Board index

My Home Page

PilotOdyssey.com By hoser...


PilotOdyssey.com Chat Room

PilotOdyssey.com Photo Album

* Login   * Register * FAQ
http://www.pilotodyssey.com/PO/adm/images/imagemenu/smiley_cool.png PilotOdyssey.com Chat    http://www.pilotodyssey.com/PO/adm/images/imagemenu/find.png PilotOdyssey.com Google Search    http://www.pilotodyssey.com/PO/adm/images/imagemenu/emoticon_tongue.png FL400 Parts    http://www.pilotodyssey.com/PO/adm/images/imagemenu/emoticon_grin.png FL350 Parts    http://www.pilotodyssey.com/PO/adm/images/imagemenu/emoticon_evilgrin.png FL250 Parts    http://www.pilotodyssey.com/PO/adm/images/imagemenu/emoticon_unhappy.png Admin Email    http://www.pilotodyssey.com/PO/adm/images/imagemenu/emoticon_grin.png PilotOdyssey.com V2.0   
It is currently Thu Oct 19, 2017 7:01 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 25 posts ] 
Author Message
 Post subject: New DCP top end #2
PostPosted: Wed May 13, 2015 4:11 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
I pulled the #1 top end honed it and sent it out with a non mudd piston to replace an rut ru I did. details on that later. So I thought I would play with another set up. On this one I used mudd #4 piston. Few pics to share.


Attachments:
Mud #4 piston.jpg
Mud #4 piston.jpg [ 57.71 KiB | Viewed 1079 times ]
Mud #4 in cylinder.jpg
Mud #4 in cylinder.jpg [ 69.41 KiB | Viewed 1079 times ]
Assembly guage number 141.jpg
Assembly guage number 141.jpg [ 43.27 KiB | Viewed 1079 times ]
Fist fire guage reading 144.jpg
Fist fire guage reading 144.jpg [ 42.36 KiB | Viewed 1079 times ]
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed May 13, 2015 4:14 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
more pics


Attachments:
First heat cyle engine temp 110.jpg
First heat cyle engine temp 110.jpg [ 50.5 KiB | Viewed 1078 times ]
First heat cycle warm dry 145.jpg
First heat cycle warm dry 145.jpg [ 61.4 KiB | Viewed 1078 times ]
First heat cycle warm wet 149.jpg
First heat cycle warm wet 149.jpg [ 66.69 KiB | Viewed 1078 times ]
low speed pass engine ater heat cycles.jpg
low speed pass engine ater heat cycles.jpg [ 54.13 KiB | Viewed 1078 times ]
after low speed pass Cold Dry 146.jpg
after low speed pass Cold Dry 146.jpg [ 69.28 KiB | Viewed 1078 times ]
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed May 13, 2015 4:27 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
more pics

I wanted to show how the ring condition to gauge pressure related from assembly through heat cycle to jet runs. This will show the how the RA of the cylinder and ring/piston prep affects the rings through break in. As we know the sooner they break in the better. Now I can use this to monitor how this cylinder, piston and other parts hold up to the Engine parameters.

Some may ask why did I settle on the 140 to 150 range for this cylinder. As one pic shows it has a milled head This head also has modified combustion chamber. The head gasket is different from stock in way of thickness and OD. The cylinder is a ported one with a high exhaust duration as well as modified intake and transfers. I did not want to exceed 150 to 155 with this duration at the rpm I intend to run to avoid detonation using pump gas. As one of the pictures shows the Engine temp is where I want this Engine to keep it out of detonation.

So we will see how it goes

The jetting right now is at 180 main EEG first clip position. The needle will most likely be changed however first I need to check the mid range and transition to the main for 6500 to 7500 rpm.


Attachments:
after low speed pass Cold Wet 150.jpg
after low speed pass Cold Wet 150.jpg [ 51.21 KiB | Viewed 1076 times ]
Head tab milled.jpg
Head tab milled.jpg [ 54.79 KiB | Viewed 1076 times ]
next day jetting short pulls.jpg
next day jetting short pulls.jpg [ 53.23 KiB | Viewed 1076 times ]
next day warm dry 145.jpg
next day warm dry 145.jpg [ 44.35 KiB | Viewed 1076 times ]
next day warm wet 148.jpg
next day warm wet 148.jpg [ 67.96 KiB | Viewed 1076 times ]
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Mon Aug 10, 2015 3:37 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
A little update on the piston.
After running this piston a while at LS and other I decided yesterday to remove the head and take a look.

Side notes when reviewing these pictures:
For the first two runs at LS I ran it fat on the new piston then leaned it down
It still could be leaned out more.
The base gasket is fixed in thickness to establish a fixed static port timing.

