Continental Engines

[Pearson]

The March issue of EAAs Sport Pilot Magazine (the one with the Jetman on the cover) has in interesting article titled "The Small Continentals". It is a good mix of the history of the small Continental engines and the differences between them. It starts on page 102.

[Doc]

Re: Continental Engines

That article was written by a fellow EEA'er from Chapter 35 in San Antonio. I am rebuilding an engine he sold me. Oscar Zuniga is a good guy with a flare for writing. Doc

[Pearson]

Re: Continental Engines

Doc,

I thought your friend wrote a very good article. I know it seems different when you are reading an article by someone you know. I used to fly with Lauren Paine who also writes a monthly article in the EAA Sport Pilot Magazine.

[jim cooper]

Re: Continental Engines

ALSO: an excellent article in "The other" T-craft (wisconsin) club newsletter on Stromberg Carbs, by Mr. Kolb. Very enlighting! Telling of original boring mistakes made in production and how the float may not seat right causing loss of horsepower. Also excellent hp rating chart of all small Cont. engines. Rated hp @ various rpm settings, etc. JC

[Pearson]

Re: Continental Engines

Jim,

Tell me more! Where is this article? I would like to try to find it online. I have a carb torn apart right now!

[jim cooper]

Re: Continental Engines

I will copy the parts you need and post it here tomorrow. It describes a production error and how to solve it. It says take off and cruise can be greatly affected if the float hits the bowl wrong., etc. etc. Makes engine run too lean. Says to check plugs and if burning light color (lean) this may be the fault of this flaw. Standby: JC OR: I shall copy it and mail it to you. JC

[mmartin1872]

Re: Continental Engines

Another Continental Engine question... I'm trying to figure out the most recent revision for the maintenance and overhaul manual, and the illustrated parts manual for the a65 and a75, and where to buy the manuals from. (I don't want to buy from Essco because i've been burnt by them before buying a flight manual, and getting an 'out of date' flight manual. AC spruce, doesn't say what revision their manuals are, and neither does univair. I can't find the 'revision date/version' either on the continental website, and i want to be sure we get the most recent revision. Now onto the story:

My dad had an engine overhaul on our engine in 1994. His airplane has an A75-9 installed. This annual he had no compression on 3 out of 4 cylinders. it was going passed the rings on 1 cylinder, and the exhaust valves on 2 other cylinders. (10 over 80 for these 3.) The mechanic took the cylinders off, reground the exhaust valves/seats (I believe) and then started working on the carbon deposits on the tops of the pistons. Well it ends up 3 out of 4 cylinders are chrome, the other one is steel, (because about 5 yrs ago, one of the jugs broke off in flight, and the mechanic had this steel jug sitting around.)
Just recently the mechanic has been informed that you can't have steel rings in a steel cylinder (i think he's wrong, but who am I to say) The rings where all steel rings, but someone has told the mechanic that he needs 'chrome' rings on a 'steel cylinder'. So he ordered the chrome rings. Broke the chrome rings. then he started f*ing around with another piston, and the bottom skirt broke while he was removing the rings. (the piston that was leaking through the rings, so i don't think it's his fault) So now we are trying to find the right piston and rings. The log book says that PN46387 Pistons where installed and B22205 STD ring set where installed at the overhaul. He's been trying to find these parts, and can't find them, and I am wondering if their part numbers may of been superseded, in a more recent revision of the overhaul manual, that our mechanic doesn't have.
This area of aircraft maintenance is defianetly not my expertise, and i don't think its the expertise of the mechanic doing the job either. Much deeper into this project, and my dad is going to just want to do the upgrade to the 85 with the electrical system.
I myself wish that 'so many chiefs hadn't worked on the engine' in the past month. 4 people worked on it, and none of them talked to each other.

My dad wants me to atleast order the right parts for the mechanic, my dad is willing to replace the 'one' steel jug with a chrome one, and replace the broken piston, and return the rings to being all steel rings. I've informed him that I NEED the most recent manuals, if I'm going to do that for him. where should I order the parts from? I'm in BC Canada. I just wish that the well intentioned mechanics that worked on this engine, knew what the f they where doing, I don't, and that's why I never touched it. (even though i'm an aircraft mechanic but i've spent my entire career working on turbine helicopters, and structures of airplanes.)

