Jab 2200 Oil Cooler in Savannah

[jaybee258]

We have a Jab 2200 powered Savannah VG and it has always had a tendency to overheat. The CHT was the main problem until I modified the cowl to make a better fit with the engine. The oil overheating is more difficult, and occurs on any long climb of say +3000' in the summer. The oil cooler is mounted just behind the exhaust silencer box. I attached 2 temperature sensors to the cooler inlet and outlet, and there was only a few degrees temp difference. The cooler seems to be doing almost nothing. We have a TOCA fitted. Also, something which seems unusual is an Airplast prop which is set very coarse for economy. It cruses at between 2000 and 2400rpm. Max rpm is about 2600. We are getting plenty air into the heads now. Just need more airflow over the oil cooler. I understand the 3300 in the Savannah has the cooler mounted in front of the sump. Anybody out there with a 2200 and oil cooler?

 

With the TOCA and good airflow over the oil cooler, I feel that we could be in the enviable position of having a Jab 2200 which does not suffer overheating

 

We are a UK microlight on 450kg.

 

Thanks guys

 

 

[Old Koreelah]

Interesting problem you have there, JB. This forum has several threads about cooling J2200 engines, and the oil cooler in particular. Many aircraft I've looked at were designed around a Rotax and rely heavily on liquid cooling taking away much of the engine heat. They often have pretty ineffective oil cooler installations. Some have no ducting to speak of, with the oil cooler just hanging wherever they could fit it. Sounds like yours isn't getting enough cool air and maybe it needs some work on the ducting downstream to ensure enough air gets sucked thru it.

 

Can you post a couple of piccies? There are heaps of us on here who have some experience of getting the oil cooler sorted. (My own J2.2 is now running max 150 CHT on climb, 130 max on cruise and the oil stays on 85-90C.)

 

 

[Ultralights]

if there is very little temp difference across the cooler, it sounds like there is little to no airflow to cool it, a rotax installation, which i have, has the oil cooler mounted behind the water cooler, or just in front of the lower cowling exit, the lip of the exit creates a low pressure area, and with aiflow coming in through the inlets and radiator, being higher pressure, then the low pressure are draws air through the oil cooler, mounted here its very efficient, in Australian summer, on days approaching or 40 deg C, the temps might rise above normal on a long climb. almost all year round i need to cover a percentage of the cooler to keep it warm. could you mount it on the lower cowling inner side just in front of the cowl exit area?

 

 

[Yenn]

My 2200 Jab with a Jab cowling, much modified to fit the Corby has the oil cooler mounted at the front of the sump with a vertical inlet for cooling air just below the crankshaft level. Works perfectly. i would suspect you are trying to cool the oil with exhaust heated air.

 

 

[jaybee258]

Thank you guys for your ideas. I will take some piccies and post them here which I think will be most useful.

 

Also, I plan to do some more accurate oil and air temperatures across the oil cooler. This could take some time as weather in the UK Pennines has been poor for some time now, but will be a great excuse to fit in a few short flights with added interest

 

Some interesting thoughts there about airflow. There are just the two inlets on the cowl for the two engine air ducts. The airflow over the cooler will be controlled by the exit air

 

 

[jaybee258]

Interesting problem you have there, JB. This forum has several threads about cooling J2200 engines, and the oil cooler in particular. Many aircraft I've looked at were designed around a Rotax and rely heavily on liquid cooling taking away much of the engine heat. They often have pretty ineffective oil cooler installations. Some have no ducting to speak of, with the oil cooler just hanging wherever they could fit it. Sounds like yours isn't getting enough cool air and maybe it needs some work on the ducting downstream to ensure enough air gets sucked thru it.Can you post a couple of piccies? There are heaps of us on here who have some experience of getting the oil cooler sorted. (My own J2.2 is now running max 150 CHT on climb, 130 max on cruise and the oil stays on 85-90C.)

Interesting problem you have there, JB. This forum has several threads about cooling J2200 engines, and the oil cooler in particular. Many aircraft I've looked at were designed around a Rotax and rely heavily on liquid cooling taking away much of the engine heat. They often have pretty ineffective oil cooler installations. Some have no ducting to speak of, with the oil cooler just hanging wherever they could fit it. Sounds like yours isn't getting enough cool air and maybe it needs some work on the ducting downstream to ensure enough air gets sucked thru it.Can you post a couple of piccies? There are heaps of us on here who have some experience of getting the oil cooler sorted. (My own J2.2 is now running max 150 CHT on climb, 130 max on cruise and the oil stays on 85-90C.)

Interesting problem you have there, JB. This forum has several threads about cooling J2200 engines, and the oil cooler in particular. Many aircraft I've looked at were designed around a Rotax and rely heavily on liquid cooling taking away much of the engine heat. They often have pretty ineffective oil cooler installations. Some have no ducting to speak of, with the oil cooler just hanging wherever they could fit it. Sounds like yours isn't getting enough cool air and maybe it needs some work on the ducting downstream to ensure enough air gets sucked thru it.Can you post a couple of piccies? There are heaps of us on here who have some experience of getting the oil cooler sorted. (My own J2.2 is now running max 150 CHT on climb, 130 max on cruise and the oil stays on 85-90C.)

