Steve, you are right - the turbine wheel had broken off already so I just removed it, disconnected the oil and water lines, re-routed the intake to avoid the compressor section, and then I went flying.  The entire conversion took 2 hours in someone else's hangar.

 

But I was just doing a temporary fix until I could upgrade the turbo.  I flew in that configuration for about 50 hrs and had very few problems except for that my power was not up to par.  I guess I was only making 130-140 h.p.   The issues were:

1)low compression rotors

2)exhaust back pressure because of the turbo manifold and turbine housing

3)poor compression in one of the rotors that I never really appreciated until I installed a re-build.

3)intake resistance (peak MAP at WOT was just over 27") because the intake was not optimized nor did it have a proper pressure recovery plenum.

4)Because of all that I now had too much prop, max RPM at WOT (in flight) was about 5500, I only had 4500 for take off.  I basically put it to full throttle on take off, and it never changed it.  Level TAS at WOT was about 145 kts at 5K'. 

 

I have about 40 hrs on the new turbo (TO4 in a stock turbine housing) and it still looks pristine.  I try to keep it under 38" but have had it up to 45. 

 

I can only cool about 28" continuously so that is a sort of normalization if you want to look at it that way.

 

Dave Leonard

 

On 6/14/06, Steve Brooks <prvt_pilot@yahoo.com> wrote:

Buly,
With your engine, removing the turbo makes sense.  You can probably get enough
horsepower with the NA setup.

In my case, with a lower compression turbo engine, I'll have to stick with the
turbo to get enough power.

I have about 42 hours now on my already used stock turbo, with no problems.  I
have been nursing it along though, and don't exceed 5-6 lbs of boost on
takeoff, and usually fly at 0-2 lbs of boost max.  Sometimes I cruise around
at less power than that to conserve fuel, if I'm just flying around.

I do think that the stock turbo is going to fail, and I have all  of the parts
to convert to a T04 turbo, which appears to be the best long term turbo
solution.

As I recall, when Dave had his turbo trouble, he gutted the turbo, and still
used his same exhaust system.  Is that what you did, or did you redo your
exhaust ?

Steve Brooks




On Tuesday 13 June 2006 11:21 pm, Bulent Aliev wrote:
> On Jun 13, 2006, at 10:13 PM, John Slade wrote:
> > Joe, Buly
> > I think the bottom line on my "escapades" is that the stock turbo
> > just isn't up to the task. So far I have about 25 hours on my T04
> > Turbonetics + external wastegate setup with zero problems. The
> > engine is purring very smoothly these days. Just a matter of using
> > the right tools for the job.
> > John
>
> Just came from the hangar. Managed to convert the engine to NA in 3
> hours. Didn't run it since it was almost 11PM and I was missing one
> plug for the cooling port for the turbo.
> While doing it, I opened up John's old stock turbo that he imported
> from NZ. Many of the turbine blades were missing chunks.
> That convinced me that it was the right thing to do. At the moment
> I'm not up-to spending another 2G's for a T4 turbo after I just spent
> $2,400 for a prop. Hope I'm able to spin the prop to the static RPM
> needed? The good part is I can convert it to a 2 blade fast :)
> Buly
>
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