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inadequate fuel flow on TO

I have a regular 360 lycoming engine with fixed pitch prop
barely broken in, 50s hrs after 12 years of work
on climb my CHT are very high (improved after 30 hrs but still high) and I cannot get enough fuel flow
I was told that the fuel flow can be improved by drilling or changing the needle that controls the flow.
any help and what needs to be done to improve flow by fiddling with the carb?
I have a precision carb LO-5193
any help appreciated
 
I have a regular 360 lycoming engine with fixed pitch prop
I have a precision carb LO-5193
any help appreciated

Andres,
I am not saying you have the wrong carb, but you do not have the normal carb we see for the 0-360 engine.
One normal is the MA4-5 10-3868...this one can be lean on some installs.
The richer version is the MA4-5 10-4164
There is lots of info in the archives about this topic and drilling jets.
 
Andres,
I am not saying you have the wrong carb, but you do not have the normal carb we see for the 0-360 engine.
One normal is the MA4-5 10-3868...this one can be lean on some installs.
The richer version is the MA4-5 10-4164
There is lots of info in the archives about this topic and drilling jets.

I think what he may have is a Precision (Marvel-Schebler) MA4-5 10-5193 carb.
Not sure what that dash-number means.........

For the OP: Do a search here on VAF and look for drilling jet, or similar. Lots of info here on this forum.

Also, I see you are in the Dallas-Ft. Worth area. Find a local EAA chapter, there are several in the area. They can likely help you, as well.
 
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Sounds just like mine last Jan/Feb/Mar until I installed the gear fairings.

If you don't yet have your fairings installed, which apparently is the Vans recommendation during break-in, I think your numbers and temps are likely normal.

EDIT: I am running one P-Mag and decided to retard its timing a few degrees, which helped with CHTs until I installed the gear fairings.
 
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I have a regular 360 lycoming engine with fixed pitch prop
barely broken in, 50s hrs after 12 years of work
on climb my CHT are very high (improved after 30 hrs but still high) and I cannot get enough fuel flow
I was told that the fuel flow can be improved by drilling or changing the needle that controls the flow.
any help and what needs to be done to improve flow by fiddling with the carb?
I have a precision carb LO-5193
any help appreciated

Increasing fuel flow can be a fix for reducing CHTs on take-off. But if your FF is in fact already reasonable then putting a richer jet in the fuel control will only make the engine loose power (and thus produce less heat), and being over-rich can actually cause premature wear on the cylinders.

High CHTs on take-off in most cases is simply a matter of insufficient cooling and that is where I would look first. Check your baffle seals with the top cowling on by using a borescope to detect poor sealing. Oversized air dams in front of cylinders 1 and 2 can also obstruct airflow in a major way.
 
That's good advice re the cooling baffles etc. especially the over-rich mixture for excessive cylinder wear.
As we all know a 360 produces around 160HP at T/off with a FP prop so the FF sounds about right. Still it's great to see so much help being handed out here, Vans sure did make a LOT of happy pilots:)
 
That's good advice re the cooling baffles etc. especially the over-rich mixture for excessive cylinder wear.
As we all know a 360 produces around 160HP at T/off with a FP prop so the FF sounds about right.

160 is maybe a little low for 2600 RPM. Obtain an accurate HP for the average installation from a Lycoming power chart, then do some simple math.

Call it 170 HP at 2600, and use 0.55 BSFC, roughly 125F ROP:

(170 HP x 0.55 BSFC) / 6 lbsgal = 15.6 GPH initial flow.
 
160 is maybe a little low for 2600 RPM. Obtain an accurate HP for the average installation from a Lycoming power chart, then do some simple math.

Call it 170 HP at 2600, and use 0.55 BSFC, roughly 125F ROP:

(170 HP x 0.55 BSFC) / 6 lbsgal = 15.6 GPH initial flow.

I just checked the data from my previous post (#4) -


15.5 gpm at 2400 rpm and 5,500 ft DA runway.

Sensenich FP prop O-360-A1A with carb.


Dynon was reporting about 80% power at 100 kts IAS - This is around 144 HP

I think your 2600 rpm for a Fixed Pitch climb may be too high. Later in the flight a lean to peak check probably put the take off at around 150 F ROP , giving a BSFC of around 0.65.

I think your 170 HP assumption may be off.

A big thank you to savvyanalysis.com and Dynon for all of the data collection and display. :)
 
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I've not seen 2600 in the climb with a FP prop unless of course it's bent fir climb perf only. Older engines down on comp often see 2300 at best. It's all a trade off with FP.
 
thanks to all responders
i have not installed the wheel pants or fairings which is next in line
my prop is a fp sensenich and i see 2600 on climb i figure i have a climb prop but temps limits my time going up
my buddy in his rv7 can outclimb me but then once level i have to pull back 2-3 inches so he can keep up with me, he has a CS prop
 
thanks to all responders
i have not installed the wheel pants or fairings which is next in line
my prop is fp.
my buddy in his rv7 can outclimb me but then once level i have to pull back 2-3 inches so he can keep up with me, he has a CS prop

Very impressive without fairings..........
 
thanks to all responders
i have not installed the wheel pants or fairings which is next in line
my prop is a fp sensenich and i see 2600 on climb i figure i have a climb prop but temps limits my time going up
my buddy in his rv7 can outclimb me but then once level i have to pull back 2-3 inches so he can keep up with me, he has a CS prop

If you?re seeing 2600 in climb, what RPM are you seeing level? Isn?t the Sensenich limited to 2600 max?
 
What are the egt when you are seeing high cht? That is important to determine if it's decent fuel mixture or if you are lean. 1100 or 1200 egt is normally recommended in full throttle take off. The most you would want to see is 125-150 rich of peak which is around max power mixture. Any leaner than that and you are losing performance and will have higher cht.

If egt are in the correct range then as suggested I would look into correcting the baffling. I had a heck of a time with baffling on my t18 but after a few flights and changes I dropped 75* off my cht.

Maybe I missed it but what cht are you seeing? Seems like everyone has their own version of "too high". Our local ap said "keep it under lycoming max and it's fine " but others seem to freak out when I say mine rise to 400 in long climb and sit at 360 for cruise. Both well within normal operating range per lycoming and far below the 525 max for an o290.
 
Before you rip into your carb, have you checked your timing?

If you have even a degree or two too much advance, you can see high CHT's.
 
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