VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: libbydiesel on April 06, 2013, 03:58:16 pm
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I was inspired by some recent events to further investigate precombustion chamber inserts.
Here's a chart of the gathered info (some of which is redundant):
| [Casting number] | [1.6 or 1.9] | [lifter type] | [turbo or n/a] | [flange dmtr] | [magnetic precups] | [cracks] | [dimples/triangles] |
| 028103373j | 1.9 | hyd | Turbo | 32mm | Yes | NO | No |
| 068103373D | 1.6 | hyd | Unknown | 32mm | Yes | NO | No |
| 068103373T | 1.6 | hyd | Turbo | 32mm | No | Yes | No |
| 068103373T | 1.6 | hyd | Turbo | 30mm | No | Yes | Yes |
| 068103373T | 1.6 | hyd | Turbo | 30mm | No | Yes | Yes |
| 068103373N | 1.6 | Solid | Turbo | 30mm | No | Yes | Yes |
| 068103373N | 1.6 | Solid | Turbo | 32mm | No | Yes | No |
| 068103373B | 1.6 | Solid | N/A | 32mm | Yes | No | No |
| From Gizmoman |
| 028103373M | 1.9 | hyd | N/A | 32mm | No | Yes | Yes |
| From Luckypabst |
| 068103373D | 1.6 | hyd | N/A | 32mm | Yes | Yes | No |
There are some interesting data points I would note. 1.6TD precups came as BOTH 30mm and 32mm with both mechanical and hydraulic heads. The magnetic precups (presumably steel rather than inconel or stainless) are NOT cracked. This is especially interesting to me because the last head listed (suffix B) was a very old 1.6 head with 11mm head bolts that showed to be just hammered. There were big cracks between the valves and even cracks between the two center exhaust valves and the precups. Despite all the obvious wear/heat, the magnetic precups were flat and had no cracks. That isn't definitive, but leads me to believe that steel precups would be BETTER than inconel.
Altrom(Napa) sells AMC brand precups for the AAZ (http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d028103391m%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d028103391m%26Dk%3d1%26Dp%3d3%26N%3d0) engine for $27. Part # 028103391M.
Eurocar Togliani (http://www.eurocartogliani.191.it/) in Italy sells precups for the 1.5, 1.6 and 1.9 engines. I just got a quote from them for 24 euros each plus approx 40 euros for shipping for a couple sets. That brings them up to approx $40 per precup.
RockAuto lists prechambers for the 1.6 non-turbo engines and yet the dimensions listed are the 30mm and 25.4mm diameters which match the TD inserts and NOT the n/a ones. They list them for approx $13 plus exorbitant shipping - $60 for a set, but unfortunately, when added to the shopping cart they post up a note saying they are not available and delete them from your cart...
I found THIS (http://www.hbaron.com/precombustion_chambers.htm) site that lists prechambers for the 1.9 but have e-mailed a while ago with no response.
I am planning on e-mailing Topline to see if they will sell any prechambers or have any source they could direct me to.
Anyone else have potential sources? Anyone have the capacity to machine new ones?
I'd welcome anyone to look through their parts stash and list up the same specs for any heads they have. I'd be happy to add them to the table.
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I have four I removed from the head. #3 was loose and I removed the others in search of water-jacket issues - none found.
The circular marks are just soot - not grooves. These things are harder than hammered cat turds.
(https://lh5.googleusercontent.com/-1OSDrBVhGdk/UWCu43vJ4VI/AAAAAAAABoI/zX62Nvp0XUc/s912/DSC00412.JPG)
They are non magnetic and have "CHU2028B" stamped in the side. No cracks, 1.0915" OD .
The head is complete with the typical small cracks between the valves. I bought a new KS head complete.
I believe the engine is an industrial 1.9 out of a forklift but I'm not positive - just guessing.
The piston pins are smaller than stock. I mention this because the cam may be a different grind as well.
(https://lh6.googleusercontent.com/-VeVec15_9hU/UWCu4gI_KkI/AAAAAAAABoA/LVpzflFd8kE/s912/DSC00411.JPG)
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Thanks for the info. You'd have to buff off the carbon/deposits to see whether or not they are cracked. What is the flange diameter, flange depth and main cylinder diameter? What is the head casting number? Can you see if the new KS inserts are magnetic or have you already installed the head on the block?
