (this Monday) i wheel it out thinking, well the turbo and drain is all good must just be the VFR cans after all, fire it up, get the usual amount of white smoke, its starts clearing after a couple of minutes, then BAM MASSIVE PLOOMS OF WHITE SMOKE like Thomas the bloody tank engine. Shut the bike down, see oil leaking from the exhaust join, pull it all apart again to find like half a cup of oil in the exhaust!!!!! God knows what the neighbors thought as i went Tropo and used every bad word i could think of very loudly.
First thought was the scavenge pump must of packed up. No, still running.
Then i thought maybe a loose connector on the scavenge pump as obviously i had moved it to pull the turbo out of the exhaust which might of righted it again, so i tried to get it to stop by fiddling with the wiring etc , but No, it kept running.
Fired it up with the turbo out to see it leak, but no, nothing, seemed to be working fine.
So i am at the end of my patience with this now, it has been run and ridden many times in this whole saga and it hasn't dumped oil in the exhaust since February now, back to square one. Or worse probably as now i still have oil everywhere and smoke to go with it!!
WHAT HAVE I MISSED???
The only thing i can think of is that the VDO pump which was second hand is intermittent in its operation and that maybe a mechanical pump would be more reliable.
Anyway, thanks to anyone who managed to read all this and NO, i am not moving the turbo,its been done enough times now that it shouldnt be that hard to run a scavange set up and i dont have the money or the motivation with this project anymore to go building new headers etc for it.
Smoking aside, Its just got me baffled how its dumped oil in the exhaust again? I can see only 2 scenarios.
1 the VDO pump is faulty
2 The oil pressure relief valve is faulty and allowed an oil pressure spike to happen (very unlikely)
Thanks all for your time
This follows on from my scavenge pump thread, and bare with me as this will be a bit long winded, but the more info the better i think.
So i am having issues with smoke on start up, oil in the exhaust etc which has been going in since February. I must have had the turbo off and on 12 times now and done more experimenting and testing than i care to mention.
So for those that don't know, my basic system is as follows.
1052cc slabby motor
TD04-13T mounted below oil level, rebuilt with genuine Mitsubishi parts
Alloy sump under turbo ( sized to allow capture of post run drain back)
VDO 12V pump returning oil back to nere fill point above engine oil level.
So with a stainless braided brake line looped above oil level and 1mm restrictor feeding the turbo when i first built the system i had no issues with smoking at any point. Very happy with it all.
My only issue was , on the side stand it was all good, but if i started it on the paddock stand, with the bike level, the supply oil gallery stays submerged and even with the supply line looped up it would siphon oil after shut down and fill the turbo housing. Once i worked this out i was just careful not to leave it on the paddock stand after running the engine.
This was the case until February this year when i fitted the VFR end cans, fired it up to listen and then got distracted and forgot to take it off the stand. I came back to it a week later, wheeled it out , fired it up and holy shit , oil came out everywhere, filled the exhaust, filled the intercooler and plenum , the works DOH!!!!
So after a long strip and flush of all contaminated components (apart from the VFR cans as too baffled to do too much with), i swore to remedy this issue . So started looking into it . I remember reading on the old forum about a guy using a FPR as a check valve and flow regulator on his turbo bike and it had done several years of service with out any issues, so i dug out a spare GPZ FPR did a quick check with it rigged up to oil gallery, and perfect. Oil flow while running, turned off motor and stopped . No drips nothing. Great, so made a fitting to mount it as nere the turbo as possible and retested. All good when the engine was cold but when it warmed up the flow at idle stopped , give it a blip of throttle and it would flow again, back to idle and it would stop. So i opened up the FPR and reduced the spring pressure until the oil stayed flowing at all times, but it would still stop any leaking after shut down.
After all this it also ended up with a 1.5mm restrictor rather than the original 1mm one.
But at this point i was getting alot of white smoke on start up. I noticed when cold, with the exhaust removed , there would be a small amount of oil coming out of the turbo on initial start up. This would stop after a few seconds but the smoke would continue. When the engine is warmed up, there is no smoke at idle , but if you give it a big rev, it smokes on the wind down.
It never did any of this before, so i convinced myself it was the oil contamination in the VFR cans causing the issue and that it may take some days of riding to clear.
So, just to clarify,
Full exhaust on = Lots of white smoke for 3-5Min's on start up.
straight out of turbo = Some smoke on start up for 2 Min's, but not as dense
Turbo removed but rest of exhaust in place= Some smoke on start up for 2 Min's, but not as dense
To do the last test i pulled the bearing center out of the exhaust housing and machined up a blanking plate to seal the housing.
I then had the turbo sitting on a box with the oil lines attached and used compressed air to spin the turbo while the engine was running to simulate it in use to see if any oil was leaking past the seals. None leaked, all good , even when not spinning, no oil leaked.
Another interesting thing i observed from this test was , with no oil pressure to the turbo, you could spin it and it would run on for several seconds, probably as we have all tried while playing with our turbos, but with the engine running and oil pressure applied, it added quite a bit of resistance to the turbine where a good hard spin would only yield maybe 1 extra rotation from when my finger left it.
I tried this a number of times and it was the same each time, engine off really free spinning, engine on and not so free spinning. I suppose this goes to show where the advantage of BB turbo's is. So put all back together and put it back in the shed.
So 2 days later (this Monday) i wheel it out thinking, well the turbo and drain is all good must just be the VFR cans after all, fire it up, get the usual amount of white smoke, its starts clearing after a couple of minutes, then BAM MASSIVE PLOOMS OF WHITE SMOKE like Thomas the bloody tank engine. Shut the bike down, see oil leaking from the exhaust join, pull it all apart again to find like half a cup of oil in the exhaust!!!!! God knows what the neighbors thought as i went Tropo and used every bad word i could think of very loudly.
First thought was the scavenge pump must of packed up. No, still running.
Then i thought maybe a loose connector on the scavenge pump as obviously i had moved it to pull the turbo out of the exhaust which might of righted it again, so i tried to get it to stop by fiddling with the wiring etc , but No, it kept running.
Fired it up with the turbo out to see it leak, but no, nothing, seemed to be working fine.
So i am at the end of my patience with this now, it has been run and ridden many times in this whole saga and it hasn't dumped oil in the exhaust since February now, back to square one. Or worse probably as now i still have oil everywhere and smoke to go with it!!
WHAT HAVE I MISSED???
The only thing i can think of is that the VDO pump which was second hand is intermittent in its operation and that maybe a mechanical pump would be more reliable.
Anyway, thanks to anyone who managed to read all this and NO, i am not moving the turbo,its been done enough times now that it shouldnt be that hard to run a scavange set up and i dont have the money or the motivation with this project anymore to go building new headers etc for it.
Smoking aside, Its just got me baffled how its dumped oil in the exhaust again? I can see only 2 scenarios.
1 the VDO pump is faulty
2 The oil pressure relief valve is faulty and allowed an oil pressure spike to happen (very unlikely)
Thanks all for your time
