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Lightspeed Variable Timing Pot Wiring

bakercdb

Member
I am looking to connect the Variable Timing Potentiometer on the Lightspeed
Plasma III (testing high altitude LOP ops).

However, wiring at the potentiometer end is not clear to me. The three pins connected on the LSE Output connector end are clear.

But, the potentiometer end just shows three unlabeled posts, and no schematic. I want to verify that I’m wiring it properly.

Thanks
 
Here's a little picture to help...

Check the pins with a VOM of course, but pin 6 should hook to the middle pin on the pot, pin 5 and pin 13 can connect to either 1 or 3 (out side pins) on the pot.
 

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Lightspeed timing, what are the actual advance numbers?

Just surfed the forum to find some actual numbers for the advance that the Lightspeed unit delivers and came across this thread. Figured that if you were able to get it working with manual adjustment you would know what the timing curve is like?

I have a single unit on the right of my 0-320 and it has always been great and I've frankly never touched it. I recently watched a Mike Busch video where he explained that advanced timing on Lycomings could cause higher temperatures?

I've always had high CHT and oil temperatures on my RV9 in warm weather, so high in the summer they need 'managing'. I would like to know what the timing would be at a typical cruise so if it is well advanced I could adjust it and see if the temperatures decrease.

Typically in the UK RV owners complain of having difficulty in getting the engines warm enough to boil the moisture off. I don't have that problem, rather the other way.

I'm just doing a top end overhaul so the plane is down at the moment so I can't do any dynamic testing myself but thought those who have these units and have tracked the timing output which the units give might be able to tell me? Quite like the idea of backing the timing down if it gets warm so maybe I'll look at fitting the potentiometer later.

My typical cruise is 2200 rpm with around 20" MAP, think that's all the unit needs to modulate the timing. Anyone any idea how advanced the timing might be at those numbers?

Thanks Regards, Clive
 
My typical cruise is 2200 rpm with around 20" MAP, think that's all the unit needs to modulate the timing. Anyone any idea how advanced the timing might be at those numbers?

Thanks Regards, Clive

My Lightspeed is retarded by 5 degrees as per the instructions for higher compression engines. At my typical 2,300 rpm and 22” the display shows around 28 degrees so add 5 for a standard installation gives about 33 degrees. Your lower power settings would give a bit more advance??

Fin 9A
 
There's also a timing display output on those boxes which you can connect to an EFIS to display (or get the standalone display Klaus sells). Search here for the op-amp required to get enough signal output to make a G3X happy.

Attached is a screenshot of my G3X-Lightspeed timing display:

1183.jpg
 
Just surfed the forum to find some actual numbers for the advance that the Lightspeed unit delivers and came across this thread. Figured that if you were able to get it working with manual adjustment you would know what the timing curve is like?

I have a single unit on the right of my 0-320 and it has always been great and I've frankly never touched it. I recently watched a Mike Busch video where he explained that advanced timing on Lycomings could cause higher temperatures?

I've always had high CHT and oil temperatures on my RV9 in warm weather, so high in the summer they need 'managing'. I would like to know what the timing would be at a typical cruise so if it is well advanced I could adjust it and see if the temperatures decrease.

Typically in the UK RV owners complain of having difficulty in getting the engines warm enough to boil the moisture off. I don't have that problem, rather the other way.

I'm just doing a top end overhaul so the plane is down at the moment so I can't do any dynamic testing myself but thought those who have these units and have tracked the timing output which the units give might be able to tell me? Quite like the idea of backing the timing down if it gets warm so maybe I'll look at fitting the potentiometer later.

My typical cruise is 2200 rpm with around 20" MAP, think that's all the unit needs to modulate the timing. Anyone any idea how advanced the timing might be at those numbers?

Thanks Regards, Clive

Lots to unpack here...

1. Dispensing with old wives tales where and when I can -- You don't need high oil temperatures to "boil off" moisture. As a thought experiment fill a shallow dish with water and let it sit out at room temperature for a week -- no water left. Heating the solution and reducing the atmospheric pressure will cause water to evaporate quicker than room temp/ambient, but it's not necessary to go right to 100°C (Phase change temp at 1 ATM).

