Kahuna

Kahuna

Moderatoring
IO-540, C4B5, RV-8, 600 hours eng & frame, left impulse mag, right lightspeed direct crank., AFP injection.

30 hours ago, I noticed on a climb out, ALL 6 cht's up ~80degreesF higher than normal. :eek:, Lower nose, check everything out, everything seems normal. Mixture works as expected, climb and decent works as expected interms of temperature. No other unusual items. Its just running much hotter than normal in CHT only.

Other items if interest.
1.Probes check out ok and calibrated.
2. On a mag check run up, mag only drops 50, EI only drops 100. Thats way off. Used to be Mag drop 100, EI drop 20.:confused:
3. In flight CHT's, mag only runs ~80 dregrees hotter than EI only. On both runs +5 degrees hotter than Mag only. Runs fine on either alone, and normal rise of EGT's one one either alone.
4. In flight, mag only runs ~6kts faster than EI only.

I just noticed the in flight differences today whilst troubleshooting in the air. I have not checked the timing of either yet. I did check tha vac lines to the EI and they are holding vac. Alll cowling baffles are intact and nothing unusual found under the hood.

So what to try next? I thought since I have 600 hous on a slick mag, I might as well replace it. Question is, does a worn mag have a failure mode with these symptons? Anything else to try? :confused:


Ive poured over everything. Suggestions?

Best,
 
Last edited:
Well, lets see---------you are either making more heat, or not getting rid of the same heat as you used to.

How are the oil temps?????

If they are still normal, or at least pretty close, I suspect your posted info is pointing at the cause, generated heat in the chambers.

If oil temp is way up also, look for an issue with the cooler, or oil flow.
 
Mike S said:
How are the oil temps?????

If they are still normal, or at least pretty close, I suspect your posted info is pointing at the cause, generated heat in the chambers.

If oil temp is way up also, look for an issue with the cooler, or oil flow.
Click to expand...

"No other unusual items. Its just running much hotter than normal in CHT only."
 
I forgot to mention that I did grab a hold of the mag with 2 hands and try and move it. It would not budge. I have to go borrow a buzz box to check the mag timing. The focus on timing just came to me today during mag check and in flight checks.
 
timing---

Based on what you said, I would be looking at the EI more than the mag. It sounds like it's timing is now retarded, causing the rpm drop at runup check, as well as the drop in speed when mag is off.
 
For what it's worth, and at the risk of piling on, I'm going to vote for timing as well....I've never seen a mag suddenly shift - don't know about EI though.....

Paul
 
This sounds like the EI is not advancing as it is supposed to. Before you call Klaus get a timing light and make sure the EI is operating as it should, the manual tells you how to do this proceedure.
 
Kahuna, I have a question regarding your #3 observation:

3. In flight CHT's, mag only runs ~80 degrees hotter than EI only. On both runs +5 degrees hotter than Mag only. Runs fine on either alone, and normal rise of EGT's one one either alone.
Click to expand...

If I understand this correctly, when running on EI alone, the temperatures are around what they used to be before this problem showed up. But, with mag only (or both), they are much hotter. Is this correct?

If so, it would seem to be the mag is somehow misbehaving, to cause a large advance in timing, perhaps bringing on some detonation. The points open to fire, I believe. Maybe the gap opened way up.

??
 
Mike,

Check the mag, not just the EI. With the way the mag on the 540 plugs in, the rubber pads could be warn or compressed and it might just be firing before it should, thus raising your CHT's. Just a thought.
 
AlexPeterson said:
Kahuna, I have a question regarding your #3 observation:



If I understand this correctly, when running on EI alone, the temperatures are around what they used to be before this problem showed up. But, with mag only (or both), they are much hotter. Is this correct?

If so, it would seem to be the mag is somehow misbehaving, to cause a large advance in timing, perhaps bringing on some detonation. The points open to fire, I believe. Maybe the gap opened way up.

??
Click to expand...

Yes Alex you are correct.
On EI alone, CHT's are where they should be.
On Mag Alone, they are very high. Which is why I suspect a mag problem.
But then "2. On a mag check run up, mag only drops 50, EI only drops 100. Thats way off. Used to be Mag drop 100, EI drop 20." has me baffled.

