M20K 252 TSIO 360 - SB Engine data

[Fix]

Do anyone of my fellow TSIO 360-SB owners (MB works too) have engine data to share?
I'm trying to get my engine to run LOP smooth as I can and need some input for reference.

I would be happy if you can share some flights with me where you have.

4000-6000 feet, 26" / 2500 rpm with 10.4g/h (LOP) and 12.6g/h (ROP)
and if you have same for 12000feet->

 

[Falcon Man]

I have run three different K models at LOP - two MB and one SB engine. Average settings at 14,000 to 18,000 were 2200 RPM, 28-30 MP and ~ 25F degrees LOP of hottest cylinder CHT, Fuel flow 10-11 gph. None of the engines ran smooth < 25F LOP. GAMI spread was 0.3-0.5 gph on stock injectors.

[Aerodon]

You need to look up the gami test to get the gami spread - the difference in fuel flow between the first and last cylinder to peak.  I think the target is 0.5 GPH, but it may be less.

The MB/SB engines should be good out the box, but Gami can help you refine them.

 

Don

 

[Pinecone]

Mine (-SB) runs well very LOP.

I did the GAMI spread test and sent the data to John-Paul and he refused to sell me GAMIjectors.

What are you trying to figure out?  If you engine is not running well LOP, the spread is too high.  You may be able to swap the factory injectors around to get it closer.  But it all starts with the test of spread between the cylinders.

I run 29.5 - 31.5 inches, 2300 RPM at 10.1 GPH.  This is about 62 - 63% power.   The different manifold pressures do not change performance, they just change how LOP you are.  When LOP, power is based on fuel flow.  I just MP to keep the CHTs below 380 with little or no cowl flap opening.

Turbo engines we can pick a power setting and adjust to run that at various amounts of LOP.  NA guys have to reduce fuel flow (thus power) get more LOP.

[Fix]

I have a GAMI spread of 0.5GPH more or less when I tested. (tested several times)

Can't get it running smooth as I want at higher altitudes. 4000->
I tried some things that Paul K suggested to me, but still it's not running smooth as I want.
Either my GAMI spread is to high or there are other things messing with me.

Have some ideas why it not running smooth and I'm trying to check them one by one.
Can see on my engine data that when I run for example 25" 2500rpm with 12.6g/h (65% ROP) I have my EGT values per each cylinder always in the same order.
I also have that same EGT order with 11.6g/g or if I fly FT/2600/26g/h.
Engine here is smooth.

Soon as I lean my mixture to 26" 2500rpm with 10.4g/h (10.1-10.3) my cylinders change EGT wise and I starting to get roughness/vibrations.
I tried different settings trying to find a sweet spot, but with no success.

So if someone can share some flights on Savvy I can try to compare if how other engines behave and that give me some clues.
I might suspect that there is a Induction leak on Cylinder 2 and maybe Cylinder 3 since those are the ones that changes.
That's why it would be very interesting to take a look on some engine data.

 

I have and/or tested.
Tempest Fine Wire plus. (gapped to 0.017") - ~500h on them since new, looks good.
SureFly + Slick 6324 (First I have 2x Slick Mags, one of them dropped little much, but within limit. Bought an SureFly, but no change with LOP)
Both mags are timed with in 0.5 degrees (if we didn't do anything wrong. Used timing pin and digital measure)
We did a Induction test, but couldn't see any leakage with soapy water and pressure also didn't change)
No other obvious signs that could give any leads.
Tighten the screws of the rubber fittings to the inductions tubes.


What I found that might be part of the problem.
I haven't test flown after this.

The other day I thought that I might check the firm/tightness of the Inductions tubes nuts at the cylinders.
Those was quite loose, if you ask me way to loose. Not that I could use my finders to loose them, but they were way to loose.
So I tighten all of them and this could absolutely be the source of problem.
If there is a induction leak it's not much, and since the nuts were looser than they should and with heat and vibrations there is a small chance that this is the problem.
Don't have high hopes that this is the problem, but glad I found it anyway.



If anyone has any other good ideas or thoughts...

[exM20K]

24 minutes ago, Fix said:

I have a GAMI spread of 0.5GPH more or less when I tested. (tested several times)

Can't get it running smooth as I want at higher altitudes. 4000->
I tried some things that Paul K suggested to me, but still it's not running smooth as I want.
Either my GAMI spread is to high or there are other things messing with me.

I'd try to start eliminating things:

1) induction leak: fly LOP at ambient MAP (eg: 10,000' at baro - 10").  If smooth LOP, you have an induction leak somewhere.

2) Spark: do a LOP mag test aloft. Is the problem isolated to one mag or bank of cylinders?

3) Fuel: any evidence of drips upstream of the fuel pump, including from the fuel selector, gasollator, and electric pump? 

When you did the soapy water thing on the induction, did you get *all* the lines such as the MAP sender, the line back to the fuel pump aneroid, the lines that pressurize the injectors?

I've been through a lot of these troubleshooting odysseys , as @kortopates can attest to, over 20 years  of Continental turbo ownership.

-dan