UPDATE: IO-390, Oilamatic PreOiler, ARI Cowl, Scimitar prop, oilcooler reloc

[bdjohn4]

Several of you wanted to see the final photo of the Oilamatic Pre-oiler installation. Here it is. Before starting, turn on the preoiler and wait a few seconds as the oil pressure comes into the green. Turn it off and start the motor.  Works great.

 

Weight and balance-wise, the preoiler is just a few pounds and is bolted to the top of the pilot's side fire-wall foot recess bucket thing (see the red-anodized preoiler pump. It takes oil from the sump and puts it into the oil filter.

 

The IO-390 is definately heavier. Even though I went from a three-blade prop to a two-blade, there is 57 lbs more weight on the nose-wheel than before (bear in mind that the airplane had not been actually weighed in a very long time, so all the little adjustments to the weight and balance could be off by a significant amount I suspect. A lot had been done to the ACFT since it was last on scales).

 

The ACFT oil temps run hotter than before (with oil cooler relocation and the ARI cowling), and it is no-longer an ACFT that you can do endless touch-and-goes on a hot, humid day in the SouthEast.

 

John

[rbridges]

have you noticed any increases at cruise?  would you go with the IO-390 if you could do it all over again?

[orionflt]

love the paint job

 

Brian

[Andy95W]

Cheapest pre-oiler is a good starter and a freshly charged battery.

With the spark plugs out, turn the engine over with the starter 2-3 times for about 20 seconds each time. With a decent battery, oil pressure will show in the green.

[bdjohn4]

Yes, gained 12-15 kts with all the mods (ARI Cowling, motor, prop, landing light lens cover, oil-cooler reloc). Cruises right around 160-162 KTAS now. Fuel burn at those speeds is higher than expected, but thats expected. Yes, I would do it over again (IO-390, that is).

 

I look at the Manifold Pressure Guage more, as the IO-390 is limited to, I believe, no more than five minutes above 24.7", so I fly around there mostly, which is pulled way back on the power below about 6k feet. Still faster than it used to be and fuel burn a lot better when at 24 squared at altitude.

 

It's not all good. The Oilamatic hoses were outrageously expensive (custom made and almost $600 due to some unusual fittings), and on these hot days around here, I need to be careful not to loiter around on the ground for too long. The oil temps don't like that. Once flying, oil temp is not an issue, but it seems it takes longer to cool down the oil once it is hot. I don't plan quick turn-arounds for the summer months anymore. I suspect cooler weather will work out fine. Fortunately I have long-range tanks and so I almost never need to stop for fuel.

John

[jetdriven]

The IO-390 is limited to 27.2" MP continuous after a five minute full power takeoff rating.

[mooniac15u]

The IO-390 is limited to 27.2" MP continuous after a five minute full power takeoff rating.

 

I'm not sure I understand how that works.  What physical factor is that limit based upon?  How long do you have to wait before running it full power again?  Is pattern work prohibited?

[jetdriven]

The IO-390 is a modified 360. Rather than go through a long certification process they simply certified it to 200hp continuous and a 5 minute takeoff limit. Taken literally, you can use the full 5 minutes every takeoff regardless of how many takeoff per hour. I wouldn't worry to much about ruining the engine, my friend with an RV-8 runs his WOT pretty much continuously. The experimental version has no such restriction.

[mooniac15u]

The IO-390 is a modified 360. Rather than go through a long certification process they simply certified it to 200hp continuous and a 5 minute takeoff limit. Taken literally, you can use the full 5 minutes every takeoff regardless of how many takeoff per hour. I wouldn't worry to much about ruining the engine, my friend with an RV-8 runs his WOT pretty much continuously. The experimental version has no such restriction.

 

Got it.  Thanks for the explanation.  I assumed there had to be some kind of failure mode that they were concerned about.  I never considered that the failure mode was regulatory.  

[KSMooniac]

Unless racing near sea level, one should be able to run WOT and be <27" MAP in under 5 minutes, right?  

[rbridges]

The IO-390 is a modified 360. Rather than go through a long certification process they simply certified it to 200hp continuous and a 5 minute takeoff limit. Taken literally, you can use the full 5 minutes every takeoff regardless of how many takeoff per hour. I wouldn't worry to much about ruining the engine, my friend with an RV-8 runs his WOT pretty much continuously. The experimental version has no such restriction.

 

didn't know that.  I thought it was an engine temp thing.