What should I have done with my Cylinders

Aircraft powered airboat discussion.
whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

What should I have done with my Cylinders

Postby whee » Wed Nov 23, 2016 2:37 pm

Hew guy here. I've been lurking for about a year and learning a bunch about engines. I must admit I don't have an airboat, though just over a year ago I vacationed in FL and went for a ride on one. It was crazy fun and if there were swamps in ID I'd have one for sure. I am building an experimental airplane and this place has been a great source for engine information. Airplane guys, even experimental, are so scared of engines they won't hardly talk about it. And they swear I'll fall out of the sky if I even think about doing engine work myself; it's ridiculous.

I've got all my parts ready for engine assembly except my cylinders and I can't decide of far into them I should go. I don't want new or freshly overhauled cylinders for the first couple hundred hours. I've experienced cooking cylinders during initial flight testing and don't want to risk that again.

The engine is a Continental IO360. Cylinders have 1300hrs on them and look to be in good shape. Compressions were good last time they were checked. I'm thinking hone, new rings, check the valves/guides and replace as necessary. Seems like that would be my least expensive but still reliable option.

Any thoughts? I don't have to tooling to replace valves/guides so I'll have to send the cylinders out for the valve work.

User avatar
glades cat
Site Supporter - III
Site Supporter - III
Posts: 2934
Joined: Mon Jan 22, 2007 2:36 pm
Location: Miami, Fl

Re: What should I have done with my Cylinders

Postby glades cat » Wed Nov 23, 2016 3:35 pm

A hone and new rings warrants proper break-in, just like overhauled cyls, if you're concerned about cooking them.
Airboaters can stop anywhere and let 'em cool off and control the heat cycles. We usually have a frosty beverage while we wait for them to cool down.
Run the used ones or break-in a new set.
"Leave a legacy...Preserve the irreplaceable"
12' x 7' sled built by Scorpion, Cont. O-470-K, 72" Whisper Tip
Rigged by Gladescat & sons in 2009

User avatar
plumcrazy
Site Supporter - V
Site Supporter - V
Posts: 8696
Joined: Thu Apr 06, 2006 10:10 am
Location: avon park

Re: What should I have done with my Cylinders

Postby plumcrazy » Wed Nov 23, 2016 3:44 pm

if im gonna be in the air i kinda wont to know whats in my engine there pretty simple really
8)

jeepinocala1111
Site Supporter - I
Site Supporter - I
Posts: 1127
Joined: Mon Apr 21, 2014 5:57 pm

Re: What should I have done with my Cylinders

Postby jeepinocala1111 » Wed Nov 23, 2016 5:42 pm

What you do is break it in on the ground then on your first flight go as high as it will go and break out a beer so if it cuts out you can either try and restart or simply finish that beer :) No just kidding find a good aircraft mechanic to make sure you do it right. Air boaters are not a great place for aircraft people if you seen the stuff that is done on airboats you'd **** a brick.

whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

Re: What should I have done with my Cylinders

Postby whee » Wed Nov 23, 2016 8:05 pm

glades cat wrote:A hone and new rings warrants proper break-in, just like overhauled cyls, if you're concerned about cooking them.
Airboaters can stop anywhere and let 'em cool off and control the heat cycles. We usually have a frosty beverage while we wait for them to cool down.
Run the used ones or break-in a new set.


Newly built experimental airplanes see some ground running before they are flown so they don't get broken in as good as planes that are already flying but proper break in isn't necessarily what I'm concerned about. Excessively high CHT's and high oil temps are my main concerns. Old rings are long gone so I have to go with new.

plumcrazy wrote:if im gonna be in the air i kinda wont to know whats in my engine there pretty simple really
8)


That's my feeling and much of the reason I'm building my own airplane. Got sick of having to get the blessing of the FAA and mechanics that I didn't necessarily agree with or feel that they were more concerned with my safety than their pocketbook.

jeepinocala1111 wrote:What you do is break it in on the ground then on your first flight go as high as it will go and break out a beer so if it cuts out you can either try and restart or simply finish that beer :) No just kidding find a good aircraft mechanic to make sure you do it right. Air boaters are not a great place for aircraft people if you seen the stuff that is done on airboats you'd **** a brick.