Goal:
To check the effect of flow with this port/head work against three different head gaskets
All three are different in way of thickness and ID.
All three gaskets are readily available


Attachments:
Pre top end inspection.jpg
Pre top end inspection.jpg [ 70.61 KiB | Viewed 1008 times ]
Post top end inspection.jpg
Post top end inspection.jpg [ 43.64 KiB | Viewed 1008 times ]
poped the top cometic gasket.jpg
poped the top cometic gasket.jpg [ 84.86 KiB | Viewed 1008 times ]
old gasket thickness.jpg
old gasket thickness.jpg [ 42.59 KiB | Viewed 1008 times ]
new gasket thickness.jpg
new gasket thickness.jpg [ 65.38 KiB | Viewed 1008 times ]
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Mon Aug 10, 2015 3:39 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
more pics

Interesting flow pattern sure not a stock pilot plot.


Attachments:
flow patteren 1 on piston .jpg
flow patteren 1 on piston .jpg [ 59.5 KiB | Viewed 1008 times ]
flow patteren 2 on piston.jpg
flow patteren 2 on piston.jpg [ 65.91 KiB | Viewed 1008 times ]
flow patteren 3 on piston cloe up.jpg
flow patteren 3 on piston cloe up.jpg [ 69.19 KiB | Viewed 1008 times ]
flow patteren 4 on piston.jpg
flow patteren 4 on piston.jpg [ 41.92 KiB | Viewed 1008 times ]
ready to bolt up for run test.jpg
ready to bolt up for run test.jpg [ 40.49 KiB | Viewed 1008 times ]
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Mon Aug 10, 2015 4:37 pm 
Offline

Joined: Mon Dec 15, 2003 2:40 pm
Posts: 22128
Location: Chicago
Holy fat batman :shock: Lean that sucker out and enjoy should be carbon over 90% of the piston :-)

Less than 150 psi? I always ran 168-172 on 91 octane.

Here is 171 PSI and still really fat http://www.pilotodyssey.com/duncanhead1.htm
Here is leaner where the carbon was out to the edges well before the bearing parts beat the carbon off lol viewtopic.php?f=25&t=443 this was back in the days where I was playing with the different head designs and compression ratios, Duncan and Pro Design heads with and without gaskets, 47cc and 49cc domes.. Somewhere on this site is many more piston wash pics.


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Mon Aug 10, 2015 6:21 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
So you think 171 static with an exhaust duration of 192 at 8000 rpm wit a UCCR of 10.5 to 1 on pump gas would be ok? Thanks for the links.

I thought the swirl pattern heading around the cylinder and out the exhaust was kinda cool. As well as the color change of the piston crown as it matches up with the head shape. The way the boost port cools of the plug area I thought was kinda cool as well as the shape it left behind compared to a stock on which is generally more so round.


Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Mon Aug 10, 2015 8:17 pm 
Offline

Joined: Mon Dec 15, 2003 2:40 pm
Posts: 22128
Location: Chicago
adnoh wrote:
So you think 171 static with an exhaust duration of 192 at 8000 rpm wit a UCCR of 10.5 to 1 on pump gas would be ok? Thanks for the links.

I thought the swirl pattern heading around the cylinder and out the exhaust was kinda cool. As well as the color change of the piston crown as it matches up with the head shape. The way the boost port cools of the plug area I thought was kinda cool as well as the shape it left behind compared to a stock on which is generally more so round.


You ever seeing any signs of detonation?

The picture is a great example of what they mean when they say 'piston wash' most the time the pistons has so much carbon on them you cant see the "wash" part .


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Tue Aug 11, 2015 11:26 am 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
No signs of detonation yet. Heck I do not want to burn up the piston yet. Baby steps until it goes then I will now the limit.
I think I previous stated that I will increase Cr as I go if not sorry.

FYI as you increase ex duration you need to watch you CR or static the more the duration the less CR you need for dynamic pumping which effects octane or max static/CR on pump gas. If you ex is much greater or increases and you restore you CR or static the dynamic pumping increases at rpm the cylinder temp and changes the LPP which can lead to detonation. This is to say you add duration and restore CR the octane level required rises based on the UCCR of the Engine. See how the ATVR Engine and Engine work has an issue. The UCCR is based off of bore/stroke and head volume at TDC (Top Dead Center). So we look at Duration/Static and UCCR for octane required to prevent any detonation with out a timing change or fuel change to maintain the proper LLP ( location of Peak Pressure) which in turn controls cylinder temps, LPP to soon will over heat a piston and send it to pre ignition and detonation. This also lowers the EGT reading. To late of a LPP and the EGT would read higher so do not jet of this or you will burn it up.

Enough back yard babble on that subject I think most have already figured that one out If not I'll share more thought on the subject, Heck hope I was correct in my thinking.

Adnoh


Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Tue Aug 11, 2015 2:26 pm 
Offline

Joined: Tue Jan 17, 2012 3:19 am
Posts: 4054
Location: Hope, B.C Canada
adnoh wrote:
No signs of detonation yet. Heck I do not want to burn up the piston yet. Baby steps until it goes then I will now the limit.
I think I previous stated that I will increase Cr as I go if not sorry.

