-----Original Message----- From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Ed Sent: Wednesday, September 12, 2007 8:03 PM To: vanagon@GERRY.VANAGON.COM Subject: Flickering Oil Light 84 auto

I have an 84 vanagon, automatic, after it gets good and warm and has been driven vfor a while I notice at idle I get a flickering oil light. Oil level is good, rasing the RPM's ever so slightly makes it go away, as does putting it in park and letting it idle. Any ideas?

Thanks, Ed Maikranz Abilene, TX 1984 Vanagon 1972 Riviera

I wrote this a while ago hope this helps

Bob

Main bearing info or Boston Bob's Tales of an engine stripper 1.9

In my time I have taken a couple of 1.9 engines apart and I would like to share with you some of the things I have seen and learned. Most 1.9 engines are pretty tired by the time I get them in fact they are mostly turned in cores in exchange for fresh rebuilds but some come from stripped vans that had other problems. The one thing that is consistent in all 1.9 engine blocks is that the crank bore in the case are out of spec. The specifications for the crankshaft bore size and the amount of bearing crush is not listed in any book I have seen. This leaves allot of room for a judgment calls based on past experience or advise from others and lack of other options. Some would tell you that if the bearing sits in the web and seems tight then that's OK and if the engine does not bind when you tighten the case bolts then you are good to go. Now we are getting to the difference between going threw an engine and rebuilding an engine. As I said not knowing the specs makes the job a little tricky so in order to understand the intent of the manufacturer I have looked back at some of the older engine specs to see if there is any details that we can use to interpret the intent of those who designed the WBX engine. The type 2/4 engine and the bug engine do have specs for the case bores and wear limits listed in the without guesswork book. The without guesswork book was handed out to techs as they went threw the dealer training programs back in the sixties and seventies. As it turns out there is some good info we can use to determine the intent of the designers of the WBX engines. First the nose bearing is the same on all flat 4 VW engines since 1961 right threw to the 91 WBX engine. The size of the bore for the nose bearing is 50 mm to 50.03 mm. and the wear limit is 50.04 mm. The next thing I noticed is that the Main bearings bore sizes are all in round numbers. Yah got to love those Germans need for order and straightforward simplicity. The two middle main bearings bores are in fact the same size on the bug main bearings bores as they are on the 1.9 WBX engine and that is 65 mm. with a wear limit of 65.03 mm. The type 2/4 main bearings bores are the same bore size as the rear main WBX bearing no big surprise! (no its not the same bearing ) The rear main bearing bore for the type 2/4 engines is 70 mm with a wear limit of 70.03 mm. With all of that in mind we can now go back and look at the WBX block and use these dimensions to determine the condition of the used 1.9 cases. The next dimensions we need to determine if the case is in useable condition is the actual size of the bearings and then we can do the math and determine the bearing crush IF ANY!!!

To repeat the statement I made at the beginning of this rant. The one thing that is consistent in all 1.9 engines is that the crank bore in the case are out of spec. With that said I can tell you that the new 1.9 bearings are 3 ths or .12 mm larger than the main bearing bore specs I have listed above. So with all this we can do the math and see that the case crush on the bearing is intended to be between .002ths. And .003ths.

Measuring the WBX block to determine the size of the crank bore can't be done without a good bore micrometer and a lot of practice. The other thing I has noticed is that the case halves tent not to bolt together as intended. The WBX block has two locating pins as do all VW air and water-cooled flat 4 engines this is done to hold the block in place so it can be machined and so the halves will return to there machined position when assembled. Over time the case halves do shift you can in fact feel the shift at the parting line when a used case is bolted and torqued together without any bearings in place. The case shift is commonly .002 to .005 ths. at the parting line and this can vary from end to end. I have tried to use a block of wood and hammer to align the halves as I bring the case halves together before I align bore with limited success and have had to developed tooling do get the cases halves back where they belong in order to align bore. This is important because when the case is not properly centered the cam bore and oil pump bores will be permanently misaligned by the new bearings in the nice round holes for the main bearing once we align bore the crank bore. One other note about used 1.9 blocks is that the thrust surface can take a pounding and the new main bearings can be loose and the case needs a thrust cut. You bug types might remember that the bug blocks commonly needed the thrust cut to keep the rear main bearing from moving.

I have also had made 20 and 40 over and thrust bearings made for the discriminating engine builder.

Be aware of cheap imitations bearings the tolerances are not what they should be

All rights reserved

Bob Donalds

Boston Engine Exchange

The Engine Exchange Deluxe

http://www.bostonengine.com