Remember I have the direct crank pickup.
crank_trigger_isos.jpg

Its timing cant change unless something goes awry in the unit. The timing does change on the EI based on MP. I put a suction gage on the line and checked suction to EI box and MP sensor (they are on the same teed line) and its holds 2psi of vac for 10 minutes so I dont have a line problem. It does not mean though that I dont have a problem in the EI box though. I suppose I could check that by taking the vac on and off while running and checking the timing. Would be hard but could be done.
 
2. On a mag check run up, mag only drops 50, EI only drops 100. Thats way off. Used to be Mag drop 100, EI drop 20.
Click to expand...

Hmmm. I think this does fit a mag with a monster advance, doesn't it? Think about it.

Usually there are not two things awry, but maybe in addition to the mag's advance, the EI is not advancing at all from baseline?

Get the timing light on the EI, with the MAP line disconnected it should read baseline. At idle with the MAP line connected, around 38 BTDC IIRC.

Maybe you are dreaming this all up?:confused:
 
High CHT

Anyone else having the same problem at your field?

Years ago I remember reading about a load of fuel that was contaminated with some type of solvent, engines still produced power but indications were not normal.
 
Ironflight said:
(snip)....I've never seen a mag suddenly shift - don't know about EI though.....

Paul
Click to expand...

I actually have seen a mag jump timing, enough to result in rapid and severe engine damage.

There is a nylon gear inside a TCM/Bendix mag. On ours (on a TCM IO-550) the gear became brittle due to faulty venting. This resulted in missing teeth and significant advancement in timing. One cylinder pegged the redline CHT in seconds (so quickly it was initially assumed to be a bad probe)

TCM, to their credit, essentially rebuilt the motor under warranty (all six cylinders, crank, pistons, etc. replaced)
 
flyeyes said:
There is a nylon gear inside a TCM/Bendix mag. On ours (on a TCM IO-550) the gear became brittle due to faulty venting. This resulted in missing teeth and significant advancement in timing. One cylinder pegged the redline CHT in seconds (so quickly it was initially assumed to be a bad probe)
Click to expand...

Boy, that sure would do it!
 
Boy, way out on a limb here and most likely going to shame myself. Somewhere way back in the memory is a bad ignition/mag switch. If this is the case you aren't really testing what you think in flight, or during runup. You might want to pull the breaker for the EI instead of switching from left to right, or some creative way of isolating.
 
Last edited:
Its timing cant change unless something goes awry in the unit. The timing does change on the EI based on MP. I put a suction gage on the line and checked suction to EI box and MP sensor (they are on the same teed line) and its holds 2psi of vac for 10 minutes so I dont have a line problem. It does not mean though that I dont have a problem in the EI box though. I suppose I could check that by taking the vac on and off while running and checking the timing. Would be hard but could be done.
Click to expand...
There are a few things that might affect the timing of the EI; there could have been contact between the magnet on the flywheel and the sensors. I have just installed a "sensor protecting plate" that Klaus is now reccomending. I have not had this happen but it must have to at least a few systems or the change would not have been advised. Also there are two magnets that fire the system, perhaps something has happened to the one that advances the system.
The difference in mag drop with the EI vs how it ran for many hours is an indication of something wrong. It could be as simple as the automotive spark plugs not performing as they once did. My bet would be a problem with the EI unit itself. We just sent back two units that had not yet been used for an upgrade. They were three years old and did not have the breather tube that now comes with the plasma III units. For that reason we sent them back and we were told that one unit would not have worked and both received some hardware upgrades.
Checking the timing is not that hard, for safety reasons it takes two people but it goes quickly and will let you know if the advance is working correctly.
 
Last edited:
I have independent toggle switches for mag and EI.
My normal routine during run up is to turn one off/on, other off/on, both off, both on. This guarantees switches work.

And on the fuel question, I have been getting fuel from 3 states over the past couple of weeks. No chance thats doing it.

I will check the mag timing and EI. Im betting its timing. I wish from the symptoms I could figure out which is the culprit. Bets are on the mag for me.
Thing is, if the mag timing were advanced, do all my symptoms make sense? Mag drop on run up only 50=yes, mag running 80degF hotter than Ei=I dont know that seems like a very large gap, speed 6ktas greater than Ei = I dont know that seems like a large gap too.

I should have given temps too. Mag only in cruise all cyl cht's ~400, EI only ~320. Both ~405. Normal would be ~350.

