FI fuel pressure, High oil temps - Help on newly flying -7A!

hecilopter · #1 03-28-2007, 07:05 AM

Helping a buddy work out squawks on new installation in a -7A. The engine is an ECI IO-360, Precision Airmotive Silverhawk FI, 9:1 pistons, dual P-mags. Oil cooler is Aero Classics from Van's mounted on cylinder #4. The engine also has the cam lubrication holes.

What should fuel pressure range be on this fuel injected system? The Dynon is showing about 15 PSI with the electric boost pump on.

Also having problems with oil temps (230+). I've read most of the other threads and most seem to say change to the SW oil cooler, put louvres in or cut out some of the cowl exit to solve. We have already replaced the vernatherm. The baffling is sealed well. The air inlet ramps on the top at the front of the cowl are sealed to prevent leakage "over the top". CHT's are in the 360 - 400 range (#4 the hottest at 400).

The problem is, I have the exact same setup except I am a carbureted XP-360, 8.5:1, mags. I have not seen oil temps over 190 since day one. Our side by side installations look identical.

Why are his temps so high? Do we need to make the cowl mods, get the more expensive SW cooler (8406R)?

Thanks!

Scott Will · #2 03-28-2007, 08:06 AM

Sounds like you and I have similar setups and similar problems. Just last night I installed a Stewart Warner 8406R to try and see if that helps.

The other day I was running about 220F in cruise. Powering back a little and I got it down to 213F or so. I don't recall the EXACT fuel pressure numbers off the top of my head but I believe they are normal. With the pump on I see about 26-28 psi if I recall. My hottest CHT is about 375-380F in cruise (#4 as well) and the front cyls usually are 25-30F cooler.

As we head into the warmer months, I am especially concerned about temps so lets keep our status posted.

RV7Guy · #3 03-28-2007, 08:36 AM

Hi guys,

I put the SW8432R on my 7. This is the large dual pass cooler. It is mounted behind the #4 Cylinder. This was important to deal with the extreme temps we experience in AZ.

My oil temps in cruise run 170. I can hit 190 in a climb and will occasionally hit 200 in an agressive climb.

I have the ECI IO360 with dual Pmags and Precision FI system. Although sealed quite well I can hit 400 + on a climb on the #4 CHT. It is transient and I don't really worry about it but monitor it closely. In cruise everything stabilizes at 360-380.

Did you check your oil temp probe?

kentb · #4 03-28-2007, 10:18 AM

It is common to place a small dam in front of the front cylinder to direct more cooling air to the back. I attached mine with screws/nutplates so that I could play around with different sized dams.

Kent

Scott Will · #5 03-28-2007, 10:34 AM

Darwin... you have any pics of your installation. Is the 8432R a drop in replacement? Was trying to look at some drawings and it appears slightly bigger. Did your existing screw holes work.

I also have some dams on the front cyl (actually speed tape) and that helps control the front cyls. Brings them up a little.

hecilopter · #6 03-28-2007, 11:31 AM

oil temp probe in boiling water along with a thermometer. They were within 2 degrees of each other. Have front dams on both the #1 and #2 cylinders. We are going to try running the P-mags in "mag" mode tonight by disconnecting the manifold pressure line and forcing them to revert to 25 degrees BTDC and see if that helps.

We want to exhaust ALL options before spending money on an oil cooler, modifying the cowl, etc.

I read a post from someone and can't find it now about making sure the ports on the engine where the oil cooler lines are attached have differential pressure to allow the oil to flow thru the cooler. Does anyone have more info on this?

Thanks!

AltonD · #7 03-28-2007, 12:10 PM

I can't find the link, you could email Walter Tondo to ask, http://www.rv7-a.com/index.htm

He had an issue where the fiberglass ramps in the front of the upper cowl were not closed off on the ends. After he closed them off, his high cylinder temp problem was gone.

Also, on his Phase One page, he has pics of changing out his oil cooler.

scott7A · #8 03-28-2007, 12:57 PM

One thing to check regarding the low fuel pressure reading is to make sure you have the right sensor type selected in the Dynon configuration. It will show a low reading with the carb version selected.

Scott
N653S RV-7A

kentb · #9 03-28-2007, 04:02 PM

I swapped my #2 and #4 probes to see if my high temp would follow the probe. It didn't, so I started looking at other things.
Don't know if you have see info on other threads about high temps, but you should check the fins on the end of the head for excess flashing and remove it if needed.

Kent

hecilopter · #10 03-29-2007, 08:53 AM

Update: This was not it, we had it hooked up correctly!

As embarassing as it may be, we have discovered after much research that there are 2 oil outlets and 1 oil inlet on the back of the accessory case on an ECI engine. May be on other engines as well. I'm still at work and have not confirmed yet, but we think we have hooked the oil cooler hoses to both the oil outlet and the optional oil outlet, thus putting equal pressure in the cooler and providing no flow thru it! We will switch the optional outlet hose to connect to the inlet and hopefully this solves the problem. Again, this is just speculation but will confirm later. See pic below. Note the oil cooler outlet, the optional oil cooler outlet, and the oil cooler return. This will be a huge relief if this is it. May solve some other people's problems as well.