Supposedly all the jugs have been measured, and are all 'standard' size, and didn't need to be rebored, or any of that sort of thing. Is it a neccessity to have 'all chrome cylinders'? or can you have 3 chrome and 1 steel, legally?

[Pearson]

Re: Continental Engines

Mike,

Can you have 3 chrome and 1 steel cylinder "legally"? I don't know. But even if you could, why would you want to. You would eventually end up in the same mess you are in now.

Chrome cylinders need cast iron rings. Steel cylinders need chrome moly rings.

I suggest you pull all four cylinders and have the three chromed ones checked to make sure you haven't worn through the chrome. And have the steel cylinder chromed using the same process as the other three.

Do yourself a favor, and just call Chester at 863 214-3083. Tell him Richard Pearson sent you.

[mmartin1872]

Re: Continental Engines

All 4 cylinders are sitting on the bench right now (well they where yesterday). The chrome looked good (I think) when I peaked at the cylinders 4 weeks ago, but I wasn't really paying much attention, because it had nothing to do with me. I've told my dad that he should have '4 chrome cylinders'. He can send out his 'steel' cylinder and get it chromed.. Perfect. I kind of thought, you could get 'cylinders chromed'. But as i said, I never messed around with piston pounders in my career yet.
My dad is kind of choked with the 'overhaul' that he had gotten, because he had the overhaul, then had to send the engine out after 50ish hours, for some reason, I don't know what it was. Then they flew another 50 hours, blew a jug off. Then they flew it till this year. Low compression. cracked 'piston' skirt, tons of carbon on the tops of the pistons, oil that looks like it's burnt to the sides of the pistons (i don't know if this is normal) smoking exhaust guides. One of the pistons, also was a '4' ring piston, and the other 3 pistons where '5' ring pistons... I don't know if it was the 'overhaul' the 'well intentioned' mechanics, or what that all this stuff got messed up with. But I just need to get it right. I'll give Chester a call... Is there any 'numbers' that he'll need in order for him to get me on the right track? Piston size? bore of the cylinders? engine model number? etc.? I just want to be sure, when I call, I don't sound like a bubbling bafoon, not knowing the stuff that I need to know, to get him to give me the answers, that I need. In the end, I'm not going to be the mechanic that signs this thing off, but I want to make sure that the job is right, because I may be the guy in the pilot seat getting my pilots license finally.

[NY86]

Re: Continental Engines

There is no reason you can not mix chrome and steel cylinders on the same engine. There are reasons you may not want to, but no legal or performance issues. Your chrome cylinder should have an orange ring painted around the base to indicate it is chrome.

The ring type only applies to the top compression ring. Steel cylinders can have either a chrome or a cast iron top compression ring. The chrome ones should last longer, but either will work. The chrome cylinder MUST NOT have a chrome ring. They will gall and seize, or at least try to seize. Lower compression rings and oil control rings are all iron/steel regardless of cylinder type.

[mmartin1872]

Re: Continental Engines

I called Chester, and he helped out quite a bit. Now my dad just has to decide, fix it - or install a c85 with the harer STC.
we'll see

[jim cooper]

Re: Continental Engines

RE: Carb problems....".Float drop was measured and did not meet.048 specification. close exam revealed float was coming in contact with main metering jet which restricted fuel flow causing engine to only produce 60-65% of power. Several additional carbs were checked (stromberg only) and half had restricted flow due to contact with main metering jet. Apparent that original machining had been done incorrectly. Check your plugs! if they burn white or light grey instead of even choclate brown then carb. is running lean which may be because of this above mentioned problem." This is the essence of the article.JC

[M Towsley]

Re: Continental Engines

Jim,

Thanks for sharing. I just spoke to a guy in northern Illinois who rebuilds just these small Strombergs. He mentioned exactly what you related from the article and told me about 2/3rd's of the Strombergs produced had this problem with float drop. He developed a way to fix the float drop problem.

[NY86]

Re: Continental Engines

I always chamfer the edge of the jet so the float does not touch it. I believe there is a service bulletin that covers this somewhere, but could be mistaken. Regardless, it is common practice.

[jim cooper]

Re: Continental Engines

Could be common practice but if half of the ones checked were bored wrong, then many may be functioning incorrectly. Knowing nothing about engines other than how to change plugs, minor maint. I am only repeating what was written. JC