Go Back   Honda-Tech > Honda and Acura Technical Forums > All Motor/ Naturally Aspirated
Sign in using an external account
Register Forgot Password?
Search


Welcome to Honda-Tech!
Welcome to Honda-Tech.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Honda-Tech community today!


Reply
 
 
 
submit to reddit
 
Thread Tools Search this Thread
Old 11-09-2008, 10:52 PM   #1
chunky
Honda-Tech Member
Garage is empty, add now
 
chunky's Avatar
 
Join Date: Dec 2001
Location: atlanta, ga, USA
Posts: 547
iTrader Rating: (0)
Send a message via AIM to chunky
Default My K20 rebuild

I know there's not a whole lot of k20 action in the Atlanta area, especially naturally aspirated, but I assure you, I own the dubious distinction of having blown up more k20 motors than anyone else in the state. Along with that comes rebuilding experience, and I'm going to share a bit of my latest rebuild in this thread.

After 20,000+ miles, my 230ish hp 9000+rpm k20 bit the dust. More specifically, the cylinder #3 piston bit the dust.

What cylinder #3 looked like
Click the image to open in full size.

What the rest looked like. You may be thinking to yourself "my, what a clean burning engine he has!" Why thank you, I like to think I know a thing or two about tuning. Click the image to open in full size.
Click the image to open in full size.

Rods & pistons laid out
Click the image to open in full size.

In case you wondered why they're called "H" beam rods.
Click the image to open in full size.

Long story short, these were CP 12.5: pistons with a thermal barrier coating on the top and anti friction coating on the skirt. I was planning to run a healthy shot of nitrous, but I never got around to it. The pistons were installed with a piston to wall of 0.0035" or 0.0036" which is okay for an n/a motor. However, what happened in the 20+K miles that she lived is that the piston to wall clearances never tightened up to what they should have been when the engine was at operating temperature. As a result, the pistons were loose in the bore and the bottom edge of the skirts all showed irregular wear. Cylinder #3 was just the first to go. The skirt fell apart and then the piston turned sideways in it's bore. Click the image to open in full size.

So based on that experience, I decided that this time around I'd go for pistons made of a lower expansion alloy. The only off the shelf pistons for a k-series made of 4032 are the supertech.

Here's some comparison pics of the CP pistons vs. the supertech pistons.

The CP has a much more nicely sculpted dome with a wider peak. However, the Supertech has visibly deeper valve reliefs and yields the same 12.5:1 compression. Just from the way the top of the CP piston is machined versus the Supertech piston, it's not difficult to see why there is a significant price difference between the two brands.
Click the image to open in full size.

The Supertech has a wider skirt that is also a little longer. The crown of the piston is also a little thicker. The supertech piston also has less taper from the crown to the bottom of the skirt. This makes sense as it is constructed from an alloy that expands less as it heats up.
Click the image to open in full size.

On the underside of the piston, it's again clear why CP costs more. It's got much nicer machining on the underside of the piston. Dual wrist pin oiling holes are present on the CP piston. The supertech piston does have a thicker skirt. The wrist pin is also shorter on the supertech piston. The CP piston will accommodate a much wider rod, although that doesn't matter much if you are using stock width crank journals.
Click the image to open in full size.

I got the block back on Friday and measured it out today.

All cleaned up.
Click the image to open in full size.

The plateau hone looks really good.
Click the image to open in full size.

My inexpensive bore gauge that gets the job done. I have to do some interpolation to read between 0.0005" increments. Also, the reading shown here is 0.00225" over since the gauge zeroed out on my piston measurement halfway between zero and one mark to the right.
Click the image to open in full size.

So, the other thing I wanted to do tonight was get a better idea of if the piston to wall clearance I specified to the machine shop was suitable or not. Last night I made up a worksheet in MathCAD to calculate the expansion of the pistons based on coefficients of thermal expansion I looked up for 4032 and 2618 alloys. Those numbers indicated I'd end up with a hot clearance of 0.0011", which seemed reasonable. However, I grew up watching mr. wizzard and bill nye the science guy, so I had to take things a step further and determine the CTEs experimentally.