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Thanks for the summary Andrew; back in 2011 when I got my 1.6TD sets from Eurocar Togliani, I contacted AMC in Spain
as prechambers were listed in their catalog as separate items - - but they replied that the weren't available except in a completely
new head.
I'll measure my old VWAG ones and post up later
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Might be interesting to measure CC's and opening size too. I know Gm changed around the openings with different power outputs.
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What's the best way to remove prechambers,
without cracking them?
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Best to use a brass punch down through the injector opening. Aim toward the wall rather than the edge of the inner lip.
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Some guys tape the opening shut then fill it with salt then use the largest punch possible through the injector hole.
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When I was searching for precups, I found the Eurocar products as you did, but the cups were slightly larger that stock; 0.5mm if I recall.
In addition, Federal Mogul UK and Belgium, I think listed 1.6 precups for the GTD engine in the Audi. (engine code RA/SB) and I think listed them as stock plus an oversize. See info below from a previous entry on the forum..
Having just received a head with cracked chambers I went on the hunt for some new ones. I looked in the Federal Mogul UK electronic catalogue for them and found some for the 1.6td head under the Audi 80 1.6td section. They are for the SB GTD engine and there are two different sizes listed but only one is available in STD size and 0.5mm oversize. My local supplier says he can get them in from Belgium for £12 each. Link: http://www.fmecat.eu/selProd2.asp?make=5&model=%20&engine=4211~SB&litre=%20&prdgrp=4&langID=1&TsVer=&engseal=0
Before I order I'm trying to establish if they will fit correctly, Federal Mogul lists the dimensions which seem to correspond with some measurements taken from this thread:
http://www.vwdiesel.net/forum/index.php?topic=2329.msg17375#msg17375
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Here's a shot of one "buffed" pre-cup. You were correct, you can't see the cracks till it's cleaned up.
(https://lh3.googleusercontent.com/-JiKK9MyeaI8/UWGCLohXBAI/AAAAAAAABpc/mXAf6IAkjJ0/s640/DSC00420.JPG)
Flange diameter - 1.2565" [31.9151]
Flange thickness - 1.1595" [29.4513]
Overall height - 0.6685" [16.9799]
Barrel diameter - 1.0915" [27.7241]
Small protrusion on the barrel OD directly opposite the port (would be upper left in photo)
CUH2028B cast in barrel OD to the right of the port.
I didn't clean them all but assume they each have similar cracks.
Here is the head number these came out of:
(https://lh4.googleusercontent.com/-vuf_-5dodz4/UWGJz4XH1lI/AAAAAAAABpw/MZTPAI9JjLU/s448/DSC00414.JPG)
The KS head has non-magnetic cups as well. However, there is no indentation in the face to the left of the port (like the one shown in the pic). The head appears to have been surfaced with the cups installed as I can barely make out the cup edge itself.
May I ask what has led you to this extensive research?
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May I ask what has led you to this extensive research?
This happened less than 3,000 miles after a complete rebuild and was a significant amount of inspiration:
(http://i13.photobucket.com/albums/a269/libbybapa/head_zps8831386c.jpg)
(http://i13.photobucket.com/albums/a269/libbybapa/cyl_zps06e4d185.jpg)
I also recently purchased a used head that is in very good condition aside from the precups having small cracks.
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:'( Man, what a disappointing event. I hate to sound so selfish but It's not much of an an inspiration for a guy who is spending mega bucks on what is becoming a two year rebuild.
When I add this to the dropped cup on theman53's build and my loose cup on #3, I have to question the effort. When I bought the van it had the 1.9 in it and I figured, diesel, strong, last long time, good. Six months later it was attached to an engine stand. I sprung for the new KS head because of the loose cup on #3 and a questionable area near a water jacket port. From what I have been reading, within a few months the new KS will have cracks between the valve seats and could possibly drop a cup into the barrel - this sucks.
Obviously you are looking for a solution. I will be watching this thread closely and offer anything I can to assist.
