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Removing cylinder head flashing

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digidocs

Joined: 04 Dec 2013
Posts: 59

Posted: Fri Jun 23, 2017 8:43 am Post subject: Removing cylinder head flashing

Hi list,



What are your favorite techniques/tools for removing the cylinder head flashing (near the top spark plug)?

So far I've discovered Tim's approach using an extension drill like an end mill and also a suggestion to try modifying a hacksaw rod blade into long rotary burr.

Thanks for your input,

David

Tim Olson

Joined: 25 Jan 2007
Posts: 2878

Posted: Fri Jun 23, 2017 8:53 am Post subject: Removing cylinder head flashing

I found a small thin file at our local farm store that fits nicely if the gap isn't completely closed.

I song have the info but it was maybe 6-8" long and maybe at most 1/2" wide and about 1/16" thick or so.  That worked well.

Tim



 	  Quote: 	
		   On Jun 23, 2017, at 11:38 AM, David Carr <junk(at)dcarr.org> wrote:

 

 Hi list,

 

 What are your favorite techniques/tools for removing the cylinder head flashing (near the top spark plug)?

 

 So far I've discovered Tim's approach using an extension drill like an end mill and also a suggestion to try modifying a hacksaw rod blade into long rotary burr.

 

 Thanks for your input,

 David

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Fri Jun 23, 2017 12:14 pm Post subject: Removing cylinder head flashing

I had good luck with one of my 3/32 (#40) drill bits, 6" long. Just made 

multiple passes and then worked it back and forth somewhat. I can't say 

I have seen significant difference, but with OAT around 100 for 9 am 

takeoff, and 80 at 6500 and 70 at 9500..I'll have to wait for some more 

normal temps to compare.

Tim, did you notice much benefit from the RTV between the cylinders, 

where you closed the gap?

On 6/23/2017 9:53 AM, Tim Olson wrote:

 	  Quote: 	

 I found a small thin file at our local farm store that fits nicely if the gap isn't completely closed.

 I song have the info but it was maybe 6-8" long and maybe at most 1/2" wide and about 1/16" thick or so.  That worked well.

 Tim

> On Jun 23, 2017, at 11:38 AM, David Carr <junk(at)dcarr.org> wrote:

>

> Hi list,

>

> What are your favorite techniques/tools for removing the cylinder head flashing (near the top spark plug)?

>

> So far I've discovered Tim's approach using an extension drill like an end mill and also a suggestion to try modifying a hacksaw rod blade into long rotary burr.

>

> Thanks for your input,

> David

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

Tim Olson

Joined: 25 Jan 2007
Posts: 2878

Posted: Fri Jun 23, 2017 12:29 pm Post subject: Removing cylinder head flashing

I didn't really have a good way to tell, sorry.  The problem is, when I 

attacked the

CHT issue, I did everything at once, so I can't say that one thing was

far better than any other.  The Cylinder flashing issue was a definite

problem though...you could just see it.  Funny that my IO-390 cylinders

from Lycoming didn't need any work at all.  Maybe these days they

do a better job, or maybe they do a better job than ECI did.



My real remaining thing I'd some day like to improve is Oil temps.

Interestingly, it used to be my CHT's that were the issue, not oil temps.

Then after fixing the CHT's, now if there is anything that limits me

from climbs on hot days it's oil temps.  I set my alarm at 216F to come

on and get me to do something.  I don't ever let it get over 225F

without great reason.  I may have seen 235F one or two times in

1250 hours.   By keeping speeds of 125kts in climb I can almost

do whatever I want, but I would prefer to be able to have my oil

temps stay under 210F even in 115kt climbs...and always be

in the 190's when straight and level.



I may just have to get into a small cowl mod to add an extra exit

scoop or something under that oil cooler.  It's not a highly pressing

issue, but would be nice to deal with for any flights out West in

the warm months, mainly.



