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Engine Specific Info and Questions => IDI Engine => Topic started by: monst on January 02, 2014, 01:01:39 pm
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Hi,
I was wondering how to determine.
what Head gasket I have on car.......
referring to notches???? that is what they ask
at the parts store......
and can I do this without removing the head?
::)
Monst
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You can't because some tool may have previously used the wrong one. Measure piston protrusion.
1 notch - 1.53mm thick to suit piston protrusion of .66mm to .86mm
2 notch - 1.57mm thick to suit piston protrusion of .87mm to .92mm
3 notch - 1.61mm thick to suit piston protrusion of .93mm to 1.02mm
Max 0.005" variation cylinder to cylinder
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Yes, it's very common for mechanics to just install a three notch to save a few minutes measuring.
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Make sure to clean all the carbon off the piston crowns before taking a measurement. I've measured before and after cleaning and the measurement changed from 3-notch to 1-notch.
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So...
I don't think I need to measure protrusion...
I have owned this car for ever....
But, Please...
if you don't mind for future reference....
How do I measure piston protrusion.....
THanks, Monst
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Piece of cake... I'd order a Robert Bentley service manual.
Then I'd get a dial indicator and a surface mount:
(http://i619.photobucket.com/albums/tt280/Hj106119/VW%20stuff/267997_1910254758485_1305330380_31880451_3690892_n.jpg)
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So...
I don't think I need to measure protrusion...
I have owned this car for ever....
You are right. Unless there is reason to suspect it for being incorrect (lazy mechanic, or whatever).. replace it with what is there already.
(http://www.vwdieselparts.com/hgasid.jpg)
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Piece of cake... I'd order a Robert Bentley service manual.
Then I'd get a dial indicator and a surface mount:
but measure inline with the wrist pin.
Unless there is reason to suspect it for being incorrect (lazy mechanic, or whatever).. replace it with what is there already.
Or if the car was consuming significant water, had a timing belt crash, or anything else that might bend a rod.
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You are right. Unless there is reason to suspect it for being incorrect (lazy mechanic, or whatever).. replace it with what is there already.
trust no one
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I have personally seen one wrong from VWOA $6500 replacement engine. According to the owner, it runs better than ever with the new correct gasket, but I put new nozzles at the same time.
We got every receipt from new, so we can be pretty sure it was them.
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Interesting...
So what do the (does the)
equipment cost and what is needed...
Just to know.......
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A feeler gauge, a straight edge, a discerning eye, and 300 scrubbie pads, gotta be clean.
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Yup, measure, measure, measure again, measure a 4th time...
The best practice is to measure both sides of each piston and then find the average of the entire set of measurements. There shouldn't be any "outliers" with drastically different results, if there are then that is an indication of a more serious engine problem such as bent rods.
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The Gasket?
Does it only go on one way
or is it symmetrical that it
could flip and go on left to right
or right to left.......
The reason I mention this is because
mine(the notches) sit to the left of the center port
where as in the picture(jeremies) sits to the left
Any takers on this question????? :P :-[
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It only goes on one way. the oil port between #3 and #4 is the key part to that. It is in the gasket and the front head bolt goes through it right there. The new gasket will say "top" or "oben" on the side that goes up.
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I looked at my gasket
and it is not notches.......
there are three circular holes.
Any thoughts?
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I goes by magic numbers more than notch, yours equates to a 3 notch then.
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dose it make that big of a difference? I am just wondering cause my car had a 3 hole on it so that is what I put back on.
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The number is important... Too thin and pistons hit stuff. Too thick and you sacrifice compression.
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Holes = metal head gasket = probably not original on IDI?
It is also not common to fail, so you will want to pressure test head as well.
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So you think my head gasket was replaced once already?
Due to holes... not notches....... "buenos notches.. :-\"
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It is almost inconceivable to me that there is an IDI still running with the original headgasket, so yes.
I'm not sure if any of the 1.6 cars left the factory with a metal gasket, I've certainly never seen one.
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Metal?
where is the gasket metal?
Mine is metal.. not sure what you mean by metal???
OEM'
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OEM's not metal?
What were/are they????
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They were OEM on 1.9L AAZ engines..
