Head reassembly question

[Casebrius]

Are the two little "tubes" that stick up from the block there to help hold the head and head gasket in place while removing and assembling? That is the only purpose I could see them serving.

[RRdawho?]

indeed.

[pbonsalb]

They are called locating dowels. It sounds like you may need some help doing this job. There is much to screw up and a head swap or gasket change on one of these cars is not for the beginner. At least get someone who has done advanced mechanical work before to help you.

Philip Bradley

[shim]

They are called locating dowels. It sounds like you may need some help doing this job. There is much to screw up and a head swap or gasket change on one of these cars is not for the beginner. At least get someone who has done advanced mechanical work before to help you.

Philip Bradley
werd.

locating dowels aka dowel pins.


i believe theres also a dowel pin on the crankshaft so you can easily line up the flywheel & i think also one on the block so you can bolt up the tranny....

[Casebrius]

These are more like 1/2" tubes than pins. Admittingly this is the deepest I've been into an engine. I was pleasantly surprised that it wasn't harder than it was removing the head. I meticulously labeled and bagged all parts, bolts and do dads. Besides being sure my head is set to TDC and crank is rotated out about 45 degrees CCW so I don't kiss valves, what else should I be aware of? There probably WON'T be any other assistance when I reassemble this engine. I am going to call in a BMW tech to make sure I time it right. Thanks for your help.

[pbonsalb]

I printed out all the DIY headgasket or cam change info that I could find here. I also had my mechanic make a couple of house calls. There really is a lot of little stuff to do while you are in there and it is easy to get distracted with other projects while the car is off the road. I definitely chased a few parts and the job took twice as long as a result as I hoped.

Philip Bradley

[Casebrius]

I pretty much ordered every nut and bolt that I thought might be a problem later on. All new exhaust studs, all new valve cover studs, nuts washers, anything that might be questionable I ordered. Do you remember what stuff gave you problems off hand? I'm away from home on business for a week so I have a chance to order anything I might need now, so it won't be a problem later. I had looked over several DIY's as well before I tackled this job. Pulling the head off was one thing, going back on will be a whole differant game I'm sure. I think I have a good grasp on timing it right, but I'm anxious about it. I know a few degrees will make a big differance in how she runs.

[pbonsalb]

I did valve stem seals, VANOS cover gasket, exhaust studs and nuts, valve cover studs and nuts and gasket and plug gaskets, exhaust gaskets, intake manifold gaskets, new studs (or bolts if OEM). I had the head pressure checked and decked until it was perfect (0.005 in my case). I also did the oil pan nut and gasket and belts and water hoses. This is also a good time to do the rest of the cooling system. I even did the motor mounts.

Philip

[Casebrius]

I need to ask the machine shop if they needed to shave/deck my head at all. Did you run a stock head gasket?

[pbonsalb]

I used a VAC gasket, .080, and ARP studs, because I have a supercharger. This caused much of my parts chasing. The standard HG kit, as sold by Pelican Parts, is pretty complete and much cheaper than buying all the parts individually.

On a naturally aspirated car, you can use a standard thickness gasket and the slight increase in CR won't be a problem. However, the BMW manual mentions a 0.3 mm thicker HG for heads that have been decked. My guess is that 0.005 or less won't cause you any problems with a stock HG. You might want to discuss that with the machine shop. The pistons come right up to the top of the deck in these cars, so tightening squish too much would be risky.

Philip