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Jimmy111
Samba Member
Joined: October 05, 2006
Posts: 2643
Location: Wyoming
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 Posted: Sun Sep 13, 2009 12:58 pm Post subject: |
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Sorry. I can see it just fine.......
Ill check it out. |
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Jimmy111
Samba Member
Joined: October 05, 2006
Posts: 2643
Location: Wyoming
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| Posted: Sun Sep 13, 2009 1:01 pm Post subject: |
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| Try now. |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 1:21 pm Post subject: |
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| Jimmy111 wrote: |
A picture says a thousand words.
90 Octane, 7-1 dynamic C/R and 360F head temp.
Link
The flame you see at the top of the piston is the F/A mis igniting before the flame front reaches it. |
So, from this video, what are you trying to tell us? explain the background, and whats going on. Is there a link to what motor and whats going on?
7-1 dynamic is a tad low. most manf shoot for 7.8-8.2 dynamic. From what ive read and seen. I havent tested every engine ever made though, so im sure some vary.
360 head temp is pretty warm for most engines. Id guess aircooled, but looking at that plug and chamber, sheesh i dont know what it is. LOL.
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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Jimmy111
Samba Member
Joined: October 05, 2006
Posts: 2643
Location: Wyoming
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| Posted: Sun Sep 13, 2009 1:38 pm Post subject: |
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Its a combustion test cylinder.
They are used to test the Octane ratings of fuels and different conbustion chamber and piston crown profiles.
The plug and jacket are oil cooled. You can adjust the head temp, plug depth and temp and location and valve material and leakage.
Just because you dont think you are detonating doesent mean you arent detonating. Its hard to hear it in a ACVW engine. Most of it you cant hear anyways. This type of detonation is very common and robs lots of power.
Baseline dynamic compression ratio is based on heat content of the charge. There is considerable added heat content in a A/C motor due to higher head temp, cylinder temp and exhaust valve temp.
And do you really think 360F is high for a VW engine??  |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 2:19 pm Post subject: |
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| Jimmy111 wrote: |
Its a combustion test cylinder.
They are used to test the Octane ratings of fuels and different conbustion chamber and piston crown profiles.
The plug and jacket are oil cooled. You can adjust the head temp, plug depth and temp and location and valve material and leakage.
Just because you dont think you are detonating doesent mean you arent detonating. Its hard to hear it in a ACVW engine. Most of it you cant hear anyways. This type of detonation is very common and robs lots of power.
Baseline dynamic compression ratio is based on heat content of the charge. There is considerable added heat content in a A/C motor due to higher head temp, cylinder temp and exhaust valve temp.
And do you really think 360F is high for a VW engine?? |
Still kinda confused as to what your saying.
Dude inaudible detonation DESTROYS motors. same as audible detonation.
And if you want proof of what im saying, you dont simply take MY word. Just as has been mentioned here, raby has already done all the trick scientific tests to prove, not only what im saying is correct, but dead on. Ive been doing this this way forever. Nice to see some tests backing it up.
If we go by what your saying, wed all be running at 5 to 1 dynamic CR, and have 400-500 degree heads.
Ive never been a big cyl head temp nutjob, if the motor runs good and the oil temp is nice and cool, i know all is well.
BUT i did decide to jump on the cyl head temp bandwagon a while back.
I drove my 57 panel loaded down, down the freeway at the speed it likes best, its top speed. 65 mph. it has a 40 HP with 83mm pistons and 8.5 to 1 Cr, and stock cam.
i drove and drove, and mind you, its over 100 degrees in vegas. i drove prob 15 miles on the I15, and stopped as quickly as i could, on the side of the freeway and ran back with my infrared temp gun.
case at 180 and heads everywhere i shot em, 260-295.
A stock height bus, with 1000 lbs in the cargo area, and plugging along down the freeway, and i have those numbers?
You have a 1600 lb bug, and what are your head temps? hopefully under 400? if the car is geared right, and your making triple stock HP, the motor should be able to take a nap and get you where your going. never even getting warm.
that is unless your setup is all wrong, timing wrong, cam and compression are wrong, shitty shroud and slipping belt.
then sure, youll have 400+ cyl head temps. ideally id hope you get no higher than 360. Thats of course on large strokers. Smaller stock motors seem to run even cooler. Just from the few ive checked, i havent done any raby style tests. Dont have the time or facility.
I just use what i know, and alot of experience building all kinds of crazy engines. Not just VWs. Im VERY picky about the way every part goes together, what its intended use is, and the clients driving habits.
In a way raby and myself are alot alike, extremely dedicated and passionate about what we are doing. And most of the time, everyone else thinks we are nuts. LOL.
I like this debate stuff too, fun. You cant always be right, cause not everyone is you, but at least the info gets to the people who read it. 