FYI as you increase ex duration you need to watch you CR or static the more the duration the less CR you need for dynamic pumping which effects octane or max static/CR on pump gas. If you ex is much greater or increases and you restore you CR or static the dynamic pumping increases at rpm the cylinder temp and changes the LPP which can lead to detonation. This is to say you add duration and restore CR the octane level required rises based on the UCCR of the Engine. See how the ATVR Engine and Engine work has an issue. The UCCR is based off of bore/stroke and head volume at TDC (Top Dead Center) (Top Dead Center). So we look at Duration/Static and UCCR for octane required to prevent any detonation with out a timing change or fuel change to maintain the proper LLP ( location of Peak Pressure) which in turn controls cylinder temps, LPP to soon will over heat a piston and send it to pre ignition and detonation. This also lowers the EGT reading. To late of a LPP and the EGT would read higher so do not jet of this or you will burn it up.

Enough back yard babble on that subject I think most have already figured that one out If not I'll share more thought on the subject, Heck hope I was correct in my thinking.

Adnoh


OK OK Adnoh I have had enough of your poo LOL.
What do you do for a living if I might ask ??
It is obvious you are not some clown when it comes to engines. I have been reading your stuff since I joined this site. You are very knowledgeable when it comes to engines and I am just curious as to what your trade is. When I read you poo I have no idea most of the time about what you are talking about but I do try to decipher it. Hope your stupid employer knows what he got. Many times that's not the case.


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed Aug 12, 2015 11:35 am 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
canadian oddy, Thank you for the kind words. As far as what I do for a living it depends on what day it is. I like to think of my self as a jack of all trades and a master of one. I own and operate my own electrical business. I'm pretty sure my wife knows what She's got (aka: boss), Still married. I just like to learn like the rest of us when it comes to our toys. I have the luxury of knowing a few professional Engine builders and they share things with me, usually when I have hit a road block. I think it's fun for them as a lot of times they just chuckle at me and shake there head. I like the poo word, maybe adopt it to my babble. Back yard hacker poo, by Adnoh. Has a ring to it don't you think. Then we can assign a turd number to it like rotten tomatoes to a movie. We can call it a turd scale. The scale can run from -1 to 5 turds, or how long you sit on the toilet reading the poo.

Back to the pics.

"H" had mentioned a couple of things I feel we should look at a little closer. He had mentioned a bump in static. Yes he is correct a bum would be helpful as long as I keep the possibility of Detonating in check. He had also mentioned Piston wash, The excess fuel leaving behind visual flow pattern. He also mentioned lean that sucker out. You see all three items can and will be done. One issue with cylinder washing is it can lead to excessive carbon build up on the piston crown and in the pic you can see evidence of that. If I was to continue to run the Engine extra rich it would build up all over the crown and lead to the piston crown holding too much heat and that is bad. On the plus side the piston wash aka: cylinder washing, can help an Engine survive in a close to pre-ignition state. This is a band aid option to what need to be done to correct the issue. For short term running no big deal for long term running a bad thing. The positive here is I have a picture of what is going on inside the cylinder according to my hack job on the ports. The heart shaped area on the piston dome defiantly shows a unique burn pattern. This is due to the boost port angle change. I had posted a while back on this change. The angle was increased which in turn changes the inlet direction from forward top of cylinder to plug center. I did this to see if it had an effect on plug temp and reduce pre ignition from a hot tip. I run a 7 range plug in this Engine gaped at .035 for this CR. What I also did was raise the roof of the boost port just slightly higher then the rest of the transfer ports. Being a electrician we go by the path of least resistance. I also use a low velocity intake set up with a lower case CR. With the case being at a positive pressure as the boost port starts to open then the pressure relief start the flow there first. This will not only aid in cooling the piston crown but also cool down the hot tip of the plug Thus leaving behind the carbon tract. Another function of this is clear the cylinder of spent gas as left over spent case has an effect on the incoming charge density. What I did like was the path and flow pattern building to a visual stream out the exhaust. What I see here is two things one cylinder evacuation being good and two the stuffing charge being at a high rate. If the velocity of the visual stream was not there then I would conclude that cylinder was not being evacuated good enough and the velocity out the pipe was not pulling enough from the transfer ports. You can look at like a steam being pulled into the river in way of current flow. Using this theory one can also conclude the Engine case will create a good negative pressure and pull fuel as well as aid in reed tip lift. The tip lift plays an important part on velocity and density. The tip lift area is what's key here or total area which controls velocity.

Change the subject a little here as the poo is starting to flow no pun intended.

Let say for a minute I was working on detonation control for a fuel injected set up. I like what I see. So I would program this set up into the map once a knock sensor pick up detonation. I could also use this as my start up program and use a slight variation for normal use or when others are driving my pilot. Then when I run with the wolf pack as Stix as kindly placed a name on our cat and mouse ridding style at the dunes, I can hit a switch allowing for the performance tune to take over. With a wiesco it can take detonation/knock for a short time where a stock arts can not. I also have posted on this.

So the next step would be increase timing, raise CR then re-jet. Then study effects. So what would be the best way to raise the CR?????? There are several way to do this with each having there own effect. Since I did a port map calculating all port using angle area I have an idea of what there good for at what rpm. Now that I have a visual glue to there effect in way of timing and port angle changes (which I also posted a port lay out for the new angles) I can work from there.

