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Changing sumps = Lycoming to Superior

chris mitchell

Well Known Member
I have a Lycoming IO-320 with the original Lycoming sump installed. I want to change it to the Superior cold air sump. AS far as I can see from internet searches, it should be a simple matter of unbolting the told one and installing the new one (new gasket and fastenings), and I will probably have to change the induction pipes and may have to trim and calibrate the oil dipstick. Is that it?

I'd be grateful for any info from anyone who has done this job.

Many thanks

Chris
 
I made this change on an IO-360. The sump came with new induction pipes. We had to make a few different brackets to get the mixture and throttle cables aligned the way we wanted them but other than that is was pretty easy.

I did not think about the oil dipstick. Have you read something that says it needs to be recalibrated? It still fits fine i.e does not bottom out.
 
As long as your 320 sump has the oil suction screen in the rear of the sump it should be an easy bolt up situation. remove existing sump and pipes ,install the new sump and pipes and calibrate the dipstick. But if you have an IO-320 that was "made" from a 320 that has the oil suction screen on the bottom of the sump, in front of the fuel in injector, then it will require modification of the accessory housing, in addition to the above conversion steps. Of course that is from an engine standpoint only, airframe parts such as brackets, exhaust pipes, air filter ducting, etc. may need modification as well.
Good Luck,
Mahlon
 
Simple job!

Thanks for the information.

The oil pipe was at the back of the sump, so it was indeed a simple unbolt and reboot task. The only minor point was that the original, Lycoming, sump has 4 studs on it, so I needed 4 additional nuts and bolts.

About to fit the induction pipes and then the job is done.

Chris
 
What are you changing for - are you looking for more power, or more even air distribution? Please report back the results.
 
I'm hoping for more power (cold air = denser charge) and less weight. Plus I think the front induction looks better than vertical induction and there is the option of some ram air effect = a little bit more power.

The weight saving over the Lycoming sump is about 5 pounds IIRC. The Sky Dynamics one is even lighter but costs about 3 times as much.

I'm trying to minimise the all up weight of the aircraft. A few ounces here, a few ounces there, it all adds up pretty quickly to something worthwhile.

Change sump.
MT prop rather than Hartzell
Little battery
Minimal instruments and electronics

And not ignoring:
Diet and more exercise for the pilot.
 
What are you changing for - are you looking for more power, or more even air distribution? Please report back the results.

Clint at Vetterman Exhausts dyno'd the two setups and said (paraphrased) the gain comes from the higher MAP relating to intake pressure and volume of the Superior sump. His opinion was that the temperature of the air was not significant enough to provide benefit. He said they proved >5 HP on the same engine with just the sump change.
 
Sump change - The practical details!

This job was easy though I approached it with a bit of trepidation - not a bad frame of mind to be in I suppose! Anyway, here, for those of you who are contemplating the same "upgrade", are the practical details.

Tools:
Wire cutter and needle nosed pliers - for removing safety wire;
1" open-ended wrench for oil fitting;
1/16" Allen key for grub screw on oil fitting;
1/2, 7/16 and 3/8 ring/open-ended spanners and sockets;
ratchet etc;
torque wrench;
thread locking stuff;
torque seal.

Parts:
New sump and gasket;
Selection of 1/4" and 5/16 UNC nuts, bolts plain and lock washers;
AN900-16, MS35769-21 copper gasket for oil pipe.

Suggested order of proceedings:

Tape up all orifices so you can't drop nuts, washers etc down them! I once saw the end of a screw driver embedded in the crown of a piston - after the customer had flown into our strip so hot aircraft could have a major overhaul.....

Remove your carburettor or fuel injection servo. The latter will be held in place with 4 x 5/16" nuts. I know nothing about carburettors!

The oil feed is on the rear of the Lycoming sump. Cut the lock wire and remove the grub screw from the oil feed pipe. Remove the oil feed fitting and little copper screen from the rear of the sump.

Undo all the nuts and bolts holding the sump in place. My sump had 4 x nuts on studs, 8 bolts into blind holes, and 8 nuts/bolts making 20 fastenings in all. The sump should come off easily. If it does't you probably missed one - look carefully before starting to pry at it!

My sump did not need studs (the Lycoming sump had 4, adjacent to the induction outlets). I would have replaced the 8 bolts in blind holes with studs but that wasn't the way it was put together - so I took that as my guide. I guess YMMV!

Clean up and inspect as required.

Bolt the new sump in place, with the new gasket. I did not tighten any bolts/nuts until I had them all in -there was a little bit of movement between sump and crank case. Once everything is in place gradually tighten the nuts, working front to back and side to side - don't just fully tighten and work round the case. Torque for 1/4" UNC bolts I have as 40-50 inch-pounds.

Refit the oil feed with a new copper gasket. I found it much easier to do this after I had taken the induction plenum off as the right rear induction pipe is a bit in the way. The little grub screw holds the feed pipe at an appropriate angle.

Refit the induction plenum - these bolts are 5/16 UNC, torque I have at 80-90 inch-pounds.

Refit the fuel injection servo. Here there are 5/16 UNC studs. Both Superior sumps I have fitted have had overly long studs fitted, that I have had to remove and shorten. I had to take the plenum to an engineering shop to get them removed, as none of my usual tricks worked (two nuts tightened together, a Snap-On stud remover, application of blow-lamp...). Also the servo was quite a loose fit on the studs so I made some little sleeves to provide better location.