Google (http://www.Google.com) man, try it out ;) it works wonders.
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AAZ is a rare bird in these parts, and bros sig implies a 1.6.
Some engines use a fiber gasket with a few metal rings, and notches to indicate thickness. Newer ones use a multi layer steel gasket with a viton coating and holes to indicate thickness.
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The number is important... Too thin and pistons hit stuff. Too thick and you sacrifice compression.
The compression difference is not really of issue. The other two factors are 'squish and quench'. Squish establishes the correct turbulence, again probably not an issue on a pre-chamber diesel. Of particular issue, tho, in a TD is quench where a significant amount of heat is transferred from the piston crown to the more cooled cylinder head. Increasing the space between piston crown and head at TDC will have negatively affect quench and cause the piston crowns to run hotter.
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That is more of what I was asking. I know to you need to chave the clearence for the piston to head but I was just wondering what the performance implications would be of running a three whan you should be running a 1 or 2 if any.
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slower, harder to start and less efficient, more polluting and hotter pistons, with possible added safety margin against lifting the head if you are running 3x factory boost level?
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The number is important... Too thin and pistons hit stuff. Too thick and you sacrifice compression.
The compression difference is not really of issue. The other two factors are 'squish and quench'. Squish establishes the correct turbulence, again probably not an issue on a pre-chamber diesel. Of particular issue, tho, in a TD is quench where a significant amount of heat is transferred from the piston crown to the more cooled cylinder head. Increasing the space between piston crown and head at TDC will have negatively affect quench and cause the piston crowns to run hotter.
Right.... ::)
cylinder head gaskets are available in thickness of 1.4 to 1.6 mm - to selectively match with engine components to maintain the compression ratio.
W. Brandstetter and R. Dziggel
Volkswagenwerk AG
Wolfsburg
http://www.4crawler.com/Diesel/SAE/vwtdsae.shtml
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Right.... ::)
No need to be like that.
Thanks for the link. I've read it.
Some folks have intentionally dropped the compression ratio, with good reason, in order to run higher boost and yet keep peak cylinder pressures in check but doing so by fitting a gasket that is thicker than spec is, IMO, the wrong approach because of the other factors I mentioned. Similarly there are folks running 1.9 heads on 1.6 engines with decent results despite the compression ratio being dropped by many magnitudes more than the drop caused by the thickest gasket on an engine that calls for the thinnest. Perhaps I could have avoided your crap attitude if I had said 'Even if dropped compression is not an issue or even desired there are two other factors to consider...'
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Quench is critical in gassers which have a premix condition causing microdetonation on the piston heads, but diesel combustion has no unburned fuel/air mix after the start of combustion - the fuel only burns as it reaches further into the air-charge (no detonation after ignition).
I've gone through a couple dozen whitepapers on diesel combustion and none mention quench. Probably because it's a crappy way to cool piston-heads, compared to the current in-piston oil circulation chambers or the squirters that preceded them.
One would think if quench (piston to head proximity) was an issue, VW would have mentioned it in the SAE doc linked above.
And as noted, squish for turbulence does not seem to pertain much to IDIs.
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One would think if quench (piston to head proximity) was an issue, VW would have mentioned it in the SAE doc linked above.
I would not assume that. There are things in that paper that are not stated, over-stated, over-simplified or even wrong. The engineers working on the project had their own set of criteria and agenda in their choices on the project and VW as an organization similarly had their own agenda in releasing that paper and the two agendas do not necessarily coincide. While it contains a fair amount of valuable information it is certainly not 'the Truth, the Whole Truth and nothing but the Truth."
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^^ Can you prove that?
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Yes, but what possible motivation would I have to go through the effort? I'm certainly not interested in jumping through hoops to accommodate anyone whose goal is to jab at me.
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Only to validate yourself. No jabs from me?
Same reasons you ever expect proof from anyone else. Validation.
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I certainly don't feel the need to validate myself to anyone. My comments speak for themselves. Sometimes I will cite sources if it is easy or I'm inspired or feeling particularly accommodating/kind. I also do not 'expect proof' from anyone else and never have. I take the information others present and apply my own critical factor to it to see if it passes my own mustard. I have on occasion asked folks if they had links to information simply to make my own self-education easy but I certainly don't expect that accommodation from anyone and if they decide to give it, it is appreciated.