MMMMMMM, pistons, they're what's for dinner. Note that I marked the measuring points with a marker to ensure measuring precision. Supertech pistons on left, one CP piston and one OEM piston on the right.
Click the image to open in full size.

They're cooking now!
Click the image to open in full size.

After crunching the numbers, results were actually reasonably close to what the values I looked up were. Well, for the 4032 and 2618 alloys. Obviously there was no table with specific information on CTEs for the OEM piston material as CTEs for cast material vary widely depending on the specific way in which the piston was cast. But I'm getting sidetracked.

1. CP CTE: 25.7 versus 24
2. Supertech CTE: 23.2 versus 21
3. Stock piston CTE: 16.9

As you can see, the 2618 alloy does in fact have a higher CTE than the 4032 alloy. As expected, the CTE of the stock piston was much lower than with either of the forged pistons. The mathematical model says that the OEM piston to wall in a hot motor would be 0.0002" to 0.0010". With the piston to wall I specified on this motor, my hot clearance should be right in the middle of the OEM range, 0.0006". In short, I chose wisely. Piston to wall is tight enough to help maximize longevity, but not so tight that I'd have to worry about seizing the motor if I run her hard on a hot day.

For kicks, here's a screenshot of my MathCAD worksheet.
Click the image to open in full size.

I also measured the expansion at the piston crown. The aftermarket pistons generally expanded a good bit more along their thrust faces at the crown than along the wrist pin axis. The CP pistons were within 0.001" along each axis. the Supertech pistons had an average difference 0.006" between the two axes, with the longer axis being the thrust face of the piston. The stock pistons were slightly oval as well having a difference of 0.002" between the two axes, with the longer axis being the thrust face of the piston.

What I find interesting is that although the CP pistons were more round at the crown than the stock pistons, the stock pistons had much more even skirt wear. This highlights two factors that set apart truly great pistons from the rest.

1. having a truly round shape at temperature
2. having a skirt profile that matches the bore at temperature

Now, I'm not sure how the Supertech pistons will stack up, but it would seem that the CP pistons left a little to be desired in the piston skirt profile. Makes you wonder why some companies charge $1600+ for a set of four pistons and what kind of intrinsic value is engineered into the product.

That's it for now. There's a lot of work left to do before I get this motor together. Hopefully, she'll be stronger and longer lasting than the last. Click the image to open in full size.
__________________
2002 ep3 - you may call her estella, current: IPS K2 Mark III coming soon, Click to see full mod list
You can take me out of the race, but you can't take the race out of me.
chunky is offline   Reply With Quote
Old 11-09-2008, 11:26 PM   #2
Combustion Contraption
Honda-Tech Member
Garage is empty, add now
 
Combustion Contraption's Avatar
 
Join Date: Jan 2003
Location: So Cal
Posts: 10,171
iTrader Rating: (0)
Send a message via AIM to Combustion Contraption
Default FV-QR

This is one of the most intelligent things I have on HT in a long time. It would stand to reason no one has responded yet and I am the first one to reply, as they are all busy making "wut camshaft/how high a compression ratio can i run" threads. Props to you.
__________________
EARL LASKEY, YOU WILL BE MISSED
CCCylinderheads.com
Combustion Contraption is offline   Reply With Quote
Old 11-09-2008, 11:52 PM   #3
PuroMotor
Honda-Tech Member
Garage is empty, add now
 
PuroMotor's Avatar
 
Join Date: Dec 2007
Location: Washington D.C
Posts: 560
iTrader Rating: (0)
Default

I wont play and say I understand all your numbers on your worksheet. But ill say that your a man with attention to detail. Awsome research. thumbs up
__________________
Battle Box Films
DarkStar Auto
PuroMotor is offline   Reply With Quote
Old 11-10-2008, 12:20 AM   #4
Nerologic
Honda-Tech Member
Garage is empty, add now
 
Nerologic's Avatar
 
Join Date: Apr 2003
Location: San Diego
Posts: 9,033
iTrader Rating: (0)
Send a message via AIM to Nerologic
Default Re: (PuroMotor)

Everyone is too busy in GDD, they forgot about this forum.

