High CHT, 470 degrees +.

[orionflt]

23 hours ago, ragedracer1977 said:

Can you upload your data to savvy?

here is my flight, I was incorrect, I hit 350 on #3 during climb out, but 20 degrees isn't a big deal in that range.

[orionflt]

@ragedracer1977,

I flew again today but when I took off I kept my cowl flaps closed. the OAT was 70 degrees and my max CHT was 360, FF during takeoff was 18.2

Where is your FF at? (I may have missed it if you previously said.)

Brian 

[ragedracer1977]

1 hour ago, orionflt said:

@ragedracer1977,

I flew again today but when I took off I kept my cowl flaps closed. the OAT was 70 degrees and my max CHT was 360, FF during takeoff was 18.2

Where is your FF at? (I may have missed it if you previously said.)

Brian 

Highest 15. something for a few seconds then under 15.

Can you share the link to it so I can look at all the parameters? @orionflt

[orionflt]

1 minute ago, ragedracer1977 said:

Highest 15. something for a few seconds then under 15.

Can you share the link to it so I can look at all the parameters? @orionflt

link sent, having trouble seeing all my recent flights but the last 2 are there

[ragedracer1977]

10 minutes ago, orionflt said:

link sent, having trouble seeing all my recent flights but the last 2 are there

I see alot, like 500 lol.

Just a quick peek, on every flight I looked at, your FF peaked near 18gph right at the start.  I think that's the breaking point for me.  I'm not getting that initial cooling, the temps start getting out of control, and then FF starts dropping with altitude, never getting a chance for the cylinders to cool.  So they're starting really hot

[orionflt]

I was just looking at the FF charts and you are at least 1.5 lean. my 18 is a little on the high side but as you can see with my temps during takeoff it is keeping everything cool.

Brian

[Skates97]

3 hours ago, ragedracer1977 said:

Highest 15. something for a few seconds then under 15.

Can you share the link to it so I can look at all the parameters? @orionflt

If you are only seeing 15 I don't know if it will solve everything but my experience makes me believe that if you either had the carb overhauled and that bulletin performed, or swapped it out with the 10-4161 it would help your cooling tremendously. 

2 hours ago, orionflt said:

I was just looking at the FF charts and you are at least 1.5 lean. my 18 is a little on the high side but as you can see with my temps during takeoff it is keeping everything cool.

Brian

Any idea from your log books if there was done to achieve the 18? That flow I think is what has your CHT's so low. If I could get another 1-2gph I believe mine would stay under 400.

[orionflt]

9 hours ago, Skates97 said:

Any idea from your log books if there was done to achieve the 18? That flow I think is what has your CHT's so low. If I could get another 1-2gph I believe mine would stay under 400.

My temps were in the 400-450 range when I first bought my plane, the only thing I really did to make a difference was to rebuild the doghouse and tighten up my baffles. there are some major holes in the back of the engine that you really don't notice unless you go looking. I blocked off and filled gaps that went from barely noticeable to close to 1/2 inch. my first pass thru the engine dropped the temps around 50 degrees, but I had missed a major gap behind the oil pressure regulator. I also added sealant to areas that were tight, just not sealed. the last thing I did was to use metal tape on the seams of the doghouse. the tape doesn't make much of a difference because i rebuilt the doghouse, but I have seen it help other planes whose doghouse needed some TLC. I am not sure what Carb I have installed and my logbooks are currently in PA but I will try to get the info posted as soon as I can. the one thing i do know is it was last overhauled in 2002 and been rock solid.

Brian

[DXB]

On 4/6/2020 at 11:08 PM, carusoam said:

 

Which reminds me to invite @DXB Dev... as he has chased a few O360 challenges over his ownership... Dev may be Corona-busy...

PP thoughts only, not a mechanic...

Best regards,

-a-

 

 

 

Wow just seeing this prodigious thread Anthony - the CHT issues have already been covered in some depth here.    Not too coronavirus'd at the moment but doubt I have any insight here that hasn't been covered in some depth.  Coincidentally I just started my own exhaust leak-CHT thread.   

[Shadrach]

On 4/12/2020 at 7:48 PM, orionflt said:

@ragedracer1977,

I flew again today but when I took off I kept my cowl flaps closed. the OAT was 70 degrees and my max CHT was 360, FF during takeoff was 18.2

Where is your FF at? (I may have missed it if you previously said.)

Brian 

You have one of the coolest running C models I’ve ever seen. You also have more FF at WOT than most C models. Your example proves that these engines can be set up properly and run moderate temps.