In a previous post I should what the static would be if I used the same head and gaskets with a 92/184 cylinder. It put the static up to 180. So what to do??? I used the angle area for this porting at .00011 to .00018 angle range. This will put the exhaust at an rpm of 5600 to 9250. Since this is a large bore cylinder I wanted to be on the higher end of the angle.
Using this calculation I can determine that the duration can be reduced a little. So either I need a thinned base gasket or have the base turned down a little. The down side to turning down the base is I set the port bottoms flush with the piston crown, not two big of deal thought. So if I turn the base down this will keep every thing up top the same with exception of the Volume above TDC (Top Dead Center) and Squish clearance. Using the head gasket thickness for this head can determine the available amount to remove from the base and maintain an adequate clearance. This also changes the mean line for a new angle area calculation. Which in turn reduces the angle area of the ports. Which also changes the rpm the port is good for. So do I want to change the port timing to increase CR or do I want to do it from the top.

Either way will have an effect on LPP as the fuel is getting squeezed tighter and changing the so called rate. The LPP will be advanced and the ex port will be lower this leaving greater heat in the cylinder longer to which the piston and cylinder will need to get rid of it though cooling. This increase thermal load on the piston. This also has an effect on the incoming charge density. This will also effect flow rate and flow pattern on the piston. The flow pattern will be changed due to a lower exhaust temp and the pipe will be retarded ( time for a poo) and upset charge density upon compression. Now the cylinder gases that is being squeezed tighter with less density and things get even hotter and future increases LPP. As this take place and cylinder temp is not kept in check the Engine spins toward pre ignition and then detonates. Would be nice to have a advance curve (retard) to fix this. So if this was fuel injected would CHT determine retard rate and fuel rate (injector open time) to wash the cylinder and achieve a lower LPP for the gas being ran in the Engine if the Cr was higher.

So carful consideration of what to do should take place.

Enough, Back Yard Hacker POO for now, got to go to work.

Adnoh

P.S. If I have miss spoke during my babble speak up. We all are for fun and adventure. Important I'm no professional Engine builder al all or in any way, just want to be clear.


Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed Aug 12, 2015 2:31 pm 
Offline

Joined: Tue Jan 17, 2012 3:19 am
Posts: 4054
Location: Hope, B.C Canada
adnoh wrote:
canadian oddy, Thank you for the kind words. As far as what I do for a living it depends on what day it is. I like to think of my self as a jack of all trades and a master of one. I own and operate my own electrical business. I'm pretty sure my wife knows what She's got (aka: boss), Still married. I just like to learn like the rest of us when it comes to our toys. I have the luxury of knowing a few professional Engine builders and they share things with me, usually when I have hit a road block. I think it's fun for them as a lot of times they just chuckle at me and shake there head. I like the poo word, maybe adopt it to my babble. Back yard hacker poo, by Adnoh. Has a ring to it don't you think. Then we can assign a turd number to it like rotten tomatoes to a movie. We can call it a turd scale. The scale can run from -1 to 5 turds, or how long you sit on the toilet reading the poo.

Back to the pics.

"H" had mentioned a couple of things I feel we should look at a little closer. He had mentioned a bump in static. Yes he is correct a bum would be helpful as long as I keep the possibility of Detonating in check. He had also mentioned Piston wash, The excess fuel leaving behind visual flow pattern. He also mentioned lean that sucker out. You see all three items can and will be done. One issue with cylinder washing is it can lead to excessive carbon build up on the piston crown and in the pic you can see evidence of that. If I was to continue to run the Engine extra rich it would build up all over the crown and lead to the piston crown holding too much heat and that is bad. On the plus side the piston wash aka: cylinder washing, can help an Engine survive in a close to pre-ignition state. This is a band aid option to what need to be done to correct the issue. For short term running no big deal for long term running a bad thing. The positive here is I have a picture of what is going on inside the cylinder according to my hack job on the ports. The heart shaped area on the piston dome defiantly shows a unique burn pattern. This is due to the boost port angle change. I had posted a while back on this change. The angle was increased which in turn changes the inlet direction from forward top of cylinder to plug center. I did this to see if it had an effect on plug temp and reduce pre ignition from a hot tip. I run a 7 range plug in this Engine gaped at .035 for this CR. What I also did was raise the roof of the boost port just slightly higher then the rest of the transfer ports. Being a electrician we go by the path of least resistance. I also use a low velocity intake set up with a lower case CR. With the case being at a positive pressure as the boost port starts to open then the pressure relief start the flow there first. This will not only aid in cooling the piston crown but also cool down the hot tip of the plug Thus leaving behind the carbon tract. Another function of this is clear the cylinder of spent gas as left over spent case has an effect on the incoming charge density. What I did like was the path and flow pattern building to a visual stream out the exhaust. What I see here is two things one cylinder evacuation being good and two the stuffing charge being at a high rate. If the velocity of the visual stream was not there then I would conclude that cylinder was not being evacuated good enough and the velocity out the pipe was not pulling enough from the transfer ports. You can look at like a steam being pulled into the river in way of current flow. Using this theory one can also conclude the Engine case will create a good negative pressure and pull fuel as well as aid in reed tip lift. The tip lift plays an important part on velocity and density. The tip lift area is what's key here or total area which controls velocity.