2. Advancing the timing alone, while holding all other parameters constant will result in a temperature increase -- the peak pressure will be achieved closer to TDC (actually a little after, before TDC would be disastrous -- things break); there's more stress on the piston, conn-rods, etc. Pre-ignition is possible here. However, if you lean out the mixture (by reducing the MAP, increasing altitude, etc.), this causes the fuel/air charge to burn slower which causes the EGTs to increase. Advancing the timing in this condition starts the fire sooner as it takes longer to burn (Leaner - Longer, Richer - Shorter) -- this moves the peak pressure point back to the optimal location (a few degrees -- maybe °14 IIRC, after TDC).

2. The Plasma timing advance curve is not documented anywhere to my knowledge. However, observing the behavior for a number of years on my two Plasma IIIs, I would say that @ full power (2700RPM, 29"MAP/ ~0 MSL) the advance is right at 20°BTDC (This makes sense, as I have a 20°BTDC magnet ring, and the engines timing is spec'd at 20°BTDC). As the MAP decreases, the timing increases -- it's a pretty flat curve, 24.3" -> 24.2° (2700 RPM), 20.5" -> 28.2° (10Kft, Full Throttle, 2500RPM).

2200RPM at 20" is pretty low power (~50%), so I would expect to see the timing at around 32° BTDC...

What CHT's do you typically experience and at what altitude, OAT, fuel flow, etc.?
 
2. Advancing the timing alone, while holding all other parameters constant will result in a temperature increase -- the peak pressure will be achieved closer to TDC (actually a little after, before TDC would be disastrous -- things break); there's more stress on the piston, conn-rods, etc. Pre-ignition is possible here. However, if you lean out the mixture (by reducing the MAP, increasing altitude, etc.), this causes the fuel/air charge to burn slower which causes the EGTs to increase.

Be sure to clarify which temperatures change here, CHT or EGT.

More timing will generally increase CHTs and reduce EGTs.

Pre-ignition (auto ignition prior to spark initiation) is a rather remote possibility on a standard compression ratio Lyc running 100LL with any reasonable amount of timing and CHTs below 380F. Detonation is a more likely scenario. These are not the same phenomena. The former being almost instantly destructive to pistons and spark plug ground electrodes, the latter can be tolerated for some time if light to moderate.

Reducing MAP or increasing altitude doesn't necessarily lean the mixture. That would depend on the device metering the fuel.
 
Be sure to clarify which temperatures change here, CHT or EGT.

More timing will generally increase CHTs and reduce EGTs.

Pre-ignition (auto ignition prior to spark initiation) is a rather remote possibility on a standard compression ratio Lyc running 100LL with any reasonable amount of timing and CHTs below 380F. Detonation is a more likely scenario. These are not the same phenomena. The former being almost instantly destructive to pistons and spark plug ground electrodes, the latter can be tolerated for some time if light to moderate.

Reducing MAP or increasing altitude doesn't necessarily lean the mixture. That would depend on the device metering the fuel.

Thank for you for the clarification Ross!
 
Lightspeed Advance

Just another data point. I run my IO540 D4A5 at 21" and 2300 RPM for 60% power. I monitor the Lightspeed advance on my GRT real time and it routinely sits a 31 degrees. I will try to use your settings next time I fly, (maintenance now), and report back to you the readings.

John Koonce
N78MU
 
Thanks for the feedback with real numbers.

Thanks for all the feedback chaps, much appreciated. I have largely ignored the Plasma box (my bad) as the engine runs smoothly and sweetly at all times apart from 30C plus ambients. It runs well lean of peak too which I love though I haven't gone LOP to reduce temperatures as in the high ambient situation I'm usually climbing full rich. Maybe something for the future.

What I hadn't considered until this month was the box might be contributing to my higher than normal oil and head temps in general. During my current down time (1000hr top end) I've been listening to Mike Busch's Savvy Ytube and Podcasts and it enlightened me to the timing effects on engine heating as described above, peak pressure and all that.