I have a Lagun knee mill and a Graziano SAG lathe - just don't have a lot of time ;D.
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Here's some more info for you, Libby...
Looks like you already have this in your database, however
Casting #0X8 103 373D (X digit is indeterminate due to casting flaw, assumed to be 6)
Hydraulic, NA 1.6
All cups magnetic
All cups cracked
32mm diameter
No dimples.
I'm about to start slicing this head so it stores more easily in my scrap bin.
Chris
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Another interesting thread - http://www.vwdiesel.net/forum/index.php?topic=32562.msg300809#msg300809 (http://www.vwdiesel.net/forum/index.php?topic=32562.msg300809#msg300809).
Didn't read the whole thread but I do recall several posts about a steel head.
Aluminum and inconel - not too good together in a high heat application IMHO.
May be a silly question but I wonder if they cast the head around the cups? The ones I removed have a tiny nipple on the side which would just broach out a meaningless groove if they were pressed in later.
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Dropping precups isn't a common issue. Gizmo, I think with your new KS head you should be fine for many thousands of miles, especially if you are very moderate with max EGTs. If it's something that has you losing sleep, your block, crank and rods will fit with TDI pistons. Add an AHU head, injectors, timing covers, pump bracket and mTDI pump and you no longer have precups to be concerned about. Another upside is you'd gain 10-15% in fuel economy. A downside is that your stock vanagon gearing would stink.
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Thanks for the reassurance and the upgrade pointers Libby. I'm way over on expenditures though.
BTW, my gearing already stinks.
Also, For your records, my engine has a K14 turbo - don't know if it is stock for the engine, but it was on the van when I bought it.
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Libbydiesel,
I had the same thing happen with my AAZ in hole number one. Ended up replacing the pistons and head of course. The amazing thing was it would run like that though pretty bad.
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Libbydiesel/all -
here's my data:
Casting #068 103 373E (original German head from 1983 Jetta 1.6TD)
Mechanical 12mm studs, TD 1.6 w/Garrett T3
Magnetic status unknown, but likely inconel
All cups cracked, most in two places
32mm diameter
No dimples.
The precups seemed tight in the head, but cracks in all four, 221,000 miles on the head, and my plan to run 15-18 peak psi boost,
led me to replace them with interference sized Eurocar Togliani cups (32.5mm). I had the head bored with approx .002 interference fit,
heated the head to 350F, froze the precups, and then staked their perimeter in 5 or 6 places away from headgasket areas. Engine
is still on the stand for install later this spring.
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I got word back from Grupo Baron, one of the sites I linked in my initial post. They list the 1.5 and 1.9 precups. I also asked if they could make some 1.6TD ones. Here's their response:
Prices for the chambers as follows:
GB-014 VW GOLF 1500 $4.17 each F.O.B.
GB-065 VOLKSWAGEN POLO 1.9D $4.13 each. F.O.B.
We can manufacture your samples, you can send them to our U.S. Address, below, the chambers are usually oversize 0.010”, if you want STD, chambers you should let us know. Minimum order is $1000.00. The chambers are made from an alloy, which we melt carbon 0.42-05, Iron balance, Manganese 0.6-0.9 Phosporus 0.04max Sulfur 0.05max, after machined they are heat treated. We export to Guatemala, Honduras, Costa Rica, Panama, Nicaragua, Barbados ,New Zeland, United States, Argentina, Dominican Republic, etc. If you are in the states import taxes are 0% due to the free trade agreement.
That all sounds very encouraging except it would take 100 heads before it was worth it.
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I got word back from Grupo Baron, one of the sites I linked in my initial post. They list the 1.5 and 1.9 precups. I also asked if they could make some 1.6TD ones. Here's their response:
Prices for the chambers as follows:
GB-014 VW GOLF 1500 $4.17 each F.O.B.
GB-065 VOLKSWAGEN POLO 1.9D $4.13 each. F.O.B.