Change the subject a little here as the poo is starting to flow no pun intended.

Let say for a minute I was working on detonation control for a fuel injected set up. I like what I see. So I would program this set up into the map once a knock sensor pick up detonation. I could also use this as my start up program and use a slight variation for normal use or when others are driving my pilot. Then when I run with the wolf pack as Stix as kindly placed a name on our cat and mouse ridding style at the dunes, I can hit a switch allowing for the performance tune to take over. With a wiesco it can take detonation/knock for a short time where a stock arts can not. I also have posted on this.

So the next step would be increase timing, raise CR then re-jet. Then study effects. So what would be the best way to raise the CR?????? There are several way to do this with each having there own effect. Since I did a port map calculating all port using angle area I have an idea of what there good for at what rpm. Now that I have a visual glue to there effect in way of timing and port angle changes (which I also posted a port lay out for the new angles) I can work from there.

In a previous post I should what the static would be if I used the same head and gaskets with a 92/184 cylinder. It put the static up to 180. So what to do??? I used the angle area for this porting at .00011 to .00018 angle range. This will put the exhaust at an rpm of 5600 to 9250. Since this is a large bore cylinder I wanted to be on the higher end of the angle.
Using this calculation I can determine that the duration can be reduced a little. So either I need a thinned base gasket or have the base turned down a little. The down side to turning down the base is I set the port bottoms flush with the piston crown, not two big of deal thought. So if I turn the base down this will keep every thing up top the same with exception of the Volume above TDC (Top Dead Center) (Top Dead Center) and Squish clearance. Using the head gasket thickness for this head can determine the available amount to remove from the base and maintain an adequate clearance. This also changes the mean line for a new angle area calculation. Which in turn reduces the angle area of the ports. Which also changes the rpm the port is good for. So do I want to change the port timing to increase CR or do I want to do it from the top.

Either way will have an effect on LPP as the fuel is getting squeezed tighter and changing the so called rate. The LPP will be advanced and the ex port will be lower this leaving greater heat in the cylinder longer to which the piston and cylinder will need to get rid of it though cooling. This increase thermal load on the piston. This also has an effect on the incoming charge density. This will also effect flow rate and flow pattern on the piston. The flow pattern will be changed due to a lower exhaust temp and the pipe will be retarded ( time for a poo) and upset charge density upon compression. Now the cylinder gases that is being squeezed tighter with less density and things get even hotter and future increases LPP. As this take place and cylinder temp is not kept in check the Engine spins toward pre ignition and then detonates. Would be nice to have a advance curve (retard) to fix this. So if this was fuel injected would CHT determine retard rate and fuel rate (injector open time) to wash the cylinder and achieve a lower LPP for the gas being ran in the Engine if the Cr was higher.

So carful consideration of what to do should take place.

Enough, Back Yard Hacker POO for now, got to go to work.

Adnoh

P.S. If I have miss spoke during my babble speak up. We all are for fun and adventure. Important I'm no professional Engine builder al all or in any way, just want to be clear.


Now I have a headache and a broken back.
"We can call it a turd scale. The scale can run from -1 to 5 turds" Baahahahahahhahahahahaha
Love that one. I think I might steal it and use it.


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed Aug 12, 2015 6:20 pm 
Offline

Joined: Mon Dec 15, 2003 2:40 pm
Posts: 22128
Location: Chicago
Any pictures of your wet line location?

I always found the most power right on the edge of detonation on a normal day and noticeably into detonation on a day of low humidity and 60 degrees. Throttle response and rev out crispness would be perfect in this condition.


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Tue Aug 18, 2015 11:57 am 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
"H", I have not checked this Wet spot as I do not want to open it up at LS. To get an accurate WOT (Wide Open Throttle) wet line I would need to do a high speed pass under load at high Engine temp. I could do some here however they wouldn't be very accurate. I may do some testing around here for something to do when time permits.

I also played with the numbers to see where the UCCR would be if I bumped the static to 170. The UCCR would be right over 13.2 to 1 for that Engine. If we look at a stock and slight modified exhaust port the UCCR would be right at and under 11 to 1 for a static of 170. So I do not think 170 would be advisable for pump gas for this Engine configuration. I could discuses that more if you would like or anybody is interested.

I would like to share a little more on the pictures. This time looking at the gasket change and why.
We have talked about raising the CR and I had full attention to do so just not sure yet on how much. Changing the gasket did in fact achieve a change in the CR. It did this by way of the gaskets thickness and ID (inside diameter). The change accounted for 1.94 cc's or -1.94 cc from the equation. So if we look at the UCCR (un-corrected compression ratio) which consist of the bore, stoke and area above the piston at TDC (Top Dead Center) the UCCR has changed or in this case increased. The CCR (corrected compression ratio) has also increased for the same reason as the UCCR. The area above the piston at TDC (Top Dead Center) has been reduced. The bore, stroke and effective stroke (the distance the piston travels after the exhaust port is closed off by the piston) as remained unchanged.
So let’s look at the numbers:
(1) Cometic #1: UCCR = 11.3255, CCR = 6.4268
(2) Athena #2: UCCR = 11.8669, CCR = 6.7113
UCCR change + .5414
CCR change + .2845