Tim

On 6/23/2017 3:13 PM, Kelly McMullen wrote:

 	  Quote: 	
		   



 I had good luck with one of my 3/32 (#40) drill bits, 6" long. Just 

 made multiple passes and then worked it back and forth somewhat. I 

 can't say I have seen significant difference, but with OAT around 100 

 for 9 am takeoff, and 80 at 6500 and 70 at 9500..I'll have to wait for 

 some more normal temps to compare.

 Tim, did you notice much benefit from the RTV between the cylinders, 

 where you closed the gap?

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Fri Jun 23, 2017 12:42 pm Post subject: Removing cylinder head flashing

Very interesting. I replaced my louvers in front of the exhaust pipes 

with the Anti-Splat cowl flaps. This was first supported by putting 1/2" 

deflector in front of the louvers, which made a noticeable improvement.

with the cowl flaps, temps are a bit lower, maybe as good as with the 

deflector in front of louvers(which would have been a lot cheaper and 

easier to stick with). However, where my oil temps had been fine, now 

mine are like yours. I did the flashing removal, but haven't tried the 

RTV yet. I just need to get my cockpit flow back to where it was flying 

the Mooney....cowl flaps open for takeoff and climb. Level off, and then 

close cowl flaps. Open them up as come into pattern to keep  CHTs from 

climbing again. I may eventually decide to install one of the louvers I 

removed, right under the oil cooler.

Your IO-390 cylinders should be perfect...they should be perfect. I 

don't know if you have priced them, but they are almost double the price 

of regular 360 angle valve cylinders.

On 6/23/2017 1:29 PM, Tim Olson wrote:

 	  Quote: 	

 I didn't really have a good way to tell, sorry.  The problem is, when I 

 attacked the

 CHT issue, I did everything at once, so I can't say that one thing was

 far better than any other.  The Cylinder flashing issue was a definite

 problem though...you could just see it.  Funny that my IO-390 cylinders

 from Lycoming didn't need any work at all.  Maybe these days they

 do a better job, or maybe they do a better job than ECI did.

 My real remaining thing I'd some day like to improve is Oil temps.

 Interestingly, it used to be my CHT's that were the issue, not oil temps.

 Then after fixing the CHT's, now if there is anything that limits me

 from climbs on hot days it's oil temps.  I set my alarm at 216F to come

 on and get me to do something.  I don't ever let it get over 225F

 without great reason.  I may have seen 235F one or two times in

 1250 hours.   By keeping speeds of 125kts in climb I can almost

 do whatever I want, but I would prefer to be able to have my oil

 temps stay under 210F even in 115kt climbs...and always be

 in the 190's when straight and level.

 I may just have to get into a small cowl mod to add an extra exit

 scoop or something under that oil cooler.  It's not a highly pressing

 issue, but would be nice to deal with for any flights out West in

 the warm months, mainly.

 Tim

 On 6/23/2017 3:13 PM, Kelly McMullen wrote:

> 

>

> I had good luck with one of my 3/32 (#40) drill bits, 6" long. Just 

> made multiple passes and then worked it back and forth somewhat. I 

> can't say I have seen significant difference, but with OAT around 100 

> for 9 am takeoff, and 80 at 6500 and 70 at 9500..I'll have to wait for 

> some more normal temps to compare.

> Tim, did you notice much benefit from the RTV between the cylinders, 

> where you closed the gap?

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Fri Jun 23, 2017 1:00 pm Post subject: Re: Removing cylinder head flashing

These results shouldn't be too surprising. By improving air flow over the cylinders, you decreased the top cowl pressure a bit. So now there's less air flow to the oil cooler.

_________________
Bob Turner
RV-10 QB

Tim Olson

Joined: 25 Jan 2007
Posts: 2878

Posted: Fri Jun 23, 2017 1:11 pm Post subject: Removing cylinder head flashing

 Yeah, the 390's aren't cheap.  At least it's good.  It gave me the 

confidence that

I may buy my next RV-10 engine as the Van's brand new engine.

My CHT's have been great for a long time. I don't ever hit 400 on climb

or anything.  If it weren't for the oil temp I wouldn't have a complaint.