Fit the new induction pipes - bolt to inlet at the cylinder end and clips/pipes at the plenum end.

In the UK, ask inspector nicely to come and check all, complete paperwork etc.

All done.

I hope that is helpful.

Chris
 
Last edited:
Just a quick note.
Just pulled the crazy long servo studs out of two new Superior sumps. They will not come out unless you heat them up nice and hot. I used MAP gas torch and with dual nuts they will pop lose with enough heat. No discoloration was caused.
 
Clint at Vetterman Exhausts dyno'd the two setups and said (paraphrased) the gain comes from the higher MAP relating to intake pressure and volume of the Superior sump. His opinion was that the temperature of the air was not significant enough to provide benefit. He said they proved >5 HP on the same engine with just the sump change.

Back in the day, we got a pretty consistent 7 hp increase over a stock vertical sump when using the superior, aero or Lycoming forward facing sump. when we first tried those sumps, we tested the same engines, with either sump on the same day, in the exact same conditions in the test cell, ie with same ambient's and same oil temps and chts and got 7 to 7.5 hp on all of the tests. Purpose of the test was to confirm a HP increase that we were comfortable to pass along to perspective customers. We always advertised a 7hp increase with the cold air sumps.
Good Luck,
Mahlon
 
Back in the day, we got a pretty consistent 7 hp increase over a stock vertical sump when using the superior, aero or Lycoming forward facing sump. when we first tried those sumps, we tested the same engines, with either sump on the same day, in the exact same conditions in the test cell, ie with same ambient's and same oil temps and chts and got 7 to 7.5 hp on all of the tests. Purpose of the test was to confirm a HP increase that we were comfortable to pass along to perspective customers. We always advertised a 7hp increase with the cold air sumps.
Good Luck,
Mahlon

How would you account for ram effect in a dyno without a prop or forward motion? Or, in the alternative, is it negligible in the real world?
 
Just a quick note.
Just pulled the crazy long servo studs out of two new Superior sumps. They will not come out unless you heat them up nice and hot. I used MAP gas torch and with dual nuts they will pop lose with enough heat. No discoloration was caused.

Are you talking about the 4 forward studs that hold the servo on?

Called Superior about them since they were too long. Was told there is a spacer that is supposed to be installed that does not come with the sump. The spacer was cheap, and the studs were perfect length when the proper spacer is on. Don't know why the sump does not come with that.
 
How would you account for ram effect in a dyno without a prop or forward motion? Or, in the alternative, is it negligible in the real world?

There was no ram effect. The increase in power was from better intake design with cooler air than the vertical sump offered. the 7 hp increase was static power increase.
I would think that the ram air effect would be almost the same with the forward facing sump as the vertical sump with an air box as long as the airspeeds were similar. Maybe not? But I would think that with the airspeed constant the air pressure build up in the vertical sump airbox would be the same as the airbox arrangement with the horizontal sump. Knowing that the horizontal sump does produce more power that it would follow that the airspeed would be higher for a given power setting and then the airbox ram pressure would be greater due to the increased airspeed and thus you would see more power over what the horizontal sump offered without ram effect. don't know.... but that is what I would assume.
Good Luck,
Mahlon
 
Back in the day, we got a pretty consistent 7 hp increase over a stock vertical sump when using the superior, aero or Lycoming forward facing sump. when we first tried those sumps, we tested the same engines, with either sump on the same day, in the exact same conditions in the test cell, ie with same ambient's and same oil temps and chts and got 7 to 7.5 hp on all of the tests. Purpose of the test was to confirm a HP increase that we were comfortable to pass along to perspective customers. We always advertised a 7hp increase with the cold air sumps.
Good Luck,
Mahlon

Mahlon,
Just to confirm, was this 7hp difference on a 320, 360, or 540? I'm assuming a 320 as the OP refers to that but just wanted to check. Presumably the figure would vary somewhat with displacement and therefore air volume consumed.
Thanks.
 
Are you talking about the 4 forward studs that hold the servo on?

Called Superior about them since they were too long. Was told there is a spacer that is supposed to be installed that does not come with the sump. The spacer was cheap, and the studs were perfect length when the proper spacer is on. Don't know why the sump does not come with that.

Well now thats interesting. Did you get that spacer from Superior direct or is it just a generic from....?
 
Mahlon,
Just to confirm, was this 7hp difference on a 320, 360, or 540? I'm assuming a 320 as the OP refers to that but just wanted to check. Presumably the figure would vary somewhat with displacement and therefore air volume consumed.
Thanks.

It was 7 hp on 320's and 360's. The 540 didn't use that style sump....there are cold air sumps available for the 540 but whenever we used them they were also other mods to the engines so I don't have a increase number for the sump alone.
Good Luck,
Mahlon
 
Well now thats interesting. Did you get that spacer from Superior direct or is it just a generic from....?

Got the spacer from Superior. Less than $10 bucks if I remember right. Twice that with shipping. No idea why hey don't include it with the $1500+ sump!!!
 
New news

A little bird told me that Lycoming is introducing a cold air sump soon. Should be one on my new motor.
 
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