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Oh. Ok. It is making sense.
You only help out when it benefits you personally? Would you say this is true? I would.
I have never given anyone that attitude.. lol "I know what you want to know.. but I won't tell you just because."
A man above, you are.. some would say Godly. (I would lol)
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You really don't feel that you are making jabs? Weird. I'm not sure how else any rational person would interpret that.
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That was my opinion of you. I was asking you if it were true.
No? Ok then it isn't.
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Oh. Ok. It is making sense.
You only help out when it benefits you personally? Would you say this is true? I would.
I have never given anyone that attitude.. lol "I know what you want to know.. but I won't tell you just because."
A man above, you are.. some would say Godly. (I would lol)
Underlined and highlighted you can see where you made a personal statement about me. I feel that type of comment is inappropriate. The following line is more vague and so a bit more appropriate. At least you are making a personal comment about yourself and not about me as I also have not given anyone that attitude. The last statement is also a personal comment. It is a bit vague. The easiest interpretation given the comment in parentheses is that you are being sarcastic and so, it must be interpreted as another derogatory personal comment.
That was my opinion of you. I was asking you if it were true.
No? Ok then it isn't.
There is no point in time where your opinion of me is appropriate to post on this forum. Similarly, my opinion of you is not appropriate for me to post on this forum and so, I don't post it. It would be appreciated if you would follow my example and cut the crap. ;)
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The butthurt form can be found in the faq.
I will head your advice and back down. :) A pleasure as always Andrew.
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I agree, that would certainly have been the most appropriate place for you to have posted all of these comments.
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I only asked you to prove what you said man..
You said no because we are not worth your time..
Why do you post here then??
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At post 37 the comments go from diesel car related to things of no value to us. Bring it back around guys. This isn't a hillbilly forum, we care what is stated and want to maintain our reputation. We used to be of top notch and things of late are dragging us down.
The discussion of quench is a good idea, it fosters growth, and knowledge of diesel cars. Whether or not you agree with someone or not, keep your personal comments to a minimum as we are here to talk about VW diesels.
I just don't know what to do with you guys. I am up for suggestion before people have to get cut out of the equation and be eliminated. The personal jabs over, it is time to all play nice and type nice. The threads are threads, they do not always go linear and that is for our benefit to continue it out for knowledge. Tyler answered the original poster in reply 5 perfectly. Keep going with it is fine, we all can learn from each other, no matter how dumb or smart you think you are.
Lets get back to diesel.
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I only asked you to prove what you said man..
You said no because we are not worth your time..
Why do you post here then??
Enough. You are putting words into his mouth, he never said anyone here was not worth his time. Last warning.
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If yo look at a piston with long term EGT damage, it is almost always at the edge of the piston crown is it not?
VW was building 60HP engines with a 40K warranty, I doubt they were too worried about it.
As for Libby's cost-benefit habits, I can say he advised me correctly on fixing my throttle arm issues, and I never gave the SOB a dime, a beer, or even or a reacharound.
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Hey, where's my dime and who are you calling an SOB? [headed to the FAQ to find that form...]
What conclusion are you coming to WRT EGT damage? That sharp edge is the most prone to heat damage and I would have to assume that additional quench would only assist in reducing it.
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That is pretty much my conclusion too.
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It is almost inconceivable to me that there is an IDI still running with the original headgasket.
hey hey mine is original.
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Hey, I've actually got an original gasket car as well. Although it hangs out in storage (92 Eco).
Do we get a prize? Perhaps Commander Putin will come by and congratulate us?
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I only asked you to prove what you said man..
You said no because we are not worth your time..
Why do you post here then??
Enough. You are putting words into his mouth, he never said anyone here was not worth his time. Last warning.
Lol what? Are you serious? What was wrong with that? How come everyone is not held to the same standards around here?
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The number is important... Too thin and pistons hit stuff. Too thick and you sacrifice compression.
