Techron is amazing!

Techron is amazing!


A little over a month ago I decided to do the Conditional on the SQ-2 a month early as I planned to take her to the Idaho backcountry last week. The compression was 60, 78, 78, 78. I could hear hissing in the exhaust pipe.


I bought a bore scope and took a look at the exhaust valve. I was pleased to find a symmetrical burn pattern with no hot spots indicated. I also saw some carbon buildup at one location on the valve and valve seat.


I had some TCP laying around and even though it's a lead scavenging agent I decided to give it a try. I doubled the recommended dosage and flew two tank fulls through the plane. Checked the compression again and got the same results. Borescoped the cylinder and saw exactly the same thing as previously.


I jumped on the Interweb to find the best carbon cleaning additive and found Chevron Techron to be recommended by BMW. That was all I needed. I bought a case from the nearest Autozone and doubled the recommended dosage. After two tank fulls I again checked the compression and it was up to 64, but I could still hear air hissing in the exhaust. I borescoped the valve and seat and the carbon buildup was gone.


I still didn't feel comfortable in taking her to the Idaho backcountry so changed my plans to take the 185 to Taos and fly-fish for four days. In the meantime I decided to first try staking the valve and if that didn't work then pulling the cylinder and lapping the valve.


Ran another couple of tanks of fuel laced with Techron and then pulled the rocker cover, removed the rocker arms, and staked the valve. Compression was now 68. Decided the best thing to do was to pull the cylinder and lap the valve. Ordered the appropriate parts and ran a couple of more tankfuls of fuel with Techron added.


Off to New Mexico I went, caught lots of rainbows and browns, and back home Friday. Went out to the hangar today to pull the cylinder and lap the valve. But first one more compression test. 75! Checked it again, 75! Woohoo! No open heart surgery required.


Techron is amazing! Oh, and I despise running ROP. When the SQ-2 needs a new engine she is getting fuel injection so I can run her LOP, which greatly diminishes carbon deposits.


If I had added Techron to the 185's fuel, which I didn't of course because she is a certificated aircraft and Techron is not approved for certificated aircraft, I would have seen the fuel gauges loose their minds and have all kinds of erratic readings. Of course if that had happened I would just revert to a calibrated fuel stick I use to visually check fuel levels. Had this happened, after a couple of tanks of just Avgas, the fuel gauges would have returned to normal. But of course none of this happened, it's all hypothetical.


From now on every time I change the oil in the SQ-2 her fuel tanks will get a dose of Techron. Awesome stuff.

There's also a fuel that begins with the letter E that is added to gasoline that causes the gas to burn cleaner and reduces carbon buildup. Since you're experimental, I'd just have to try it.:smile:

Barnstormer said:

...I would have seen the fuel gauges loose their minds and have all kinds of erratic readings. Of course if that had happened I would just revert to a calibrated fuel stick I use to visually check fuel levels. Had this happened, after a couple of tanks of just Avgas, the fuel gauges would have returned to normal.

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strange... those fuel senders in tanks ARE CAR PARTS.... Stewart Warner 818B or 818C or something in the 810 -820 range can't remember exactly(813??)...

Soooo, is Marvel mystery oil APPROVED??

My sending units are McFarlane, not sure if they are constructed in the same way. Marvel Mystery Oil isn't approved, but it sure works great for scavenging lead.

Regarding MMO in Experimental AC, I know the label says 4oz per 10 Gallons. Is that the best ratio for us in airplane engines (Continentl O-200)?

Rich

180Marty said:

There's also a fuel that begins with the letter E that is added to gasoline that causes the gas to burn cleaner and reduces carbon buildup. Since you're experimental, I'd just have to try it.:smile:

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Thanks Marty, unfortunately the engine compression is too high to run anything but Avgas.

Richgj3 said:

Regarding MMO in Experimental AC, I know the label says 4oz per 10 Gallons. Is that the best ratio for us in airplane engines (Continentl O-200)?

Rich

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Rich, I've been using the recommended dosage of MMO as a preventative in both radial and flat engines for years and have never had any lead buildup.

Thanks Phil

I had lead issues on exhaust valves early on in a new engine (O-200) on two cylinders. After repairing those I started using TCP and MMO and have gone quite a while with no issues. Now I have what I think is a sticking valve that manifests itself as an intermittent stumble that lasts less than two seconds every couple of hours.

I'm not sure what to do at this point. Pull all the cylinders? Do the "rope trick" and check the clearance of the valves in the guides? I do have access to a bore scope and the condition inspection is coming up, so I guess we will look and make the call. As much as I'd like to believe I could fix this with an additive, that's probably not in the cards.

