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  #1  
Old 08-04-2012, 12:46 PM
fstringham7a fstringham7a is offline
 
Join Date: Mar 2005
Location: St. George
Posts: 973
Default RE: OT/CHT/OP solved ?? !!!!

A year ago this past June I noted that my Oil Pressure was low ( this problem was from the beginning ... low 50 in cruise ) , CHT's were finally showing that the engine probably was totally broken in, and the oil temp was climbing through what I considered the roof ( near 250 on a hot desert 100 plus degree day after a 1000 ft a minute climb to 7000 ..... 240 plus in the pattern .....). These threads will give more detail about my problem, VAF friends suggestions, and my attempts at solutions!!!!!!

http://www.vansairforce.com/communit...e+low+pressure

http://www.vansairforce.com/communit...t=hot+oil+temp

http://www.vansairforce.com/communit...=high+oil+temp

Sonny and I were traveling down the same road ......

http://www.vansairforce.com/communit...p+low+pressure

Bruce gave me a great idea or two ........

http://www.vansairforce.com/communit...ad.php?t=73164

So in a nut shell: These were the things I did with test flights between each test.

1. Dynon Temp probe changed ( it wasn't the problem but decided to put in a new one and it died on the first flight .... the third one is solid).

2. New heavier spring was installed on the oil pressure adjustment ( oil pressure in cruise is between the high 60's and mid 70's)

3. Vernatherm was inspected and tested. It was functioning properly. New appropriate gasket was in stalled.

4. Oil cooler was removed (SW 8406 7 row) to see if it had any problems. Oil hoses were also check. No problem here ????? Except mayde too small for this fire breathing dragon og an ECi engine!!!!!

Up to this point the lower than normal oil pressure was corrected but the oil temp was still too high. CHT's were all normal in all phases of flight.

5. Ordered up a new double by pass oil cooler (a SW 8432R clone) from Pacific Oil Cooler and new Oil Hoses from TS Flightlines. Fabed a new mount off of the #4 cylinder baffle and put it all to gether and tested ......

6. Oh I forgot to mention that the PMags were all tested for proper function and properly timed and the cyclinders were all given a compression test and were all solid. Plus I really gave the baffling a good going over to seal up all potential air leaks.

Yes ... the oil temps were down in all flight configurations, CHT's were still great, and the oil pressure was still in the mid 70"s. But ..... this was in pretty cool Jan. 2012 time period. Sonny said in one of the posts... lets see what happens this coming summer. Well I agreed and noted that the temps were still up a little higher than I wanted in climb even in the cool weather so I commited myself to surgery on the cowl as Bruce had done on his as noted in the thread above.

Drum roll.....cymbal clang ...... the results are:

In my last flight with ground temps in the 100 degree range and near 60 degrees at 10.5K. I put the plane in a high power climb from 3300 feet at take off to 10.5K and the oil temp finally hit 223. Now that may be hot but remember my oil temp would hit near 250 by 7k before all the changes. I leveled off and the temp finally settled in at 198 and slowly went down even more to 189. So in climb the temps are down by 30 plus and in cruise the temp is down by 10 degrees .... using the 198 as a base... ( Oil temps before the changes in the plane would hoover around 210 in cruise). Now for the money shot !!!!! Head down for some touch and goes. The temps never got above 213 even working the plane pretty hard for three circuits and ground temps at 100 degrees.

So after a year plus of testing, changing stuff, sprending $$$$$$, reading and studying about these issues, checking all the treads here at VAF with similar problems, getting alot of help from all the engine GURUS here at VAF and locally I can finally say the low OP high OT is solved. YES YES I know that the temp in climb hit that high number of 223 but remember I was pushing it pretty hard and it was on a very hot day. So considering what it was to where it now is........LETS GO FLYIN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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Last edited by fstringham7a : 08-04-2012 at 01:31 PM.
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  #2  
Old 08-04-2012, 02:44 PM
hydroguy2's Avatar
hydroguy2 hydroguy2 is offline
 
Join Date: Sep 2006
Location: Townsend, Montana
Posts: 3,179
Default

way to stay at it until solved.
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  #3  
Old 08-04-2012, 03:53 PM
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Neal@F14 Neal@F14 is offline
 
Join Date: Aug 2007
Location: Wichita Falls, TX
Posts: 2,182
Default

Good to hear the results. The ECI engines just simply need bigger oil coolers and enough airflow thru them than a regular Lyc of the same size.

Hitting 223 oil temp in a long hard climb is perfectly fine and acceptable on a hot day... it'll ensure you've got all the water vapor condensation cooked out of your oil

We're probably going to have to open up the lower cowl exit on the RV-8 a little bit to help it out too. It's been reaching 230's in climbs on these 110+ degree Texas summer afternoons. Having the 4-pipe exhaust probably clogs up the cowl exit a little too much.
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  #4  
Old 08-04-2012, 05:17 PM
fstringham7a fstringham7a is offline
 
Join Date: Mar 2005
Location: St. George
Posts: 973
Default RE: Cowl Surgery Helped

I lowered the air exit area by about 2 1/8 inches. I didn't do any fancy calculations to determine that number. Probably should have been a bit more analytical about it!!! I can say that it did help along with the new cooler to get the OT down a bunch and also helped the CHT's by a few degrees in all flight configurations.

I did reprint with some of the left over Stewarts paint I had and it layed on Terrible so I will redo the paint job this coming fall after a summer of finally flying without the heavy concern of the OT!!!???




Quote:
Originally Posted by Neal@F14 View Post
Good to hear the results. The ECI engines just simply need bigger oil coolers and enough airflow thru them than a regular Lyc of the same size.

Hitting 223 oil temp in a long hard climb is perfectly fine and acceptable on a hot day... it'll ensure you've got all the water vapor condensation cooked out of your oil

We're probably going to have to open up the lower cowl exit on the RV-8 a little bit to help it out too. It's been reaching 230's in climbs on these 110+ degree Texas summer afternoons. Having the 4-pipe exhaust probably clogs up the cowl exit a little too much.
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  #5  
Old 08-04-2012, 06:16 PM
N787TR N787TR is offline
 
Join Date: Oct 2006
Location: Carbondale, Co
Posts: 49
Default Speed?

Frank,

This sounds like a very familiar path to what I have done, short of cowling surgery. Did you note a loss of airspeed?
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  #6  
Old 08-05-2012, 08:49 PM
fstringham7a fstringham7a is offline
 
Join Date: Mar 2005
Location: St. George
Posts: 973
Default RE : Not Sure

Quote:
Originally Posted by N787TR View Post
Frank,

This sounds like a very familiar path to what I have done, short of cowling surgery. Did you note a loss of airspeed?

I didn't focus on the speed issue. I probably will never know the answer to that because I didnt establish a proper test protocol coupled with data collection that would give that answer.

I do know that when I fly and see how really fast these little hot rods fly I am amazed!!!!! It is fun to look back at my aprs track in see how fast it is going during different phases of a particular flight.

I will leave the speed stuff to the real pros like Bob and Brian
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