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Turbo plumbing for a simpleton


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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.

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

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

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

22.4hp :D

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! 

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31 minutes ago, El Gringo said:

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

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

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

22.4hp :D

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.

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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

24212313247_b6affeb7e5_c.jpg

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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

24212313247_b6affeb7e5_c.jpg

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

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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 :D

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!

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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.

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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)

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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

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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?

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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 O.o

4 hours ago, Captain Chaos said:

 

you ate MY cheese?  O.o

Yeah, sorry about that, was delicious:D

Edited by El Gringo
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  • 4 weeks later...
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 by El Gringo
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