So you're saying the deflector in front of the louvre lowered the

CHT's  (I mean, is the CHT temp the thing you were chasing, or oil temp),

but then adding the cowl flap didn't really make a big difference over

the deflector, right?  So either solution helped for CHT's, but

then now with EITHER of them you began to have higher oil temps?

I just want to understand what cause and effect you had.  I don't

want to go cutting cowl holes unless I have a good idea that it'll work.

Maybe I'll try just adding an aft curled down lip to the cowl exit

and see how that goes.  Something that I can tape on.

I do have the oil cooler throttle valve to keep the oil temps higher

in the winter.  Sadly when you live here, but travel all over, you need

something to help with both high and low oil temps. 

As Bob just noted, maybe the good flow thru the cylinders is actually

hurting our oil cooler capabilities.   Or maybe it's the angle that the

oil cooler is at.  If you see how they did the RV14 cooler, it lays

horizontal.  My RV-14 has zero CHT or Oil temp issues.  In fact, the

Cylinders run super cool.  So they did something right on that plane

that would be nice to do on the -10.

Tim

On 6/23/2017 3:39 PM, Kelly McMullen wrote:

 	  Quote: 	

 Very interesting. I replaced my louvers in front of the exhaust pipes 

 with the Anti-Splat cowl flaps. This was first supported by putting 

 1/2" deflector in front of the louvers, which made a noticeable 

 improvement.

 with the cowl flaps, temps are a bit lower, maybe as good as with the 

 deflector in front of louvers(which would have been a lot cheaper and 

 easier to stick with). However, where my oil temps had been fine, now 

 mine are like yours. I did the flashing removal, but haven't tried the 

 RTV yet. I just need to get my cockpit flow back to where it was 

 flying the Mooney....cowl flaps open for takeoff and climb. Level off, 

 and then close cowl flaps. Open them up as come into pattern to keep  

 CHTs from climbing again. I may eventually decide to install one of 

 the louvers I removed, right under the oil cooler.

 Your IO-390 cylinders should be perfect...they should be perfect. I 

 don't know if you have priced them, but they are almost double the 

 price of regular 360 angle valve cylinders.

 On 6/23/2017 1:29 PM, Tim Olson wrote:

> 

>

> I didn't really have a good way to tell, sorry.  The problem is, when 

> I attacked the

> CHT issue, I did everything at once, so I can't say that one thing was

> far better than any other.  The Cylinder flashing issue was a definite

> problem though...you could just see it.  Funny that my IO-390 cylinders

> from Lycoming didn't need any work at all.  Maybe these days they

> do a better job, or maybe they do a better job than ECI did.

>

> My real remaining thing I'd some day like to improve is Oil temps.

> Interestingly, it used to be my CHT's that were the issue, not oil 

> temps.

> Then after fixing the CHT's, now if there is anything that limits me

> from climbs on hot days it's oil temps.  I set my alarm at 216F to come

> on and get me to do something.  I don't ever let it get over 225F

> without great reason.  I may have seen 235F one or two times in

> 1250 hours.   By keeping speeds of 125kts in climb I can almost

> do whatever I want, but I would prefer to be able to have my oil

> temps stay under 210F even in 115kt climbs...and always be

> in the 190's when straight and level.

>

> I may just have to get into a small cowl mod to add an extra exit

> scoop or something under that oil cooler.  It's not a highly pressing

> issue, but would be nice to deal with for any flights out West in

> the warm months, mainly.

>

> Tim

Deems Davis

Joined: 09 Jan 2006
Posts: 925

Posted: Fri Jun 23, 2017 1:40 pm Post subject: Removing cylinder head flashing

Kelly,



I messed with cht, and oil temps for far too long, I can say that louvers had no noticeable effect. Adding the bigger cooler also had negligible effect. I final solution that solved the issue, was to fashion a ram air intake that combined with the close-out plate on the bottom of the cowl that fits in front of the nose gear. Attached a 3" scat tube and ran that into a fiberglass right angle reducer that coupled with the 3" scat tube and affixed to the top of the oil cooler. Closed off the old oil cooler air intake behind #6. The difference was dramatic, IMO for anything other than cold environs the 10 oil cooler mounting and plumbing is inadequate. For us in the desert the oil cooler demands it's own dedicated air supply. And as you would surmise #6 cyl was now inline with all others, and all others showed a drop in CHTs.

