Turbo plumbing for a simpleton

[Gixer1460]

Its probably the oil in the feed line and core seeping past the turbo bearings after shut down - its not unknown. A sump will help as will running the drain scavenge pump for 30 secs / a minute after engine off to drain the core and feed line.

[MeanBean49]

What Gixer1460 said. 

I get a bit of a drip from mine after it sits for a bit after running, i just cycle the oil pump for a bit after letting it sit for a bit. A lot of people put check valves in the feed line to help. Personally im happy for the odd drip or bit of smoke on startup, shows in getting oil to the turbo.

[wombat258]

I run a sump, and a check valve in the oil supply line. Never had a drop of oil leak from the turbo, and never a trace of smoke from the exhaust.

[Blubber]

Hope today will be a success 

[El Gringo]

Ladies and Jellyspoons drum roll please.......................................

The final figure was...................................

A whopping..............................

22.4hp 

Fuck knows what was going on but it got to 6.5K rpm and hit a wall, on every run, in pretty much the same place.

Just signed off and wouldn't pull through it, didn't sound like it was missing but that was as much as it would do.

Tried taping up the filter, tried increasing the fuel pressure - as soon as it got to about 0.4bar on the boost gauge it gave up

On the plus side, minimal oil leakage from the scavenge pump and drain, none really from the turbo itself, no fuel leaks, no coolant leaks and it didn't grenade (not that it got anywhere near having chance to!)

So, next step, i've got another CDI to try just incase it's that, then to go back through and check all the hoses etc

Not the great result we wanted but not a disaster! 

[El Gringo]

 

[MeanBean49]

31 minutes ago, El Gringo said:

Ladies and Jellyspoons drum roll please.......................................

The final figure was...................................

A whopping..............................

22.4hp 

Fuck knows what was going on but it got to 6.5K rpm and hit a wall, on every run, in pretty much the same place.

Just signed off and wouldn't pull through it, didn't sound like it was missing but that was as much as it would do.

Tried taping up the filter, tried increasing the fuel pressure - as soon as it got to about 0.4bar on the boost gauge it gave up

On the plus side, minimal oil leakage from the scavenge pump and drain, none really from the turbo itself, no fuel leaks, no coolant leaks and it didn't grenade (not that it got anywhere near having chance to!)

So, next step, i've got another CDI to try just incase it's that, then to go back through and check all the hoses etc

Not the great result we wanted but not a disaster! 

Normally means too big on the mains. The 1127/1157 motors are really sensitive to jetting. Mine runs spot on with 137.5's in it, go to 145's and hits a brick wall at 6k. Sounds fine not under load. Try riding/dyno'ing and it wont go.

[El Gringo]

13 minutes ago, MeanBean49 said:

Normally means too big on the mains. The 1127/1157 motors are really sensitive to jetting. Mine runs spot on with 137.5's in it, go to 145's and hits a brick wall at 6k. Sounds fine not under load. Try riding/dyno'ing and it wont go.

Hmmm interesting, the dyno guy said that sometimes when they're massively rich it shows on the graph as lean for whatever reason

That would kind of follow. I's one avenue to look at

[Blubber]

 

You have got massive power, causing huge amount of wheel spin thus lowering your read out.... Or something like that  

[MeanBean49]

13 minutes ago, El Gringo said:

Hmmm interesting, the dyno guy said that sometimes when they're massively rich it shows on the graph as lean for whatever reason

That would kind of follow. I's one avenue to look at

Worth a try mate. You can get the same thing if its too small on the mains too.Have a look at the plugs, might help, then again this can be miss leading too, if its that rich its not firing/burning you wont get the black soot you would expect. 6k is right about where you would expect it to be fully on the main jet

[Captain Chaos]

My guess was closest.

What do I win?

[wombat258]

Looks like you are blowing out the spark with the rich mixture. Close up the plug gaps and lean out the mixture.

[El Gringo]

13 hours ago, Captain Chaos said:

My guess was closest.

What do I win?

Erm......... the adulation of your adoring fans and a block of cheese 

10 hours ago, wombat258 said:

Looks like you are blowing out the spark with the rich mixture. Close up the plug gaps and lean out the mixture.

Thanks for the info Wombat, that follows what the dyno guy and Rob said - i'm on the hunt for some new main jets as I type!

[Arttu]

14 hours ago, El Gringo said:

Hmmm interesting, the dyno guy said that sometimes when they're massively rich it shows on the graph as lean for whatever reason

Yep. Lambda sensors basically read unburnt oxygen from exhaust gases. So when it's too rich to ignite mixture there is plenty of unused oxygen in exhaust and that results lean reading. Trickiest situation is when you are at borderline, still running but missing every second stroke or so. In that case AFR reading usually settles around 12 which is perfectly fine looking for a turbo engine...

