Last night I re-made the burst hose. Then I made a new hose that completely bypassed/eliminated the front oil cooler from the oil cooling equation. I reinstalled the burst hose with a very slightly different routing and moved the oil filter mount about 1/2 inch to relieve strain that may have been present. I got everything plumbed back together last night, with the front oil cooler out of the mix, but due to rain could not crank her up (I didn't want to get my hanger mates Long-EZ drenched) last night.

Tonight I returned, topped off the oil, pushed the plane onto the ramp and fired her up. I let her idle a while, then pushed her to WOT. Oil pressure was about the same as before at around 30 psi at lower idle (1400/1500 rpm) and around 75 psi at full bore (about 6000+ rpm). Shut down, got out for the inspection and there is NO sign of seepage around the oil filter. Temps were about the same as before with the oil temp being 20-30 degrees over coolant.

Will hopefully get to re-test tomorrow.

NOW for my next step. As has been mentioned here, using oil to a front oil cooler is less than ideal. Velocity uses it in their stock Lycoming installations since they do not have a water/coolant option. However, we do.

My question to the collective is; would it be acceptable to use the aviation oil cooler that is already installed in conjunction with my currant water coolant system. My thinking is that an oil cooler, if I understand correctly, is more "durable" and able to withstand more pressure than the standard water radiator. Of course, there may be reasons other than pressure that would factor in, I just don't know them.

IIRC, oil pressure has been up to 75 psi, whereas stock coolant pressure caps are at about 13 and some in our uses some use 21psi caps. Thus, seemingly, this stock aviation cooler should be up to the task of being plumbed into my coolant system to provide heat for the cabin. I would think, perhaps in errors, that it should be at least as durable as a standard heater core. It would save a nice bit of time not having to redo the glass and plumbing at the front of the plane. I would like, in an ideal world, to remove the oil cooler from then nose, flush it and reinstall as a water radiator.

If this is deemed acceptable, the plumbing at the firewall back (pusher, ya know) should be pretty straight forward. I will have to put some thought into which water ports would be best to use without sacrificing my currently nicely operating coolant system. My first thought is to use the ports that are designed for heating use by Mazda. I recall the out going port is the one on the left (plug side) rear of the engine, but memory fails me as to where the heater line returns to the engine. I have a second gen turbo block. On John Slade's port identification page it shows a return port on what looks like the lower water pump with a turbo water port above it, however, this is not the same on mine. I do have a port in a somewhat simular place, but it does not look much like Johns (which is a 3rd gen), IIRC. I am curious as to how this will affect my current routing of hoses which seems to be working.

Of course, this may not be the correct route. Perhaps I should install the 3rd gen oil cooler where the aviation one is now and just bite the bullet on the glass work and pluming while still using oil...or, buy an actual heater core and use water. Donno, yet...kinda thinking out loud and soliciting suggestions.

All that being said, my friend David Staten mentioned this to me back in the day, that the aviation oil cooler may be a problem. At the time I remember saying "lets stick to the plans". Well, looks as if David was right. He is a smart guy and even though he bowed out of the project ages ago, his insight is still sought and appreciated. Steel sharpens steel. <g>

All the best,

Chris Barber

Houston