I don't want to complain about "back in the day" everything was better, but back then people looked into these sub-forums and actually found "tech." Now as you can see, these type of threads are very few in between...

Props to the OP Click the image to open in full size.
__________________
EVERYONE is watching, but only a handful are listening.
Nerologic is offline   Reply With Quote
Old 11-10-2008, 01:21 AM   #5
Team Evol Tyrone
Honda-Tech Member
Garage is empty, add now
 
Team Evol Tyrone's Avatar
 
Join Date: May 2003
Location: San Diego, ca, united states
Posts: 1,350
iTrader Rating: (0)
Default Re: (Nerologic)

Chunky some I used to see in Cylinder three was temp was always hotter so I took my ring gap numbers and went up about 2 on cylinder three. Another way you could do it is add fuel to Cylinder three if you had the right EMS. Good thread though wish more people would do write ups like this. Instead every one does my build threads where everythings sourced out instead of them having true knowledge to build it themselves.
__________________
To SURVIVE war you must become war!
Team Evol Tyrone is offline   Reply With Quote
Old 11-10-2008, 05:56 AM   #6
chunky
Honda-Tech Member
Garage is empty, add now
 
chunky's Avatar
 
Join Date: Dec 2001
Location: atlanta, ga, USA
Posts: 547
iTrader Rating: (0)
Send a message via AIM to chunky
Default

Thanks guys.

In regards to cylinder #3 running hotter, when I had my injectors flow tested & cleaned, I put the highest flowing on on cylinder #3. It wasn't a huge adjustment though. I also set the ring gap a little looser on cylinder #3, but only 0.001"

Ahh well. It sucks that the last engine blew, but I've found that you can learn a lot from what went wrong with a build, and then apply it to future builds. That's what I'm attempting to do here.
__________________
2002 ep3 - you may call her estella, current: IPS K2 Mark III coming soon, Click to see full mod list
You can take me out of the race, but you can't take the race out of me.
chunky is offline   Reply With Quote
Old 11-10-2008, 06:03 AM   #7
JDM JEFFREY
Honda-Tech Member
Garage is empty, add now
 
JDM JEFFREY's Avatar
 
Join Date: Dec 2004
Location: CALI
Posts: 3,236
iTrader Rating: (1)
Default Re: (chunky)

Quote:
Originally Posted by chunky
Thanks guys.


Ahh well. It sucks that the last engine blew, but I've found that you can learn a lot from what went wrong with a build, and then apply it to future builds. That's what I'm attempting to do here.

Click the image to open in full size. Click the image to open in full size.
__________________
West coast Fastest H2b A/M Street car 10.72@132.57 best 10.448@129
RLZ engineering ,QSD,SKUNK2,LASKEY RACING,KINSLER,SUPERTECH,Esa, KS tuned,Exospeed,MYERS COMPETITION MANIFOLDS,FCS FAB
JDM JEFFREY is offline   Reply With Quote
Old 11-10-2008, 06:06 AM   #8
00MRSi
Member
Garage is empty, add now
 
Join Date: Mar 2002
Location: NJ, USA
Posts: 4,174
iTrader Rating: (0)
Default Re: (JDM JEFFREY)

Great information. Thanks for taking the time to share it with us.

What is your day job? Click the image to open in full size.
00MRSi is offline   Reply With Quote
Old 11-10-2008, 06:10 AM   #9
chunky
Honda-Tech Member
Garage is empty, add now
 
chunky's Avatar
 
Join Date: Dec 2001
Location: atlanta, ga, USA
Posts: 547
iTrader Rating: (0)
Send a message via AIM to chunky
Default Re: (00MRSi)

Quote:
Originally Posted by 00MRSi
Great information. Thanks for taking the time to share it with us.