All is good with my 0-320B3B most of the time but the CHT and the Oil temperature are the problematic ones when the ambient starts to rise past 30C/86F. In the UK that wasn't very often but these past few years it's increasingly our pleasure. The oil temperature is indicative of the situation and what I watch most keenly. The CHT's get to 200C/400f when the oil starts to run up. Leaving Corsica this summer I managed to peg the oil temperature at 112C/234F by creeping the climb up to 8000' and once there daren't land back in France for the next 4 hrs as the ground temps rose to 35C~40C) during the day. Landing for a break would have meant the end of flying for the day. Fuel flow in the cruise is a little over 6 galls low level.

I've improved the cooling over the years with baffle+seal improvements and a cowl flap under No4 to open when needed, I've checked and tested everything I could think off cooling wise but I'm still not comfy when the ambients are high. I thought poor sealing of the plenum to the cowl was the problem but though changes there have improved things I look forward to see what retarding the Plasma does.
BTW the left side is a standard slick (25 degrees) as is the rest of the engine installation aside from a firewall mounted cooler on a 3" pipe rather on the back of the baffle by No4. FP prop.

The numbers that have been shared above are what I was hoping and suggest it's worth looking at so I really appreciate you guys taking the time to post information for me.

I did have some E mail exchanges with Klaus but he wasn't willing to admit any actual figures which is why I came over here. His answer to my question as to: what sort of advance 2200 rpm and 20" would give? was to 'read the manual, it's all there'.

So I look forward to getting flying again and when I get the opportunity will retard the base setting though as it's now winter the effect on temperature will be difficult to see. I have checked it statically since the teardown and sadly it already appears at about 16 degrees against the 20 I expected to find it at. I did ask Klaus if leaving the MAP input off would stop the timing being advanced so I could fix it for test purposes but he told me that 'that would make no sense as it would be the same as wide open throttle' though that was what I was wanting to do, I assumed it would be at 20 degrees and stay there.
I intend to bring out the actual timing numbers via the wiring as shown above. I have a Dynon EMS and haven't looked to see if it has a spare indication I could use but will be happy with a multimeter for testing purposes. Oh, a question for those who have it, what does the potentiometer to the the advance?, would be neat if I could retard things during the hot trips to Europe and then tweak it back when I get closer to Blighty.

Thanks again, further comments/suggestions welcomed, Regards, Clive
 
More numbers please...

What is your IAS during climb out? How about when you're "cruising" at 2200RPM/20"?
 
Thanks for all the feedback chaps, much appreciated. I have largely ignored the Plasma box (my bad) as the engine runs smoothly and sweetly at all times apart from 30C plus ambients. It runs well lean of peak too which I love though I haven't gone LOP to reduce temperatures as in the high ambient situation I'm usually climbing full rich. Maybe something for the future.

What I hadn't considered until this month was the box might be contributing to my higher than normal oil and head temps in general. During my current down time (1000hr top end) I've been listening to Mike Busch's Savvy Ytube and Podcasts and it enlightened me to the timing effects on engine heating as described above, peak pressure and all that.

All is good with my 0-320B3B most of the time but the CHT and the Oil temperature are the problematic ones when the ambient starts to rise past 30C/86F. In the UK that wasn't very often but these past few years it's increasingly our pleasure. The oil temperature is indicative of the situation and what I watch most keenly. The CHT's get to 200C/400f when the oil starts to run up. Leaving Corsica this summer I managed to peg the oil temperature at 112C/234F by creeping the climb up to 8000' and once there daren't land back in France for the next 4 hrs as the ground temps rose to 35C~40C) during the day. Landing for a break would have meant the end of flying for the day. Fuel flow in the cruise is a little over 6 galls low level.

I've improved the cooling over the years with baffle+seal improvements and a cowl flap under No4 to open when needed, I've checked and tested everything I could think off cooling wise but I'm still not comfy when the ambients are high. I thought poor sealing of the plenum to the cowl was the problem but though changes there have improved things I look forward to see what retarding the Plasma does.
BTW the left side is a standard slick (25 degrees) as is the rest of the engine installation aside from a firewall mounted cooler on a 3" pipe rather on the back of the baffle by No4. FP prop.

