A-65 Engine noise

[Guest]

Re: A-65 Engine noise

drude: Do have Bendix, but went for the new snap ring impulse. On a previous reply I was asked why I think it's from the cam. The lobe spacing on an opposed four banger is such that at one position the lobe if forced to a rappid over the center by another lobe. I think it's #4 exhaust. This can be heard when turning the engine over by hand. At the same time, there is a slight clunk at the crank and cam gear where the lash in the teeth can be heard from the lobe being forced over. On that note, I have new gears and the lash is at the minimum clearance of .009.
It's beginning to look like it may very well be all normal after all from reading some of the other posts. It is a new tollerance engine, with nothing left to throw at it for parts so I guess I just have to live with it.

Has anyone put a C-85/0200 spider on a 65 and found any extra takeoff rpms or is it one of those urban legand things?
Ron

Hi Ron, I noticed that with the valve train too.

Always remember it as a click not thump, could be a memory problem.

These are probably dumb questions, cam bearing to cam have good clearances? wonder if you get the same noise if while turning prop you pull it forward (or push it backward) so the crank is in a constant thrust position? maybe the overcenter impulse of torque is bumping crank against thrust surface?

I don't find mine noisy. But wife also says I can't hear. Maybe I am getting a double benefit!

Dave.

[Ron Babos]

Re: A-65 Engine noise

Dave: Just moving the prop, it is more of a click clack sound like you say. It may turn into the clunk sound as the engine is running. The sound, when moving the prop sounds like it's in the head area but using a listening rod it is loudest at the case area. It just seems to echo in the tappet cover of that particular cylinder. The source may be one and the same. The crank end play is fine. I'ts a different sound that I usually hear when pulling the plane out. The cam bearings are near minimum. If the engine is running it is not louder on one side than the other, and is most noticable when standing in front, and of course when sitting inside. From there it tends to come from the left side slightly, but then again my right ear sucks.
Ron

[Ragwing nut]

Re: A-65 Engine noise

If you have impulse mags installed they will make the clacking sound you are hearing. Others may be quieter due to orginal cheesebox non impulse mags. As far as being louder on start up and quieter after unning a bit, I don't recall you saying anything about the hydraulic units. Sounds like they may be bleeding down and you have excessive tappet lash until they pump up and tighten the valve train up.

Legally you can't install the 85 spider, but it will not make much difference with the 1 1/4 venturi still installed restricting airflow. The only difference between a C75-12 and C85-12 is the 65 spider and carb installed fyi.

Mike

[Guest]

Re: A-65 Engine noise

If you have impulse mags installed they will make the clacking sound you are hearing. Others may be quieter due to orginal cheesebox non impulse mags. As far as being louder on start up and quieter after unning a bit, I don't recall you saying anything about the hydraulic units. Sounds like they may be bleeding down and you have excessive tappet lash until they pump up and tighten the valve train up.

Legally you can't install the 85 spider, but it will not make much difference with the 1 1/4 venturi still installed restricting airflow. The only difference between a C75-12 and C85-12 is the 65 spider and carb installed fyi.

Mike

Hi Mike & Ron,

I forgot about it till Mike said it; I don't have impulse mags on the A65.

I have Bendix SF4 with gears, no impulse. Maybe that's why mine appears "quite" to me.

Dave.

[Ron Babos]

Re: A-65 Engine noise

Dave: Yup, have a set of those in the basement with shielded harness. They came with the original engine. As far as mags go, once the engine is over 300rpm the iimpulse is not in play on my engine.
Ron

[alwaysoar]

Re: A-65 Engine noise

I have flown a lot of Continentals, even recently on six different airplanes this summer. They all have that "rap" or clunk. It's louder in TCrafts than some others (e.g. Cessna 150's) because TCrafts are noisier to begin with. It's louder on the ground at low RPM because there is less other engine noise. I attributed it to my Slicks, but it may be something else all together. My engine has only about 100SMOH, so I don't worry about it. If something comes flying off, I'll let everyone know.

Ed@BTV VT
TF 527

[Ron Babos]

Re: A-65 Engine noise

alwaysoar: That's about how I'm starting to feel about it. Can't seem to get rid of it so if it breaks, at least I know what it was. Read an interesting thing that in the early days at Lycon, they tore an engine down twice because of the same kind of sounds. They found nothing wrong with it and blamed it on piston slap. 65 pistons don't have a lot of skirt area in relation to length. That could at least account for the higher rpm rattle sound, but not the lower rpm clunk that they all seem to be born with.Sure would be nice to know the root cause of the sound and why some are noisier than others.
Ron

[high time cub]

Re: A-65 Engine noise

Hi Ron,
Here's the fix.... it will probably cost you a 100+ bucks (Canadian) or a tank of gas, may be both.

1-Find someone with a Kinner-powered Canadian Fleet Finch.
2-Go for a ride and wait 20 minutes (in the summer time) for the 2 gallons of 50 wt. oil to warm up.
3- Listen carefully as that long-stroke, solid lifter relic from the 1930's "smoothes out" and settles in @ 1650 rpm.
4- (this step is really important) After landing, immediately climb in and fly your Champ (we know, Ron, it's ok) and your C-65 will be fixed!

For those small pesky C-65 oil leaks, follow steps 1-3, then after landing, spend the next hour helping clean the oil and grease off the old double- holer!

Jim (sometimes-tolerated Cub interloper on this site)

[Ron Babos]

Re: A-65 Engine noise

Jim: Actually, there is a Finch about 30 miles away. That Kinner sure is a weird sounding thing. I got your point though. Don't have any oil leaks, as it's built by me. Being experimental I went to all modern sealing methods including using round cylinder base rings instead of those mickey cont square section rings. Now that you mentioned that OTHER plane that I fly, I'm probably done like toast . But then again, we share the same engine. I like Taylorcrafts too, really
Ron

[alwaysoar]

Re: A-65 Engine noise

Hi Jim, Know exactly what you mean. When are you coming back?

Ed

[high time cub]

Re: A-65 Engine noise

Ed,
I was there for the wild wind and snow! Flew High Time twenty minutes due west and never left the airport! Did you get much snow on your side of the lake?

[alwaysoar]

Re: A-65 Engine noise

Snow? Oh, yeah. The white stuff. No, we don't get any snow around here.

When are you coming back?

Ed

[high time cub]

Re: A-65 Engine noise

Ed,
Soon, I'll Call.