Rich

unfortunately the engine compression is too high to run anything but Avgas

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Phil, you could jet the carburetor for E85 that is 105 octane and is available in Austin and use it for your local flying. Learn to pull the mixture when you have 100LL in the tanks just like the guys over at Texas Skyways do with the O 470 UTS. You'd be running clean fuel most of the time with the carbon producing fuel on your occasional trip to Idaho.

stewartb said:

Marketing is amazing. Here's the Techron MSDS. It looks a lot like MMO on paper. Also similar to Seafoam but Seafoam adds isopropyl alcohol to their recipe.

https://cglapps.chevron.com/msdspds/MSDSDetailPage.aspx?docDataId=283264&docFormat=PDF

For comparison-

Marvel Mystery Oil- https://www.turtlewax.com/docs/default-source/msds-english/msds-consumer/marvel-mystery-oil

Seafoam- http://www.mta.ca/administration/fa...Engine treatment - SeaFoam Sales Co. 2010.pdf


You can find users who swear by all three. It doesn't look like it'd matter much which one you choose unless you have some moisture in the tanks and then Seafoam has the advantage. I used to use MMO and liked that the red dye bonded with water so if you sumped any water it came out bright red, which is nice.

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The MMO link appears to be dead. But thanks for the MSDS on Techron. Benzene. If memory serves me correctly that is the stuff you could buy in the 60's/70's, drop a filthy, fouled spark plug in, and moments later the plug was spotless. Boy I miss those days. Of course the stuff could kill you which is why it was pulled from the shelves. If memory serves.

Benzene is high octane which is good but a carcinogen that is bad. That is why my ethanol friends promote E as a cleaner fuel
replacement. On a side note, I can remember cleaning spark plug leads with MEK---probably not good.

Fuel additives with solvents are a topic I'd like to discuss with a petroleum engineer. One of my favorite solvents is gasoline.

I use a little MMO now and then - watched a Jacobs expert using it, and figured it couldn't hurt. It doesn't.

But every now and then I get a weak cylinder - no doubt like the original poster. Rather than pull it right then and there I give it between two weeks and a month, and about 3/4 of the time it fixes itself.

Think about it: Folks with starters get a compression check once a year, and a weak cylinder is pulled at that point. Those of us who hand- start get a compression check every cold start, which for me is once a day. The once a year compression check either picks up a cylinder that has been dead an average of a half year, or picks up a cinder under a valve that would probably fix itself.

stewartb said:

...One of my favorite solvents is gasoline.

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Really? I've never been known to use gasoline as a solvent. Okay, there was that one time...oh and then there was....and oh yea...

Bob, do you think your hand can tell the difference between 60/80 and 78/80 on one of your cylinders?

Yes.

I agree with Bob. yes.

Agree. When it was 60 I could feel the difference easily as I pulled the prop thru the other cylinders. Now that it's 75 I can't tell the difference.

I don't need to hand prop. I can feel a low cylinder in my butt. Or many other engine imperfections. Don't believe me? Ask my mechanics!

Stewart,

Would that be on the cheek where you carry your wallet? LOL !!

John Scott

After the past week of chasing a gremlin? That's likely to be true. :-(
No bother. I've never complained about spending money to make my airplanes run properly and I've never been satisfied with less than ideal engine operation.

Since we're talking pulling the prop through, here's my experience. I do two shots of prime and pull through 4 or 5 blades and then one more shot and hopefully it starts in one blade. When pulling through,some blades really snap with the MT prop and some feel a little soft like Oh Oh. The other day I did a compression check and 76 was the lowest. I like the way I did my last compression test, too, I listen for the impulse snap and back up just a little, stand back from the prop and apply the air and watch the pressure build. I don't hold the prop and I didn't have one prop run away so TDC is pretty easy on my engine.

We have one 90 hp Cub that doesn't pass the pull test at all. Something is leaking - so I told the owner to get a compression test, and it passed. It still doesn't pass the pull test.

A friend was selling a Helio - flunked the FAA Repair Station pre-buy compression test, so I had the potential customer hold the diff pressure gauge while I held the prop under pressure - passed. We never did have any problem.

Hey Barnstormer....what size Continental engine are you using Techron in?

Pat

Hypothetically speaking, an IO520D. ;-)

My 96 cherokee(jeep) always needed a dose of techron injector cleaner about every six months...that need went away when they added alcohol to gasoline....

I recently noticed that the wikipedia entry for MMO listed one percent lard as an ingredient. There used to be a product called Lard Oil which machinists used as a cutting oil, and it smelled pretty bad after a while...but worked great.
The addition of alcohol to car gas reduced it's lubricity, and MMO probably is a good thing for fuel pumps and injectors, just from the lubricity standpoint.

https://en.wikipedia.org/wiki/Marvel_Mystery_Oil


By the way, they took out the oil of wintergreen....