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1.6 Head - Good or tear it down?
by
AndyL
on 07 Mar, 2010 00:19
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G'day all...
Simple question... Did I have a horseshoe up my arse when I bought this engine (as every other parts been bad) or is this a good sign?
Do I need to start pulling valves to look for cracks - pics I see online seem to show that they're quite evident at this stage... Or am I totally wrong?
Thanks in advance!
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#1
by
8v-of-fury
on 07 Mar, 2010 01:26
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How many miles on that head? I don't even see the cracks between valves! that is a spectacular looking head
I see no reason to tear it down.
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#2
by
AndyL
on 07 Mar, 2010 09:55
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No real knowledge of the history, came out of a 91 jetta I grabbed for the engine... Every part of the engine so far has been closer to scrap than useful... Until I got to the head... Think there was ~350,000kms on the car.
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#3
by
Henchman
on 07 Mar, 2010 11:20
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Maybe the valve stem seals, as they are probably worn. Is the dish between the valves normally that deep on a 1.6? The 1.9 head seems to have a smaller dish, perhaps more prone to cracking.....
Ian
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#4
by
burn_your_money
on 07 Mar, 2010 12:15
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#5
by
AndyL
on 07 Mar, 2010 12:17
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Different year/castings maybe?
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#6
by
burn_your_money
on 07 Mar, 2010 12:37
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I didn't get the part number, sorry
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#7
by
sawedoffgolf
on 07 Mar, 2010 22:07
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#8
by
burn_your_money
on 07 Mar, 2010 22:20
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#9
by
Dakotakid
on 07 Mar, 2010 22:35
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When you look at it (in person), is there any evidence of cracks being filled? I saved and enlarged your photo and it looks like original meat in there.
Personally, I would go the extra mile and disassemble to check to see how much valve wobble is present (indicator of guide and valve stem wear), check the margins, clean the valves, hand lap the valves, check springs, and renew the stem seals.
Yes, it takes time and effort, but it sure allows you to understand what it is you've got (or...don't got!).
Edit: When I said original material, I am not refering to depth of material. Last year I bought a rebuilt head from "Jack" in Ohio and I could see that the cracks between the valves had been filled and milled. I do believe the depth of material between the valves was like this example in the OP photo. The head I bought sure does run good!
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#10
by
wolf_walker
on 08 Mar, 2010 00:18
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Anyone that see's a large volume of these decided if the deeper/larger milled spots are less crack prone?
None of mine are remotely that deep that I recall, never even seen one in person that deeply milled.
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#11
by
Henchman
on 08 Mar, 2010 07:14
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Here are some other heads I have sold in the past
no grooves. It was a 1.9 head. I was told by Dr.Diesel that the lack of grooves was a sure sign it was rebuilt
http://img.photobucket.com/albums/v603/burnyourmoney/DSC07799.jpg
a 1.9
http://img.photobucket.com/albums/v603/burnyourmoney/DSC07747.jpg
Are you saying that the head with no grooves means it has been rebuilt with the head milled down and valve pockets redone? That sounds like a lot of material considering those groves are 1-3mm deep and technically considered "not machinable". The 1.9's I have seen have a narrower gap and groove between valve, always have tiny cracks (after 300k km tho), known to have not been rebuilt. Are the valves a little smaller on the 1.6?
Ian
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#12
by
burn_your_money
on 08 Mar, 2010 07:54
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I've never measured the valves so I don't know. I had no idea why that head was perfectly flat but Dr.Diesel is the guy who advised me that it was because it had been machined. It wouldn't surprise me for someone to weld it up like that. I think this forum has proved many times that "none machinable" parts can in fact be machined.
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#13
by
theman53
on 08 Mar, 2010 08:01
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It looks fine to me. This is my Mech head from my jetta build thread. The pic is a bit shiny, but the groves look groovy to me.
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#14
by
Henchman
on 08 Mar, 2010 16:06
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I've never measured the valves so I don't know. I had no idea why that head was perfectly flat but Dr.Diesel is the guy who advised me that it was because it had been machined. It wouldn't surprise me for someone to weld it up like that. I think this forum has proved many times that "none machinable" parts can in fact be machined.
Now I get it. They weld up the gap (presumably because of a deep crack), then the head is machined and the valve seats cleaned up. I assume VW milled out that thin bridge between the valves to stop if from breaking off, and causing even more damage? As for the "non machinable", VW probably figures "if we tell them it can be machined, then we have to tell them how, to what spec, max warpage and so on". Easier just to tell the customer it's "non-serviceable", here is a new one, or would you prefer a new car?
Ian