What is your day job? Click the image to open in full size.
Job? what job? I'm a grad student, ME. Click the image to open in full size.
__________________
2002 ep3 - you may call her estella, current: IPS K2 Mark III coming soon, Click to see full mod list
You can take me out of the race, but you can't take the race out of me.
chunky is offline   Reply With Quote
Old 11-10-2008, 06:13 AM   #10
00MRSi
Member
Garage is empty, add now
 
Join Date: Mar 2002
Location: NJ, USA
Posts: 4,174
iTrader Rating: (0)
Default Re: (chunky)

Quote:
Originally Posted by chunky

Job? what job? I'm a grad student, ME. Click the image to open in full size.
Ok. I figured you were an engineer.. Click the image to open in full size.
00MRSi is offline   Reply With Quote
Old 11-10-2008, 08:07 AM   #11
BuildOff
Honda-Tech Member
Garage is empty, add now
 
BuildOff's Avatar
 
Join Date: Oct 2008
Location: Cali
Posts: 15
iTrader Rating: (0)
Default Re: My K20 rebuild (chunky)

In an attempt to decipher what the cause and effect were on your last build, can you show the back sides of the bearings, the con-ron/ cap parting surfaces, and the wristpin bore measurements (top-bottom & side-side). With a slightly generous piston to wall clearance of ~3.6 thou, it's hard to believe that the piston to cylinder gap is the downfall of this build. Seems much more likely that there were small amounts of detonation that killed the piston, and therefore it snowballed into what you saw when you opened the engine.

I may be wrong, but that is a slightly educated guess...

On a much brighter note, it is quite refreshing to see a little knowledge being shown by a youngster! Click the image to open in full size.
BuildOff is offline   Reply With Quote
Old 11-10-2008, 08:44 AM   #12
chunky
Honda-Tech Member
Garage is empty, add now
 
chunky's Avatar
 
Join Date: Dec 2001
Location: atlanta, ga, USA
Posts: 547
iTrader Rating: (0)
Send a message via AIM to chunky
Default Re: My K20 rebuild (BuildOff)

Quote:
Originally Posted by BuildOff
In an attempt to decipher what the cause and effect were on your last build, can you show the back sides of the bearings, the con-ron/ cap parting surfaces, and the wristpin bore measurements (top-bottom & side-side). With a slightly generous piston to wall clearance of ~3.6 thou, it's hard to believe that the piston to cylinder gap is the downfall of this build. Seems much more likely that there were small amounts of detonation that killed the piston, and therefore it snowballed into what you saw when you opened the engine.

I may be wrong, but that is a slightly educated guess...

On a much brighter note, it is quite refreshing to see a little knowledge being shown by a youngster! Click the image to open in full size.
I looked at the bearings and there was no sign of detonation. The engine was very well tuned and i had actually refreshed the rod bearings not long before the engine let go. I heard a slight ticking noise one afternoon when I started my car between two tour bus sized SUVs. Although I hadn't really driven the car hard that morning, I thought I might be dealing with a rod bearing that was on it's way out. I pulled the bearings and they looked minty. I put new rod bearings in, but the noise did not go away. I know now that the sound was the start of bad things happening with the pistons.

The installed piston to wall was not excessive by most standards, but my best guess at the moment is that it was too much for a coated piston top. With less heat getting into the piston, the resultant lower expansion would translate into a looser hot clearance. So what I've learned is that the cold clearance doesn't mean a whole lot. You have to consider how things look when they get hot.

I measured the wrist pin bores, and they were not elongated. The con rod bearing/mating surfaces also looked good. I have a very high level of confidence that the engine was not killed by knock as I tuned the motor myself (making seasonal adjustments as necessary) and always ran with the factory knock sensor enabled, which is very sensitive. Aside from which, all the other piston tops/bearings looked perfect. If it was detonation of the scale that would cause this, I would have seen damage in more than one cylinder.
__________________
2002 ep3 - you may call her estella, current: IPS K2 Mark III coming soon, Click to see full mod list
You can take me out of the race, but you can't take the race out of me.
chunky is offline   Reply With Quote
Old 11-10-2008, 09:05 AM   #13
mar778c
Honda-Tech Member
Garage is empty, add now
 
mar778c's Avatar
 
Join Date: Mar 2004
Location: PA, USA
Posts: 7,026
iTrader Rating: (1)
Default Re: (chunky)

