BMW Luxury Touring Community banner

1 - 15 of 15 Posts

·
Registered
Joined
·
2,341 Posts
Discussion Starter #1
Ok, I have checked valves many times but this time looks like I have to adjust. I'm using the Gunsmoke procedure (I haven't removed a spark plug).

I have two intakes the need clearance adjustment and it doesn't appear that I will be able to swap any as they are all running on the low end of the 'OK' scale between .015 mm to .017 mm. The exhaust are all in mid range so I don't think I will mess with them.. Both of these intakes were barely .015 MM last time I did this 18K ago..

Questions:

Tool....

The tool needed to hold back the cam chain tension is said to be a #30 drill but searches here seem to indicate that I need a 1/8" drill to hold off the cam tension. Is this correct? would it be better to use a allen wrench?

Depressing the Cam chain tension..

I'm reading this as using a flat screw driver I should push the tension into (away from me) the cavity until the keeper holds it.. Is this correct?


Cable ties....

The procedure says to get the #1 cylinder in mid stroke however that is the one of the two I need to adjust. I need to do 1A and 3A intake buckets as they are 0.11 mm and 0.12 mm respectively. I read that I'm doing this to unload the cam but I read here that this isn't always necessary.. Just get the cam positioned so I have a min of pressure on intakes... and then cable tie the chain to the sprocket. I assume that the chain will be loose but not too loose because I already have the tension held off.

I will probably find my best cam position and then do the cam tension hold off and then directly pull the intake cam just after doing the cables ties on both cam sprockets.. Does anyone see anything wrong with that.. seems simpler than the Gunsmoke directions.. so am I missing something..
 

·
Registered
Joined
·
718 Posts
Questions:

Tool....

The tool needed to hold back the cam chain tension is said to be a #30 drill but searches here seem to indicate that I need a 1/8" drill to hold off the cam tension. Is this correct? would it be better to use a allen wrench?

Allen wrench will work, drill bit will work... anything of that approximate size that to hold the tensioner.

Depressing the Cam chain tension..

I'm reading this as using a flat screw driver I should push the tension into (away from me) the cavity until the keeper holds it.. Is this correct?

Yes!

Cable ties....

The procedure says to get the #1 cylinder in mid stroke however that is the one of the two I need to adjust. I need to do 1A and 3A intake buckets as they are 0.11 mm and 0.12 mm respectively. I read that I'm doing this to unload the cam but I read here that this isn't always necessary.. Just get the cam positioned so I have a min of pressure on intakes... and then cable tie the chain to the sprocket. I assume that the chain will be loose but not too loose because I already have the tension held off.

I will probably find my best cam position and then do the cam tension hold off and then directly pull the intake cam just after doing the cables ties on both cam sprockets.. Does anyone see anything wrong with that.. seems simpler than the Gunsmoke directions.. so am I missing something..

It's ok just to unload the cam as long as you absolutely understand the concept. If your not sure, use the #1 on mid stroke method.
 

·
Registered
Joined
·
2,341 Posts
Discussion Starter #3
Dean_BMW said:
It's ok just to unload the cam as long as you absolutely understand the concept. If your not sure, use the #1 on mid stroke method.
Maybe I don't understand the concept...

If I take the mid stroke method I have the engine set at a particular point. The cam makes four revs for four cycles of the #1 piston. So the cam position needs to be in the same relative position when I put it back in. All the position of the #1 piston is doing is giving me a reference point of the engine.

I believe that the intake cam should be keyed to the intake sprocket so it should go on only one way and as long as the engine doesn't move the chain and position of the cam should also not move. Unloading all the cam 'keepers' should release the CAM and reversing should load the valves if the keepers are uniformly seated..

The whole in my thought would be that the sprocket and cam or not keyed and that doesn't seem to be logical.

After thinking about it I won't have any reason to not removing the #1 spark plug because I have already made my measurements and this time going in I am only going to document all the intake buckets so I can order the one two I need. Not sure if I will unload the exhaust cam to record them so I know them for future reference. It would have been much easier this time if I knew the bucket sizes..
 

·
Registered
Joined
·
110 Posts
Hi Jack,

I just got through last night adjusting 7 of the 8 intake valves using the Gunsmoke method on my 05 with 32000 miles. Three of those were barely at the minimum speck so I decided to go ahead and change them. Plus I run this thing to redline several times a day, having to much fun. I guess I need a K1200S.

I didn't even bother finding out where the number 1 cylinder was as I had no intention to rotate the crank shaft once I started the project. That may be more critical if you are going to be pulling both cams.