I think you guys are a great place for information. You build your engines, maintain them and run them. You don't want to be stuck out in the swap any more than I want my engine to quite. You guys are willing to talk about engines and share your opinions, most airplane guys don't. I'm certainly not going to be bolting a Holley carb to my intake but I'm not going to follow Continental's "Mandatory Replacement Parts List" either.


User avatar
John Fenner
Southern Airboat Member
Posts: 2515
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: What should I have done with my Cylinders

Postby John Fenner » Thu Nov 24, 2016 9:05 am

If everything is within tolerance from valve guides and seating correctly and the valve faces aren't worn, as well as the ring lands, clean it all up, inspect, fresh hone and rings, let it eat.
I never finish anyth,,,.

User avatar
Whitebear
Site Supporter - VIII
Site Supporter - VIII
Posts: 16479
Joined: Thu Jan 05, 2006 7:49 pm
Location: Palm Bay, Fl
Contact:

Re: What should I have done with my Cylinders

Postby Whitebear » Thu Nov 24, 2016 11:22 am

1,300 hours is not a high time engine. Just inspect and fix anything it needs. I am surprised the rings are shot at 1,300 hours. Im not an aircraft mechanic, by any means, but We managed well over twice that many hours in our old O-470 230 HP 1966 Cessna Skylane and it was still flying with good compression numbers when we sold it. if you are flying with a controllable prop you can just keep the MP backed off some. Unless you are building a speed demon you plan on running at 90% power all the time. Point is if the engine has not been abused, do the inspections and freshen up what needs it and keep on running it.
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.

jeepinocala1111
Site Supporter - I
Site Supporter - I
Posts: 1127
Joined: Mon Apr 21, 2014 5:57 pm

Re: What should I have done with my Cylinders

Postby jeepinocala1111 » Fri Nov 25, 2016 11:32 am

jeepinocala1111 wrote:What you do is break it in on the ground then on your first flight go as high as it will go and break out a beer so if it cuts out you can either try and restart or simply finish that beer :) No just kidding find a good aircraft mechanic to make sure you do it right. Air boaters are not a great place for aircraft people if you seen the stuff that is done on airboats you'd **** a brick.


I think you guys are a great place for information. You build your engines, maintain them and run them. You don't want to be stuck out in the swap any more than I want my engine to quite. You guys are willing to talk about engines and share your opinions, most airplane guys don't. I'm certainly not going to be bolting a Holley carb to my intake but I'm not going to follow Continental's "Mandatory Replacement Parts List" either.[/quote]


Yeah the last ac engine I took apart had two (TWO) of the carter pins on the rod bolts. Take that one up in the air. Do it right or we may get to read about you and hope it's not a nose dive on some kids in a park. Honestly call Jim Lauderdale look him up he is in Belleview , Fl he will give you a good direction.

whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

Re: What should I have done with my Cylinders

Postby whee » Sat Nov 26, 2016 9:37 am

Thanks for the help guys. I have a path forward.

This engine sucked an exhaust valve after having some cylinder work done, buy a certified cylinder shop, and the airplane was totaled on landing. I bought the engine as a core, did a complete teardown, had the case overhauled, all steel parts inspected and except for the cylinders it will be a fresh engine.

Gary S
Site Supporter - I
Site Supporter - I
Posts: 1316
Joined: Wed Mar 03, 2010 3:30 pm
Location: Redlands

Re: What should I have done with my Cylinders

Postby Gary S » Sun Nov 27, 2016 5:58 am

If you had the case overhauled what did you do with the crank?

whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

Re: What should I have done with my Cylinders

Postby whee » Sun Nov 27, 2016 8:38 am

Sent it in for overhaul but it was cracked. Bought a freshly overhauled crank that was ground 0.010 under. I can't believe how expensive M010 bearings are for this engine, $2000[FLUSHED FACE]

whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

Re: What should I have done with my Cylinders

Postby whee » Thu Jan 12, 2017 4:30 pm

Just finished measuring the bores on my cylinders. 4 of them are just outside standard bore specs but still round. I need to decide if I want to send them off and get them coated or buy +5 oversized pistons. You guys have any recommendations? Not really looking forward to buying new pistons and it doesn't look like there are any aftermarket available. Continental want $330 for the standard size so I can't imagine what they are going to want for oversized.