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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CJG
Samba Member
Joined: November 07, 2005
Posts: 571
Location: Phoenix
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| Posted: Sun Sep 13, 2009 2:51 pm Post subject: |
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I had a 2110 with 44x37.5 with a 121 Web cam 9.1 compression and made 163 HP, later that year I shered the flywheel and it came apart and turned it into a 2275 with the same heads and a 86B and made 206 @ 6500 RPM. Its all in the combo, heads, Compression, Cam, Displacement.
I have seen a lot of Dyno pulls and the results, I'm not fooled |
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Bad bug
Samba Member
Joined: March 11, 2006
Posts: 1127
Location: Jamaica
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| Posted: Sun Sep 13, 2009 4:55 pm Post subject: |
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| CJG were you still running 9:1 compression when you made that power, what octane fuel were you using. |
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CJG
Samba Member
Joined: November 07, 2005
Posts: 571
Location: Phoenix
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| Posted: Sun Sep 13, 2009 5:19 pm Post subject: |
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| 10.1 when i went to 2275 and the 86B Web |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 6:37 pm Post subject: |
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| CJG wrote: |
| 10.1 when i went to 2275 and the 86B Web |
There you go. nice man. 
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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MinamiKotaro
Samba Member
Joined: July 18, 2008
Posts: 1039
Location: Somewhere in TN
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| Posted: Sun Sep 13, 2009 6:56 pm Post subject: |
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Dad runs 10.3 in his 2386 with an FK-87. It runs decent on 92 pump, no detonation. The butt dyno says it likes 100 octane a lot better, though.
He wants to drop it to around 9:1 and get an FK-8 or 86a. The FK-87 is just not the right cam for how he drives.
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2276cc
MegaSquirt-extra v3.57
Check out my ongoing story. |
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Bad bug
Samba Member
Joined: March 11, 2006
Posts: 1127
Location: Jamaica
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| Posted: Sun Sep 13, 2009 7:04 pm Post subject: |
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| What instruments did you guys use to verify that there was no detonation. |
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Jimmy111
Samba Member
Joined: October 05, 2006
Posts: 2643
Location: Wyoming
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| Posted: Sun Sep 13, 2009 7:12 pm Post subject: |
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| Bad bug wrote: |
| What instruments did you guys use to verify that there was no detonation. |
You heard them. A Butt guage and a calibrated wet finger.... :  |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 7:27 pm Post subject: |
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Dont know if the last 2 posts are directed at everyone, or at minami. But what did anyone use to verify detonation for the last 60 years?
Their ears, and how long the motor lasted, its called knowledge.
NOW in the last 20 years of course we have some trick tech to try and accomplish that. Who here if anyone has spent over a mill on R&D for WHERE to correctly position the knock sensor on an aircooled motor.....anyone here...... anyone.... looks about.
DIDNT THINK SO.
I would kill to have AEM ems and all the proper sensors on an aircooled 2 liter, and KNOW that they are reading correctly. But i dont think you can correctly tell me where the knock sensor can go with the myriad of engine combos and materials inside them, that we have in this group.
SO most of us go with what we know works. Match it all up, and keep combustion chamber/head temps down as far as we can.
Make sure our clients dont expect a 2387 superflo headed monster to carry 4 people down the road 1000 miles to the next bug show.
Its just not the correct setup for such use.
Im enjoying this post alot. Theres some hard heads, and im one of them. But you couldnt have this talk 10 years ago, youd get slapped in the face with either years of baja building retards, or the berg tech book.
I know, i was "that" guy. cal-look forums guy most likely to wear a firesuit. LOL. driving 11 to 1 cars everywhere. 
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 7:30 pm Post subject: |
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| MinamiKotaro wrote: |
Dad runs 10.3 in his 2386 with an FK-87. It runs decent on 92 pump, no detonation. The butt dyno says it likes 100 octane a lot better, though.
He wants to drop it to around 9:1 and get an FK-8 or 86a. The FK-87 is just not the right cam for how he drives. |
If thats what the butt dyno says, then the motor is probably not happy. 10.3 is not enough for an FK87.
Tell him leave it at 10 and run an 86c, as was just mentioned a few posts back.
he will love that, and have less issues. Any idea what his deck height is?
damn, i take it back. that motor and that cam, 10.3 should be pretty good (for 91 octane) maybe even a bit high, just when you think your smert, you own yourself. I just ran the numbers, heres what i got.
Static compression ratio of 10.3:1.
Effective stroke is 2.64 inches.
Your dynamic compression ratio is 8.10:1 .
Your dynamic cranking pressure is 161.56 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of PSI is 8.10 :1.
V/P (Volume to Pressure Index) is 55
I need to know what altitude your at, what rod length, and what deck height hes running. To help with some more answers.
Running a wideband on it? Be nice to know your not on the lean side.
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters.