The cam sprockets are keyed to the ends of the cam shafts preventing you from installing the sprockets out of time. Once you remove the bolts in the end of the cams that hold the sprockets on you will see the slots in the end of the cams that key the sprockets on. I found that when the intake cam slot was pointing straight up the cam was under the least amount of pressure. Also you will have to remove the exhaust cam sprocket as well in order to get the chain guide out of the way. Also everyone as said to use a 19mm wrench to hold the cams still when torquing the cam sprocket bolts, but my craftsman 18mm wrench fits the cams perfectly. A 19 is way too loose.

Don't forget to use at least two cable ties on each sprocket!!!

When you reinstall the bearing caps, get them all started and go down with each nut one turn at a time to prevent putting one cap in a bind, which could possibly bent something.

I wouldn't remove the spark plug as you will want to recheck the clearance once you are done and you wouldn't want anything between the valve and the cylinder head that could throw off your measurement.

If the engine has sit overnight like mine had. You will have to apply very little pressure with the screwdriver in order to get the drill or allen wrench into the hole to lock the chain tensioner.

I hope this helps


Wayne Mann
 

·
Registered
Joined
·
2,341 Posts
Discussion Starter #5
Wayne, Thanks for responding.

That is what I am looking for. I think I will do as you did and just unload the tensioner. Now hopefully I can get to this tonight so I can order the parts for next week.
 

·
Registered
Joined
·
12,165 Posts
To unload the tensioner, you use a long screwdriver, inserted so that the end of it is resting on top of the lower run of the chain, then use it to pry the lower run of the chain, and it's tensioner rail, DOWN, until the holding tool (a 1/8", or 3MM, or just about anything about that size) that will slip readily into the hole. There is a groove in the end of the tensioner piston that the tool will slip into when the tensioner is depressed down far enough.

IF you have taken all the measurements, then it is OK to remove the spark plug, just be aware that you should not re-check the measurements after all the work is done, as an incorrect reading may be obtained.

It is not really all that important where the engine is when you remove the cams, as you should not turn it any while they are off, then they should go back onto the cams and align with the alignment pins easily. Be sure you get the cams pushed all the way back against the cams BEFORE tightening the sprocket retaining bolts! Some have sheared off part of the pins or the sprocket holes when they were not fully aligned when the bolt is tightened.

There is no position of the engine where the cams are fully "unloaded", as there is no point in engine rotation where all valves are fully closed. There will always be some valves partially open. When removing the caps, do so by only turning each nut no more than a couple turns, doing this to each in order until all are loose, then spin them off. Same way going back on, only tighten each one a couple of turns in order until the cams are pulled back down. If you tighten one or two too much, the cam can be "sprung", and it can be warped or the bearing caps damaged. The idea is to keep the cams straight when removing and re-installing them.

You cannot tell if you can swap lifters or not to adjust the clearances until you find what ones are in place. If for instance the two you need to loosen 0.002" happen to be a 2.85 and a 2.80, you can put the 2.80 where the 2.85 was and buy a 2.75 to put where the 2.80 was. (Each 0.05 MM step in lifter sizes is 0.002", or close enough, as it is actually 0.0019685)
 

·
Registered
Joined
·
467 Posts
Cylinders at mid stroke

jackd said:
The procedure says to get the #1 cylinder in mid stroke ...............
If you were to leave the engine at TDC (any cylinder) and rotate the camshaft (for instance while reinstalling after changing buckets,) you stand the chance of bending valves on the cylinders that the piston is up at the top.

The purpose of having the cylinders at mid stroke is to provide working room for the valves to move while rotating the camshaft to line up the "keyway' between the cam and sprocket, OR, to provide the same room necessary to rotate the cam (after removing the sprocket) to find the "unloaded spot" before removing the bearing caps.

Cylinder being at TDC and turning the cam to open a valve to full lift, the valve will hit the top of the piston and bend the stem. If you have ever looked at a valve stem on a "brick" cylinder head they are really tiny. Would probably bend easily. Of course if you did it that way it would require removal of the head.....................I'm sure you have the picture.

HTH and Good Luck!

BTW The cam bearing caps are numbered so as to put them back in the same spot they were removed from. If you have both cams removed at the same time the #6 and the #9 caps can easily be mixed. Make sure you mark them with an underscore or something. DAMHIK
 

·
Registered
Joined
·
2,341 Posts
Discussion Starter #8
Thanks guys. I feel a little easier doing this for the first time.. ;)
 

·
Registered
Joined
·
2,341 Posts
Discussion Starter #9
Well, I found it to be easier once I had the tools in my hand but I made a mistake so I stopped for the evening.. :(

It's a good/bad news thing.. I got the cams back in and the sprockets on the keys so I didn't damage them and I look at my parts and I still didn't put that plastic guide under the chain..... and of course the sprockets need to come off to put that on.... so tomorrow is another day...