On Fri, Jun 23, 2017 at 1:39 PM, Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)> wrote:

 	  Quote: 	
		  --> RV10-List message posted by: Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)>

 

 Very interesting. I replaced my louvers in front of the exhaust pipes with the Anti-Splat cowl flaps. This was first supported by putting 1/2" deflector in front of the louvers, which made a noticeable improvement.

 with the cowl flaps, temps are a bit lower, maybe as good as with the deflector in front of louvers(which would have been a lot cheaper and easier to stick with). However, where my oil temps had been fine, now mine are like yours. I did the flashing removal, but haven't tried the RTV yet. I just need to get my cockpit flow back to where it was flying the Mooney....cowl flaps open for takeoff and climb. Level off, and then close cowl flaps. Open them up as come into pattern to keep  CHTs from climbing again. I may eventually decide to install one of the louvers I removed, right under the oil cooler.

 Your IO-390 cylinders should be perfect...they should be perfect. I don't know if you have priced them, but they are almost double the price of regular 360 angle valve cylinders.

 

 On 6/23/2017 1:29 PM, Tim Olson wrote:

  	  Quote: 	
		   --> RV10-List message posted by: Tim Olson <Tim(at)MyRV10.com>

 

 I didn't really have a good way to tell, sorry.  The problem is, when I attacked the

 CHT issue, I did everything at once, so I can't say that one thing was

 far better than any other.  The Cylinder flashing issue was a definite

 problem though...you could just see it.  Funny that my IO-390 cylinders

 from Lycoming didn't need any work at all.  Maybe these days they

 do a better job, or maybe they do a better job than ECI did.

 

 My real remaining thing I'd some day like to improve is Oil temps.

 Interestingly, it used to be my CHT's that were the issue, not oil temps.

 Then after fixing the CHT's, now if there is anything that limits me

 from climbs on hot days it's oil temps.  I set my alarm at 216F to come

 on and get me to do something.  I don't ever let it get over 225F

 without great reason.  I may have seen 235F one or two times in

 1250 hours.   By keeping speeds of 125kts in climb I can almost

 do whatever I want, but I would prefer to be able to have my oil

 temps stay under 210F even in 115kt climbs...and always be

 in the 190's when straight and level.

 

 I may just have to get into a small cowl mod to add an extra exit

 scoop or something under that oil cooler.  It's not a highly pressing

 issue, but would be nice to deal with for any flights out West in

 the warm months, mainly.

 

 Tim

 

 

 On 6/23/2017 3:13 PM, Kelly McMullen wrote:

  	  Quote: 	
		   --> RV10-List message posted by: Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)>

 

 I had good luck with one of my 3/32 (#40) drill bits, 6" long. Just made multiple passes and then worked it back and forth somewhat. I can't say I have seen significant difference, but with OAT around 100 for 9 am takeoff, and 80 at 6500 and 70 at 9500..I'll have to wait for some more normal temps to compare.

 Tim, did you notice much benefit from the RTV between the cylinders, where you closed the gap? 

 	
 

 

 

 

 	
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bhoppe2

Joined: 09 Apr 2015
Posts: 15
Location: Nolensville, TN

Posted: Fri Jun 23, 2017 2:38 pm Post subject: Removing cylinder head flashing

Kelly, 

I have looked at the Anti-Splat cowl flap.  What caught my interest is your comment about "putting 1/2" deflector in front of the louvers".  Please describe this deflector in a little more detail.  If you have a photo, that would be very helpful.

My main concern has been high CHTs, especially on cylinder #6 on initial climb out.  It will usually go above 400F especially in the summer in TN, then drops under 400.  At cruise, all CHTs typically are 350-380F or lower depending how far LOP, with #6 still being the hottest.  I normally have a 30F CHT range between the hottest land coolest cylinders.  One theory is that the air for the oil cooler is diverting cooling air from #6.  