Also where is a good place to order a replacement slick mag model 6351? Googling was not very helpful.
 
Tom Martin said:
There are a few things that might affect the timing of the EI; there could have been contact between the magnet on the flywheel and the sensors. I have just installed a "sensor protecting plate" that Klaus is now reccomending. I have not had this happen but it must have to at least a few systems or the change would not have been advised. Also there are two magnets that fire the system, perhaps something has happened to the one that advances the system.
The difference in mag drop with the EI vs how it ran for many hours is an indication of something wrong. It could be as simple as the automotive spark plugs not performing as they once did. My bet would be a problem with the EI unit itself. We just sent back two units that had not yet been used for an upgrade. They were three years old and did not have the breather tube that now comes with the plasma III units. For that reason we sent them back and we were told that one unit would not have worked and both received some hardware upgrades.
Checking the timing is not that hard, for safety reasons it takes two people but it goes quickly and will let you know if the advance is working correctly.
Click to expand...

There would appear to be no evidence that the EI timing is off. All data points to the mag's timing, including the runup drops (see my earlier post). The engine runs hot with mag only, and cool with EI only.
 
Spruce, Believe it or Not...

Kahuna said:
Also where is a good place to order a replacement slick mag model 6351? Googling was not very helpful.
Click to expand...

Believe it or not Spruce seemed to have the best prices on Slick mags.
 
Update.
Found mag timing to be 40degbtdc. I dont know how or why it got there but that is where it was.
While I was not able to find the slick mag on ACS on-line.
I was able to call them and they had one. SO Ill put that in tomorrow.
Also tomorrow Ill check the EI timing. That is still an unanswered ?.

I took the mag apart. Plastic gears were fine. Nothing looked unusual.
Put it back together and will return for core.

I also pulled the screen and filter to check for metal. Nothing found.

Will install new mag tomorrow and check EI and report back.
Im still stumped as to why an advanced timing of 40 degrees btdc produces more heat and more power. :confused:

Perhaps someone can spoon feed me on that.
More tomorrow.
 
Kahuna said:
Im still stumped as to why an advanced timing of 40 degrees btdc produces more heat and more power. :confused:

Perhaps someone can spoon feed me on that.
More tomorrow.
Click to expand...

Well, to get really basic, and not overly technical, here goes.

Heat is what makes the power.

Advancing the timing allows the heat to begin earlier in the cycle, and it stays in the chamber longer. The longer it is in the chamber, the higher the CHT.

A little advance, under the correct conditions of load, temp, M.P., ETC makes more power--------what the EI does.

Too much advance makes so much extra power that things break.

Luckily, you seem to have caught the problem before the broken parts happened.
 
Kahuna said:
Update.
Found mag timing to be 40degbtdc. I dont know how or why it got there but that is where it was.

snip...

Im still stumped as to why an advanced timing of 40 degrees btdc produces more heat and more power.
Click to expand...

It's pretty simple, really. The more the timing is advanced, the more time there is for the hot combustion gases to transfer heat to the cylinder heads, and the colder the exhaust gases get. When the timing is severely retarded, the opposite happens, the cyl. heads get cool, and the exhaust pipes can glow red hot from the still burning fuel - air mix in them.

If it had advanced any more you probably would have lost power and started to detonate. :eek:
 
OK so if you take my data at face value, 15 degrees advanced(going from 25 to 40) produces 80 degrees more cht heat and 6kts of speed in the 190kt range on my plane. That a lot of heat and not a lot of speed change.

Would i hear the detonation happening(knock) or would I not hear it until something broke?

And if anyone has a good theory on how my mag timing went from 25 to 40 overnight?(I know this cause my engine mornitor screamed at me with the high cht's). The plastic gears looked like they would be hard to jump. The accy gear cant jump I dont think. And all the teeth were on the 2 nylon gears in the mag.
 
Kahuna said:
Update.
Found mag timing to be 40degbtdc. I dont know how or why it got there but that is where it was.
While I was not able to find the slick mag on ACS on-line.
I was able to call them and they had one. SO Ill put that in tomorrow.
Also tomorrow Ill check the EI timing. That is still an unanswered ?.

I took the mag apart. Plastic gears were fine. Nothing looked unusual.
Put it back together and will return for core.

I also pulled the screen and filter to check for metal. Nothing found.