The good news is I believe I was able to swap buckets around from the exhaust to the intake.. I had (2) 2.90 buckets and they were the tight intakes.. I was able to move (2) 2.85 buckets off the exhausts from exhausts that were on the high side of the spec..

I will see if I figured right when I get this all back together..

I didn't remove a spark plug so I should be able to measure...
 

·
Registered
Joined
·
805 Posts
Hey Jack, I just caught up with this thread. Sounds like you have everything well in hand, but give me a holler if I can help any. You do NOT want to let me anywhere near the tensioner (Tom could give you an earful), but I could fetch beverages!
 

·
Registered
Joined
·
2,341 Posts
Discussion Starter #11
I should finish up tonight after work. Hopefully I wont need to buy any parts.. I will check it after I get all the parts back in! :histerica
 

·
Registered
Joined
·
12,165 Posts
jackd said:
Well, I found it to be easier once I had the tools in my hand but I made a mistake so I stopped for the evening.. :(

It's a good/bad news thing.. I got the cams back in and the sprockets on the keys so I didn't damage them and I look at my parts and I still didn't put that plastic guide under the chain..... and of course the sprockets need to come off to put that on.... so tomorrow is another day...

The good news is I believe I was able to swap buckets around from the exhaust to the intake.. I had (2) 2.90 buckets and they were the tight intakes.. I was able to move (2) 2.85 buckets off the exhausts from exhausts that were on the high side of the spec..

I will see if I figured right when I get this all back together..

I didn't remove a spark plug so I should be able to measure...
I do not think you can just swap lifters between valves without replacing any and still come up with good measurements on all. I have never seen one that was 0.002" too loose, which you would need to be able to swap that lifter to another valve to loosen it and still have the one you removed it from come in within spec.

I can see how one could swap and still have them barely in spec, but I would never do swaps that will leave any valve at the tightest allowable measurement, as that one will be too tight very soon. I always shoot for max allowable clearance, or even slightly looser if possible. They will continue to tighten up over time, not get looser, unless something far more problematic is happening.
 

·
Registered
Joined
·
2,341 Posts
Discussion Starter #13
dshealey said:
I do not think you can just swap lifters between valves without replacing any and still come up with good measurements on all. I have never seen one that was 0.002" too loose, which you would need to be able to swap that lifter to another valve to loosen it and still have the one you removed it from come in within spec.

I can see how one could swap and still have them barely in spec, but I would never do swaps that will leave any valve at the tightest allowable measurement, as that one will be too tight very soon. I always shoot for max allowable clearance, or even slightly looser if possible. They will continue to tighten up over time, not get looser, unless something far more problematic is happening.
Well, I have lots of them that are barely in spec and most of them have the same size bucket (2.85 mm). I had two exhaust valves that were much different than all the others (at the high side of spec) and had buckets that could be swapped in to make the two that I needed to be within spec..

Yes it seems that the majority of valves are tightening from where I measured them last time but I wasn't really specific in my measurements. I used a metric gauge and basically I had three sizes.. a .15 mm, a .20 mm and .30 mm and I used all three as a go and a no go condition.. This time I used a combo of gauges and added a .01 mm and a .02 mm and combinations to record within a .0x mm of where I believe I am now.

I now know all the bucket sizes and next time I check the valves I can estimate what I need and then do as you suggest and move everyone to the high side of the spec.. if possible.

Of course I have not done the final check on what I did last night. I hope to tonight.. If everything is above spec I will check again at the end of this season and order a bunch of cam followers and get that done over the winter. Right now I have majority of intakes running at .16 or .17 mm and adding any height should take them out of spec.

I don't want to run out of spec but if I can adjust to .20 MM when I do it then I can coast for a while and just do checks.

This is all predicated on that I understand what I did.. I'm feeling good about this and certainly much better than a few days ago but I won't know that till I'm finished.. :D I don't think I would have tackled this with this board.

I'm by no stretch of any imagination, even mine... a real mechanic.. I only have tools.
 

·
Registered
Joined
·
12,165 Posts
jackd said:
--------------------------------------------
I'm by no stretch of any imagination, even mine... a real mechanic.. I only have tools.
:rotf:
:histerica

That was a good one! Guess what, there are some "techs" at dealers who fit that description. Unfortunately, they get paid.

You know your limitations, but are willing to learn and reduce them. Applause follows.
 

·
Registered
Joined
·
2,341 Posts
Discussion Starter #15
I just want to put an end to this thread in case someone is searching on valve adjustment.. :)

I did not swap any buckets as it did not make sense. I bought two and replaced two so I was able to adjust everything.

There was another thread that went along with this thread. If your interested in this thread you might want to read that one also.
 
1 - 15 of 15 Posts
Top