The head gasket used which we will call #1 was a Cometic. Not a real big fan of these however there cheep and do seal good. They have their place in the pecking order though. For my application it was not a great choice. For testing though it served its purpose. The #1 gasket has a compressed thickness of 1.1 mm and an average ID of 82.55 mm. You notice I said average ID and that is one item I do not really care for when it comes to the Cometic. If you measure it in an X and Y orientation than you will notice it varies in width or is oval. This gasket out of four I use has the greatest amount of out of round. Not a real big deal however noticeable. The Cometic adhering properties makes it hard to get the head off if you leave the cylinder on the Engine and take the most about of clean up and prep for a new gasket. This could lead to cylinder or head matting surface damage or damage to the head it’s self depending on removal method. Gasket #2 is an Athena and has a compressed thickness of .71 mm and an ID of 81.3 mm. I like this choice due it matches the 80.5mm bore better and is close to a stock head gasket. One can look at this like reducing the head volume by 1.94 cc with the exception that the heads physical shape and configuration has not changes. If this was a stock head than removing that amount would not be a big deal as one could simply mill the head about .5 mm since the stock head has a recessed pocket (see pictures) of about1.9 mm which accounts for about 9.8 ccs. The ID of this pocket is about 81 mm. Since MY head has been milled right at 2 mm’s flush with the squish band already and the squish area ratio and combustion chamber has been modified and is fixed, I do not want to touch it YET so I can use my existing squish data for that head. Looking at the pictures of the static gauge reading you will notice it did not change hardly any if any at all even with an increase in CR.

So why make the change?
It’s a matter of Squish and Squish velocity. It lowers the combustion chambers roof closer and sparks plug electrode closer to the piston. This also reduces the Squish clearance. It takes the Squish from 1.6mm to 1.26 mm. When you reduce this clearance it increases the squish velocity and creates more turbulence in the combustion chamber as well as a higher compressed state of the gas. As the gas compressed state raises the heating effect on the gas increases or for better words Compression Heating. When this takes place you improve thermal efficiency. “Efficiency = 1 - (1/compression ratio)^gamma-1”

This translates into higher heat load on the piston to which needs to be dissipated into the surrounding area and atmosphere via the coolant system. This also heats of the surrounding metal parts which has an effect on the incoming fuel charge. Staying with the IDEA of Fuel Cools the higher we raise this temperature the more fuel we need to resist detonation from higher heat load. Based on this you can see where direct injection has a big advantage with high CR. Unfortunately we do not have direct injection yet. If we look at the Flame Propagation and discuss flame speed the reduction of squish plays a role in this. The mixture strength at temperature also plays a part in the flame speed. This flame speed, degrees of spark ignition is what sets the LPP or Location of peak pressure. Keep in mind the timing is controlled by a CDI (Capacitor Discharge Ignition) and Fixed Static set point. We do not have a way for the CDI (Capacitor Discharge Ignition) to adjust for differentials in Flame front. So we design the Engine changes around these fixed settings. Every time we re-jet, alter the port timing or space above the piston at TDC (Top Dead Center) or head we alter the Flame speed and Location of Peak Pressure. This LPP changes constantly with rpm. As mentioned above the compression heating effect plays a part in this as it heats things up inside the cylinder and has an effect on the incoming charge. As this takes place the fuel is subject to greater heat for its density and can lead to detonation.

This takes up to the duration of the exhaust port and its effect on the LPP based off of CCR. We go from a static environment to a dynamic one or the engines rotating assembly in motion due to combustion. We all have seen the Engine demo “H” has put on this site if not you should. The exhaust port acts like a super charger and adds pressure to the atmospheric pressure state at port closure. This to say when the exhaust port closes the area inside the cylinder is at an atmospheric condition during cranking compression reading. During combustion the return wave of the pipe pushes the intake charge back into the cylinder prior to closing off the port. This takes that cylinder area from atmospheric to a pressurized state then continues to compress and rise in pressure from there. An important key is to time the exhaust wave with port closure. Wave refraction to soon and pressure will drop off as it bleeds back into the pipe, too late and the wave pressure hits the face of the piston skirt leaving power on the table. The up side to hitting the face is that is does lube the skirt well. The down side is advances the LPP which could be bad. When looking at this one also should take into account just what the port in this case exhaust port can do in way of flow. When we discuss flow of a port we have to do Angle Area calculations to see at what the port is good for. I need to stay on tract so talk about that later and continue to cover, Duration and CR related to LPP.
The pipes wave speed is based off of heat, hotter gases flow quicker. See how a shift to a lower EGT would result in lower speed and affect the dynamic cylinder pressure. This would advance the LPP and build higher cylinder temps and then it could continue to build until either pre ignition set in or detonation would accrue or both if your jetting was to lean for the octane used at a given SI (spark Ignition) timing. You could go from a rich to lean it matter of seconds. A CHT and EGT used together would see this coming. This of course your Engine parameters must be close or at Detonation levels.



