Machine shop called...said I had to come look...

[vdubspeed]

DAMN. I swear I'm going to die if I can't get a good 1.6 head.

First off...I had FOUR heads to start with. Only ONE was worthy of a rebuild. The others had stripped/cracked injector bosses and snapped cam bearing journal.

So I drop off an 85 turbo head that was the best. cracks between all valves. That's fine. Shop called and says the exhaust guides are trashed and might need new exhaust valves since he can't grind them(sodium filled...it's a caution in the Bentley). I take him another complete head for the exhaust valves incase the hand lapping doesn't work and while I'm there...I see a SMALL crack in one prechamber cup.

Should I have him install the N/A cups or will the small crack be okay. And for the exhaust valves...what do you guys do when you get up there on the upper mileage motors.

Thanks,

Jason

[R.O.R-2.0]

n/a pre-cups wont fit in a TD head.. i believe 1.5D and TD pre cups are the same diameter..

[sdwarf36]

I got a NA precup in my TD head. The only difference is material. I had one that was way too cracked to reuse (almost all the way across.) A couple of little cracks near the opening are normal from what I've seen.
 Worn valve guides are normal on these (and even the gasser) heads-due to how short they are. No biggie to change them-and are fairly cheap too.

[R.O.R-2.0]

no, early TD and early n/a heads DO NOT have the same size pre-cups..

maybe some of the later stuff..

and if the head has steel pre-cups in it, its rebuilt..

ALL FACTORY VW HEADS (that i have dealt with) have all had Inco pre-cups..

the only engine ive seen with factory steel cups was a 1977 1.5D, and it was out of a rabbit with manual brakes..

ill say it again..

if you have a VW head with steel cups, they probably are NOT factory, and its probably been rebuilt at some point in its life..

[RabbitJockey]

how bad is the crack in the prechamber?  can you get a good picture of it

[Mark(The Miser)UK]

Small cracks are common and act as stress relief. Why does the shop need to grind a valve? Lapping would do, but probably unneccessary. VAG book says don't machine, grind them" That is from 1982 when ex valves may possibly still have had sodium filling. I'm no machinist but I guess that is just an issue of hardness/work hardening.

I thought it was the guides that were shot...
The official sideways maximum slop is up to 1.3mm. As measured with new valve, tip flush with top of valve guide gauged to edge of valve face.

Exhaust valve slop has no effect on emissions, whearas on the inlets may do.

They are friends of yours??