Real Big Engineering BrainStorm Needed Here!!!
 

Okay, you engineering types. It may not be a 911, but it certainly is an interesting engineering problem. How do I get these off without using the $1200 factory tool:

http://forums.pelicanparts.com/101-projects-discussion-forum-bmw-3-series/93194-okay-everyone-need-your-help-advice-camshaft-removal.html

-Wayne

Wayne;
To develop on your popsicle stick idea (which I think is a good one); I'd fabricate 2 large washers out of a soft metal -- most likely a couple of pieces of thick aluminum stock. The thickness should be a little less then the maximimum valve lift. The ID should be a little larger then the valve stem diameter at the valve seat, and the OD should be a little larger then the valve seat. Cut a notch to the ID which is the same measurement across as the ID. This will leave you with a "C" shaped piece of metal.

Use these "C's" to shim the valves open at close to maximum lift. Rotate the cams just enough to relieve the pressure on lifters and then remove the camshafts. You should then be able to just use your standard valve spring removal tool to remove the "C's".

Some thoughts:
1) Why not popcicle sticks? Since they can only support the valve on two sides the pressures are not evenly distributed around the valve. Since this will be at something close to full lift, the spring forces should be fairly substantial.

2) Why aluminum? I think any soft metal will do. The objective is to have it give enough so that it spreads the load around most of the valve and doesn't damage the seating surfaces.

Risks: I don't know if the valve head can withstand the forces involved. Due to the cam's ramp angles at 0 lift, I doubt that the valve sees a significant increase in force when it closes. But then again -- how much do two valves cost when compared to the cam removal tool?

Other thoughts: What does this tool look like anyhow?

Just posted on the other BBS with my take on your problem. Does that count toward 300,000???

I may have missed the point here but, if the camshafts are hollow can you not put a bright steel (or similar) bar down the camshaft which protrudes at both ends - clamp down the ends, release the camshaft clamps and then equally release the clamps on your bar.

Or do I just not understand the problem???

I'm in the middle of doing the head etc on my 16v 944S2. The dual overhead cam setup looks the same as your BMW.Here is the homemade tool that I borrowed. My friend's dad made this tool when they were working on his 944S. It essentially duplicated the factory tool.
-Chris
http://forums.pelicanparts.com/uploads/camHolders.jpg http://forums.pelicanparts.com/uploads/sparkPlugEnd.jpg

Roy I would think that would put undue stress on the camshaft not so much breaking in half but by crushing force.

wayne,

i have read the thread and although i don't have the answer :( i would suggest if you loosened the camshaft apart from the where the depressed valves are i don't think trhe cam will sit there happily balancing on the two lobes. i think part of the reason it can do that now is that it is clamped down along its length.

are the studs not long enough to allow you to slowly release it a bit at a time along the whole length??

if not, that home made tool looks good..

On the Jag 6 cylinder (LOOONG dual overhead hollow cams) you just slowly and evenly loosen the cap nuts allowing the cam to rise slowly up. Is cam breakage a reality or just paranoia?

Wayne,

if everything else fails there is always the 20$ into the coffee box method over at the friendly garage where they have the tools and let you borrow them for 15 minutes.

That's what I would do if camshaft fracture is a real concern and one needs the tool to not mess up the job.
Ingo

Is that RAP music I hear ? :D :rolleyes:

Anyway. . .
That's perfect! The load will be balanced on the journal designed to carry the load.
(read: no need for wedgies :eek: )

Putting it back may be another story, as the cam may want to slip off the one lobe. Either in or out, keep the cam from turnning on you; and you'll have the perfect sol'n.

yes, this is how it is usually done, but this is more fragile than most.....maybe it will be ok:(

Wayne,
I posted your question on the Roadfly forum as I am a member of the E32 board. I will post credible replies here for you to consider. Below is the first reply with it's associated link.
Rick

<br>
<font color=blue>Message Title: Believe a couple of ways to do it...don't..(m)
Posted by: George Mann on 2003-01-06 at 13:12:48
(posted from: Host: dialup-67.25.218.94.dial1.detroit1.level3.net IP: 67.25.218.94)

Message:

(Believe a couple of ways to do it...don't) need a fancy camshaft removal tool. The important point is..you absolutely don't remove the cam with any perpendicular force on it period for risk of hurting the cam..or yourself. That said..you need a small simple valve spring compressor. You need to rotate the cam such that a couple of valves/springs are not under load and compress those springs and remove those valves. If you can now rotate the cam to where the previous removed valves were such that not one cam lobe is under load..simply unbolt the cam. Repeat for the other cam. When both cams are out..compress each spring and remove each valve. You will want a spring compressor anyway to remove the valves if you are going to perform a valve job. Even without a valve job, maybe you just want to hand lap the valves..you want to replace the seals..which is simple and cheap. Common sense should be your guide.
Do not remove a single cam journal cap with any part of the cam under
load by a valve or eccentric.
Good Luck,
George
90 735iL/145k
<br>
http://bimmer.roadfly.org/bmw/forums/e32/forum.php?postid=1581819&page=1

Another reply:
<br>
<font color=blue>Message Title: Re: BMWCamshaft question from Pelican board moderator
Posted by: Phil S. on 2003-01-06 at 14:24:31
(posted from: Host: pw-162-66-50-1.painewebber.com IP: 162.66.50.1)

Message:

The factory cam shaft remover is just a big fixture that bolts to the head, and holds the camshaft in the head journals while the removable top section of the journals are taken off. You then rotate the lever on the fixture, and it raises the cam(s) evenly, without the possibilty of snapping it in half. When I did the valve springs on an e24 M6 years ago with the help of a master mechanic friend of mine, we had the tool, but he loosened each saddle bolt about 1/2 turn at a time, going up and down the saddles. Indirectly, this worked exactly as the removal tool is meant to. I don't recall whether we used the tool to reinstall the cams, but if you're carefull, it can be done. Caveat emptor however.<br>

http://bimmer.roadfly.org/bmw/forums/e32/forum.php?postid=1582259&page=1

James says:
"On the Jag 6 cylinder (LOOONG dual overhead hollow cams) you just slowly and evenly loosen the cap nuts allowing the cam to rise slowly up"

I've done this on a Jag 6 as well, but those cams aren't hollow. No telling how brittle the bimmer cams are. With older vehicles, cam timing would have more than a couple of valves under tension. Must be low duration cams. My $.02 solution is on the bimmer board.

Sherwood

Well, this so far off topic already I guess it's OK to discuss Jags. The cam I have in my hands right now has a hole drilled down the center and lube holes in the base circle of each cam lobe. Now, these may not be as large a hole a a BMW, but it IS hollow.
http://forums.pelicanparts.com/uploa...adsectcorr.jpg

I don’t like the idea of loosening the all of the cam bearing caps with two valves under pressure, especially with a cast hollow cam. There is a ton of leverage that my play into the sequence if it is not unloaded equally.

I think you should fabricate some phenolic or wooden washers that are "C" shaped and insert them under the valve heads and the combustion chamber while the valves are open slightly more than your second photo shows, then rotate the cam until all of the lobes are off the cam. This will unload the cam completely.

If you must loosen the bearing caps without unloading all of the pressure, remove the forward 5 caps of the seven, and loosen the last two of the bearing caps methodically and evenly.

Keith

Isn't the same too l used to re-install the cams. I would think that almost every method mentioned here and on the BWW BBS would work for removal, care being used. But when reversing this procedure of backing off the nuts to going up and down the row and tightening, or tightening the ones over the valves first, followed by the ones not under compression, is when the cam breaks. That is when you wish you had the tool. So I vote for removing it yourself, and having the tool or someone having the tool before re-installing.

Here Wayne, maybe this will help Check out this web site, there is info there on the cam and maybe you could rent it from Brett Anderson.

_http://member.rivernet.com.au/btaylor/BMWText/technical/CamshaftRemoval.html


Date: Mon, 21 Feb 2000
From: "Brett Anderson" <brett@koalamotorsport.com>
Subject: [uuc] Re: M50 Camshaft removal

I strongly recommend against it.

The M42/44/50/52 cams are hollow.

I've seen professional techs break these cams when removing them, and they
know the risks.

I have the tool for this job, it costs about $500 but I'm sure I could rent
it to you for a little less than that.

