Rajay Turbocharger STC

[Jeff]

[CLIPCLIP]

[Charlie Tripp]

[CLIPCLIP]

[Charlie Tripp]

[Phil Ciholas]

Somewhat off topic, but a good starting point. I put new turbos on my 260C a few months ago and have been chasing oil leaking into the turbos since. Tried all the usual suspects including replacing the inlet check valve three times and the outlet check valve once even though it is obviously well scavenged. Even replaced the slightly lower and offending turbo.

We are now down to assuming the oil is coming from the crossover plumbing between the turbos. On the 260C turbo, the feed line comes through a check valve (532A-2MP-27) then goes to a tee with a pressure switch for the warning light (not standard on 260C turbo's, but added to mine), then another tee that has an 0.093" diameter orifice. The other legs of the tee feed the two turbos. The outlets of the turbos run to a common catch can (vented to breather) which is drawn down by a scavenge pump through a flapper style check valve.

What we suspect is that all the oil downstream of the orifice is siphoning out to the low turbo after shutdown. This also raises the concern that the orifice and warning system are ineffective in supplying equal oil to both turbos or monitoring that both get some.

One potential solution is to feed the turbos independently: the feed line would go to a tee first, then two separate check valves, monitor switches, and restrictors for each turbo. This would make it like the oil feed to a single turbo, like on the PA30/39. Except we can't determine if there is even a restrictor orifice on a PA30/39 turbo installation. For the same flow as my 0.093" orifice gives two turbos, the PA30/39 should have an orifice about 0.065" diameter.

Can anyone tell me if it does, and what the Rajay part number is?
And yes, I've checked with Bob at Rajay parts, and am still waiting on an answer. I'm afraid it may be hidden in a fitting improperly called out as a regular AN fitting, and so he can't find it, or it might not exist at all.

So can anyone tell me if there is an orifice anywhere in the turbo oil feed line on a PA30/39? Ideally it is between the pressure switch and the turbo itself.

Thanks!
Phil

[T210DRVR]

A little off topic but we've had continual problems with the oil filters for the turbos plugging. The result was low oil pressure to the turbo and having to stop using the turbo's until we had a chance to pull the filters and back flush. The original filters are no longer available though at least one shop in the Portland area has been working on an STC to place a different style of filter in the line.

We were talking with the Rajay guy in Florida that owns the STC and he has given us written documentation to allow for the removal of the filters. This is good news as the bloody things have been plugging about every fifty hours or so.

[CLIPCLIP]

"the bloody things have been plugging about every fifty hours or so."

i have ch48108 oil filters (same as the engine's) on the turbos and i do change them every 50 hours at each oil change. so you might consider installing remote spin-on oil filters to solve your problem, whereas removing the old filters altogether may end up trashing your turbos as they are extremely sensitive to any kind of contaminant.

cheers,

françois

[T210DRVR]

I have CH48110 or 108 on my bird. I don't recall having a dedicated turbo oil filter setup on my T210, C340' or turbo Arrow. Were any early Comanches delivered without engine oil filters? Could it be that the in line filter was put on to protect from unfiltered engine oil?

[CLIPCLIP]

That's probably it. mine came with "rock catchers", AKA screens, to filter engine oil, while filters were installed on the turbos.

i've kept the turbo filters and changed to real oil filters for the engine.

françois

[Larry Crowley]

Has anyone heard of the oil pressure from the engine to the filter being too high and allowing the oil to flow past the check valve? Creating an overflow in the turbo and overwhelming the scavenger pump. We continue to have major leaking out of the exhaust.

thanks

Larry

[Steve Von Gruben]

Larry, I kept having oil out the tail pipe even after installing the return line check valves also. A mechanic friend told me to take the check valves back off the engine and look inside of them from the end. They have a "trap door"style of shut off in them that has a hinge point. He said to orient the hinge up when installing and that should fix my problem. I did that and problem went away. I also marked the valve for future reference. Hope this helps.