Monday, December 8, 2008

Head Gasket Part 4

I received the remanufactured head last Tuesday evening (12/2) from UPS. As always happens, when you are interested in seeing what you've ordered, the delivery never arrives when you expect. Our normal UPS delivery time is between 1 pm and 3 pm. So, when does this show up, after 5 pm. I stayed home all day for nothing.

The package was torn up a bit, but it appeared that the head made it through OK. I was anxious to see what it looked like and was surprised at what I got. I was under the impression that I was getting a totally ready Head, but that's not what I got. The Head had been cleaned and machined, the valves were installed, but there were no Camshafts, Lifters, etc. Very disheartening. Bentley's manual talks about a special tool you need to remove the Camshafts. I don't have one, besides, they are very expensive.

I had purchased another book about working on BMW's called "101 Performance Projects For Your BMW 3 Series 1982 - 2000" by Wayne R. Dempsey. I don't have a 3 Series, but the motor in my 5 Series is the same as in the 3 Series. I bought the book because it had lots of good information about working on the M50 motor. In the book there is a chapter called "Camshaft Replacement". In this chapter he outlines how to removed the Camshafts without using the "Special Tool" you're supposed to use.

Following Mr. Dempsey's directions, I was able to safely remove both Camshafts from my old Head. I experimented with the Camshaft position until the lifters of cylinder numbers 2 through 6 had no pressure on the valves. One of the things that wasn't mentioned in Mr. Dempsey's book was that you have to remove the bearing cap on the front side (cars front) of the #1 cylinder also, or you could be in danger of breaking the camshaft. It has to come off along with the numbers 2 - 6 caps. The caps are labeled A1 - A7 on the exhaust side and E1 - E7 on the intake side. I removed A3 - A7 then removed A1. Once that was done, you remove A2. This probably doesn't make much sense, so if you are thinking about doing this, I would buy Mr. Dempsey's book, you can get it at, I think I paid about $20 for it (well worth it I might add). This job like he says in the book is a two person job. You have to make sure that the Camshaft does not move while you are slowly loosening the two nuts on the #1 cylinder bearing cap. If you aren't careful, the valve springs WILL snap the camshaft around. I had my wife helping me and it was a good thing she had a firm grip on the wrench, because the Cam slipped and would have gone all the way around if she hadn't been holding on. Don't know if it would have caused the Cam to break, but I'm glad I didn't find out.

Once I removed the Camshaft, I needed to remove the "bearing ledge". It is the housing that the lifters sit in and the Camshaft mounts to. The exhaust side came off pretty easy, but the intake side took a little persuading but came off without a hitch. Make sure the indexing dowels are in the proper place. One of the dowels on the exhaust side stayed with the bearing ledge when I removed it. I just pulled it out with some needle nose pliers and put is where it was supposed to be.

Putting the Camshafts back on was a little more dicey than removing them, at least for me. One thing that I would recommend is once you get the bearing ledge back in to place, put the bearing caps on the bearings with indexing dowels and tighten them down to seat them before you start trying to put the Cams back in (just make sure you take those caps back off before you try and put the Cam on). I found that trying to get the bearing cap for the #1 cylinder (A2 for exhaust and E2 for intake) back on was tougher than taking them off. What I did was move the cam lobes away from center until I could get the nuts started on the bearing cap. I made sure the nuts wouldn't come off and then slowly and with great care turned the camshaft to where the lobe was almost centered on the lifter. Once it was more centered and with my wife holding the Cam steady, I slowly tightened down the nuts (1/4 of a turn at a time, alternating between the two nuts) on the #1 cylinder bearing cap until it was snug. My wife then held the camshaft from turning/slipping and I put the remainder of the caps and nuts on and snugged them down. Once I had all the cap nuts snugged down, I torqued them to specs and was done.

Now, I'm just waiting for an order of parts to arrive so I can continue to work on putting it back together.

Here is a picture I took when putting the bearing ledger back on the head:

One trick I figured out when trying to put the bearing ledgers back on was to lay them upside down on your bench and then turn the head upside down and guide the studs into the ledger. If you try to drop the ledger on to the head when it is oriented like it sits on the car, the lifters want to fall out. As it is, they fall out when you remove the ledger from the head very easily.

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