Author Topic: Somethings wrong. (Read 18917 times)

elementskater_xx · « **Reply #30 on:** June 11, 2008, 06:03:09 PM »

Quote from: peerless;51075

Can you elaborate on this tool?

I haven't seen it, nor read about it before in the service manual. Am I missing something?

According to what the book says it's a tool to keep the cams aligned while working on the engine. Someone gave me a schematic of it, but i can't get it made.

elementskater_xx · « **Reply #31 on:** June 11, 2008, 06:05:11 PM »

Quote from: Wise Old Dog;51071

http://cgi.ebay.com/ebaymotors/BMW-Camshaft-Alignment-Locking-Cam-Timing-Holding-Tool_W0QQcmdZViewItemQQcategoryZ35625QQihZ015QQitemZ250257935612QQrdZ1QQsspagenameZWDVW
You also need a tensioner tool to get the chain tight. The one on the engine is too weak for this procedure.

Alright man i just bid on this.

colin86325 · « **Reply #32 on:** June 11, 2008, 06:12:26 PM »

Quote from: peerless;51075

Can you elaborate on this tool?

I haven't seen it, nor read about it before in the service manual. Am I missing something?

This was on that CAD drawing that I gave you to show your machinist. It's basically a piece of rod that threads into the tensioner hole, is adjustable, and can be locked in place with a nut.

Wise Old Dog · « **Reply #33 on:** June 11, 2008, 06:29:25 PM »

http://cgi.ebay.com/ebaymotors/Cam-Alignment-Engine-Vanos-Tools-6-for-BMW-Repair_W0QQcmdZViewItemQQcategoryZ43998QQihZ007QQitemZ170228028271QQrdZ1QQsspagenameZWDVW#ebayphotohosting
114220 is the tensioner

nomad · « **Reply #34 on:** June 11, 2008, 07:04:12 PM »

Make sure you lock the flywheel into place at cyl #1 TDC when you time the cams and chain. From the pics you have it right.

Follow the directions letter for letter in the manual on how to time the chain.

I did not use the cam locking tool as you see on ebay. I used the "two adjustable wrenches and a C-clamp method that many have used on other cars.
All you are looking to do is keep the cams from moving around on you as they will be under tension from the valve springs.

Here is a pic of how you'd position the wrenches on the flats of the cams to hold them while you time them.
Hope this helps. You really need to make sure you take all the slack out of the timing chain and that everything is hooked up right and ready to go.

Petebee · « **Reply #35 on:** June 11, 2008, 09:43:29 PM »

Quote from: nomad;51087

Make sure you lock the flywheel into place at cyl #1 TDC when you time the cams and chain. From the pics you have it right.

Follow the directions letter for letter in the manual on how to time the chain.

I did not use the cam locking tool as you see on ebay. I used the "two adjustable wrenches and a C-clamp method that many have used on other cars.
All you are looking to do is keep the cams from moving around on you as they will be under tension from the valve springs.

Here is a pic of how you'd position the wrenches on the flats of the cams to hold them while you time them.
Hope this helps. You really need to make sure you take all the slack out of the timing chain and that everything is hooked up right and ready to go.

Did you use the wrenches to hold the flat section on the cams (in between the lobes) or the squared off ends of the camshafts that are opposite of the timing gear?

I am collecting parts to replace the timing components on my daily and I want to make sure that I secure the cams properly.

I bought a used engine for its unworn cam sprockets and I've been practicing removing/replacing on that before I dig into the real job. The cams slipped a tiny bit during one of my practice stints...maybe a few degrees of rotation (they weren't locked in place) but I just moved them back into position so the flat sides on the ends were lined up flat horizontally. I'd prefer to lock the cams when I attempt for real on the daily driver.

With all of the problems people have been having lately with this I'm somewhat squeamish

nomad · « **Reply #36 on:** June 11, 2008, 11:38:09 PM »

I'm thinking the square ends of the cam shafts. I've seen it done on the flat sections of the shaft in miatas. I think there is less room on this though.

Wrenches can also be used of course.