Will install new mag tomorrow and check EI and report back.
Im still stumped as to why an advanced timing of 40 degrees btdc produces more heat and more power. :confused:

Perhaps someone can spoon feed me on that.
More tomorrow.
Click to expand...

When was the last time you checked your mag timing? How many hours are on the mag? I don't think you need a new one. Just yesterday on a Saratoga I maintain I found the right mag advanced by ten degrees or so...retimed it and life is good again. I check e-gap (internal advance) every 500 hours on either a slick or bendix. The e-gap changes as the cam wears.
 
rocketbob said:
When was the last time you checked your mag timing? How many hours are on the mag?
Click to expand...
\

Last annual 200 flying hours ago.

rocketbob said:
How many hours are on the mag?
Click to expand...
600 total

While Im sure I could have corrected the timing, and gotten more hours on it, 600 is enough to be paying attention to it and the unexplained timing change was enough to spook me into a new one. I fly too much to far away places to have a questionmark hanging over my mag/plane.
 
Wear in the points, or the wear block that opens the points, will change the timing.

But, I suspect it will retard, not advance, from the wear.
 
Well, I for one have found this very instructional!

Thanks everybody, and Kahuna for continuing to educates me on these things!

Sure hope your fix takes care of it all!!
 
Kahuna said:
Update.
snip
I'm still stumped as to why an advanced timing of 40 degrees btdc produces more heat and more power. :confused:

Perhaps someone can spoon feed me on that.
More tomorrow.
Click to expand...

Kahuna, glad you found the problem.

You might have had light detonation going on. It won't hurt the engine in the short term, but will greatly increase heat transfer to the cylinder walls. It wipes away the boundary layer, which acts as an insulator. I would think if the plugs look fine, your engine is probably fine also.

Someone around here had very high cht's after installing an EI, and he found that there seemed to be an advance threshold where the temps went up rapidly. It is likely not just due to the additional time the mixture is burning, although that matters also.
 
Way to go!

But at the risk of stating the obvious...Would a second EI be a better choice..I've never heard of a Lightspeed going bad...

Frank
 
Kahuna said:
.....And if anyone has a good theory on how my mag timing went from 25 to 40 overnight?.....
Click to expand...

Not over night.

But a combination of heat and vibration could cause the mag to slip under the mounting clamps. I always wondered why it was necessary to check timing at every annual - the darn things must slip - maybe sometimes a lot!
 
frankh said:
But at the risk of stating the obvious...Would a second EI be a better choice..I've never heard of a Lightspeed going bad...

Frank
Click to expand...

Actually it would. Except for one problem, on the 6cyl LSE install, a second unit requires a lot of work, pulling the prop, putting in a new direct crank pickup, blah blah blah.

On my rv-6 4cyl, I did just that. When my mag gave out ~500 hours, I installed a second LSE unit and flew it another thousand trouble free hours under a dual LSE single bat single alt set up. That install was easy since the 4cyl can use hall effect pick ups and can easily be done in a day.

Over the next 3 weeks I have 2 air shows and a formaton clinic from Texas to Ohio to the Carolinas. I got no hope/time of switching to dual LSE in my 6 cylinder with all that going on.
I got 2 days to get the back in the air AND work my day job.
 
David-aviator said:
Not over night.

But a combination of heat and vibration could cause the mag to slip under the mounting clamps. I always wondered why it was necessary to check timing at every annual - the darn things must slip - maybe sometimes a lot!
Click to expand...

Not a chance. From my post on the first page "I did grab a hold of the mag with 2 hands and try and move it. It would not budge"

No combination of heat and vibration is gonna let a mag move that will not turn from a 2 handed grip.
 
Kahuna said:
Not a chance. From my post on the first page "I did grab a hold of the mag with 2 hands and try and move it. It would not budge"

No combination of heat and vibration is gonna let a mag move that will not turn from a 2 handed grip.
Click to expand...

If we assume the above is true for the sake of this analysis, there isn't too many more things to check.

1) Point contact broke. Normal wear would move the timing very slowly, but if the contact broke it could shift "overnight". If the rub block broke it would close the points and retard the timing, but if a point contact fractured it would open the points and advance the timing.

2) Drive gear slipped on the shaft. Haven't seen one of these mags, but I assume the gear is keyed or pinned in place?