I recently reinstalled the air deflector in front of cyl#2 and put RTV between the cylinders.  That helped the temperature spread only a little, but every little bit helps.

It helped to balance my injectors, including on climb out.  Now, all EGTs peak within 0.1GPH.  Typically, no problems with oil temp.  I have an adjustable damper on the oil cooler, but it only lowers #6 CHT 1 or 2 degrees when I partially close it to raise oil temp by 20 degrees.

Thanks,

Bruce Hoppe

RV-10 N720JH

Sent from my iPad

Bruce Hoppe

Sent from my iPad

 	  Quote: 	
		   On Jun 23, 2017, at 3:39 PM, Kelly McMullen <kellym(at)aviating.com> wrote:

 Very interesting. I replaced my louvers in front of the exhaust pipes with the Anti-Splat cowl flaps. This was first supported by putting 1/2" deflector in front of the louvers, which made a noticeable improvement.

 with the cowl flaps, temps are a bit lower, maybe as good as with the deflector in front of louvers(which would have been a lot cheaper and easier to stick with). However, where my oil temps had been fine, now mine are like yours. I did the flashing removal, but haven't tried the RTV yet. I just need to get my cockpit flow back to where it was flying the Mooney....cowl flaps open for takeoff and climb. Level off, and then close cowl flaps. Open them up as come into pattern to keep  CHTs from climbing again. I may eventually decide to install one of the louvers I removed, right under the oil cooler.

 Your IO-390 cylinders should be perfect...they should be perfect. I don't know if you have priced them, but they are almost double the price of regular 360 angle valve cylinders.

> On 6/23/2017 1:29 PM, Tim Olson wrote:

> 

> I didn't really have a good way to tell, sorry.  The problem is, when I attacked the

> CHT issue, I did everything at once, so I can't say that one thing was

> far better than any other.  The Cylinder flashing issue was a definite

> problem though...you could just see it.  Funny that my IO-390 cylinders

> from Lycoming didn't need any work at all.  Maybe these days they

> do a better job, or maybe they do a better job than ECI did.

> My real remaining thing I'd some day like to improve is Oil temps.

> Interestingly, it used to be my CHT's that were the issue, not oil temps.

> Then after fixing the CHT's, now if there is anything that limits me

> from climbs on hot days it's oil temps.  I set my alarm at 216F to come

> on and get me to do something.  I don't ever let it get over 225F

> without great reason.  I may have seen 235F one or two times in

> 1250 hours.   By keeping speeds of 125kts in climb I can almost

> do whatever I want, but I would prefer to be able to have my oil

> temps stay under 210F even in 115kt climbs...and always be

> in the 190's when straight and level.

> I may just have to get into a small cowl mod to add an extra exit

> scoop or something under that oil cooler.  It's not a highly pressing

> issue, but would be nice to deal with for any flights out West in

> the warm months, mainly.

> Tim

>> On 6/23/2017 3:13 PM, Kelly McMullen wrote:

>> 

>> 

>> I had good luck with one of my 3/32 (#40) drill bits, 6" long. Just made multiple passes and then worked it back and forth somewhat. I can't say I have seen significant difference, but with OAT around 100 for 9 am takeoff, and 80 at 6500 and 70 at 9500..I'll have to wait for some more normal temps to compare.

>> Tim, did you notice much benefit from the RTV between the cylinders, where you closed the gap?

_________________
Bruce Hoppe

Kelly McMullen

Joined: 16 Apr 2008
Posts: 1188
Location: Sun Lakes AZ

Posted: Fri Jun 23, 2017 3:48 pm Post subject: Removing cylinder head flashing

Good to hear from you Deems. That certainly is worthy of some thought. Getting more pressure over #6 would definitely help. My concern would be getting enough ram air pressure in front of nose gear to adequately cool the oil.



Tim, my original issue was high CHTs. Adding the lip in front of the louvers helped, and I don't recall any downside to oil temp.



I only saw higher oil temp after I swapped from louvers to cowl flaps.