Last edited by mightymouse on Sun Sep 13, 2009 7:40 pm; edited 1 time in total |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 7:37 pm Post subject: |
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here, play with this. Their webpage is awesome for tools you can use.
http://wallaceracing.com/dynamic-cr.php
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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Jake Raby
Samba Member
Joined: August 23, 2003
Posts: 7433
Location: Aircooled Heaven USA
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| Posted: Sun Sep 13, 2009 8:40 pm Post subject: |
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I have found peak power at 360F with most all of my engines... Its at that point the engine seems to have the perfect expansion as well..
The engine in my 912E has lived 155K miles at 360F, 1700 of those miles on Road race courses above 6K RPM most of the time...
I shoot for 350-360*F for most any competition engines.. In last weekend's race our FP 914 ran an entire 30 minute regional race with the head temps between 345-365F... Thats the way I intended and we worked on the chassis dyno under load tweak the temps right there.
We lapped all bot 4 cars in the race and two of them we lapped twice. (21 car field)
360F read under the spark plug is NOT an elevated CHT.
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Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell" |
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catbox
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Joined: May 16, 2007
Posts: 865
Location: Portland, Oregon
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| Posted: Sun Sep 13, 2009 11:15 pm Post subject: |
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to reduce some of the temps in the chamber couldnt you have the chambers valve faces and exhaust port thermal barrier coated?
wouldnt that put the "to hot" ideas to rest and help keep the heat where it needs to be, as in the gasses routed to the tailpipe... |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 11:21 pm Post subject: |
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There you have it. Jake finally finds his way here and....360 it is.
Just looking at the number, feels high. but if all the tests show thats perf, add that to the notebook.
I would figure 3-350 would be decent, with 400 being scary territory.
But in my mind, i also think, where do you test at? where would you suggest to anyone that you would get an average cyl head temp?
Surely right above the plug would be the hottest, whereas maybe an inch from there when the heat finds more metal and then fins, must be cooler by quite a bit.. Also near the exhaust ports i would figure would be pretty warm.
Like i mentioned, ive used the infrared temp gun on alot of stuff, and move it all over slowly, looking for highest temp.
Just happens that the last 2 motors i built were bone stock 1600s. with stock cam, 8.5 to 1 cr, and a decent header and single muffler. Both are in traveling cars.
I drove them in 2 diff cars and same section of freeway. they both have all stock tin doghouse setup etc.
Case temp all over was around 180-190, and the heads and tops of the cylinders were right around 300, give or take 20 degrees F either direction depending on the section of road. I even shoot right next to the exhaust port, seems to be no differnt. 295, 308, 312.
Like i said, thats all around the head. Not RIGHT at the spark plug. So i wonder what i have at that exact spot.
I like to use those stock 16's to balance my head, cause i figure cant really go wrong with a stock motor with correct jets and timing.
Cause its been 103-112 here the last 2 months, and thats the time window in which both were here. *shrugs*
Hope this stuff helps people. Now i wanna do this next 2165 and see what its numbers are, thing is, it will most likely be driven around on 110 leaded. so, kinda not on the same page as pump gas head temps.
later dave 
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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mightymouse
Samba Member
Joined: May 26, 2004
Posts: 4220
Location: las vegas
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| Posted: Sun Sep 13, 2009 11:22 pm Post subject: |
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| catbox wrote: |
to reduce some of the temps in the chamber couldnt you have the chambers valve faces and exhaust port thermal barrier coated?
wouldnt that put the "to hot" ideas to rest and help keep the heat where it needs to be, as in the gasses routed to the tailpipe... |
def sweet idea. To keep from any hot spots pre igniting the fuel.
Whats the latest known success with that stuff? been a while since i looked into it.
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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Alexander_Monday
Samba Member
Joined: November 09, 2007
Posts: 306
Location: Springfield Missouri
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| Posted: Mon Sep 14, 2009 5:35 am Post subject: |
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| mightymouse wrote: |
| Like i mentioned, ive used the infrared temp gun on alot of stuff, and move it all over slowly, looking for highest temp. |
I would not trust ir gun readings for an absolute temperature reading unless you know for sure the emissivity of what you are shooting.
They are fine for the comparison of changes in the same spot and for generalizations.
I'll let raytek explain:
http://support.fluke.com/raytek-sales/Download/Asset/9250315_ENG_A_W.PDF
An excerpt from the above document:
"The emissivity of a metal depends on wavelength and temperature. Since metals often reflect, they tend to have a low emissivity which can produce differing and unreliable results."
http://www.raytek.com/Raytek/en-r0/IREducation/Emissivity.htm
http://www.raytek.com/Raytek/en-r0/IREducation/EmissivityTableMetals.htm
As you can see there is a large range of variance even for the same metal with different finish and oxidation attributes.
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| andk5591 wrote: |
The original german engineers have attained sainthood and it is impossible to improve perfection.
Anything that anyone does to deviate from the original designs will be made to wrench on 20 year old Yugos with Harbor Freight tools in hell. |
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