Since the effect in UCCR and CR are so minor one might ask, what’s the big deal?
(1) It takes us closer the fuel ability to resist detonation.
(2) This also increases the engines Thermal Efficiency which builds more MBT for the engines timing and fuel choice.
(3) It accounts for a higher ER (Expansion Ratio) which allows more energy to be extracted.


This does not cover the whole picture however gives you an idea on my decision process. This experiment basically provides me with information for future builds and other ideas. These pistons will not reach circulations other than in my personal or loaner cylinder/engines.
If you have any question please ask and I will do the best I can to answer or other on this board can chime in and answer.
Please do not use this to go adjust your Engine parameters based on what you read. Heck I could be all wet and this is all worthless information.
I Hope after reading this you get an Idea of the way my Hacker head works. Please feel free to rate according the new POO scale.

Adnoh


Attachments:
Stock head.jpg
Stock head.jpg [ 58.26 KiB | Viewed 901 times ]
measuring the depth.jpg
measuring the depth.jpg [ 56.69 KiB | Viewed 901 times ]
1.9 mm in depth.jpg
1.9 mm in depth.jpg [ 33.7 KiB | Viewed 901 times ]
enigne at TDC ccs used 2  37 cc total above piston at TDC.JPG
enigne at TDC ccs used 2 37 cc total above piston at TDC.JPG [ 118.11 KiB | Viewed 901 times ]
fluid in cylinder to base of plug notice offset of plug from center.JPG
fluid in cylinder to base of plug notice offset of plug from center.JPG [ 93.33 KiB | Viewed 901 times ]
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Tue Aug 18, 2015 2:29 pm 
Offline

Joined: Tue Jan 17, 2012 3:19 am
Posts: 4054
Location: Hope, B.C Canada
I like reading this thread but it is way over my head. Even though I am laying here with a broken back for the next three months I have lots of time to read but can't seem to concentrate, but one of the things you said here caught my attention.
You said " Keep in mind the timing is controlled by a CDI (Capacitor Discharge Ignition) (Capacitor Discharge Ignition) and Fixed Static set point. We do not have a way for the CDI (Capacitor Discharge Ignition) (Capacitor Discharge Ignition) to adjust for differentials in Flame front. So we design the Engine changes around these fixed settings."
The reason this caught my attention was that at one point during my many Engine re-builds I was thinking about making an adjustable pick up coil mount. Wouldn't this affectively adjust the timing ??
Just curious as to what you think of this idea. Stupid idea ?? Would it even work ??


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Tue Aug 18, 2015 6:18 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
I would say noting stupid about it. I do adjust mine in way of degree keys. You also can alter the flywheel trigger
A short cut in Cr is the v1 v2 method, cylinder cc ( bore and stroke) + volume above the piston at TDC (Top Dead Center) then divide by volume above piston at TDC (Top Dead Center). That will get you close. That is why I posted the 37 cc of total volume above the piston at TDC (Top Dead Center) If one looks for corrected they can simply use the ccs at port closure. I know your laided up so I 'll try to post up stuff to keep your mind busy.


Attachments:

Timing set up 1.wmv [ 3.54 MiB | Viewed 889 times ]

Timing set up 2.wmv [ 3.87 MiB | Viewed 889 times ]
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Tue Aug 18, 2015 6:30 pm 
Offline

Joined: Tue Jan 17, 2012 3:19 am
Posts: 4054
Location: Hope, B.C Canada
Hey ---- where did you get that offset flywheel key ??
Did you make your own or buy it ??


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed Aug 19, 2015 10:08 am 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
I make my own. Here is a pic of both degree wheels for the flywheel side. I use a CD and glue it to it then bolt it up. If you use a degree wheel on the clutch side and the CD degree wheel on the other with a pointer you can play with the numbers. When doing this be sure to watch you piston position. After all your playing with fire. You can and should make extra copies of these as to log you changes and map out your Engine. This to say note you ex open and close then draw lines from degree mark to center using different colors for intake and exhaust. Red for exhaust Blue for intake and Yellow or green for ignition timing and ignition timing change.

First before any changes please try to understand what is going on inside first. Find your port timing, angle area etc. and piston positions, total cc etc. You head also needs to be mapped. After all if you do not your piston collection will get larger.

I would say start with trying to understand the factory's thoughts on the engines static setting and go from there. There was a reason the set them were they did for the Engine.

I will also include a piston position sheet for the pilot and you or I can make you one for the ody.