Brett Anderson
www.koalamotorsport.com
Home of the E30 M3 CD-ROM repair manual

> From: "Steve Boorman" <steveb@baydel.com>
> Subject: [uuc] M50 Camshaft removal
>
> Has anybody had experience removing the camshafts in a M50 engine
> without using the special BMW tool for holding the bearing caps
> down?
>
> Steve Boorman


Steve

"A Porsche does more then just go fast in a straight line"

here are my thoughts..........
the goal is to get the cam out without any deflection at all, so to remove the bearing caps for the cam you need to "pressurize" the cam itself to their journals to avoid deflection.

below is a photoshoped pic (i'm average at PS) for a jig which could be made in less than an hour once you have your measurments.

get the proper threaded rod for the spark plug holes ( indicated by the "blue" lines) that will extend above the head, to these you will affix hinges of any sturdy sort via bolts/washers (the hinges MUST BE STRONG)

the grey lines should be boxed steel, this will keep the jig from "bowing", these will need holes drilled to affix wood "holders" for the cam and the hinges, the wood is indicated by the red lines, these should be cut to conform to the cam in between the lobes.
these will be attatched to another piece of boxed steel on the other side of the cam.

then you'll need a heavier threaded rod (the blue vertical line with "threads"), this can be attatched to the studs on the side of the head via drilled boxed steel which the rod needs to be bolted to.
the boxed steel which holds the wood opposite the hinges will need a hole drilled to secure the jig to the heavy threaded rod, once it's bolted down and secure you can simply unbolt the bolt on the front rod which will make the jig hinge upward keeping even pressure on the cam.
you wont want to over-torque anything that attatches to the head, having it snug should be plenty as long as there is no play. i would also zip tie the cam around the wood to keep everything even when the valves push up one side of the cam.

i have this figured out in my head, i hope i typed what i'm thinking correctly :)

http://forums.pelicanparts.com/uploads/bellbmwhead.jpg

i like the idea, but are you sure - less than an hour??

if you have boxed steel, wood, the bolts needed, and a drill press...........yes. i could make this in an hour if i had the head in front of me, although i DO do custom stuff for a living..........maybee 2 hours:D

Someone else suggested wrapping the valve with rope - I thought that was an excellent idea because it would evenly support the valve and certainly wouldn't damage it. I'm not sure how I would be able to compress the valve so that it could be opened, when it comes back from the machine shop though...

-Wayne

Wayne: How long would you need the tool for? (If overnight shipping was included.)

if you want to simply open the valves to take the pressure off of the cam you can use the 2 popsicle sticks with a third in between (like a door shim in your house) to open them a hair more to take all the pressure off of the cam. i would use a stick on 2 sides of the valve though to keep from bending them under the pressure.

yeah, i was thinking along those lines.

how about some thin wooden (or some other suitably soft material) "wedges" with groves (for the valve stems), open the valve, pop in the wedge, do them all then remove the cam.

I think the rope is going to work - I got some today, but it's too thin - I'll go get some thicker rope tomorrow...

-Wayne

Wayne, I can get some telfon sheeting used on the bottoms of airboats in Lousiana. I have some about 3/8's thick and can get some thinner. It wouldn't hurt the valves, can be shaped to any size or shape by cutting or sanding. I can send you some if you would like to try it. My friend with an airboat business throws away large sheets of it when he replaces with new.

Rough drawing I know, but something like this could be made from a piece of teflon sheeting. handle on one end to ease installation and removal, the other end cut for the valve stem and tapered to slide under the valve. Teflon is soft enough to prevent scratching, doesn't compress easily so it will hold the valve open, and slippery enough to pull out when you're done. Just a thought

I've got multiple sizes of rope right now - I'm going to try relieving the tension tonite...

-Wayne

Take one bolt out. Find out the thread size and pitch. Get enough bolts, nuts and washers to replace the existing cam tower bolts, but make sure that the bolts are about 3 times the actual length of the existing bolts. Then replace the existing bolts with a bolt which has a nut and washer threaded on it. After the new bolt has been installed, tighten down the nut until it holds the cam tower in place. Do this for all the bolts in the head. Then loosen the bolts 1/2 turn at a time. This will result in the pressure being released evenly.

Clay Perrine

Got it out - the studs are long enough to account for the total valve lift. See here:

http://forums.pelicanparts.com/101-projects-discussion-forum-bmw-3-series/93628-camshaft-removal-results.html

-Wayne

:rolleyes:

no science required then, well done;)