However, remember, I am flying in triple digit temps, and comparing to a month ago when temps were more in the 80s. I had high CHT on climb all winter, as well as during phase 1 last summer. The main method for CHT control was to get power under 65% and airspeed above 120. In cruise everything was fine as long as I didn't go above 70% power. Originally, if I didn't pay attention CHT would easily go above 430. Now, 1, 5 and 6 will go to 410 in climb if I try to go above 500 fpm for very long.



-sent from the I-droid implanted in my forearm

 

On Fri, Jun 23, 2017 at 2:39 PM, Deems Davis <deemsdavis(at)cox.net (deemsdavis(at)cox.net)> wrote:

 	  Quote: 	
		  Kelly,



I messed with cht, and oil temps for far too long, I can say that louvers had no noticeable effect. Adding the bigger cooler also had negligible effect. I final solution that solved the issue, was to fashion a ram air intake that combined with the close-out plate on the bottom of the cowl that fits in front of the nose gear. Attached a 3" scat tube and ran that into a fiberglass right angle reducer that coupled with the 3" scat tube and affixed to the top of the oil cooler. Closed off the old oil cooler air intake behind #6. The difference was dramatic, IMO for anything other than cold environs the 10 oil cooler mounting and plumbing is inadequate. For us in the desert the oil cooler demands it's own dedicated air supply. And as you would surmise #6 cyl was now inline with all others, and all others showed a drop in CHTs.

On Fri, Jun 23, 2017 at 1:39 PM, Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)> wrote:

 	  Quote: 	
		  --> RV10-List message posted by: Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)>

 

 Very interesting. I replaced my louvers in front of the exhaust pipes with the Anti-Splat cowl flaps. This was first supported by putting 1/2" deflector in front of the louvers, which made a noticeable improvement.

 with the cowl flaps, temps are a bit lower, maybe as good as with the deflector in front of louvers(which would have been a lot cheaper and easier to stick with). However, where my oil temps had been fine, now mine are like yours. I did the flashing removal, but haven't tried the RTV yet. I just need to get my cockpit flow back to where it was flying the Mooney....cowl flaps open for takeoff and climb. Level off, and then close cowl flaps. Open them up as come into pattern to keep  CHTs from climbing again. I may eventually decide to install one of the louvers I removed, right under the oil cooler.

 Your IO-390 cylinders should be perfect...they should be perfect. I don't know if you have priced them, but they are almost double the price of regular 360 angle valve cylinders.

 

 On 6/23/2017 1:29 PM, Tim Olson wrote:

 



 	  Quote: 	
		   --> RV10-List message posted by: Tim Olson <Tim(at)MyRV10.com>

 

 I didn't really have a good way to tell, sorry.  The problem is, when I attacked the

 CHT issue, I did everything at once, so I can't say that one thing was

 far better than any other.  The Cylinder flashing issue was a definite

 problem though...you could just see it.  Funny that my IO-390 cylinders

 from Lycoming didn't need any work at all.  Maybe these days they

 do a better job, or maybe they do a better job than ECI did.

 

 My real remaining thing I'd some day like to improve is Oil temps.

 Interestingly, it used to be my CHT's that were the issue, not oil temps.

 Then after fixing the CHT's, now if there is anything that limits me

 from climbs on hot days it's oil temps.  I set my alarm at 216F to come

 on and get me to do something.  I don't ever let it get over 225F

 without great reason.  I may have seen 235F one or two times in

 1250 hours.   By keeping speeds of 125kts in climb I can almost

 do whatever I want, but I would prefer to be able to have my oil

 temps stay under 210F even in 115kt climbs...and always be

 in the 190's when straight and level.

 

 I may just have to get into a small cowl mod to add an extra exit

 scoop or something under that oil cooler.  It's not a highly pressing

 issue, but would be nice to deal with for any flights out West in

 the warm months, mainly.