3.5 thou on a CP piston is pretty big but thanks for sharing the re-build.
__________________
Good people:
Synapse Motorsports, CHEETAH, 4g hatch, Innovative MotorWorks, Importdps, Dynamic Performance, and Nutzurchin
mar778c is offline   Reply With Quote
Old 11-10-2008, 09:27 AM   #14
flyrod
Honda-Tech Member
Garage is empty, add now
 
flyrod's Avatar
 
Join Date: Feb 2002
Location: land of the sheep, home of the hypocrite
Posts: 2,072
iTrader Rating: (0)
Send a message via AIM to flyrod
Default Re: My K20 rebuild (chunky)

Nice tech write up! Was there a lot of piston slap on cold startup? Did the knock sensor pick up any extra noise? I was getting a lot of noise on the knock sensor at certain RPM ranges, which I think must be the pistons. (http://www.honda-tech.com/zerothread?id=2318492) What were the signs of the piston going out besides the ticking? Did you notice anything wrong before the piston went sideways? Good luck on the rebuild!


Modified by flyrod at 11:34 AM 11/10/2008
__________________
Stuff for sale: K20A longblock Hondata Stage 4B Chipped P28's
Lots of 4th Gen Prelude stuff: STR fuel rail NIB, Si Brakes, ABS
H22 cams, etc.
flyrod is offline   Reply With Quote
Old 11-10-2008, 09:29 AM   #15
bjones
Junior Member
Garage is empty, add now
 
bjones's Avatar
 
Join Date: May 2007
Location: usa
Posts: 559
iTrader Rating: (0)
Default Re: (mar778c)

informational thread Click the image to open in full size.
bjones is offline   Reply With Quote
Old 11-10-2008, 09:43 AM   #16
4g hatch
Honda-Tech Member
Garage is empty, add now
 
Join Date: Apr 2007
Location: back woods, va, usa
Posts: 2,525
iTrader Rating: (0)
Default Re: (mar778c)

#3 cylinder always gets the hottest. anyway im glad to see someone in here share some actual all-motor tech. maybe people like me could learn more Click the image to open in full size.
__________________
"whatever you do today,you have to sleep with tonight". quote: arron tippen
"trust no one,do it yourself" me
member#1 of the ive been screwed by donf club
4g hatch is offline   Reply With Quote
Old 11-10-2008, 10:25 AM   #17
chunky
Honda-Tech Member
Garage is empty, add now
 
chunky's Avatar
 
Join Date: Dec 2001
Location: atlanta, ga, USA
Posts: 547
iTrader Rating: (0)
Send a message via AIM to chunky
Default Re: (mar778c)

Quote:
Originally Posted by mar778c
3.5 thou on a CP piston is pretty big but thanks for sharing the re-build.
When I put them in, they said that it was at the loose end of what they recommend. If my memory serves me correctly, they recommended a 0.0033" for an N/A motor which according to my model results in a hot clearance of 0.00051" piston to wall. At 0.0036" clearance, the model shows hot piston to wall of 0.00081". Not excessive by any means. I think the problem is that the thermal barrier coating kept the pistons from fully expanding, resulting in a larger than expected piston to wall when hot.
__________________
2002 ep3 - you may call her estella, current: IPS K2 Mark III coming soon, Click to see full mod list
You can take me out of the race, but you can't take the race out of me.
chunky is offline   Reply With Quote
Old 11-10-2008, 10:29 AM   #18
chunky
Honda-Tech Member
Garage is empty, add now
 
chunky's Avatar
 
Join Date: Dec 2001
Location: atlanta, ga, USA
Posts: 547
iTrader Rating: (0)
Send a message via AIM to chunky
Default Re: My K20 rebuild (flyrod)

Quote:
Originally Posted by flyrod
Nice tech write up! Was there a lot of piston slap on cold startup? Did the knock sensor pick up any extra noise? I was getting a lot of noise on the knock sensor at certain RPM ranges, which I think must be the pistons. (http://www.honda-tech.com/zerothread?id=2318492) What were the signs of the piston going out besides the ticking? Did you notice anything wrong before the piston went sideways? Good luck on the rebuild!


