Thread: boost lost???

Originally Posted by isuzurover

You don't need to tell Serg that! His workshop is so clean you could perform brain surgery on his workbenches. I am sure the turbo will be cleaner than new by the time it goes back in.

Originally Posted by uninformed

thanks Rick. Should I be cleaning the pin and plate with anything inparticualr before repair? also the rod hole?

As far as cleaning the turbo. Id be happy to if there is a correct product/procedure for it..at this stage Im not looking to dismantle it.

Naa, just clean it as if you were going to weld it.

Don't worry about me, I'm just paranoid about pipes and hoses being open, I tape and cap as soon as things are undone, but I'm a little OCD about it too.

My neighbour is a brilliant bush mechanic, but Nev just leaves things like oil lines, turbo's and complete engines wide open for days at a time when working on them so I start twitching like Sheldon in 'The Big Bang Theory' when I walk into his shed (and I'm messy as all get out, just really OCD about some things )

Originally Posted by uninformed

thanks Rick. Should I be cleaning the pin and plate with anything inparticualr before repair? also the rod hole?

As far as cleaning the turbo. Id be happy to if there is a correct product/procedure for it..at this stage Im not looking to dismantle it.

Whatever you do - don't use brake cleaner! It turns into a toxic gas if you try welding or brazing!!!

You need to make sure the joint you will braze has been cleaned to bare metal and is free of oil. So good degreaser followed by sandpaper will be fine. After that, the flux your neighbour will have will do the rest.

As for the turbo, the turbine side will be well and truly cleaned every time it gets to high EGTs. For the compressor (inlet) side, have a look for oil/soot deposits. Cleaning these off will improve turbo life. You will need to a solvent or degreaser that won't harm aluminium.

You could also flush the oil galleries in case there is any coking, but if you use good oil and change it regularly then there probably isn't much point...

Originally Posted by isuzurover

Whatever you do - don't use brake cleaner! It turns into a toxic gas if you try welding or brazing!!!


[snip]

Shouldn't it all have evaporated by the time you get a torch near it ?

Originally Posted by rick130

Shouldn't it all have evaporated by the time you get a torch near it ?

Brake Cleaner = Phosgene Article

NO BRAKE CLEANER EVER!!!!!!!!!!!!!

I was already aware of that one. (thank god!) I just use acetone and let dry. The pin-plate was done using 45% silver rod and ezy-flow flux. First attemp did not work. The silver did not want to take to the pin, the plate yes, but the pin no. so I popped it out and we cleaned again and put some flux on the pin not just the rod this time. Second time is better and will have to do, but we both got the distinct feeling that it didnt take 100%...the silver was pooling over to the side on the plate rather than going do in to the hole....the pin is not moving independant of the plate. Only time will tell

The rod was just cleaned with acetone and filled completely with manganize bronze flux coated rod. Now I just have to drill and file it flat, hook it all up and check the function

You'll possibly find there was some plating left on the pin.

Overheating will also oxidise the base metal and kill things quickly, and it's really easy to do with steel as it retains heat so well compared to copper or even brass.

45% rod capillaries very well when things are clean and fluxed well, as well as with the right heat.

It's also difficult sometimes with two distinctly different masses to get the heat the same on both pieces, in this case I'm guessing you could overheat the rod easily without getting quite enough heat into the pin.

It's tricky at times.

ok so it was the pin into the plate. Plate is about 2.5mm thick, maybe 3 at max. The pin is of various dia, up to about 9mm at max, 7.5 where the actuator rod slips over it, then a c clip groove and of coarse the little nib end that went into the plate. From what you are saying Im guessing the plate was hotter than the pin? The smallest tip I had was a #8...would have been nice to have something smaller but you have to make do with what you have I guess.

Actuator rod travel: so now I can put it back together. I had to take the rod end/fitting off to braze it. It was seated up against a lock nut which I have tried not to move (tried). When the actuator is in the retracted position the little plate is up against a stop. That part is fine...atm if I put it back together I have to put a little pressure in the actuator to extend it so the rod will fit over the pin/plate...once seated it is fine. At approx 18psi the actuator rod is extended, but not to the extent that it is moving the plate its full range of movement...now its not far off it, say only 2-3mm but im wondering if I should adjust the rod fitting down so it slips over the pin/plate with zero pressure thus not loosing any shaft travel??? should I be using the full range of the plate (vnt adjuster)???

a variable that may have come into play is where I drilled the hole in the rod fitting. As I had to completely weld/fill the hole I had no indication as to how close to the end of the rod it was....I just used basic engineering and said that if the hole has 3mm of material left on each side then it only needs 3mm left on the end...this would be close to where it was but I cant say for sure how accurate???

looking at the below pic that Rick posted earlier. If this is the same model Turbo as mine (it looks the same in the actuator area) it has the lock nut(yellow) at the top of the rod fitting sitting just a few mm below the theads of the small mounting bolts(red). Currently mine is about 1mm higher than the bottom of the threads....IS that anything to go by???

Originally Posted by uninformed

ok so it was the pin into the plate. Plate is about 2.5mm thick, maybe 3 at max. The pin is of various dia, up to about 9mm at max, 7.5 where the actuator rod slips over it, then a c clip groove and of coarse the little nib end that went into the plate. From what you are saying Im guessing the plate was hotter than the pin? The smallest tip I had was a #8...would have been nice to have something smaller but you have to make do with what you have I guess.

Actuator rod travel: so now I can put it back together. I had to take the rod end/fitting off to braze it. It was seated up against a lock nut which I have tried not to move (tried). When the actuator is in the retracted position the little plate is up against a stop. That part is fine...atm if I put it back together I have to put a little pressure in the actuator to extend it so the rod will fit over the pin/plate...once seated it is fine. At approx 18psi the actuator rod is extended, but not to the extent that it is moving the plate its full range of movement...now its not far off it, say only 2-3mm but im wondering if I should adjust the rod fitting down so it slips over the pin/plate with zero pressure thus not loosing any shaft travel??? should I be using the full range of the plate (vnt adjuster)???

a variable that may have come into play is where I drilled the hole in the rod fitting. As I had to completely weld/fill the hole I had no indication as to how close to the end of the rod it was....I just used basic engineering and said that if the hole has 3mm of material left on each side then it only needs 3mm left on the end...this would be close to where it was but I cant say for sure how accurate???

looking at the below pic that Rick posted earlier. If this is the same model Turbo as mine (it looks the same in the actuator area) it has the lock nut(yellow) at the top of the rod fitting sitting just a few mm below the theads of the small mounting bolts(red). Currently mine is about 1mm higher than the bottom of the threads....IS that anything to go by???

As I have not set up a turbo little less a VNT I am only speculating and cannot speak from experience.

I think that as long as you can idle the engine and it has no trouble starting then you can probably go for the full range of travel on the rod, If the vanes are closed up too much then I'd expect that the back pressure on the exhaust will make it harder to idle and may need an increase in fuel to get it to idle. May run a bit warmer as a result of the extra fuel and additional back pressure. If it does not idle I would open the vanes up a bit more instead of adding fuel. You may give up a bit of travel on the control system but it will be more efficient by dropping the back pressure on the exhaust.