Attachments:
DeegreeDisk-ccw.jpg
DeegreeDisk-ccw.jpg [ 42.33 KiB | Viewed 875 times ]
DeegreeDisk-cw.jpg
DeegreeDisk-cw.jpg [ 42.08 KiB | Viewed 875 times ]
pilot crank angle.pdf [227.71 KiB]
Downloaded 26 times
Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed Aug 19, 2015 1:52 pm 
Offline

Joined: Tue Jan 17, 2012 3:19 am
Posts: 4054
Location: Hope, B.C Canada
Almost all stock engines can get some performance improvement by increasing the timing a bit in my opinion. When I ran race cars I had a rotary powered Lola T360 formula car with a 12A peripheral port rotary Engine. You could advance the timing but it was dangerous. If I remember right two or three degrees. Anymore and you would snap the apex seals or flatten the apex springs. You can always tell if a rotary Engine is toast because it will be very hard to start. I think the same applies to stock Honda oddy engines. Most of us have stock engines with a thinner head gasket (no port work) and maybe a pipe. I am sure I could get some performance benefit with advancing the timing but how much ?? And is it worth the risk ?? Adnoh what would you say is a safe advance on an Engine like that ?? Got any measurements for me on your key ?? The reason I ask is because my Engine theory is non existent. It scrambles my brain every time I read something of yours. The only thing I think I know is shave the head and increase timing advance and it goes fast.


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Fri Aug 28, 2015 11:16 am 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
"The only thing I think I know is shave the head and increase timing advance and it goes fast."

I used to think that way and I even had a few piston collection like yours. This is when I started talking with Engine builders and trying to understand what the heck I was trying to do. I really think this is why they talk with me today as they get a kick out of me and I think it makes there day. They most likely go home and tell there wife's and have a laugh together.

I blew up about six odys pistons before I got a handle on it, Plus the guy driving never knew when to let off. As far and most engines go, in stock or mildly modified form I would agree a little more pressure and timing is ok. Each is there own animal though. I have seen where less advance and lower octane produces better result then the higher octane and more advance. It all depends on the Engine design and operation. I know that is a grapy answer however true.

Just for conversation sake since you use fuel to reduce detonation and lets say you use a 50 50 mix. I would start with finding the mix limit for a given Engine temp at given/fixed high rpm and go from there. Knowing your port timing and CR will aid you in this. The you can adjust you LPP for MBT. You have time on your hands goggle the terms and read up. While reading consider you fuel choice into it. You can quickly grasp it way over anything I spew.


Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Wed Sep 30, 2015 9:48 pm 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
Well I decided to take a new approach on mudd piston #3. The piston will be fit at a negative clearance number. By this I mean the piston will have a coating applied that will yield a negative clearance number if the coated piston was measured. For this the piston to wall clearance is set in way of the MFG/ adnoh for ring end gap and then a coating applied in excess to allow for a press fit. Unlike a coated Wiseco with a tither clearance for the coated piston this one will go negative. Basically the piston will wear to the bore. Picture to follow as I build in new thread. I have yet to set the Engine parameters as of yet however working on them. This build most likely to use a fuel injection set up as well. If I make this ride on the 6th the Engine will be removed and modified to accept the application. I may opt to install the piston to get a base line and then have another piston done in order to compare to the new set up. I do know the new set up will have all new /rebuilt parts for a tight application. This way I can see the effect upon related Engine parts. This new approach has a budget of $3500.00. The goal is to achieve a good /better than stock replacement piston for the pilot and odyssey. Money spent so far $1375.00.


Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Thu Oct 01, 2015 2:03 am 
Offline

Joined: Thu Sep 09, 2010 11:44 am
Posts: 357
Location: Indiana
If you wanna put any of these set ups on my 90 for R and D let me know, be more than happy to participate.


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Thu Oct 01, 2015 9:21 am 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
Good to here. I have already done one for your 90 and a few other items as well. I think we will have a lunch tech talk. I can and will go over some of my thought on the process. Nothing ventured nothing gained. One thing for sure is this should do away with most or all of the scuffing issue we face, that of course it's a very poor cylinder to start with.

Remember this is at my expense so you have nothing to loose other than down time and garage time. If this work well then a 350 will be next. The thrust forces will be greater on the 350 due to stroke and rod length. I have been working on a long rod kit for the 350 to work with this piston set up. Since the cylinder is air cooled on the 350 the cylinder distortion is greater than on a pilot. This will also reduce cold seizure issues. Heading out of town this morning and hope to see you Tuesday.


Top
 Profile  
 
 Post subject: Re: New DCP top end #2
PostPosted: Sat Oct 03, 2015 6:35 pm 
Offline

Joined: Thu Sep 09, 2010 11:44 am
Posts: 357
Location: Indiana
Sounds good. Im here at LS today. Beer and cheese cubes on ice. Im anxious to hear ur thoughts on my Engine. And im paying u for ur time to date. Already decided see u tuesday.


Top
 Profile E-mail  
 
 Post subject: Re: New DCP top end #2
PostPosted: Mon Oct 05, 2015 9:57 am 
Offline

Joined: Fri Jan 12, 2007 2:17 pm
Posts: 2854
Location: Wichita ks
couple of pics of share.


Attachments:
Resize of IMG_20151004_183944299.jpg
Resize of IMG_20151004_183944299.jpg [ 36.46 KiB | Viewed 709 times ]
Resize of IMG_20151004_184018499.jpg
Resize of IMG_20151004_184018499.jpg [ 40.41 KiB | Viewed 709 times ]
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 25 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Registered users: Baidu [Spider], Bing [Bot], daddyrat, FloridaEdd, go oddy, Google [Bot], methodical, New To Odesseys, speedchaser, wyeeoddy, Yahoo [Bot]


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group