Modified by flyrod at 11:34 AM 11/10/2008
Nope, no piston slap at all through most of the motor's life. Looking back, the engine did get a little noisier towards the end, but it wasn't bad until i heard the ticking sound. The ticking sound got progressively worse until it was full blown piston slap after about 140 miles. Before the motor actually let go, I knew it was time to park her when the knock sensor went off. I was trying to limp her home (I was 3 miles from home) when she let go. I should have just parked & called AAA. Click the image to open in full size.

Basically, it sounded at first just like a very slight rod knock, and then grew slowly into an audible diesel truck sound.
__________________
2002 ep3 - you may call her estella, current: IPS K2 Mark III coming soon, Click to see full mod list
You can take me out of the race, but you can't take the race out of me.
chunky is offline   Reply With Quote
Old 11-10-2008, 11:02 PM   #19
6SPD_EK
Honda-Tech Member
Garage is empty, add now
 
6SPD_EK's Avatar
 
Join Date: Feb 2001
Location: 6th gear, NY
Posts: 7,078
iTrader Rating: (0)
Default Re: (chunky)

very informative thread

Quote:
Originally Posted by chunky
I think the problem is that the thermal barrier coating kept the pistons from fully expanding, resulting in a larger than expected piston to wall when hot.
makes me want to look into clearances more closely before putting in some swain coated wiseco's in my build.

what thermal barrier coating was on your CP's?

6SPD_EK is offline   Reply With Quote
Old 11-11-2008, 07:18 AM   #20
alterdcreations
Honda-Tech Member
Garage is empty, add now
 
alterdcreations's Avatar
 
Join Date: Feb 2006
Location: Single camshafting for now in, N.Y.
Posts: 3,789
iTrader Rating: (0)
Default Re: (6SPD_EK)

do you have a oven big enough for the block?
how much do the cylinder walls expand in relation to the pistons?
__________________
Home to Swiss Army Knives and Watches!!! "she'll love it"...and you might also get a nice suprise www.secrethiddentreasures.com
Need motor work H-B-D series....Pm me
alterdcreations is offline   Reply With Quote
Old 11-11-2008, 02:51 PM   #21
mar778c
Honda-Tech Member
Garage is empty, add now
 
mar778c's Avatar
 
Join Date: Mar 2004
Location: PA, USA
Posts: 7,026
iTrader Rating: (1)
Default Re: (chunky)

Quote:
Originally Posted by chunky

When I put them in, they said that it was at the loose end of what they recommend. If my memory serves me correctly, they recommended a 0.0033" for an N/A motor which according to my model results in a hot clearance of 0.00051" piston to wall. At 0.0036" clearance, the model shows hot piston to wall of 0.00081". Not excessive by any means. I think the problem is that the thermal barrier coating kept the pistons from fully expanding, resulting in a larger than expected piston to wall when hot.
I think those clearances were too big. I built one or two motors with CP pistons and the clearance is normally .00085 to .0009"/in of piston diameter. In the case of a 86 mm bore, should have about .003" piston to wall clearance.

If your wall clearance is too big the piston will not develop the proper oil wedge on the thrust face.
__________________
Good people:
Synapse Motorsports, CHEETAH, 4g hatch, Innovative MotorWorks, Importdps, Dynamic Performance, and Nutzurchin
mar778c is offline   Reply With Quote
Old 11-12-2008, 11:16 AM   #22
pogeeboy27
Honda-Tech Member
Garage is empty, add now
 
pogeeboy27's Avatar
 
Join Date: Aug 2005
Location: Honolulu, HI
Posts: 302
iTrader Rating: (2)
Default Re: FV-QR (Combustion Contraption)

