My IO-375 runs hot in OATs below 60F. This is on my RV7A with new engine from Aerosport with 25 hrs on it and the rings seem to be seated as oil consumption is hardly noticeable.
If this keeps up I am going to have trouble this summer. I have gone over my baffling again and again sealing up any places where air might escape before doing it's engine cooling duty. (Washer behind #3 rear baffle etc.) I verified correct routing of the oil cooler hoses so air should not be trapped in the oil cooler. Running 8432R oil cooler on modified RV10 firewall mount, feeding it with 4" scat off the rear baffle and have 4" butterfly valve to control the air flow, it is working properly. I even made special baffle wraps to fit the tapered cylinder fins on the ECI tapered cylinders, they wrap nicely against the cyl. fins forcing the air between the fins. Differential pressure from top of engine to behind the baffles is always above 10" WC, up to 14" WC at speed with EZ Cool flaps open. Air cannot escape through the upper cowl inlet ramps, they are sealed.
I had anticipated that I would need to partially close the oil air door except in the hot temps of summer, not so. It looks like I will need to keep my EZ Cool cowl flaps open whenever I run at full power, ( I think they are especially helpful on A models as the gear tubes block the normal air exit). Even with them open, at best power mixture setting, it will heat up above my limits.
I can easily control the temps by running way rich of peak, or lean of peak, but if I run at best power, even up above 8000', oil T will head up above 200F, and CHTs will climb above 400F. Both of those are temp limits I would like to keep in place. I know some people feel OK with higher temps than that, I do not, especially with OATs as low as they have been.
I am still running mineral oil for break in, maybe I will see improvement when I change that out?
Could I still be experiencing an extra warm engine due to break in after running it hard for the first 20 hrs? I hear that the Nickle Carbide cylinders generally break in pretty fast.
Possibly related, I am running dual PMags. I set them up for max advance of 26 degrees during the first 20 hrs. Now running A curve and this change did not appear to affect the engine temperatures. During those first 20 hrs I always had more than 24" MAP, and way ROP, trying to make sure I got a good break in.
I am looking for some feedback from others with similar engine configuration that might shed light on this business. Maybe it will get better after some more hours on it??
OK same subject but different: While inspecting for problems and thinking about the heat I look at the cabin heat valve, and see that when closed, it dumps that heat right into the back side of the engine area. The heater seems to work real good in the cabin so I am thinking I don't really need to be dumping that heat near the fuel pump and PMags. So I have this idea of ducting the hot air down closer to the cowl exit. Anybody tried that?
Maybe there is enough air flow back there to get that hot air out before it contributes to heating up items on the accessory case, but who knows?
Randall in Sedona
Maybe I should just keep flying it and try to be patient...
If this keeps up I am going to have trouble this summer. I have gone over my baffling again and again sealing up any places where air might escape before doing it's engine cooling duty. (Washer behind #3 rear baffle etc.) I verified correct routing of the oil cooler hoses so air should not be trapped in the oil cooler. Running 8432R oil cooler on modified RV10 firewall mount, feeding it with 4" scat off the rear baffle and have 4" butterfly valve to control the air flow, it is working properly. I even made special baffle wraps to fit the tapered cylinder fins on the ECI tapered cylinders, they wrap nicely against the cyl. fins forcing the air between the fins. Differential pressure from top of engine to behind the baffles is always above 10" WC, up to 14" WC at speed with EZ Cool flaps open. Air cannot escape through the upper cowl inlet ramps, they are sealed.
I had anticipated that I would need to partially close the oil air door except in the hot temps of summer, not so. It looks like I will need to keep my EZ Cool cowl flaps open whenever I run at full power, ( I think they are especially helpful on A models as the gear tubes block the normal air exit). Even with them open, at best power mixture setting, it will heat up above my limits.
I can easily control the temps by running way rich of peak, or lean of peak, but if I run at best power, even up above 8000', oil T will head up above 200F, and CHTs will climb above 400F. Both of those are temp limits I would like to keep in place. I know some people feel OK with higher temps than that, I do not, especially with OATs as low as they have been.
I am still running mineral oil for break in, maybe I will see improvement when I change that out?
Could I still be experiencing an extra warm engine due to break in after running it hard for the first 20 hrs? I hear that the Nickle Carbide cylinders generally break in pretty fast.
Possibly related, I am running dual PMags. I set them up for max advance of 26 degrees during the first 20 hrs. Now running A curve and this change did not appear to affect the engine temperatures. During those first 20 hrs I always had more than 24" MAP, and way ROP, trying to make sure I got a good break in.
I am looking for some feedback from others with similar engine configuration that might shed light on this business. Maybe it will get better after some more hours on it??
OK same subject but different: While inspecting for problems and thinking about the heat I look at the cabin heat valve, and see that when closed, it dumps that heat right into the back side of the engine area. The heater seems to work real good in the cabin so I am thinking I don't really need to be dumping that heat near the fuel pump and PMags. So I have this idea of ducting the hot air down closer to the cowl exit. Anybody tried that?
Maybe there is enough air flow back there to get that hot air out before it contributes to heating up items on the accessory case, but who knows?
Randall in Sedona
Maybe I should just keep flying it and try to be patient...