 

 Tim

 

 

 On 6/23/2017 3:13 PM, Kelly McMullen wrote:

  	  Quote: 	
		   --> RV10-List message posted by: Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)>

 

 I had good luck with one of my 3/32 (#40) drill bits, 6" long. Just made multiple passes and then worked it back and forth somewhat. I can't say I have seen significant difference, but with OAT around 100 for 9 am takeoff, and 80 at 6500 and 70 at 9500..I'll have to wait for some more normal temps to compare.

 Tim, did you notice much benefit from the RTV between the cylinders, where you closed the gap? 

 	
 

 

 

 

 	
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 -List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?RV10-List

 ===========

  FORUMS -

 eferrer" target="_blank">http://forums.matronics.com

 ===========

 WIKI -

 errer" target="_blank">http://wiki.matronics.com

 ===========

 b Site -

           -Matt Dralle, List Admin.

 rel="noreferrer" target="_blank">http://www.matronics.com/contribution

 ===========

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor
KCHD

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Fri Jun 23, 2017 6:50 pm Post subject: Removing cylinder head flashing

Bruce, if you will recall the Z channel that is used for stringers in 

the tail cone. I used that, cut one curve off, to have thin, 1/2 right 

angles. I cut to width of the louvers. then used Gorilla brand duct tape 

to tape them in place, just as a temporary trial. I noticed about 20-30 

degree drop in CHT.

On 6/23/2017 3:37 PM, Bruce Hoppe wrote:

 	  Quote: 	

 Kelly,

 I have looked at the Anti-Splat cowl flap.  What caught my interest is your comment about "putting 1/2" deflector in front of the louvers".  Please describe this deflector in a little more detail.  If you have a photo, that would be very helpful.

 My main concern has been high CHTs, especially on cylinder #6 on initial climb out.  It will usually go above 400F especially in the summer in TN, then drops under 400.  At cruise, all CHTs typically are 350-380F or lower depending how far LOP, with #6 still being the hottest.  I normally have a 30F CHT range between the hottest land coolest cylinders.  One theory is that the air for the oil cooler is diverting cooling air from #6.

 I recently reinstalled the air deflector in front of cyl#2 and put RTV between the cylinders.  That helped the temperature spread only a little, but every little bit helps.

 It helped to balance my injectors, including on climb out.  Now, all EGTs peak within 0.1GPH.  Typically, no problems with oil temp.  I have an adjustable damper on the oil cooler, but it only lowers #6 CHT 1 or 2 degrees when I partially close it to raise oil temp by 20 degrees.

 Thanks,

 Bruce Hoppe

 RV-10 N720JH

 Sent from my iPad

 Bruce Hoppe

 Sent from my iPad

> On Jun 23, 2017, at 3:39 PM, Kelly McMullen <kellym(at)aviating.com> wrote:

>

> 

>

> Very interesting. I replaced my louvers in front of the exhaust pipes with the Anti-Splat cowl flaps. This was first supported by putting 1/2" deflector in front of the louvers, which made a noticeable improvement.

> with the cowl flaps, temps are a bit lower, maybe as good as with the deflector in front of louvers(which would have been a lot cheaper and easier to stick with). However, where my oil temps had been fine, now mine are like yours. I did the flashing removal, but haven't tried the RTV yet. I just need to get my cockpit flow back to where it was flying the Mooney....cowl flaps open for takeoff and climb. Level off, and then close cowl flaps. Open them up as come into pattern to keep  CHTs from climbing again. I may eventually decide to install one of the louvers I removed, right under the oil cooler.

> Your IO-390 cylinders should be perfect...they should be perfect. I don't know if you have priced them, but they are almost double the price of regular 360 angle valve cylinders.

>

>> On 6/23/2017 1:29 PM, Tim Olson wrote:

>> 

>> I didn't really have a good way to tell, sorry.  The problem is, when I attacked the

>> CHT issue, I did everything at once, so I can't say that one thing was

>> far better than any other.  The Cylinder flashing issue was a definite

>> problem though...you could just see it.  Funny that my IO-390 cylinders

>> from Lycoming didn't need any work at all.  Maybe these days they

>> do a better job, or maybe they do a better job than ECI did.

>> My real remaining thing I'd some day like to improve is Oil temps.

