M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: iszekeres on November 13, 2006, 01:24:51 AM
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I have just finished up replacing the timing case, most all of the timing parts, lower and upper pans and the steering rack this weekend. Miracle of miracles....nothing leaks!! But I do have a question or two about the cam positioning.
I did not have a tool to hold the cams in place when I removed the chain and sprockets. I did pin the flywheel to keep the crank from moving. When the tension on the cams was released by removing the old chain, one or both of the cams had moved some. I didn't think it would be a huge issue, as all I needed to do was center the cam mounting bolts in the slotted holes in the cam sprockets, make sure the indexing marks were pointed up, and make sure the flats at the rear of the cams were level with each other. I counted 15 pins between indexing marks when I reassembled. I did not put a straightedge across the flats in the back, as they looked reasonably level to each other.
Fast forward 6 hours and I am ready to fire this thing up. Huzza! It started, but sounded like a truck! From what I had read I realized I must have been one tooth off when I reassembled. I did not want to pull all of that off the front of the car again....it wasn't leaking and I didn't want to tempt fate! Looking at the flats at the back of the cams, I could see the intake cam was slightly off...placing a straightedge across them made this more noticable.
Looking at the engine while standing in front of the car:
Exhaust cam level --- Intake cam \\\ (exaggerated) The gap seemed to be a few mm at most.
Crap....well I really did not want to tear everything apart again! I loosened the intake cam sprocket and moved the intake cam CCW (looking at it from the front of the car) Now the flats at the rear of the cams are level with each other:
Exhaust cam --- Intake cam ---
Is this an acceptable fix? Am I overlooking something? I am assuming that the sides of the flats should be 90 degrees to the surface of the head when #1 is at TDC. I realize this keeps me from being able to adjust the intake cam, but I am not interested in that....just want to have it set to the stock position.
The engine fired right up after this fix, and sounds good to me. I haven't taken it out yet as I am waiting to get the front end aligned.
Did I mention the oil drain plug seal, lower pan gasket, the upper pan gasket, th dipstick tube o-ring, the crankshaft seal, the block to timing case gasket, the timing case cover to timing case gasket, the profile gasket, the upper timing case gasket, the gasket between the upper and lower timing covers, the oil filter housing gasket and o-ring, the water pump o-ring, the thermostat o-ring , the thermostat housing gasket, the camshaft position sensor o-ring,the valve cover gasket, and the power steering banjo seals aren't leaking? :D
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Great. Last time I did all that (the oil pump had failed), I heard a tick-tick-tick sound from the engine. Turned out I had bent a valve when I let the camshafts "float". Since I had left it alone, it ended up tearing up the head and piston before it broke off. On the other hand, if you don't hear anything unusual, it is possibly just fine (you hope).
The cams should be flat when the #1 piston is at TDC. If not, then you have a non-spec setup. Having said that, there was a fix that specified tipping the cams in towards each other (a 3mm drill bit on the outside of the cam locator tool) for better idle (and perhaps better power, I've never been clear on that). Still, having them off is not necessarily good (or bad). I've often wanted to actually fool around with it (within reason) to see if I could get more power out of it, but I never have.
I have no idea what the actual clearence is, and whether you could have piston/valve contact at redline if the camshaft is pointing out at #1 TDC. Seems an expensive way to find out.
I'd imagine, if you have an independent BMW (or german) repair shop, they'd let you borrow the tool if you did the work in their parking lot. The dealer may even let you borrow the tool. It can't hurt to call and ask. It's a simple tool to use, I've seen it. I made my own out of angle steel, but it is, frankly, horrible and not very accurate, so I haven't tried it on the new (junkyard) engine, for fear of messing that one up as well.
-Guy
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Scroll down to the drawing and picture of the cam alignment tool.
http://www.m42club.com/forums/showthread.php?t=1188
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Nice alignment tool. Sometimes Ghetto makes the most economical sense and becomes the most feasible at times.
Don't second guess cam timing. Just buy the alignment tool or make one and do it right.
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Looking at the old sprocket as it sits here on my desk....seems as though it allows for adjustment of one tooth in either direction. Everything is all lined up properly now, and the only ticking I hear is from the injectors....the engine is very quiet and smooth now that I have replaced the timing parts.
I will try not to worry about it too much!
Not to hijack my own thread, but since replacing the steering rack I need to get the front end re-aligned. I have a service appointment set up at my local BMW dealer, and they are quoting me 180 for the alignment, 1.5 hours work.
I noticed the previous owner had gotten his alignment done at a Firestone shop for 80 bucks. Is it worth the extra cash to have the dealer do this?
Much thanks to everyone, you all have been a great help!!!
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Glad you got everything worked out. Just find any competent shop that has a good Hunter Laser alignment rack. Make sure they are extra careful in clamping the transmitters onto the wheels. A lot of them tend to leave marks if they're not careful.
Unless you have an all out race custom suspension setup, the only thing you can adjust is the toe on stock cars I believe.
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Toe is the only adjustable setting on an E30 unless you add special parts.
http://www.m42club.com/forums/showthread.php?t=1192&highlight=front+alignment
There are a number of ways to set toe that do not involve an alignment machine. Try Google. I've set 200 mph stock cars with a tape measure before.
You can substitute a couple of 2' levels for the plate in the pic above if you have someone hold the other side.
I haven't paid for a toe alignment in decades.
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Thanks for the tip....the Firestone down the street has Hunter equipment and will do it for 69 bucks....cant beat it!
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How about a DIY write up?
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That would be excellent if he had the time.....I would love it! I am reading through various methods now.....seems foolish to have someone do it for even 70 bucks when it seems as though you can get it just as accurate with a bit of time.