We can manufacture your samples, you can send them to our U.S. Address, below, the chambers are usually oversize 0.010”, if you want STD, chambers you should let us know. Minimum order is $1000.00. The chambers are made from an alloy, which we melt carbon 0.42-05, Iron balance, Manganese 0.6-0.9 Phosporus 0.04max Sulfur 0.05max, after machined they are heat treated. We export to Guatemala, Honduras, Costa Rica, Panama, Nicaragua, Barbados ,New Zeland, United States, Argentina, Dominican Republic, etc. If you are in the states import taxes are 0% due to the free trade agreement.
That all sounds very encouraging except it would take 100 heads before it was worth it.
How do you figure? I think the value of these precups is at least $50 per set, if they're good parts, and 4 per head, assuming you could buy them at about $5 each, and sell them as sets for $50, you would recoup your initial minimum investment after selling about 30 sets.
Would they sell? I don't know. Owners of old VWs are notorious cheapskates and would probably just want to replace one or two... When I worked at a Napa, it was always the diesel Volkswagen owners who would try to buy just one brake pad or brake pads for one side of the car only... It's something that kind of frustrates me about this community.
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Yeah, my math was screwy. It actually might be worthwhile.
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We could set up a group buy??? I would approve. That way we could all get a set or 10 and be happy. I would probably only get a few as I will go to the 1.9L engines after this 1.6.
BTW, great info Libby. I was incorrect in what my research had found in the TD being 30mm only. Just happens that every head I had that was TD had 30mm.
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I was thinking that it might also be worthwhile to design a pre-chamber insert that would fit the 1.9 head, but result in the combustion chamber size of the 1.6. That would allow easy use of the new OEM 1.9 heads on 1.6TD blocks without the downsides of the smoke and harder starting caused by the low compression of a franken.
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I was thinking that it might also be worthwhile to design a pre-chamber insert that would fit the 1.9 head, but result in the combustion chamber size of the 1.6. That would allow easy use of the new OEM 1.9 heads on 1.6TD blocks without the downsides of the smoke and harder starting caused by the low compression of a franken.
wouldn't that require a reshaping of the dome inside the head?
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Re: Libbydiesel's suggestion of 1.6L volume sized prechambers for 1.9 heads is a good one, I guess that I'd personally rather see the effort towards 1.6L oversize pistons in a TDI configuration though. That should really jump start the m-TDI pump, strengthened clutch & 02A/02J transmission transplant businesses...and also enable 15 percent better economy in all the 1.6L hydro blocks we have. My $.02
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I was thinking that it might also be worthwhile to design a pre-chamber insert that would fit the 1.9 head, but result in the combustion chamber size of the 1.6. That would allow easy use of the new OEM 1.9 heads on 1.6TD blocks without the downsides of the smoke and harder starting caused by the low compression of a franken.
wouldn't that require a reshaping of the dome inside the head?
I don't think so. I think that it would be possible to make the bowl of the precup less deep to compensate for a deeper dish in the 1.9 head. I will do further measuring/comparing as time allows.
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Re: Libbydiesel's suggestion of 1.6L volume sized prechambers for 1.9 heads is a good one, I guess that I'd personally rather see the effort towards 1.6L oversize pistons in a TDI configuration though. That should really jump start the m-TDI pump, strengthened clutch & 02A/02J transmission transplant businesses...and also enable 15 percent better economy in all the 1.6L hydro blocks we have. My $.02
I'd love to see oversize 1.6TDI pistons, but precups are a lot less expensive than custom pistons. 1.9TDI engines are fairly readily available and a 1.9TDI tuned to the power output of a 1.6TDI would get virtually the same fuel economy. I think most people currently choosing a 1.6TD vs a 1.9TDI would balk at the cost of custom pistons, a TDI head, mTDI fuel pump, etc...
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great points Andrew; you've covered it well why my idea blows. Anyway, I'd be in for a couple of sets of tailored prechambers for use of 1.9 heads on 1.6 blocks with a more suitable compression ratio, especially if the fallout issue could also be addressed someway better as well.
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I didn't mean to say that a 1.6TDI was intrinsically a bad idea. I think it would be very cool and have done considerable thinking/investigating in the past on how to accomplish it. I just keep coming to the conclusion that it's not really cost effective.