3) Aren't these driven off the camshaft? Could the cam gear have slipped or jumped a tooth? :eek: Probably not!

4) The point mounting surface cracked or slipped.

That's all I got...
 
high CHT's

just to add to the "why high CHT's?" question. The increased time that the combustion heat is in the combustion chamber is only one small factor. Knock/detonation is another possible factor, but if it were occuring, chances are you'd be sweeping up the pieces.

Most of the extra heat is coming from the extra peak cylinder pressure that is generated by advancing the ignition - with pressure comes temperature. You are talking of temperatures into the thousands of degrees at P_max which is where most of the heat transfer is taking place (due to the high temperature gradient)

A
 
Update.
It was the mag out of time. Uknown reason. :confused:

New mag on and runs fine.
I sure learned a lot from this. Main take away is high CHT's can be timing. What got me down the right path was the mag check and the inflight difference in CHT's that has been discussed earlier.

Until the mag check I was convinced it was in the plenum some where and if I just flew it and kept the temps down Id be fine. That was a mistake. The advanced mag timing could have destroyed the motor or worse, ME:eek:

Also another item is I have been very slack with the ground mag checks. I switch fast and dont really pay attention to the actual rpm drop. "If it keeps running smooth and just drops a little then its fine," was my attitude. That too was a mistake. I need to take the time and pay attention to the drops. I would have nailed this much sooner, in fact immediately, had I done that.

Thanks to Alan Adamson for coming by to help today. Much appreciated.

Case closed.
thanks to all the replies.
 
<<15 degrees advanced(going from 25 to 40) produces 80 degrees more cht heat >>

Takes time to burn fuel. You fire the plug 25 before TDC to get peak cylinder pressure 12 to 14 after TDC. With timing 15 degrees advanced, peak pressure was at TDC or a little before.

Mike, I know you said "case closed", but don't be in a rush. Andy, Alex, and others are right; detonation was possible. If you haven't already done so, pull the plugs and look close at them with a magnifier. If you see little tiny silver balls, boroscope the cylinders.
 
As Mike and I were discussing this morning, his issue is yet another reason to get a full-blown engine monitor for your engine. It probably would have gone unnoticed for a longer time with steam gauges. Imagine diagnosing this if you had just a CHT and EGT probe on #3.
 
DanH said:
<<15 degrees advanced(going from 25 to 40) produces 80 degrees more cht heat >>

Takes time to burn fuel. You fire the plug 25 before TDC to get peak cylinder pressure 12 to 14 after TDC. With timing 15 degrees advanced, peak pressure was at TDC or a little before.

Mike, I know you said "case closed", but don't be in a rush. Andy, Alex, and others are right; detonation was possible. If you haven't already done so, pull the plugs and look close at them with a magnifier. If you see little tiny silver balls, boroscope the cylinders.
Click to expand...

Oh great. Gimmie this advice after I got her all cowled up and sign off:mad: I looked at the plugs but not under a magnifying glass.

OK, OK, OK, Ill pull the top cowl tomorrow and do that. I can borescope the cylinders whilst Im at it. What am I looking for in there? Im serious...... Ill expect to see what I normally see and Im no doctor on this patient. One scored cylinder wall and top piston looks the same as the next to me. In fact they always look like they should not provide any power yet they always seem to. They look nasty, and beat up, covered in carbon and other mineral items I know nothing about.

Now dont get smart and tell me to look for big holes in the top of the piston. I would recognize a problem there. But given that Im developing full power on all cylinders, what am I going to look for in there?
 
Ignition Timing

Kahuna said:
Now dont get smart and tell me to look for big holes in the top of the piston. I would recognize a problem there. But given that Im developing full power on all cylinders, what am I going to look for in there?
Click to expand...

Take a look for a lack of carbon deposits, as well as broken spark plug ceramics. Read more about this here:http://www.sacskyranch.com/deton.htm

Both the Sky Ranch Engineering Manual and Magneto Ignition System books sold by Sacremento Sky Ranch are very good reading. The knowledge base online at Sacremento Sky Ranch is also excellent.

This thread is a must read for anyone NOT condidering installing one of the excellent engine monitors that are now available.

Hope this helps.
 
Mike,
For the most part, if the plugs are clean you're fine. I just think you should take a good look at them under the circumstances; a conservative view. I sincerely hope it is all a waste of time.