[Prior owner]

My FF at takeoff is 16.4 - 16.5. 

[Prior owner]

I’m glad no one has suggested pumping the throttle furiously to increase FF on takeoff... surely someone has done it though. Lol

[orionflt]

Just now, Shadrach said:

You have one of the coolest running C models I’ve ever seen. You also have more FF at WOT than most C models. Your example proves that these engines can be set up properly and run moderate temps.

 

13 minutes ago, PilotCoyote said:

My FF at takeoff is 16.4 - 16.5. 

that is the correct FF according to the Lycoming O-360 operators manual, But 18 seems to be the best to keep the engine running cool. 

Brian

[MIm20c]

Ok, so who has the proper 18 gph drill bit for the main jet?  Also please post a picture of the carb so I know what to drill on. 

[ragedracer1977]

I spoke to a guy at Marvel over the weekend.  I have a new Carb coming today.  We'll see what happens.  Im going to try to get it installed this afternoon and I'll be sure to post numbers after!

[ShuRugal]

You have one of the coolest running C models I’ve ever seen. You also have more FF at WOT than most C models. Your example proves that these engines can be set up properly and run moderate temps.

Mine doesn't run quite as chilly as Brian's, but I don't think I have seen the analog gauge get over 400 once since I got the plane in 2017. (Granted, that is the analog gauge, so I have no idea what it's doing when I'm not looking at it. For all I know, it's spinning around and giving me extra thrust)

 

Just looked at my equipment list, and I have the 4164 carburetor. Dog house was also pretty well sealed by the previous owner.

 

 

 

 

[Lionudakis]

I might have missed it if already mentioned, There is a mod to the carb that adds an "M' to the part number, and brings fuel flow up to around 18-18.5. 

From TCDS.. Carburetor MA4-5, Flow Setting P/N 10-3878, 10-3878-M, or 10-4164-1).

[Shadrach]

1 hour ago, orionflt said:

 

that is the correct FF according to the Lycoming O-360 operators manual, But 18 seems to be the best to keep the engine running cool. 

Brian

The question is why are you getting IO360 fuel flows out of an O360. You can say what you want about cleaning and sealing up your doghouse, but if you were running 16.4 GPH at WOT, you’d not be enjoying those super cool CHT’s.

Edited April 14, 2020 by Shadrach

[Shadrach]

57 minutes ago, MIm20c said:

Ok, so who has the proper 18 gph drill bit for the main jet?  Also please post a picture of the carb so I know what to drill on. 

I suspect that some of these carbs have had field modifications that are unlogged.

[Shadrach]

9 minutes ago, Lionudakis said:

I might have missed it if already mentioned, There is a mod to the carb that adds an "M' to the part number, and brings fuel flow up to around 18-18.5. 

From TCDS.. Carburetor MA4-5, Flow Setting P/N 10-3878, 10-3878-M, or 10-4164-1).

From what I’ve seen, that mod brings it to 16.5 not 18.5. Where did you get the 18.5 number?

[Prior owner]

2 minutes ago, Shadrach said:

From what I’ve seen, that mod brings it to 16.5 not 18.5. Where did you get the 18.5 number?

 I Believe that is correct. My carb is a 4164 stamped “M” with 16.4-16.5 gph

[Lionudakis]

5 minutes ago, Shadrach said:

From what I’ve seen, that mod brings it to 16.5 not 18.5. Where did you get the 18.5 number?

Mine was modded to the "M" around 8 years ago,  before I had a fuel flow so I don't have a side by side. Mine flows 18 normally. I do not remember where I'd read or heard the numbers back then.

[ragedracer1977]

New Carb installed, unfortunately that's as far as we got.  

Did a short ground run to get the idle and idle mixture set, but it was too late to put the cowl back on and go fly.

So, you'll have to wait until tomorrow to see how it turns out. 

[ragedracer1977]

Just one quick note.  When you're doing the first start up after replacing the carb, you should be getting fuel pressure.

If you're not, cranking the prop for 30 seconds is useless... Especially if you forgot to turn the fuel selector back to a tank after you turned it to off so you didn't drip fuel all over when you unhooked the lines... 

Don't ask how I know....

[Matt_AZ]

12 hours ago, ragedracer1977 said:

Just one quick note.  When you're doing the first start up after replacing the carb, you should be getting fuel pressure.

If you're not, cranking the prop for 30 seconds is useless... Especially if you forgot to turn the fuel selector back to a tank after you turned it to off so you didn't drip fuel all over when you unhooked the lines... 

Don't ask how I know....

I had that same fuel pressure problem with my new carb.