The compression difference is not really of issue. The other two factors are 'squish and quench'. Squish establishes the correct turbulence, again probably not an issue on a pre-chamber diesel. Of particular issue, tho, in a TD is quench where a significant amount of heat is transferred from the piston crown to the more cooled cylinder head. Increasing the space between piston crown and head at TDC will have negatively affect quench and cause the piston crowns to run hotter.
EDIT:16 posts since I started writing this whilst doing other jobs, so I my need to edit but it's 3am here and I'm too tired...!
These are strange comments Andrew. I feel I have to comment because you are held in high esteem by your followers, due to your vast experience, you my be having an off day and unintentionally misleading your members:
1)A bit rash to say that compression changes by changes in gasket re unimportant especially as most engines are getting quite old now and starting issues are likely to be waiting in the back ground with these IDI's.
2) Required turbulence is, and has been since Ricardo optimized it back in the 1920's at a rotational speed of 7 or was it 8 times the engine rpm. using chamber size and throat combo.
3) If 'quench' had anything to do with these IDI engines, how do you account for the effect or no effect, of using different materials for headgaskets.
For example for some unknown reason I have a few genuine 1 & 2 hole asbestos gaskets [I use/require 3 hole], which surely insulate the head differently to the more usual 'plastic' ones, or then there is the 1.9 metal one, which must allow for greater heat transfer out of the head.
You've referred to this squish and quench stuff before. All I've ever found is gasser research and DI diesel references to the gasser research 'possibly' being applicable.
What references do you possess or, better still colaberating experience of these effects do you have? I would suggest that the process of 4 strokes act to quench piston temperatures, along with my factually correct retardation of timing... Surely there is more heat radiating from the head, and especially the precup, than from the rapidly reducing heat in a decompressing piston chamber. Come to think of it an engine with the combustion chamber in the piston might benefit from heat transfer across the void to the cylinder head...
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3) If 'quench' had anything to do with these IDI engines, how do you account for the effect or no effect, of using different materials for headgaskets.
For example for some unknown reason I have a few genuine 1 & 2 hole asbestos gaskets [I use/require 3 hole], which surely insulate the head differently to the more usual 'plastic' ones, or then there is the 1.9 metal one, which must allow for greater heat transfer out of the head.
Headgaskets are spec'd by compressed thickness. a 3 notch metal one installed thickness is the same as a 3 notch fiber which will have been thicker on the shelf.
MLS ones seal better for longer and withstand greater stress than fiber ones, hence have replaced them in almost every automotive application. They may or may not transfer heat differently, but the difference for better or worseis far outweighed by the reliability gained by going MLS.
When you say 'plastic', you are referring to the Viton coating on an MLS gasket correct?
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I always measure the piston protrusion and use the correct thickness gasket. I measure the piston protrusion by carefully scrubbing off the carbon from the piston crown and use a straight edge across the surface of the crown parallel to the wrist pin bore. I then use feeler gauges to determine the protrusion of the piston on both sides. I write down the larger of the two measurements and proceed to the next piston. After measuring all four I find the highest protrusion and use that to determine the gasket for use.
I have a dial indicator and adjustable magnetic base and have used it a couple times to measure protrusion but I find the feeler gauges to be more accurate. The arms of the dial indicator base intrinsically have some flex to them and it is necessary to move the mount over to the block to zero it and then back to the piston and I find that moving the base can skew the reading. A test to see if the reading is skewed is to move the needle to the block, zero it, move it to the piston, measure it and then move it back to the block to see if goes back to zero correctly.
For a bit of time I have been planning on taking a machined flat that is 3/8-1/2" thick and drilling and tapping it to 8x1.00 in the center so I could thread in my pump timing dial indicator adapter. I believe that using that along with two equal thickness valve shims would be faster than the straightedge/feeler gauges and more accurate than the magnetic base with the dial indicator. In order to use it, place the valve shims under the ends of the flat on top of a true flat surface and zero the dial indicator. Then place one valve shim on either side of the piston and the flat across like a bridge.