The numbers that have been shared above are what I was hoping and suggest it's worth looking at so I really appreciate you guys taking the time to post information for me.

I did have some E mail exchanges with Klaus but he wasn't willing to admit any actual figures which is why I came over here. His answer to my question as to: what sort of advance 2200 rpm and 20" would give? was to 'read the manual, it's all there'.

So I look forward to getting flying again and when I get the opportunity will retard the base setting though as it's now winter the effect on temperature will be difficult to see. I have checked it statically since the teardown and sadly it already appears at about 16 degrees against the 20 I expected to find it at. I did ask Klaus if leaving the MAP input off would stop the timing being advanced so I could fix it for test purposes but he told me that 'that would make no sense as it would be the same as wide open throttle' though that was what I was wanting to do, I assumed it would be at 20 degrees and stay there.
I intend to bring out the actual timing numbers via the wiring as shown above. I have a Dynon EMS and haven't looked to see if it has a spare indication I could use but will be happy with a multimeter for testing purposes. Oh, a question for those who have it, what does the potentiometer to the the advance?, would be neat if I could retard things during the hot trips to Europe and then tweak it back when I get closer to Blighty.

Thanks again, further comments/suggestions welcomed, Regards, Clive

I use EI and also have variable advance via a pot, thought not this brand. Generally speaking rich mixtures like less advance and lean mixtures like more. Much above 25", I am at 25 degrees and then it starts advancing as MAP drops. This is great for LOP cruise, but is problematic for ROP climbs. When climbing ROP, you are best to stay at or near book advance (20 or 25), however, once the MAP starts falling, the advance starts coming in. For me, if I don't stop that advance with the knob, CHTs and OT start to rise (starts around 7k or 8k in my case). Remember that the air is also getting thinner as you climb, so it is doing less efficient cooling work. Once LOP in cruise, the knob goes back to the tables advance. With the 10 I have been doing more LOP climbs as the extra advance isn't creating as much heat and is more manageable and saves fuel.

You are lucky to have adjustable advance and suggest you study and experiment more to learn how to optimize it for each engine configuration: RPM, MAP, mixture, etc. I think you will find that in most ROP situations, you will be pretty close to 20*, though a bit higher in the lower MAP regions. You can be a bit sloppy down low, but as you climb, cooling efficiency drops and you need to be tighter in the management of advance to keep temps in check. Even when I climb LOP, temps can get a bit high over 10 or 11K. This is less about too much timing and more about cooling system efficiency in the thinner air, however, dropping advance below optimum while LOP helps to reduce the heat output. Once in cruise up high, I can do whatever I want as the extra speed mitigates all the cooling issues related to the thinner air.

Larry
 
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SNIP

I did have some E mail exchanges with Klaus but he wasn't willing to admit any actual figures which is why I came over here. His answer to my question as to: what sort of advance 2200 rpm and 20" would give? was to 'read the manual, it's all there'. SNIP

Reading Klaus’ manual, it appears that for a standard 25 degree BTDC (mag) engine Klaus’ ignition could go as far as ~43 degrees. I suspect however that in practical cruise it would not be that advance, so I’d guess something around 36 degrees. Excerpts:

“Engines Normally Timed at 25 degrees BTDC
(Leading Magnet Installed At 45 degrees Before TDC):
These are usually engines with compression ratios less than 8.7:1.
- At idle the timing display should indicate 40o ± 2o when the manifold pressure hose is connected and 21o ± 2o when disconnected.”

These imply a timing advance range of 19-22 degrees. Comparing to a fixed mag set at 25 degrees this yields:
- At idle timing is ~21 degrees BTDC
- Most advance condition is timing at ~43 degrees BTDC

What is unknown is the RPM relationship with timing. Considering the timing range at idle with/without manifold line connected perhaps there is no RPM to timing curve input. Don’t know.

I refer you back to the nice work over the last few years on timing effects on our engines. Boiling them all down, for a parallel valve Lycoming engine I believe 9 degrees of total advance (so 25-34 degrees BTDC) is the practical limit that can be used to get a bump in engine efficiency up high. Any more than that you tend to get higher CHTs and no additional power. That 9 degrees would be a low MP.

