Camshaft bearing - AHU engine

I am renovating an AHU engine for my VW Golf Mk3. When dissembling the cylinder head I noticed there was bearings for the camshaft. From an old 1Z engine I have, there is not bearings for the camshaft, it just roll in the head aluminum, of course with oil pressure similar to any big end bearing.

So I purchased some bearings matching the cylinder head part number (028103373N) and prepared to measure them with plastic gauge. But when opening the bearings I see no holes in them for the oil pressure – and I can’t seem to find any other bearings with holes.

Below some pictures showing the bearings, the two bearing caps (AHU and 1Z) and some camshaft bearings found for a 2.0 Tdi engine like I had expected them to be.

Please advise?

What you have there are bearings for a PD motor. I don't think that will work for you. It appears that maybe this cylinder head had an overheat or oil loss that probably fried the journals. In those cases, we weld up the journal and rebore with an alignment bar. It would be very strange to lose only the #2 or #4 bearing cap, which I see has been bored, without also losing also #1 and #3.

I have never put any of those bearings into the older IDI or TDI engines, as I have only seen disasters from those who did. Who would have sold you those PD bearings??

We never use plastigage for anything. Measure the journal and measure the bore. .001 -.002" clearance for cam journals.

Just for kicks, I will see if the PD bearings would even possibly work, even if you drilled the galley hole, but I doubt it. I have seen bearing sets like those from SilverSeal, but once again, never even considered using them.

Then it is a good thing I had it planned and changed the valve sealing...

After some measurements and a study of the GLYCO catalog I actually found some that seems to fit :-o from the engine code HM, a 1.6L Petrol from the early 90' VAG cars.

GLYCO N118/5 should fit - alone based on measurements.

Zutsko said:

Then it is a good thing I had it planned and changed the valve sealing...

After some measurements and a study of the GLYCO catalog I actually found some that seems to fit :-o from the engine code HM, a 1.6L Petrol from the early 90' VAG cars.

GLYCO N118/5 should fit - alone based on measurements.

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Don't forget to reply back after you have it all together. If it works that will be good information, same if it ends up in failure.

The trouble is getting the proper align bore clearances. Getting the proper crush is difficult with those bearings. Few machinists have the proper align bore hone. We happen to have it, but our feeling is it's too risky for us to spend the time getting a cylinder head fixed up only to gall the journals of the cam.

I hope you prove me wrong. An immediate response is not what we need. We need to know what happens in a year or two. That would be useful information.

Thanks guys, I have them mounted and the clearance measured - they fit perfect.

I expect to have the engine completed and mounted within a few weeks (the stupid work takes all my spare time ).

It make sense to come up with a reply after some serious use, not just a 1,000 miles. The car runs around 30,000 miles a year (yep 50,000 km) so I will relative quickly notice if the bearings will fail.

Any news on your camshaft bearing? Did they hold up fine?

I'm in the same process and my machine shop offers me the option to fit bearings or to re-face the caps and re line bore them centered to the head journals.

Thanks!

marco_lh said:

Any news on your camshaft bearing? Did they hold up fine?

I'm in the same process and my machine shop offers me the option to fit bearings or to re-face the caps and re line bore them centered to the head journals.

Thanks!

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What shop is this? I would not recommend you have them do any work to the head. They clearly do not understand tdi engines. The head has to be heated and torqued before and during decking. A warped head will be destroyed if decked traditionally. Same with the cam journals.
You need to talk with frank06.
Been going down the rabbit hole on my ahu as well and you cant just sleve the cam journals. They must be fixed properly.