Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Old 07-05-2018, 10:25 AM
findane findane is offline
Join Date: Oct 2014
Location: Naples, FL
Posts: 46
Default Oil Cooler on James Plenum

I have an IO320 with a cold air horizontal induction and a James plenum. James suggests a oil cooler behind the #4 cylinder attached to the baffle. After speaking with Bill at Airflow Systems, because of the cold air induction, he recommended a remotely located 13 row cooler with a minimum 4" outlet behind the #4 cylinder. I'm afraid the 4" outlet would scavenge too much air from the #4. Would it be advisable to make a 3" outlet behind #3 and #4 running to the oil cooler?
Dues paid for 2019
Reply With Quote
Old 07-05-2018, 11:13 AM
N941WR's Avatar
N941WR N941WR is offline
Join Date: Jan 2005
Location: SC
Posts: 12,137

I put a Stewart Warner 10599R oil cooler on my #4 cylinder and it worked much better than the"stock"oil cooler with my O-360.

It seems to do a great job at all OAT's.

Don't forget to strengthen the corner of the baffles or they will crack.

The crack:

The fix, new baffles and a big piece of AA:
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
Reply With Quote
Old 07-05-2018, 01:23 PM
airguy's Avatar
airguy airguy is offline
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 4,592

I'm running the Stewart-Warner 10-row on 9A IO360, firewall mounted with 4" SCAT to it. My left cylinders (2 & 4) run about 15 degrees warmer CHT than the right cylinders during climb and pretty well match during cruise. My plenum does not have sufficient clearance above the top of the engine though, so my cross-flow from the other side of the engine plenum is not quite sufficient to make up for the mass loss behind #4.

It's noticeable, but certainly not a problem.
Greg Niehues - PPSEL, IFR, Repairman Cert.
Garden City, TX VAF 2019 dues paid
N16GN flying 400 hrs and counting! Built an off-plan 9A with too much fuel and too much HP. Should drop dead any minute now.
Reply With Quote
Old 07-05-2018, 01:29 PM
rjcthree's Avatar
rjcthree rjcthree is offline
Join Date: Jan 2007
Location: Bay Village, OH
Posts: 778
Default 3” to 4”

I just made the change from a 3” scat to 4” scat to feed my remote 9-row, and the #4 CHT didn’t change more than 5F- it was, and remains my coolest CHT. They may or may not have gone up, Its that close. My baffles are better than average, I’ve been on this Oil temperature road for a while. That my 9 row is not quite up to the task at high ambient is a separate issue (and/or my expectations are not realistic). .
RV-9A N183RC/90432: tip-up, O320H2, Ellison, Dynon D180
RV-8 83718, wing kit in work with a four year plan
2011-2019 VAF contributor

Last edited by rjcthree : 07-05-2018 at 06:47 PM. Reason: Clarity
Reply With Quote
Old 07-05-2018, 06:24 PM
Larry DeCamp's Avatar
Larry DeCamp Larry DeCamp is offline
Join Date: Apr 2010
Location: Clinton, Indiana
Posts: 806
Default Good timing on this topic !

After reading recent comments on oil temperature, I investigated my options for my IO360/8:5 application today. Vans sent me a 7 row with my baffle kit. Bill (AFS) suggested a 13 row because you RV guys are always trying to put 10lb in a 9lb bag. He did offer that James cowels are historically good on CHT but suffer on OT.
I called VAN’S tech support and they said the 7 row will be fine for normal use and their next option was the huge 13 row for squirted pistons etc.

So, what is the correct course of action ??
Larry DeCamp
RV-3B flying w/ carb / Pmags / Catto 2b / Steam
RV-4 fastback w/ Superior XP360/AFP/G3X/CPI/Catto3b
Clinton, IN
Reply With Quote
Old 07-05-2018, 07:22 PM
Carl Froehlich's Avatar
Carl Froehlich Carl Froehlich is offline
Join Date: Dec 2007
Location: Dogwood Airpark (VA42)
Posts: 2,014

Or - for the parallel valve IO-360 the 10 row 2004X Airflow Systems cooler could fit the bill:

Reply With Quote
Old 07-05-2018, 07:54 PM
BillL BillL is offline
Join Date: Sep 2007
Location: Central IL
Posts: 4,951

In my RV7, I am using the SJ cowl,standard vans IO360M1b (180hp) baffle mounted 20002a cooler and so far it is cooling well up to 90F OAT. It did not reach 200F until the end of 4 T&G and full WOT/2700 rpm climbs in the pattern.

It was running 195F on a WOT-2500 RPM climb to 17,000 at max gross weight.

I do have a suprisingly good pressure delta across the cooler. (edit) Upper pressures measured with and w/o the oil cooler shutter open showed zero change in pressure and CHT. There is certainly a limit on how much a cooler can flow and not affect the system, balance is important. The 20002a is apparently not pulling enough flow to show that change.

The cooler must be matched to the air mass and pressure available to cool properly, the standard cooler does work for me. That said, I am not sure what temperature would result with a WOT-2700RPM, 80 kt climb @ 100F OAT and full gross. I don't even know what the design climb, OAT, CHT, Oil temp goals are for this engine. If it is 500F CHT, and 270F oil temps, @ 100F OAT, for 3 minutes, then maybe it is good.

1st Flight 1-27-18
Phase II 8-3-18
Repairman 11-15-18
Instrument Currency 12-17-18
Shrunken Exit = ??
No Photo? => PM me.

Last edited by BillL : 07-06-2018 at 05:28 AM.
Reply With Quote
Old 07-05-2018, 09:38 PM
db1yg's Avatar
db1yg db1yg is offline
Join Date: Mar 2006
Posts: 618
Default Oil Cooler on Firewall

Hi Peter,

I have an RV9a with a stock compression (8.5 to 1) IO360, James cowl and plenum, and a firewall mounted Stewart Warner 10599 cooler which gets its cooling air from above/behind the #4 cylinder through a 4"duct. In cruise my cht's run within 8 degrees of each other--#4 being in the middle. Oil temps stay very cool with summer climb temps never above 195-200 and winter oil temps are seldom above 170-175 or so. I actually think I have excess oil cooling and would probably be fine with the next size down SW cooler. Ref the cht's, it appears that once you get into a cruise condition the pressure build up inside a well sealed plenum is sufficient to offset any pressure drop due to the 4" cooler pick up opening---at least that appears to be the case on my airplane given the very close cht's.

If the cooler must be firewall mounted, I would suggest that you go with a single duct (4") from as high above/behind #4 as possible, fabricate a smooth fiberglass cooler diffuser and pick up port, and spend the time necessary to insure the ducting is smooth inside and the flow transitions (curves) are gentle.

PM me if you would like some pictures.

Good luck and of course,


Dave B.
RV9a/ECiIO360/James Cowl/WW RV200 Prop
Flying since 3/06 and still smiling!!!
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 02:19 AM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.