User avatar
John Fenner
Southern Airboat Member
Posts: 2515
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: What should I have done with my Cylinders

Postby John Fenner » Fri Jan 13, 2017 12:22 pm

Old school used to knurl the skirts to snug them up however if the ring lands are worn the process is moot.
I never finish anyth,,,.

whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

Re: What should I have done with my Cylinders

Postby whee » Fri Jan 13, 2017 1:25 pm

Thanks for the reply Mr. Fenner.

I've been able to talk to a few overhaul shops that were willing to share info. Since my cylinders are right at the service limit for standard size I could run +5 rings on my standard pistons. Appetantly that is somewhat regularly done on certified airplanes. Or I can have my bores plated back to new limits, ($175 Chrome, $250 Nickel). I already have new standard size rings so I'll check my ring end gap and if it's within spec I'll run them. If the gap is too big I'll get some +5 rings.

Lwells
Southern Airboat Member
Posts: 234
Joined: Sat Nov 15, 2014 9:18 pm
Location: okeechobee

Re: What should I have done with my Cylinders

Postby Lwells » Fri Jan 13, 2017 3:32 pm

If you have done all this other work on the engine then it wouldn't make since not to have the cylinders done also. Then you have a complete overhauled engine good for many hours or should you decide to sell later it would bring good money. After you install this engine put a bottle of marvel mystery oil in the engine with the oil and put a bottle in the gas. Down the rode a couple hundred hours put it in it again and you will never have valve problems and cylinders will seat right in. I should say no problems with sticking valves. Also, after engine gets broke in put a bottle of Lucas oil conditioner in engine at an oil change . I had a rocker cover come loose and leaked all the oil out. Engine started loosing power and I noticed oil pressure on 0 over the smoky mtns. I backed the throttle off a little and engine picked back up on RPMs. I flew 35 mile with no oil pressure and landed on a coal strip job, engine still running. I had slick 50 in engine but basically same stuff, Lucas oil didn't exist at the time. Made a believer out of me though.

whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

Re: What should I have done with my Cylinders

Postby whee » Fri Jan 20, 2017 1:53 pm

That's a pretty cool story Lwells, I'll have to check out the Lucas additive. I too am a believer in MMO, it is great stuff. I don't want to do a full cylinder rebuild because of the issues I've seen before when flight testing a scratch built airplane while trying to break in an engine. Basically the engine doesn't get broke in properly and the cylinders start losing compression very early in life. Doing it this was I'll have a solid bottom end and once any airframe issues are resolved I can top the engine, but I'll probably keep flying it till it starts showing signs of needing top end work. Also, because I'm building this engine myself any potential buyer is going to consider it a core anyways...but that doesn't matter. This is my forever plane.

Thanks again guys!

Moritz
Southern Airboat Member
Posts: 512
Joined: Tue Mar 07, 2006 9:57 pm
Location: Texas

Re: What should I have done with my Cylinders

Postby Moritz » Tue Feb 07, 2017 4:06 am

If you go to plating the cylinders it take different material for the rings. What is on the cylinders wall dictates what kind
Of rings you run.

whee
Southern Airboat Member
Posts: 11
Joined: Fri May 27, 2016 2:38 pm

Re: What should I have done with my Cylinders

Postby whee » Tue Feb 07, 2017 5:19 pm

Thanks Moritz, I knew that but it's great to have people double checking.

We pulled all the valves and measured them. Everything was within new specs so we lapped and reinstalled. We found that our pistons weren't in as good of shaped as we would have liked so we are sourcing some new forged pistons that use modern domestic rings.


Return to “Aircraft Power Only”

Who is online

Users browsing this forum: No registered users and 9 guests