On a rebuild, if the block is not skimmed at all, it is not uncommon to find that the piston protrusion is below the spec for the 1-notch gasket. New pistons typically move the wrist pin bore closer to the crown in order to allow for surfacing the block head gasket surface. Reconditioned rods can also reduce the piston protrusion. Several years ago, I had one rebuild that had protrusion to low for a 1-notch and I didn't figure that out until I had the bottom end assembled with the pistons in the bores. It really stunk to have to disassemble it all (thankfully I had purchased ARP rod and main fasteners) in order to get the head gasket deck skimmed more. Since that happened I have rebuilt several of these engines and taken a different approach in order to avoid that issu. Since then, the protrusion has come out right where I wanted it each time. When rebuilding one of these engines I like to measure the piston protrusion with the old pistons and the reconditioned rods before taking the block to the machine shop for boring. I then measure the wrist pin bore to crown height on the old and the new pistons. Once I know the protrusion of the old pistons and the wrist pin bore to crown measurement of both, simple math lets me know how much to tell the machinist to trim from the block head gasket surface. I typically make the protrusion fall right in the upper range of the two notch as the AAZ 1-notch gasket is less available and more expensive and if there is any issue with the machining or measuring the odds are still good that I will not fall outside the range for all three. I still re-measure protrusion after getting the block back from the machinist in order to make sure of the measurement before ordering the head gasket.
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3) If 'quench' had anything to do with these IDI engines, how do you account for the effect or no effect, of using different materials for headgaskets.
For example for some unknown reason I have a few genuine 1 & 2 hole asbestos gaskets [I use/require 3 hole], which surely insulate the head differently to the more usual 'plastic' ones, or then there is the 1.9 metal one, which must allow for greater heat transfer out of the head.
Headgaskets are spec'd by compressed thickness. a 3 notch metal one installed thickness is the same as a 3 notch fiber which will have been thicker on the shelf.
MLS ones seal better for longer and withstand greater stress than fiber ones, hence have replaced them in almost every automotive application. They may or may not transfer heat differently, but the difference for better or worse, is far outweighed by the reliability gained by going MLS.
When you say 'plastic', you are referring to the Viton coating on an MLS gasket correct?
Hi,
Sorry for the vagueness. For 'plastic' I was actually referring to the run of the mill later fibre ones, which, incidentally seem to compress more.
It was only, what must be the vastly contrasting heat transfer properties between asbestos, non asbestos, and Mls gaskets, which may, or may not influence how an engine performs, or heats, or indeed cools in this context.
Anyway where is the IDI research on the influence of quench/squish? Patents office perhaps?
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AFAIK all IDIs of every brand are tight squish motors where the piston protrudes above deck. There must be a reason.
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AFAIK all IDIs of every brand are tight squish motors where the piston protrudes above deck. There must be a reason.
To get most of the air into the swirl chamber?
A simple calculation should give us the difference in rotation of the air mass in the chamber between virtual touching of piston to head, and, perhaps pistons that are a mm or so lower and flush with the deck. Ricardo seemed to think [heck he did a lot of research] or rather knew that a certain number of swirls performed best.
Has the protrusion also to do with manufacture of a gasket, initially of asbestos, later of other fibers, that needed encasing in that thin shield of metal to void breakup.
Maybe the AAZ missed an opportunity to drop the height of the pistons and use a gasket of a few thou. Are there graphs of strength of clamped gaskets and their thickness...
Could some air being left outside the chamber actually help complete late combustion, as the pistons decend?
Of course the TD and late N/A's all had the oil cooling under the pistons, taking the heat in the other direction.
I'm just trying to think, did the 1.4 n/a Citroen AX have flush pistons? They had wet liners, used the same injectors as the VW, and got 80+mpg genuine. That was Al block/head, whilst the later 1.5 changed to cast iron block.
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I have talked to a couple machinists, granted they are not experts, and they have said the combustion is supposed to take place in the prechamber. To add the volume to the top of the piston area for no reason can retard the combustion event or add dwell to the flame travel as it can slow the burn. If what they say is true then I think what Libby and 745 have commented on makes sense. The "quench" "squish" etc isn't in the prechamber and the added burn time is on top of the piston, therefore making it hotter there than it normally would be, but a lower temp overall as the event contained in the prechamber would be a quicker hotter burn.
All theory and guessing from the machinist and my head, but it makes sense to me. I think we have a great discussion here.
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Lots of good info in this old thread... http://www.vwdiesel.net/forum/index.php?topic=8369.0
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I only asked you to prove what you said man..