Quote:
Originally Posted by Combustion Contraption
This is one of the most intelligent things I have on HT in a long time. It would stand to reason no one has responded yet and I am the first one to reply, as they are all busy making "wut camshaft/how high a compression ratio can i run" threads. Props to you.
I agree. What happened to all the usual people with all their "theoretical" ideas about what went wrong and what to do next? ME ftw! Click the image to open in full size.
To the OP, where did you get the coefficients of thermal expansion? The ones online don't seem to list the coefficients of different grades of alloys.
__________________
"There are 2 things no man will admit he cannot do well: drive and make love."
-Sir Stirling Moss
pogeeboy27 is offline   Reply With Quote
Old 11-12-2008, 01:57 PM   #23
chunky
Honda-Tech Member
Garage is empty, add now
 
chunky's Avatar
 
Join Date: Dec 2001
Location: atlanta, ga, USA
Posts: 547
iTrader Rating: (0)
Send a message via AIM to chunky
Default Re: FV-QR (pogeeboy27)

Quote:
Originally Posted by mar778c
I think those clearances were too big. I built one or two motors with CP pistons and the clearance is normally .00085 to .0009"/in of piston diameter. In the case of a 86 mm bore, should have about .003" piston to wall clearance.

If your wall clearance is too big the piston will not develop the proper oil wedge on the thrust face.
Yeah, looking back, I would have done things differently. Now, using my model, I'd do a 0.0033" for an uncoated piston and 0.003" for a coated piston.

Hopefully I've picked a good number for these Supertech pistons.

Quote:
Originally Posted by pogeeboy27
I agree. What happened to all the usual people with all their "theoretical" ideas about what went wrong and what to do next? ME ftw! Click the image to open in full size.
To the OP, where did you get the coefficients of thermal expansion? The ones online don't seem to list the coefficients of different grades of alloys.
I used http://www.matweb.com
__________________
2002 ep3 - you may call her estella, current: IPS K2 Mark III coming soon, Click to see full mod list
You can take me out of the race, but you can't take the race out of me.
chunky is offline   Reply With Quote
Old 11-12-2008, 02:01 PM   #24
mar778c
Honda-Tech Member
Garage is empty, add now
 
mar778c's Avatar
 
Join Date: Mar 2004
Location: PA, USA
Posts: 7,026
iTrader Rating: (1)
Default Re: FV-QR (chunky)

Quote:
Originally Posted by chunky
Hopefully I've picked a good number for these Supertech pistons.
What clearances are you shooting for?


Modified by mar778c at 9:07 PM 11/12/2008
__________________
Good people:
Synapse Motorsports, CHEETAH, 4g hatch, Innovative MotorWorks, Importdps, Dynamic Performance, and Nutzurchin
mar778c is offline   Reply With Quote
Old 11-13-2008, 08:01 AM   #25
Lubo_25
Junior Member
Garage is empty, add now
 
Lubo_25's Avatar
 
Join Date: Dec 2006
Location: hamilton, ontario, canada
Posts: 875
iTrader Rating: (0)
Default Re: FV-QR (chunky)

seeing how cp pistons have thin skirts the tbc coatings dont have much to do with them not expanding enough to provide proper sealing...the piston will always expand to its designated alloy amount...all depends on the machine work done...

changing piston alloys will help slightly but to me toleranced machine work is everything Click the image to open in full size.
__________________
Gord Bush Performance-precision Machine shop and cylinder head modifications
(1-416-259-9700)
Pro Art Metals Inc.-custom fabrication, machining, and machine building
Only F/G/H motors here...
Lubo_25 is offline   Reply With Quote
 
 
 
submit to reddit
Reply

Tags
bottom, cams, end, engine, honda, ii, ips, k2, k20, k20a, kit, mark, motor, rebuild, rebuilding, rebuilt, sale

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -8. The time now is 07:08 AM.



2008 Copyright, InternetBrands Inc.
Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for Honda-Tech.com content, comments, or advertising. Honda-Tech.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse Honda-Tech.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.
Emails & Contact Details