I do have personal experience on a new RV-7 with dual Plasma III ignitions. The engine had ~100 hours on it with the (new) owner fighting continuous high CHT problems. He was flying full rich and low power in an attempt to keep CHTs below 420. A buddy and I went to look. We verified the boxes timed per the install manual then put a timing light on the engine. The timing was right at 42 degrees (both boxes) and this was independent of RPM or manifold pressure. The boxes got sent back to Klaus and repaired.

My recommendation:
- Verify timing at idle with a timing light (MP line removed). Ignore what the box is telling you.
- If the ignitions check out with the timing light, experiment with limiting timing to something closer to 34 degrees. The timing pot may help but you may need adjust the initial timing set point as well. This should be done in small steps to evaluate progress (or lack of progress).

Carl
 
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Lots to unpack here...

1. Dispensing with old wives tales where and when I can -- You don't need high oil temperatures to "boil off" moisture. As a thought experiment fill a shallow dish with water and let it sit out at room temperature for a week -- no water left. Heating the solution and reducing the atmospheric pressure will cause water to evaporate quicker than room temp/ambient, but it's not necessary to go right to 100°C (Phase change temp at 1 ATM).


The above statement is true. The problem is the water that is trapped under the oil and not exposed to air, will not evaporate until the oil is once again flowing..... And being right on the bottom of the sump, it is the first to be picked up in very small amounts.

If you have a bad moisture problem, it could show up on your dipstick and inside the tube as a murky mixture of oil and water looking like coffee with cream, frothing.
 
Oh, a question for those who have it, what does the potentiometer to the the advance?, would be neat if I could retard things during the hot trips to Europe and then tweak it back when I get closer to Blighty.

According to the Lightspeed manual the potentiometer will adjust the timing +-5 degrees at around the mid point of the timing range but cannot expand the overall timing range.

I have the Lightspeed display and potentiometer and the display shows possible timing changes of about +- 10 degrees. I guess I have to believe the manual is correct - might test for the actual advance when adjusting the potentiometer with a timing light at my next annual??

I had high CHT’s after installing new cylinders at 1,200 hours. I subsequently added the cowl flap and a Vans cowl louver (on the right side). CHT’s are now OK but maybe due to the cylinders breaking in??
Fin
9A
 
Wow, great support guys!

Wow, thanks for all your thoughts.

So I read the manual many times and my rumination is what suggested I might be having CHT issues because the the resultant timing and the postings from you guys back that up. 36 degrees that Carl suggests certainly won't be helping my situation and it's got to be in that ballpark.

Especially interesting to hear the RV7 experiences which is just where I am in really hot ambients.

Until recently I was very wary of really slowing down (to 100kts and below) in case the lack of cooling air made the situation worse, but I flew alongside my son at 95 knots out of a friends strip on one of the hottest days of the back end of our summer and the temps stayed low, I then realised my escape numbers were to just slow to under 100 kts and everything would cool down, can't recall the rev's but would be at 1800 or so. The plasma at that would be well advanced so not helping but the actual heat produced from the combustion must have been low enough for the airflow to strip it way. As I sped up to leave him behind the temperatures rose back to the higher numbers that I was used to at cruise climb 115kts or cruise ~135knots.

Fin, appreciate your experiences and plan to do the same. I've just ordered a display and a potentiometer. I will be breaking in honed cylinders when I next fly so doing checks with a timing light won't be possible until I've got past the break in period but I'll have a good play then. I have ordered a miniature 3 way valve to vent the MAP connection into the plasma so the timing drops to minimum, hoping it will work ok on vacuum so I'll have to do some checks with it (don't want to allow air down the line into the engine). It has a toggle switch so won't look out of place on the panel. Then after break in as Carl suggests I'll find out as much as I can about what is happening and hopefully get a full understanding of the effects as Larry explained.

The only check I could do atm was to statically check the timing using the LED light going out as per the manual, that appears to be at 18 degrees BTC. Not far from the desired 20 but on the 'cool side'. I haven't moved it as it maybe got there after being dynamically checked and adjusted by the previous owner. He is no longer with us I'm afraid so I can't find out the history.