You said no because we are not worth your time..
Why do you post here then??
Enough. You are putting words into his mouth, he never said anyone here was not worth his time. Last warning.
Can a moderator give warning to another moderator? Is there a moderator pecking order?
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I only asked you to prove what you said man..
You said no because we are not worth your time..
Why do you post here then??
Enough. You are putting words into his mouth, he never said anyone here was not worth his time. Last warning.
Can a moderator give warning to another moderator? Is there a moderator pecking order?
8v was demoded a few months ago. His entire account deleted hence his new account has a "!" at the end.
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I only asked you to prove what you said man..
You said no because we are not worth your time..
Why do you post here then??
Enough. You are putting words into his mouth, he never said anyone here was not worth his time. Last warning.
Can a moderator give warning to another moderator? Is there a moderator pecking order?
8v was demoded a few months ago. His entire account deleted hence his new account has a "!" at the end.
Really!!! What happened?
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Somehow I don't buy this quenching theory by just doing fluid dynamic analysis in my head. ;D To dissipate heat from the piston crown efficiently by quenching, it needs dwell time and contact to the head. There is no contact and the dwell time is what? milliseconds? Unless I see some proof, I am sticking to it.
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Remind the machinist in you head the piston is stationary at TDC and BDC
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There is no contact and the dwell time is what? milliseconds?
1200rpm = 20r/s
1sec / 20 = .05s/rev
50ms / 360 = .138ms/degree crank
So, if you want to say dwell is ten degrees, then that's ~1.4ms.
Check that math... I've buggered it before.
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Does 4 stroke have to be factored in? Clearly getting near to my bed time as my brain is fuzzing. ;D
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Remind the machinist in you head the piston is stationary at TDC and BDC
Stationary for what, a milli-second? not enough time to transfer much heat. I can put my fingers on hot coals for a milli-second without much heat transfer won't get burned.
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Remind the machinist in you head the piston is stationary at TDC and BDC
Stationary for what, a milli-second? not enough time to transfer much heat. I can put my fingers on hot coals for a milli-second without much heat transfer won't get burned.
Isn't the goal to not transfer heat? Unless you are running the piston up to touch the head and sending heat from the crown to the head that way ::)
We are protecting the most delicate part of the piston at the time heat is the highest.
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Remind the machinist in you head the piston is stationary at TDC and BDC
Stationary for what, a milli-second? not enough time to transfer much heat. I can put my fingers on hot coals for a milli-second without much heat transfer won't get burned.
Do it several gazillion times for a few hours. I'll bet you have some odd looking fingers ;D
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This argument is kind if metaphysical. It is no more relevant than arguing about how many fairies can dance on the head of a pin.
Has anybody here actually put in a 3 notch when a one notch was called for????
Well I have. I did that once when I did not have the correct "notch" in stock. Fresh motor that I wanted to put some miles on. I ordered the 1 notch and drove the car for over a month with the 3 notch before I swapped out the correct gasket. I was expecting more power, less smoke, better starts, and better mileage. I can not attest to cold start performance because it was not cold here then, but I noticed NO DIFFERENCE. Nothing, Nada.
It did not feel faster, did not start better, did not smoke less, and the fuel mileage did not go up.
So I ask you how important is it really?
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I did it on my last build as to increase performance since I was running higher boost. I noticed that every time I started the engine it ran rougher and had white smoke out the tailpipe. It could be 95f out and still white smoke if you were watching.
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I did it on my last build as to increase performance since I was running higher boost. I noticed that every time I started the engine it ran rougher and had white smoke out the tailpipe. It could be 95f out and still white smoke if you were watching.
I bet he won't believe you.
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Remind the machinist in you head the piston is stationary at TDC and BDC
Stationary for what, a milli-second? not enough time to transfer much heat. I can put my fingers on hot coals for a milli-second without much heat transfer won't get burned.
Isn't the goal to not transfer heat? Unless you are running the piston up to touch the head and sending heat from the crown to the head that way ::)
We are protecting the most delicate part of the piston at the time heat is the highest.