>> Interestingly, it used to be my CHT's that were the issue, not oil temps.

>> Then after fixing the CHT's, now if there is anything that limits me

>> from climbs on hot days it's oil temps.  I set my alarm at 216F to come

>> on and get me to do something.  I don't ever let it get over 225F

>> without great reason.  I may have seen 235F one or two times in

>> 1250 hours.   By keeping speeds of 125kts in climb I can almost

>> do whatever I want, but I would prefer to be able to have my oil

>> temps stay under 210F even in 115kt climbs...and always be

>> in the 190's when straight and level.

>> I may just have to get into a small cowl mod to add an extra exit

>> scoop or something under that oil cooler.  It's not a highly pressing

>> issue, but would be nice to deal with for any flights out West in

>> the warm months, mainly.

>> Tim

>>> On 6/23/2017 3:13 PM, Kelly McMullen wrote:

>>> 

>>>

>>> I had good luck with one of my 3/32 (#40) drill bits, 6" long. Just made multiple passes and then worked it back and forth somewhat. I can't say I have seen significant difference, but with OAT around 100 for 9 am takeoff, and 80 at 6500 and 70 at 9500..I'll have to wait for some more normal temps to compare.

>>> Tim, did you notice much benefit from the RTV between the cylinders, where you closed the gap?

>

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

Greg McFarlane

Joined: 12 Apr 2012
Posts: 57
Location: Albany Western Australia

Posted: Sat Jun 24, 2017 4:03 am Post subject: Re: Removing cylinder head flashing

I was concerned about high CHT & Oil temps in local RV10s here  so I was very lucky to get some details from Deems about his mod when I was fitting my engine, I took his idea a bit further and I'm pleased to say that it has worked out extremely well. I can keep CHT under 350 and oil at 180. (we have mid 30 to 40*C conditions at times)  As the pics show I added an intake for the oil cooler to the bottom cowl, a manifold then takes the air to the left of the front wheel slot (1/2" below the fab) and then via a 4" scat to the vertically mounted standard oil filter. Air is regulated by a push/pull butterfly valve at the oil cooler    (Not visible) and exhausts out of the oil cooler couple inches from the side of the cowl. No air is bled off the top of the engine so all is available for CHT cooling. CHTs are even on all cylinders.  I didn't fit the flimsy louvres or cowl flaps but installed letterbox vents on both sides. I did fit a "cowl flap" on the side of the cowl next to the oil cooler because I didn't know if the air flow through the cooler would be enough, but this hasn't  been needed so I've now permently fixed it shut. One downside to the mod is that the scat hose must be removed before taking the bottom cowl off, not a big deal, the scat is a push fit into the manifold and is secured by hand with a -3 bolt into a nut plate. Anyway, not really about CHT flashing but related to the cooling discussion.      Cheers from Western Australia

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digidocs

Joined: 04 Dec 2013
Posts: 59

Posted: Sat Jun 24, 2017 9:00 pm Post subject: Removing cylinder head flashing

Thanks for all of the advice on the flashing!  This list is a great resource.



David

On Fri, Jun 23, 2017 at 11:53 AM, Tim Olson <Tim(at)myrv10.com (Tim(at)myrv10.com)> wrote:

 	  Quote: 	
		  --> RV10-List message posted by: Tim Olson <Tim(at)MyRV10.com>

 

 I found a small thin file at our local farm store that fits nicely if the gap isn't completely closed.

 I song have the info but it was maybe 6-8" long and maybe at most 1/2" wide and about 1/16" thick or so.  That worked well.

 Tim

 

 > On Jun 23, 2017, at 11:38 AM, David Carr <junk(at)dcarr.org (junk(at)dcarr.org)> wrote:

 >

 > Hi list,

 >

 > What are your favorite techniques/tools for removing the cylinder head flashing (near the top spark plug)?

 >

 > So far I've discovered Tim's approach using an extension drill like an end mill and also a suggestion to try modifying a hacksaw rod blade into long rotary burr.

 >

 > Thanks for your input,

 > David

 

 

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