RunRyder RC
 3  Topic Subscribe
WATCH
 1 page 701 views
Scorpion Power Scorpion Power
HelicopterMain Discussion › How hot?
03-10-2003 05:57 PM  14 years agoPost 1
bravoh

rrNovice

South America

My Posts: All  Forum  Topic

I've been running an OS70 on my X-spec and I'm not sure if its running a little hot. Does anybody know what the normal operating temperature for these engines is?
Thanks

PM  EMAIL  GALLERY  Attn:RR  Quote
03-10-2003 05:59 PM  14 years agoPost 2
Waldo

rrVeteran

Middle of the corn​patch (Iowa)

My Posts: All  Forum  Topic

180 to 220, it all depends on whom you talk to.

[b]Bill[/b]

PM  EMAIL  GALLERY  Attn:RR  Quote
03-10-2003 06:16 PM  14 years agoPost 3
runboy

rrKey Veteran

Phoenix

My Posts: All  Forum  Topic

And how you meassure it Don't go by temperature alone. Sound/response/feel should be your primary indicator.

[url]http://www.avitop.com/[/url]

PM  EMAIL  HOMEPAGE  Attn:RR  Quote
03-10-2003 06:29 PM  14 years agoPost 4
akpatterson2000

rrNovice

Limerock, CT

My Posts: All  Forum  Topic

As the temp increases the piston expands, hence, too hot=siezed engine. However, if the engine is to cold it will not get the best performance and flight time will suffer. It needs the heat to atomize the fuel, witch gives a more complete and powerful combustion stroke. Typically, engines temps are from 195 to 210ish. You should be fine within that range. Runboy is correct with sound/response/feel, however these are directly related to temp. If the temp is off sound/response/feel will be off. Having a known temp helps you quantify your feelings about how it is running. Tune you carb to the way you like the sound/response/feel and they find out the temp. Then when the weather changes it is more reassuring to a adjust to carb to get the engine temp back, then going on a gut feeling. for example, If it is a cold day it needs more fuel, but how many clicks on the carb. Even if you get to know how many clicks on the needle it takes, things change and wear out. So was the change enough? Is it running hot or cold? Temp will tell you if it the change worked. Buy a temp monitor and know, not guess.

PM  EMAIL  GALLERY  Attn:RR  Quote
03-10-2003 06:31 PM  14 years agoPost 5
Simmer

rrElite Veteran

Massachusetts

My Posts: All  Forum  Topic

235 to 240 I heard

PM  EMAIL  GALLERY  Attn:RR  Quote
03-10-2003 07:59 PM  14 years agoPost 6
runboy

rrKey Veteran

Phoenix

My Posts: All  Forum  Topic

I agree that using temperature would be great, but, the main reason why you should be carefull about using temperature is because it can be hard to get an accurate reading.

If you use a temp gun your problem will be that you are not really seeing the max temperature encountered on the flight. And if you use an on board temperature device like theb Venom (I use that one) The temperature will greatly depend on how you install it and the accurasy of the Venom (Which some people claim is not that great)

So it can be hard to compare these numbers, but it is a great tool for yourself on a day to day basis.

235 to 240 sounds a little hot to me.

[url]http://www.avitop.com/[/url]

PM  EMAIL  HOMEPAGE  Attn:RR  Quote
03-10-2003 08:53 PM  14 years agoPost 7
akpatterson2000

rrNovice

Limerock, CT

My Posts: All  Forum  Topic

RUNBOY

Yes, I was woundering the about venom monitor. I have one and I can' t get the "sensor" to rest on a large surface area on the engine. How do you mount it? I wonder if there's an adhesive the is also a good conductor of heat. I have also calibrated mine on the heli with the raytec gun. However, I think that the"sensor" moves around and gives inconsistant readings. Also I checked my monitor by placing just red part of the sensor in hot water, got that temp then ckecked the water temp with the rytech gun. they were within 1 degree. I feel that the monitor is accurite, but like you say, it depends on the placement.

PM  EMAIL  GALLERY  Attn:RR  Quote
03-10-2003 08:57 PM  14 years agoPost 8
bravoh

rrNovice

South America

My Posts: All  Forum  Topic

Thanks a lot guys, I was running at about 180 and someone told me that was waaay too hot. This worried me because I didn't feel I was getting all the power from my engine and closing the needle more would make it even hotter.
I'll now try closing the needle a couple of clicks, this should give me more power and still keep me under 220.
Thanks

PM  EMAIL  GALLERY  Attn:RR  Quote
03-10-2003 09:13 PM  14 years agoPost 9
Paul Woodcock

rrElite Veteran

Dubai - United Arab​Emirates

My Posts: All  Forum  Topic

Hi. I have never seen one of these Venom gauges. Is it a CHT gauge or an EGT gauge (thats Cylinder Head Temp. and Exhause Gas Temp)

My comment are based on my full size fixed wing piston engine flying....so how valid it is for model helis is questionable.

We usually set the EGT +/- 50deg F rich of peak mixture. The CHT we basically ignore......just monitor and keep cool with increased airflow and/or reduced power. , ie fly faster with less power (stop climbing) or open the cowl flaps. The EGT is very quick to pick up a hot running situation and the CHT is much slower. Usually when your CHT gets hot you have big problems and some fairly quick steps need to be taken to sort it out.

The OS 140 efi has its temp probe on the side of the case near the exhaust flange and on the lowest row of cooling fins. This must be fairly close to an EGT.

Where is the Venom mounted ? How meaningful are the readings from the Venom ?

Thanks

Paul

PM  EMAIL  GALLERY  Attn:RR  Quote
03-10-2003 09:31 PM  14 years agoPost 10
akpatterson2000

rrNovice

Limerock, CT

My Posts: All  Forum  Topic

Pwood

The venom monitor is basically a CHT. It's simply a wire loop, that wraps around the cylinder, with some kind of resistor, I think, in it. It works on that theory that heat adds resistence. I think that the unit sends a signal to the loop and when the loops gets hot the value of the current that is aloud through changes. So say at 50 degress the resistor have X amount of ohms and the unit sends out 5 volt and loop returns 4.9 , than as is gets hot. the resistence goes up, so then the return voltage is say, 3 volts. The unit is calibrated to figure the relation of heat and return voltage. I hope that is a clear explination. The loop just slips over the cylinder. However, it dosn't get full contact.

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 701 views
Scorpion Power Scorpion Power
HelicopterMain Discussion › How hot?
 Print TOPIC  Make Suggestion 

 3  Topic Subscribe

Sunday, November 19 - 5:38 pm - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online