I was questioning the statement from libbydiesel (copied below), the part that increasing space between piston crown and head at TDC by using a thicker head gasket will have negatively affect quench and cause the piston crowns to run hotter. I take it that Libby meant quench is needed for piston crown in a TD engine and having too thick a head gasket negatively affects quench, which is more important than the lowering of compression due to thicker head gasket.
"The compression difference is not really of issue. The other two factors are 'squish and quench'. Squish establishes the correct turbulence, again probably not an issue on a pre-chamber diesel. Of particular issue, tho, in a TD is quench where a significant amount of heat is transferred from the piston crown to the more cooled cylinder head. Increasing the space between piston crown and head at TDC will have negatively affect quench and cause the piston crowns to run hotter."
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Lots of good info in this old thread... http://www.vwdiesel.net/forum/index.php?topic=8369.0
If you look at page 6 of this thread you will see that sauerkraut has done this experiment. Later he went with the same engine but a 1.9 head and the correct gasket and it ran well. The 1.9 has bigger prechambers and therefore lower CR, but the starting issue was solved. Granted it is one car, one guy, one engine, one experiment, but it sounds like a good one and that our theories are not far off.
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This argument is kind if metaphysical. It is no more relevant than arguing about how many fairies can dance on the head of a pin.
Has anybody here actually put in a 3 notch when a one notch was called for????
Well I have. I did that once when I did not have the correct "notch" in stock. Fresh motor that I wanted to put some miles on. I ordered the 1 notch and drove the car for over a month with the 3 notch before I swapped out the correct gasket. I was expecting more power, less smoke, better starts, and better mileage. I can not attest to cold start performance because it was not cold here then, but I noticed NO DIFFERENCE. Nothing, Nada.
It did not feel faster, did not start better, did not smoke less, and the fuel mileage did not go up.
So I ask you how important is it really?
Argument promotes understanding... Reinforcement for those who already understand, and understanding for those who don't.
Dictatorial stifling of debate, by the use of the Drone like weapon of banning everyone who doesn't agree with the party line or 'The One' smells of Communism, Fascism etc, and we don't want that, do we!
Re the thicker than necessary gasket experiment:
Cold weather may have shown something.
Having a fresh engine, probably meant that even the lowered compression was better than an un-rebuilt, but otherwise functional high mileage engine...
Still, useful information.
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A 1-notcher is ~.87mm thick, a 3-notcher is ~1.02
V1 / V2 = rC
397 / 17.26 = 23.0
398 / 18.28 = 21.77
21.77 / 23 = 5.3% change
Considering other variables, 5.3% change in compression ratio might be hard to detect.
Compare to a midlife engine: let's say 350psi... 350/450 = .777 or 23% change
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A 1-notcher is ~.87mm thick, a 3-notcher is ~1.02
V1 / V2 = rC
397 / 17.26 = 23.0
398 / 18.28 = 21.77
21.77 / 23 = 5.3% change
Considering other variables, 5.3% change in compression ratio might be hard to detect.
Compare to a midlife engine: let's say 350psi... 350/450 = .777 or 23% change
Well not according to what sauerkraut had on his engine that was fresh. The HG made for harder starting and was fixed when he went to the 1.9 head *with larger swirl chambers* and the correct gasket. Page 6 of the link shows his problems.
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Ja, I don't doubt that... I'm mostly throwing numbers into the mix, particularly comparing HG volume vs wear.
We're dealing with nuanced assessment in a dynamic environment, and opinion is surely gonna vary.
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I only asked you to prove what you said man..
You said no because we are not worth your time..
Why do you post here then??
Enough. You are putting words into his mouth, he never said anyone here was not worth his time. Last warning.
Can a moderator give warning to another moderator? Is there a moderator pecking order?
8v was demoded a few months ago. His entire account deleted hence his new account has a "!" at the end.
Really!!! What happened?
Nobody want to tell me what happened? What happened to 8v-of-fury's posts? They seem to be all gone. Did he do a Libby and deleted every post he ever made? That would be a shame since he contributed a lot to this forum. Is that "feature" still available? What's next? Is Libby going to do a second round of total delete?
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All the fracas got scrubbed.
He globally deleted?... well, that sucks.
Edit: seems some stuff still there.