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I didn't mean to say that a 1.6TDI was intrinsically a bad idea. I think it would be very cool and have done considerable thinking/investigating in the past on how to accomplish it. I just keep coming to the conclusion that it's not really cost effective.
i agree, it has been done with 1.5 crank and tdi pistons before, but that is quite a different 1.6. it would be sweet but i don't see the point, and i can't imagine it would get much better fuel economy the only difference would be less energy wasted moving air ur not using except at full pedal, and more energy lost on friction with the cylinder walls from the larger bore and longer stroke.
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Libbydiesel/all -
here's my data:
Casting #068 103 373E (original German head from 1983 Jetta 1.6TD)
Mechanical 12mm studs, TD 1.6 w/Garrett T3
Magnetic status unknown, but likely inconel
All cups cracked, most in two places
32mm diameter
No dimples.
The precups seemed tight in the head, but cracks in all four, 221,000 miles on the head, and my plan to run 15-18 peak psi boost,
led me to replace them with interference sized Eurocar Togliani cups (32.5mm). I had the head bored with approx .002 interference fit,
heated the head to 350F, froze the precups, and then staked their perimeter in 5 or 6 places away from headgasket areas. Engine
is still on the stand for install later this spring.
How much did it cost to have the head bored for the oversized precups? Thanks.
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here was the prechambers from my 1.6td its a true td solid lifter head and had no cracks between the valves, i still didn't install the head, are these safe???
number 1
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl1.jpg)
number 2
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl2.jpg)
number 3
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl3.jpg)
and cylinder number 4
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl4.jpg)
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There is NO WAY I'd run it like that. The #2 cup looks especially bad. In 1,000 miles the front part could fall into the cylinder.
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I'm thinking the stickout is probably a bit shy too.
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I'm thinking the stickout is probably a bit shy too.
they are flush, the machine shop milled the head for no reason, they made it sound like they do that on most heads they get in to make sure no one comes back. its more of a pita problem for me tho and i know this head was flat and true. but i griped about that on here before haha.
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Recently saw a comment on NOT staking/peening precups... no comment on why not. Any thoughts?
Also measured a Topline 1.6 mech head: 32mm precups. (No casting number AFAICT.)
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My cyl head guy recommended doing it on the block/deck grinder vs the normal cutting machine. He said the chambers are hard to cut and the grinder does a nicer finish
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You can see in pics 1 and 3 where the machine skipped off the precup. looks like it maybe wipes them to the left in the bore as it hangs momentarily on the hard leading edge too.
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To me, every pic shows grinding marks which shows the entire head was skimmed with the pre chambers installed.
I remember when I had my head from the 92 Eco pressure tested after blowing a head gasket, the shop wanted to skim the head flat with a sander for $60. I told them NO! NO!NO!, the head warpage is within spec, leave it the f**K alone.
here was the prechambers from my 1.6td its a true td solid lifter head and had no cracks between the valves, i still didn't install the head, are these safe???
number 1
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl1.jpg)
number 2
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl2.jpg)
number 3
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl3.jpg)
and cylinder number 4
(http://img.photobucket.com/albums/v306/Trev0rbr/cyl4.jpg)
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ktzdsl - The charge for the prechamber machining was part of the entire head rebuild...I recall less than $100.00 for the custom sized
interference cutter and installation work.
RabbitJockey - I wouldn't run prechambers as cracked as those either in any sort of nice rig: my $.02 FWIW.
attached are photos of my 1.6TD prechambers from Eurocar Togliani showing how staking would flow a little material under the face of the
prechamber to add a little security to their installation.
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Hmm maybe ill see if there's an actual diesel shop around here who could install those for me with proper protrusion
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So that ball in the prechamber side would push some metal in the head around? How exactly does that improve the security of the installation?
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So that ball in the prechamber side would push some metal in the head around? How exactly does that improve the security of the installation?
I looked at my old head which I removed all four cups from. There is a groove machined in the cup bore that matches the nipple. It defiantly isn't gouged out as I had first thought as well. Apparently it's there to insure proper alignment.
In my opinion, it would take some serious staking to move the aluminum at that depth. If I were putting new "over-sized" cups in, I'd heat the head and freeze the cup which I think was mentioned in here somewhere already. I believe they mentioned an. 002" press fit but there must be a specification somewhere.