REFLECTOR: High temps

[Christopher Martin]

I had the same sort of oil temp issue in my Lyc. IO540. The temps were
great during the first 400 hours of operation and then they started warm
up. Originally they were 195 and very solid at that temp. After 400 hours
they started to slowly ramp up to 220. It turned out that the Vera Therm
had become ineffective. I removed it and measured the in length from room
temp to boiling water. It expanded only 1/16 of an inch. I purchased a new
one and it measured 3/8 of an inch in the same temp change.  Needless to
say, installing the Vera Therm restored the temp to the 195 number.

Chris Martin
Velocity XL RG, 560 hours

Christopher Martin
christophercmartin at earthlink.net



> [Original Message]
> From: Jim Sower <canarder at frontiernet.net>
> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
> Date: 1/16/2005 6:42:40 PM
> Subject: Re: REFLECTOR: High temps
>
> I am running a LIO-360-C1E and even after a lot of work on the baffling 
> have CHTs around 375 - 400 with occasional excursions to 425 which I try 
> to correct for.  From the beginning, my oil temp never ever budged off 
> of 180, but more recently I have had oil temps up to 210 - 220 on 
> occasion.  I think part of this might have to do with the firewall oil 
> cooler which exhausts right into the plenum - the high pressure air for 
> cooling the cylinders.  There can't possibly be much air flow through 
> that cooler, and I regard it as a significant design defect.  At some 
> juncture (after I get the engine running again and the plane annualed) I 
> am going to exhaust it to outside air under the cowl.
>
> Glad I'm not the only one with high CHTs ... Jim S.
>
> Sid Knox wrote:
>
> > Hi Jim,
> > I too have an early '90's 173 RG with a Lyc IO-360 B1B that I bought 
> > from the builder about three years ago. The builder had tried two 
> > earlier cooling air schemes and had just completed the conversion to 
> > the two top NACA ducts and pressure shroud. He reported that it was 
> > running cooler than previously. I have been plagued with high cyl 
> > temps from day one (" high" for me is anything over 400F). OTOH, my 
> > oil temp runs too low and I have to partially block off the front 
> > cooler to ever see 180F. And yes, all cht temps have been verified 
> > with independent thermocouples at the top plugs and oil temp verified 
> > by inserting a tc probe directly into the sump (via filler tube) 
> > immediately after shut-down.
> > I balanced my injectors so I can run at least 50F LOP and that along 
> > with keeping power below about 60% keeps temps below 380F. I don't go 
> > as fast as most Velocities but running cool, clean and burning less 
> > than 7 gph puts a smile on my face.
> > I did a lot of reading on the reflector about other's experiences 
> > regards cooling. What I come away with is that some have cooling 
> > issues, some don't (or won't admit it or don't have the 
> > instrumentation to know one way or the other). Some use the NACA 
> > ducts. Some add VGs at inlet to the ducts and claim a large decrease 
> > (one guy at Oshkosh told me he dropped cht by 30F. I added VGs and saw 
> > maybe 10 if that much).
> >
> > There are times when I would like to burn a little more fuel and go 
> > faster so I am still seeking answers.
> > Two ideas I picked-up (from the reflector) that I will persue when the 
> > weather gets better so I can work in the hanger are:
> > 1) verify proper ignition timing with a timing light. I'm still 
> > puzzling over this one as to how to do it without getting chopped-up 
> > by the prop.
> > 2) add a scoop to one of the NACA ducts (one side only for initial 
> > data taking). Yes, drag, but don't most of our flying decisions 
> > involve trade-offs?
> >
> > Opinion follows: if those temps you see are real, you have a genuine 
> > cause for concern/alarm.
> >
> > Sid Knox
> > Oklahoma
> >
> > Velocity N199RS
> > Starduster N666SK
> > KR2 N24TC
> > W7QJQ
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "Jim & Sharon Beck" <jsbeck at charter.net
<mailto:jsbeck at charter.net>>
> > To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org 
> > <mailto:reflector at tvbf.org>>
> > Sent: Tuesday, January 11, 2005 10:28 PM
> > Subject: REFLECTOR: High temps
> >
> >
> >
> > I have a 173 RG that was completed in 2001 and then not flown until 
> > recently and since I did not build it my questions may seem simple to 
> > you more experienced builders & pilots. It has a newly rebuild IO 360 
> > A1B6 that now has about 10 hours on it. The 2 front cylinders are 
> > running about 425 to 450 and the oil tem is running about 225 at 
> > cruise. Should I be considering a second oil cooler or might these 
> > temps come down as it breaks in. These a winter time temperatures so 
> > it seems when summer comes I'll be over redline. Anyone help on this 
> > or thoughts would be appreciated.
> > Jim
>
>
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