VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: jpedro on July 09, 2010, 03:37:05 am
-
So i was reading in my haynes repair manual tonight i cannt mill my head! Its warped about 6 thouh which is not so bad but i brought it to a machine shop here they said they couldnt do it but one down south could so i left it with them but what are the tollerances for a warped head? If not i have an extra head but it has small cracks between valves which are tiny but when i was using that head i broke a timming belt n dropped a couple valves got the out n got new ones for it but would just replacing vavles and seals be ok or do they get screwed in the process of all that. What are my options guys?
-
I just had about 0.015" taken off my head. I think when I was researching that you can take off about 0.030". I think there is a valve face depth spec that you need to meet by cutting the valve seats and then there is a valve stem height that you need to check and adjust by shaving the stem. I don't think you would have to worry about any of that at 0.006"
-
VW says do not re-surface. Burn_your_money is correct I have done hundreds of these heads 0.006" is peanuts you should not have to worry about adjusting the valves. I believe VW spec. is 0.004" or less is ok, I could be wrong :-\ If it was mine I would resurface and stuff it back in its home assuming the 0.006" warp is the only issue. Cheers
-
wheew thats a sigh of relive. i thought id need a new head and yes that was the only problem with it. so its in the shop cannt wait to have this sucker up and running again.
-
Surface the head,.. the head will still be warped,
at least as far as the cam knows.
The cam will rock in it's journals.
Bend straight, line bore, surface.
-
Surface the head,.. the head will still be warped,
at least as far as the cam knows.
I've read about that before. Pretty intriquing stuff.
Inline with why VW said no resurfacing of them back then.
Guess a lot of us get by with more than we think we do sometimes.
I've wondered about Who would one go to, to get a head bent back ? Can't even imagine the process to reclaim .006-.015 , it might be simple today, but it makes me chuckle just thinking about it.
JPedro - perhaps a good idea to have your shop check the line bore on your cam journals before letting them resurface it. Maybe you'll be lucky enough to be within borderline.
-
There's a local place that will heat a head up and bend it straight,
A shop had one of mine sent to a place south of here,
they bent it straight and line bored it.
Took awhile to get the head put on and find a good enough body running,..
couple years later I start the engine and it has low oil pressure.
I hooked my oil primer up to a drill and spun the oil pump,
oil just gushed out around the cam.
I plasti-guaged it and it was sloppy.
Took it back to them myself, they had changed ownership.
I told them the line-bore they did was sloppy.
Went through a local shop, that did the rest of the rebuild, to get it done.
So I didn't have a reciept.
"How can you be sure we did the work, there's nothing in our records?"
Me,"It's hard to believe you could bend a head straight and not leave some sort of tool marks."
He shined a flashlight down one of the headbolt holes and said, "OK".
Tried to charge me another $100,
I wasn't paying twice for the job.
I've sent work to them since, with a little, "Make sure the clearances are tight" jab, so they know it's me.
Head went back on, oil pressure was great.
And the lesson is:
Mind your cam clearances people.
-
Can you plasti-gauge cam-to-journal clearances ?
What is the (1.6) spec , if so ?
And another thought, for us cheapskaters -
after a head is determined warped - its gonna need the valves taken out to surface it and do whatever, at minimum.
So could one check the rotation resistance of cam re-installed after the valves etc are outta the way - and go forward with resurfacing IF cam rotated smooth and plasti-gauge tests were within spec ?
In effort to dodge the bending and line boring.
This is for the iceskaters hoping to make it across the pond without paying for a roundtrip lift ticket over the pond.
-
I think max on the cam clearance is .002"
You can check for cam rocking with the buckets out.
How easy it spins won't tell much.