I would also guess that you are going massively rich at that point. On the other hand it could be too lean as well But going to lean that quickly would require some drastic problem in fuel supply, float bowl pressurization not working, missing boost reference for pressure regulator or something like that.

[Gixer1460]

Dunno what's wrong - but it ain't right! LOL. I would have thought any ignition should keep up at only 1/2 bar boost but closing the gaps is good advice regardless.  Press on - its troubleshooting time - it took me 4 variations of turbo components till mine came good!

[El Gringo]

Aye, stripped it down, carbs off ready for jets when i can find some

Good news is the oil i thought was coming from the turbine outlet isn't (or doesn't appear to be) - i think it's dropping down from above, probably from the knackered exhaust thread hole.

The drain hose fitting from the turbo was making a bid for freedom so that'll need nipping up again.

The other good news, after 5-6 albeit short and steady runs on the dyno it has used incredibly little fuel, there was probably a litre or so in the tank, i put a full 5 litre can in and have just drained back out virtually 5 litres (he says making a comedy pretence about fuel economy)

[gsx]

Any news ? Been following this one 

[El Gringo]

On 12/22/2017 at 3:51 PM, gsx said:

Any news ? Been following this one 

Not as yet, got it striped down ready for the smaller main jets and then i decided to sit down and eat a lot of cheese and drink a lot of port over Christmas!

Will be ordering up some jets in the next week or so, so hopefully back on the dyno to test the theory sometime in January

[MeanBean49]

1 hour ago, El Gringo said:

Not as yet, got it striped down ready for the smaller main jets and then i decided to sit down and eat a lot of cheese and drink a lot of port over Christmas!

Will be ordering up some jets in the next week or so, so hopefully back on the dyno to test the theory sometime in January

Smaller mains?

[Captain Chaos]

On 16/12/2017 at 10:18 AM, El Gringo said:

 a block of cheese 

 

1 hour ago, El Gringo said:

sit down and eat a lot of cheese

you ate MY cheese? 

[El Gringo]

4 hours ago, MeanBean49 said:

Smaller mains?

Aye, i thought that's where we were going with it, working on the theory it's too rich and blowing the sparks out?! You mentioned you went from 145s to 137.5s a bit further up the page 

4 hours ago, Captain Chaos said:

 

you ate MY cheese? 

Yeah, sorry about that, was delicious

Edited December 27, 2017 by El Gringo

[MeanBean49]

1 hour ago, El Gringo said:

Aye, i thought that's where we were going with it, working on the theory it's too rich and blowing the sparks out?! You mentioned you went from 145s to 137.5s a bit further up the page 

Yeah, sorry about that, was delicious

Yeah sorry mate, minds gone to jelly over crimbo

[El Gringo]

1 hour ago, MeanBean49 said:

Yeah sorry mate, minds gone to jelly over crimbo

 No worries mate, had me panicking for a minute there!

My mind turned to jelly too, and cake, and christmas pudding, and cheese, etc etc ad inifinitum

[Blubber]

@El Gringo  calling Ek gringo.....

Any updates or even progress on this?

[El Gringo]

23 hours ago, Blubber said:

@El Gringo  calling Ek gringo.....

Any updates or even progress on this?

You Called? 

Funny you should shout, we've been back to the dyno today - it did not go well unfortunately........

Switched to 92.5 main jets (from 100s) and got a proper fuel pressure gauge and re set to 1.5psi base pressure when running.

End result - a small improvement - 22.96hp! a whole half a HP!!!!! Yay!!!!!!!!!!!!

Fuck and Indeed Bollocks!!!!

We tried a second CDI - same, brick wall at 6,5k rpm

We tried more fuel pressure - same, brick wall at 6,5k rpm

With the smaller mains - same, brick wall at 6,5k rpm

I'm now working on the theory that it's something that's not allowing the slides to lift

Can anyone shout up on the theory for pressure above/below the diaphragms?

We've got the holes in the slides to allow pressure above the diaphragms and i've got a small hole (3.2mm) drilled through the carb body to allow boost pressure to under the diaphragms - so it should be balanced.

I'm running out of ideas now

Good news is the fuel reg seems to work, at approx 1.5 psi boost the gauge was showing roughly 2.5 psi of fuel pressure, so around 1psi above boost which is nice.

We also tried it with the up pipe disconnected and no fuel pressure and again it crapped out at 6,5K rpm but seemed to go rich as opposed to lean

 

 

 

 

Edited January 20, 2018 by El Gringo