So thanks again for the support and taking the time to post back, I really appreciate it. It will be a great relief to me if the Plasma turns out to be contributing to my engine temperatures as modulating what it does may mean next years touring season in Europe will be rather more stress free.

As an aside here's some pictures from the trip last summer, approaching Corsica where we had and RV fly in with 11 planes from the UK.

Regards, Clive
 

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Wow, thanks for all your thoughts.

So I read the manual many times and my rumination is what suggested I might be having CHT issues because the the resultant timing and the postings from you guys back that up. 36 degrees that Carl suggests certainly won't be helping my situation and it's got to be in that ballpark.

Especially interesting to hear the RV7 experiences which is just where I am in really hot ambients.

Until recently I was very wary of really slowing down (to 100kts and below) in case the lack of cooling air made the situation worse, but I flew alongside my son at 95 knots out of a friends strip on one of the hottest days of the back end of our summer and the temps stayed low, I then realised my escape numbers were to just slow to under 100 kts and everything would cool down, can't recall the rev's but would be at 1800 or so. The plasma at that would be well advanced so not helping but the actual heat produced from the combustion must have been low enough for the airflow to strip it way. As I sped up to leave him behind the temperatures rose back to the higher numbers that I was used to at cruise climb 115kts or cruise ~135knots.

Fin, appreciate your experiences and plan to do the same. I've just ordered a display and a potentiometer. I will be breaking in honed cylinders when I next fly so doing checks with a timing light won't be possible until I've got past the break in period but I'll have a good play then. I have ordered a miniature 3 way valve to vent the MAP connection into the plasma so the timing drops to minimum, hoping it will work ok on vacuum so I'll have to do some checks with it (don't want to allow air down the line into the engine). It has a toggle switch so won't look out of place on the panel. Then after break in as Carl suggests I'll find out as much as I can about what is happening and hopefully get a full understanding of the effects as Larry explained.

The only check I could do atm was to statically check the timing using the LED light going out as per the manual, that appears to be at 18 degrees BTC. Not far from the desired 20 but on the 'cool side'. I haven't moved it as it maybe got there after being dynamically checked and adjusted by the previous owner. He is no longer with us I'm afraid so I can't find out the history.

So thanks again for the support and taking the time to post back, I really appreciate it. It will be a great relief to me if the Plasma turns out to be contributing to my engine temperatures as modulating what it does may mean next years touring season in Europe will be rather more stress free.

As an aside here's some pictures from the trip last summer, approaching Corsica where we had and RV fly in with 11 planes from the UK.

Regards, Clive

That light is to be set at TDC 0* for Lightspeed.....:eek:
 
And there we have it!

That light is to be set at TDC 0* for Lightspeed.....:eek:

Well spotted! :eek::mad:

I'm afraid I didn't sequentially read through the manual and read the setting as 20 degrees to statically 'time' the Plasma base position. I was using page the 'LSE TIMING DATA' page which only talks about 20 degrees. It does say one should use a timing strobe light to check the timing and I've always avoided that as I'm not a fan of whirling propellers. Reading through it now it's clear at TDC #1 to set the position of the sensor back in the installation section. I'm indebted to you Gasman. Statically it would seem that the unit is currently set ~18 degrees advanced as it's starting point. Not great and likely the root of my problem temperature problems. I can only assume the 18 degrees was the original owners attempt at 20 degrees. I'm surprised it's not kicked back though I imagine the plasma is inhibited with the starter key, I'll check the drawing/hook up.

This is great, something to cause it to run hot, the smoking gun I've been looking for!

I have to admit again I should have looked at the EI unit years ago but as the engine ran so well and the builder was a very knowledgeable guy I didn't question it, rather I was looking for traditional cooling solutions for my temperature problems (airflow through engine and oil cooler).
I have faithfully timed the slick each year thinking that was doing all the starting and the EI was only working at revs with MAP reference. TBH I hadn't considered that timing was an issue with warm CHT it's only after listening to Mr Savvy that I learned that fact.

Thanks again for the comments and for taking the time to review the manual and my ramblings above. I look forward to getting back in the air and seeing the results of the timing correction.