If I remember correctly, the exhaust cam should be done first, then tighten down the cam gear, and move on to the intake cam. With the gear loose on the shaft you can move the cam slightly so that it is straight across the flats. This of course means the cam gear itself has to be on the right tooth. There is only one "correct" position, so if it's not perfect then keep trying. Once you have the gears on the right tooth of the chain, the cams in the right location (flat across the rear square ends) and the cam gear bolts centered in the slots then it'll all make sense.

elementskater_xx · « **Reply #37 on:** June 13, 2008, 10:06:29 AM »

I have put the head on. I tightened all the head bolts down to 22 ft/lbs then an additional 90 deg and then an additional 90 degs. I put a 8mm allen key in the flywheel at tdc. My cam squares int he back are flush with each other, i put a pencil on them and they are flat. I am not sure how they sit in compoarision to the head, But the cams are flat with each other. My sprochet wheels in the front on the cams are 15 links away from each other intermideant. Now from my understanding this is correct and how it should be?

elementskater_xx · « **Reply #38 on:** June 13, 2008, 10:27:27 AM »

15 Links apart:

Right timming gear:

Left timming gear:

Cam square lobes flat:

Cam Lobes Flat:

So here is where I am at. Here is where i seem to always fuck it up. So if any one can see soemthing wrong please tell. Me. lso when i turn the crank by hand, i feel some preasure in certain spot when i am turning it.

elementskater_xx · « **Reply #39 on:** June 13, 2008, 10:37:31 AM »

Also there is a squeking noise that comes when i get to approx tdc.

peerless · « **Reply #40 on:** June 13, 2008, 10:54:22 AM »

Quote from: colin86325;51079

This was on that CAD drawing that I gave you to show your machinist. It's basically a piece of rod that threads into the tensioner hole, is adjustable, and can be locked in place with a nut.

Hmm, makes sense, but I don't remember it on the cad drawings. I only remember the cam locking tool and the tdc pin?

I do remember trying to set the gears properly and thinking 'A tool to tension up this chain would be great'. I just stuck the tensioner in there and did the best I could with the cams locked.

elementskater_xx · « **Reply #41 on:** June 13, 2008, 11:19:48 AM »

The cam gear bolts do not look centerd, do i have to tear it all down again to get those centerd?

nomad · « **Reply #42 on:** June 13, 2008, 01:25:36 PM »

for reference:
http://www.esatclear.ie/~bpurcell/318istimingchain.html

Cam gear bolts are not centered, when it is all put together right they will be centered.

Use the trick I posted to hold your cams with the rear flats even. In the photo your exhaust cam is off, not flat, it looks a bit anti-clockwise and the intake cam looks a tiny bit clockwise, see how it's not even with the valve cover mounting surface?

All you have to do is take off the cam gear bolts and let them slide off the cams, then realign. I did the same thing you did the first time and puzzled over it, then adjusted it, tried again and it was right.

What is really important is if you have the cams themselves in the right position to begin with: front lobes pointing towards each other

When the cams are in this correct position
and
When the flywheel is at TDC
and
When the flats of the rear lobes are clamped firmly in a perfectly flat position
and
The tensioner is not applying force to the chain
then
The cam gears will go on in a perfect alignment with the cam gear bolts truly centered in the cam gear elliptical holes.

15 rivets inclusive from arrow to arrow is correct, but remember that you may be one tooth off on both cam gears if they are not lined up correctly.

BTW
The head looked nice to me and the block seems ok. Not sure if you bent rods as mentioned before from having the coolant in the cylinders. Other than that I hope it goes well.

Post pics when you get it all timed up.

EDIT:
I think you may just need to loosen the cam gear bolts, reposition and lock the cams and you may be good to go.

Wise Old Dog · « **Reply #43 on:** June 13, 2008, 01:25:41 PM »

Gear bolts are not to be centered. The gears have slotted holes for adjustment.
You will never get it exact unless you can tighten the chain up to simulate the "tug" that the crankshaft gear puts on the chain while running. Thats what the tool does. In other words, If you set up your chain like you are doing now. And you get it so it looks perfect. When you run the engine, the crank gear pulls on the long stretch of chain from the intake gear so hard, that it will tighten that part of the chain to the point where your adjustment is off a little. Think of it like pre-loading the chain. Many people on this board have done it your way and do not have any problems, as it is only off a tad. And you really don't know it's off unless you have the tensioner tool to check it with. I'm just letting you know how it should be done.

nomad · « **Reply #44 on:** June 13, 2008, 01:43:52 PM »

Wise-
Can you give a reference as to where you are to position the cam relative to the cam gear slots? A manual perhaps? I'd like to make adjustments if there is indeed another factory spec. I understand what you're saying about the cam possibly being pulled to one side or the other relative to its installed position. I'm going off of the Bentley manual specs. From what I read this is stock baseline. I'd love to have a factory BMW detailed tech manual though, especially if it is different in any way.

15 links on a chain will always be 15 links so the intake and exhaust will always be where you set them relative to each other. Less stretch than on a rubber timing belt. I've heard people have good luck tuning M42 intake cam advanced 5 degrees, which is where the gear slots come into play too.