Sources: Check the Sky Ranch read Jon linked. You can call a good engine shop for thoughts on the effect of really advanced timing, or ring up George at GAMI; I think they've run some radical timing in the test cell. If you do, please report back.

Little balls of aluminum on a plug can only come from something aluminum in the combustion chamber. Only two parts are aluminum, the piston crown and the head casting. Normally both are coated with that ugly carbon and mineral stuff you mentioned. In order to melt aluminum, the carbon had to be burned and blasted off the surface. You're really looking for bare metal. If the metal is merely bare, great. If it is eroded (pits, craters, missing chunks) you have a problem.

Metal loss at the piston edge over the top ring land or in the piston center; bad news. Two strokes will tend to cave in the center of the piston dome. I don't know if Lycoming pistons will do that, but look for a depression.

Metal loss in the chamber dome near a valve seat, or between the valve seats; not good. Look at the edges of the valves too. A little loss in some odd corner of the chamber wouldn't bother me much.

Don't worry about the cylinder walls unless you see signs of scuffing and metal transfer. Detonation really heats the piston; it swells and may try to stick in the bore. I wouldn't expect it unless things got really bad; aircraft engine piston-to-wall clearances are huge compared to other engine types.

Cutting the oil filter is a good idea. Very high cylinder pressures can overload bearings.
 
Last edited:
If you look at your data from the engine monitor, detonation will show as a sharp increase in egt and then a plateau at that much higher level. Upon inspection of the cylinders, if you had detonation the cylinders will be very, very clean. Most all piston dome deposits will be gone and the top of the piston will be clean. There may be SLIGHT evidence of melting all over the piston top or dome with insignificant detonation. Serious detonation will normally burn the piston away, especially around the outer diameter. The piston will get the appearance, as if you held a grit blast nozzle in one place for a long time and wore the piston away with the grit. As one poster suggested, you may also get the burned away appearance around the perimeter of the valve seats. Any significant burning will normally result in compression loss and failure of compression test. Insignificant minor melting scars on the dome of the piston aren't too much to worry about but anything above and beyond that may need more attention. If your engine monitor data doesn't show a graph out with a steep increase and high egt plateau, in my opinion, it is very unlikely you had any serious detonation.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
 
Dan and Mahlon,
Excellent. Simple enough. Easy to do.
Ive printed off these comments and will check it out. Ill do a compression check while Im there.
Thanks for the helpful advise. Ill use it today and report back my findings.

One item to note. WHen I sold my RV-6A a couple years back, the pre-buy A&P borescoped my cylinders and told me there was no way my engine had 1500 hours on it. He said it looked like 300 hours on how clean it was. He actually got in a pissing contest with me on it. Like I had changed the cylinders and was hiding something. He literally wrote in his report that he suspected I had an engine problem and had replaced the cylinders and not logged it for some reason. I only mention this because I attributed that(clean look) to my running LOP constantly in cruise, which is where I spend most of my time since I travel a lot. Plus I ran it hard and often. I do the same thing on my 8. So I expect to find clean, but Ill absolutely look for the other items mentioned.

Best,
 
Excess heat in the combustion chamber acts like a self cleaning oven. The extra heat burns the deposits off just like when you use the self cleaning oven feature on your oven at home. If an engine has lots of heat from detonation or from very lean mixture, advanced timing or any other reason, you can get a self cleaning effect in the combustion chamber that will burn off normal combustion deposits. That is why one of the possible telltale sign is the clean pistons.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
 
mahlon_r said:
Excess heat in the combustion chamber acts like a self cleaning oven. The extra heat burns the deposits off just like when you use the self cleaning oven feature on your oven at home. If an engine has lots of heat from detonation or from very lean mixture, advanced timing or any other reason, you can get a self cleaning effect in the combustion chamber that will burn off normal combustion deposits. That is why one of the possible telltale sign is the clean pistons.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
Click to expand...

OK now Im scratching my head and getting side tracked (the main reason I pay attention to these boards:D). So if I run 50 LOP, and the CHT's are always 45 degrees colder than running 50ROP, then would you expect it to be cleaner in the cylinder with LOP or ROP? Perhaps if I could measure top of piston temperature that would answer my question. I guess lower cht's do not translate into lower combustion temps. Nor do lower EGT's for that matter since the EGT probe is down stream from the comustion.
 
You must log in or register to reply here.