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Will this head work??? Please Help
by
GTD0023
on 13 Oct, 2008 09:25
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I send my 1.9 TD head to the workshop to flatten. But when i got it back i was surprised to see how much material they removed.
They removed so much that now the valves are on the same height as the bottom of the head. i know they used to be a little inward.
So the question is: will this head still work?
I know my CR will be higher, but how bad is going to be?
Will my performance drop?
will i be able to push 20-25 psi??
Any help is very much appreciated.
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#1
by
the caveman
on 13 Oct, 2008 09:32
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Honestly as far as i'm concerned and what we were told at VW no diesel head can be shaved. If they took that much off then i wouidn't use it. The compression will be way too high and there'll be a good chance that the inserts will fall out and ruin the rest of the motor.
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#2
by
GTD0023
on 13 Oct, 2008 09:43
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o oh
. I don't wanna take any chances and risk further damage.
I've spend too much money on this.
Does anyone have any experience with this situation?
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#3
by
zukgod1
on 13 Oct, 2008 10:42
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Honestly as far as i'm concerned and what we were told at VW no diesel head can be shaved. If they took that much off then i wouidn't use it. The compression will be way too high and there'll be a good chance that the inserts will fall out and ruin the rest of the motor.
Well not exactly.
It wont change the compression but it they removed that much material there is a possibility of valve contact I think. I mean there isn't suppose to be an issue with that unless there is a failure of some sort but higher RPMs may be a problem.
Caveman brings up another point on the precups, the surface that actually holds them in is part of the upper shoulder (looking at the head upside down) if that area is shaved to thin the surface area holding the chamber in is reduced quite a bit.
I suppose you could peen the precup in so it wouldn't fall out but I still think there may be a higher RPM valve piston clearance issue. Is it a solid lifter head or Hyd?
Can you post up a pic?
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#4
by
dillenger1
on 13 Oct, 2008 10:46
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get a 3 notch gasket on there.shaving the head wont change compression,because your piston protrusion is still the same.The heads are flat to begin with.The valve relief is the gasket itself.As long as the valves dont go below the contact surface.
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#5
by
GTD0023
on 13 Oct, 2008 11:21
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i will post a pic later after work.
it is a hyd lifter head.
zukgod1 said:
I suppose you could peen the precup in so it wouldn't fall out but I still think there may be a higher RPM valve piston clearance issue
how do you "peen" the precups ?
It is a 1.9 so 5.5-6.0k is as high as it would probably go. is that still too high?
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#6
by
dillenger1
on 13 Oct, 2008 11:31
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I wouldnt peen them myself.Id have a shop do it.
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#7
by
saurkraut
on 13 Oct, 2008 12:07
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get a 3 notch gasket on there.shaving the head wont change compression,because your piston protrusion is still the same.The heads are flat to begin with.The valve relief is the gasket itself.As long as the valves dont go below the contact surface.
A thicker head gasket may screw up cold starts. Gasket tickness makes very little difference in the compression ratio, but VW saw fit to give us three options to maintain something. And I suspect its squish band which deals with piston cooling, and swirl chamber effectiness.
If they took that much off, i suspect the swirl chamber covers are really thin. And thats a recipe for disaster, if one of those falls appart.
Here's a head for $100.00:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=16815
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#8
by
zukgod1
on 13 Oct, 2008 12:45
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I wouldnt peen them myself.Id have a shop do it.
Why not?
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#9
by
dillenger1
on 13 Oct, 2008 12:52
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I wouldnt want to take a chance hitting my head with a drift.
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#10
by
zukgod1
on 13 Oct, 2008 13:38
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I wouldnt want to take a chance hitting my head with a drift.
Oh come on!!
Done in the correct places it's fine and very easy to do.
Here is a pic of one.
Mine is peened much more than this for reference.
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#11
by
zukgod1
on 13 Oct, 2008 13:39
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i will post a pic later after work.
it is a hyd lifter head.
zukgod1 said:
I suppose you could peen the precup in so it wouldn't fall out but I still think there may be a higher RPM valve piston clearance issue
how do you "peen" the precups ?
It is a 1.9 so 5.5-6.0k is as high as it would probably go. is that still too high?
Here ya go.
I still want to see a pic of your head though, we need to get a scale of how much they actually removed.
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#12
by
autoholic
on 13 Oct, 2008 14:37
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I had to take a few thou off of my head (block too), but they machined the valve seats also so it was about the same in the end. Did they tell you how much they shaved off? You may be able to regrind the seats and valves to get you back to spec.
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#13
by
zukgod1
on 13 Oct, 2008 14:40
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I had to take a few thou off of my head (block too), but they machined the valve seats also so it was about the same in the end. Did they tell you how much they shaved off? You may be able to regrind the seats and valves to get you back to spec.
They shaved the valve seats?
?? :shock:
did they also remove material off the valve stem?
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#14
by
autoholic
on 13 Oct, 2008 15:02
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Yes, they re-ground the seats to clean up some pitting, re-ground the valves and took some material off the stems to get the valve adj in spec (with room to shim either way).
Had a complete valve job done with new guides also of course.
As I mentioned in some earlier posts, I should have just bought a new head, but the place that did this one is a reputable shop and this is what he said he would do if it were his. It's off now, and all seems good. These heads are getting hard to find in rebuildable shape, this was the 3rd I brought them untill they were willing to work with it.