I'll post back with what I find. Regards, Clive
 
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Thanks Gasman

Checked your link and what a great idea, using a phone and strapping the timing light down and viewing remotely has got to be the safest way. Can also see the actual effect of moving the potentiometer when I get that fitted.

The Forums of the WWW are a great way to gain from the knowledge of others and regarding all things RV this is the best.

Hope to start putting the engine back together next week and will report back the effects of the timing change and any other data of interest so it's recorded here with the other helpful info above.

Thanks and Regards, Clive
 
Back in the air again, oil leaking out the Hall Effect pick up..

Reporting back after my timing set up debacle as explained earlier in this thread.

Post top end rebuild, new shells, small ends, rings, hone and valve seats fettled.

I've been flying again now for 6 weeks and started ease the revs back a few hours ago after 12 hours in the air. Probably being a bit paranoid with the hard running but after all the work I want to try and minimise the oil usage going forward. So I was thinking it might be time to have a play with the timing light now I can do some idling. So I came back here for a look to see what we discussed and to get myself familiar with the information everyone supplied, thanks again.

BTW, the oil temperature is definitely in a different place that it was before and my overheating problem has undoubtedly been due to me not finding the incorrectly set base position of the pick up at static zero. What still surprises me is the extra, potentially 18 degrees, advance didn't cause more of a running problem.

Now, even flat out I didn't see anything much over 100C OT despite the CHT's being very high due to the break in. Most of the time I can see the OT being controlled by the vernatherm. In fact it was all classic with the way the characteristics of the break in, temperatures, oil usage etc went. Oil change at 6 hours, I used unleaded fuel, in fact still am, while I was using straight oil I didn't want any lead to dirty things up at all.

I did find out the effect of a 'slight retard' on the timing as when not taking much care with the base timing, after renewing the gasket on the hall effect transducer chasing an oil leak (more later), I flew and as I climbed away the EGT's went high and the engine wasn't running happy and CHT's were cold (this was at 7K, wasn't so bad at sea level). I quickly realised what I'd done, or not done, and returned to check the static and found it minus about 4 degrees. Having someone to 'help' move the prop for you isn't the way but I didn't want offend. Anyhow, on my own I carefully reset to a proper zero at No1 TDC and all was well.

So problem solved and I look forward to a summer of flying in a hot Europe.

I will do some checks with a timing light shortly and see what it's actually doing and report back.

Back to the oil leak.

One thing about a strip down is to look forward to a nice clean dry engine.

I've had a pesky leak for some time and have been round the houses trying to find out where it's coming from. I found I had a cracked push rod tube, just where you can't see it, that's been replaced along with another suspect one. A leak from the prop cavity drain pipe, replaced all the fittings and pipe, and with all the new seals and O rings I was looking forward to a dry engine.

Alas it wasn't to be so. So I started on things I'd not been near, even though I was degreasing after each gasket change, and I've done all the jewelry on accessory case, I still had a leak. Lots of flights post resealing 'the next thing it must be' but still a puddle on the floor the next day.

Got there in the end tho, turned out to be oil coming out of the side of the green LED lens on the back of the hall effect transducer unit. The one that's bolted into the mag hole. With my aircraft being a taildragger it could drip and get blown onto the pipes, wires and throttle clamp down the exhaust and completely flumox me to as to where it was coming from. Found it after cleaning up and then NOT going flying and yet there was a new puddle the next day.

The seal is a 24x15x5, which amazingly I had in stock as it's similar to the one used on a Jabiru distributor shaft. So, oil leak fixed.

Problem now is the bearings are less than perfect so the seal will go again sometime and the bearings will I imagine get worse. I've E mailed Klaus as to the sizes and hope they are standard and will press out OK.

Anyone seen a bearing/seal issue before with the pickup that's mounted in the Mag position? This is after about 1000 hrs.

Pictures, you can't see the joy on my face as I found it though. Usually a unit like that, I imagine, would have a drain hole but with it needing to be oriented any which way during timing where would it be drilled. Electronics seem none the worse for their bath, fingers crossed.

Regards, Clive
 

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