Interesting problem you have there, JB. This forum has several threads about cooling J2200 engines, and the oil cooler in particular. Many aircraft I've looked at were designed around a Rotax and rely heavily on liquid cooling taking away much of the engine heat. They often have pretty ineffective oil cooler installations. Some have no ducting to speak of, with the oil cooler just hanging wherever they could fit it. Sounds like yours isn't getting enough cool air and maybe it needs some work on the ducting downstream to ensure enough air gets sucked thru it.Can you post a couple of piccies? There are heaps of us on here who have some experience of getting the oil cooler sorted. (My own J2.2 is now running max 150 CHT on climb, 130 max on cruise and the oil stays on 85-90C.)

Hi Old Koreelah. I have posted some pics in media under 3 axis. Named Jab Savannah. Hope you can find them

The sump is not finned and there is no room for the oil cooler at the front.

 

I am not sure which way the air is supposed to flow through the cooler, but I think downwards by looking at the tiny bit of dust in the cooler.

 

Thanks

 

 

[bexrbetter]

The sump is not finned and there is no room for the oil cooler at the front.

Try a smaller, curved motorcycle oil cooler. Try Ebay or Earls in the UK.

 

curved motorcycle oil coolers‏ - חיפוש ב-Google

 

 

[geoffreywh]

i've got an Jab oil cooler you may have

 

 

[Old Koreelah]

Hi Old Koreelah. I have posted some pics in media under 3 axis. Named Jab Savannah. Hope you can find themThe sump is not finned and there is no room for the oil cooler at the front.

 

I am not sure which way the air is supposed to flow through the cooler, but I think downwards by looking at the tiny bit of dust in the cooler.

 

Thanks

I found the pix, JB. Just behind a hot muffler, side on to the airflow. I don't think I've seen a worse location for an oil cooler. Could you rotate its mount thru about 90 degrees and add a shroud down to the exit? That way air would be sucked thru it. Trouble is, by the time air gets to that spot, it's already heated to about 60 degrees or more.

Alternately, there seems to be some spare room on the lower LHS just in front of the firewall. Perhaps remount the cooler there with its own air inlet and outlet?

 

 

[jaybee258]

I found the pix, JB. Just behind a hot muffler, side on to the airflow. I don't think I've seen a worse location for an oil cooler. Could you rotate its mount thru about 90 degrees and add a shroud down to the exit? That way air would be sucked thru it. Trouble is, by the time air gets to that spot, it's already heated to about 60 degrees or more.Alternately, there seems to be some spare room on the lower LHS just in front of the firewall. Perhaps remount the cooler there with its own air inlet and outlet?

Thank you for those thoughts. In rotating it by 90 degrees, do you mean to lower the front of the radiator and keeping the rear of it fixed? That would lower the rad so that it just started to protrude below the skirt of the cowl. The exhaust pipes are a bit in the way for anything less. Am I right in thinking this would be in an area of maximum flow out of the engine bay? What about the cool airflow passing around the outside the cowl? I guess the radiator does not want to be too low.

 

UK weather is cool now, and the radiator does not warm up much now, and probably more by the exhaust than any hot oil. I have ordered digital thermometers so I can monitor anything I try in addition to some pressure differentials across the radiator

 

Many thanks

 

 

[jaybee258]

i've got an Jab oil cooler you may have

Thanks for the kind offer.

 

I think I will try a bit of repositioning of the existing one first. Things are very tight behind the cowl air inlet at the front

 

 

[bexrbetter]

You might try wrapping the muffler in a blanket too. Try a shop that sells turbochargers for the blankets, Maybe they sell the material, I don't know.

 

 

[jaybee258]

You might try wrapping the muffler in a blanket too. Try a shop that sells turbochargers for the blankets, Maybe they sell the material, I don't know.

Great ideas and very easy to try. Thank you

 

 

[dave66]

We have a Jab 2200 powered Savannah VG and it has always had a tendency to overheat. The CHT was the main problem until I modified the cowl to make a better fit with the engine. The oil overheating is more difficult, and occurs on any long climb of say +3000' in the summer. The oil cooler is mounted just behind the exhaust silencer box. I attached 2 temperature sensors to the cooler inlet and outlet, and there was only a few degrees temp difference. The cooler seems to be doing almost nothing. We have a TOCA fitted. Also, something which seems unusual is an Airplast prop which is set very coarse for economy. It cruses at between 2000 and 2400rpm. Max rpm is about 2600. We are getting plenty air into the heads now. Just need more airflow over the oil cooler. I understand the 3300 in the Savannah has the cooler mounted in front of the sump. Anybody out there with a 2200 and oil cooler?With the TOCA and good airflow over the oil cooler, I feel that we could be in the enviable position of having a Jab 2200 which does not suffer overheating

We are a UK microlight on 450kg.

 

Thanks guys

Hi JB, Our Savannah VG 2010 build has been running with no oil cooler (Jab 2200) since build, no problems with overheating, however, last Thursday, 19 04 2018, 27 degrees and the hottest day for a long time, after a 1 1/2 hour flight the oil temp was up and pressure dropped to 2 bars, normal pressure for our one is around the 3 and a bit bars, at 2400 rpm, I have the oil cooler kit and am thinking of fitting it next service, I looked at your pcs on media, did you sort it ? Thanks Dave.