cam chain to tight

thanks guys, as you can tell in my last post I was at the end of my rope for one day. I should have gone to bed but I had the combination of opportunity and motivation so off I went. Anyway, i will try it with the tensioner back in place. That's got to be it, i have ruled out any other possible explanation. Baldy It does turn freely with the cams out. And thanks, I have been counting off the pins wrong. Here's to one more try!
Oh one more question. Should both cams fall nicely into place? meaning, the lobe on the #6 valve is in the down postion pushing on the valve bucket when set to the timing marks. I have to tighten the cam caps down to get the whole cam to sit right in there. Does that seem right to you guys?

The cam will always fall fairly easily into place at one end but must be forced down at the other simply because there are no positions where all valves are closed at the same time across all 4 cylinders.

Alrighty than, that settles it. My problem must be the fact that when I am hand turning (with a 17 mil wrench of course) without the tensioner installed and the chain just binds up. If that is the way the cams lay down, and that makes complete sence. Of course there is never a position where all the valves would be closed at the same time. So it has to be the uninstalled cam chain tensioner....thanks guys!! I will try again tomorrow and let ya know how it all goes.

is this one of the reasons cam cap bolts tend to be stripped out. Do u have to be careful bolting down the side that is lifted due to cam / valve interaction?

I think it's time to call a real mechanic. I took the cams out, again. Reinstalled cams, Put 1&4 at TDC, lined up the EX on the exhaust cam with the head, lined up the intake cam with Z/5 . I installed the cam chain tensioner, and started slowly turning the crankshaft hoping to make a complete rotation of the cam shafts. Once again I got about 85-90 percent the way around....and dam it! She don't want to go anymore. Something ain't right and I can't figure it out

Could something be fitted wrongly despite your procedure to make the valves hit the pistons? Because the chain will not alter its length as you turn the engine.

I'm following this thread with interest. Sometimes taking a day off, or three and going back..sheds new light.


Back to the problem. My cam tensioner was leaking, removed, replaced oil seal reinstalled according to manual.
Have you absolutely cleaned the whole tensioner? I was flipping out as mine wasn't going on right, removed it again, took some 1000 grit paper to rod/shaft, clean the hell out of it, q-tips, acetone etc. there was crap in the groove where the pin goes (know what I mean?), everything went back on right. I wondered how many miles it had been dragging like that.

My concern: before I put the 17mm cap back on, it says if the pin is higher than 7.5mm turn the engine around, mine is now 3-4mm above the top, time to replace those springs or we're still good?
Going to do a frame off...maybe not this winter, but next and I'm amassing parts and knowhow prior.

If you can turn over the engine without the cams in then your problem is in the cam timing. Put the engine at TDC and install the exhaust cam with the arrow foward and level with the head. Count 36 pins back starting with 0 at the pin at the arrow on the exhaust cam. Do not install any cam caps yet. Install the intake cam with the 36th pin at the exhaust cam arrow. This arrow will not line up perfectly with the head. It is usually a little higher. Double check everything. Install the cam caps finger tight. Now start tightening the cam caps, start with the cap that is above the lobe that facing down, this cap will be higher thatn the others. Do not fully tighten the screws, do this in a criss cross ammer. You want the caps to go down evenly. Once the caps are tightened check everything again. Install the idler sprocket above the chain. Install the chain tensioner. Check everything again, if all is correct the rotate the engine.

The cam bearing fit is so close and tight on the 550, that you must absolutely tighten all of the caps extremely evenly. The best way is to count turns on the bolts. If they start to go uneven, the cam will bind. You have to learn to detect the difference between when the cam is binding and when you are just fighting valve-spring pressure. The bind sort of lock up. The spring pressure feels tight but not a solid bind.

You should easily be able to install the caps all the way down using a nut driver. Don't use a ratchet or any other wrench. Nut driver only, until all the caps are seated.

By the way, you are not installing the cams with the sprockets and chain on, correct? That's the hard way in my opinion. You then have to juggle to many things. Also, make sure that tach drive is NOT in there. That messes things up everytime.

It's much easier to get a proper cam install, with no binding/stripping threads, with the chain off the sprockets.

I can give you details on that later. Right now, you should take out both cams, and get a mirror and a good flashlight. You need to inspect the crankshaft sprocket and chain guides, to make sure nothing fell in. It should not be difficult to get a bunch of extra chain slack with the tensioner out. That leads me to think something fell down the tunnel.

Do you have all 4 cam plugs accounted for? That's what usually falls down the chain tunnel. Then when you turn the crankshaft, the foreign object gets mashed into the sprockets and stays there. The chain keeps it from falling into the pan. In that condition, the cams can never be timed, and any rotation of the crank beyond a few degrees usually leads to piston/valve collision.

With the cams out and tensioner out. Inspect the guides to make sure they are all there and in place.

Pull up on the chain and rock the crank back and forth to release any folded chain links, then do a full 360 rotation on the crank while inspecting every tooth on the crank sprocket using a mirror and flashlight. This usually takes two people unless you get creative with mirror/flashlight mounting. Only turn forward, (same direction as the wheels turn). If you can do several turns of the crank, and don't feel the chain jump or pull unevenly, then you are ready to install the cams.

On at least one cam (intake I think), while it is out, I take the sprocket off, but make sure to clean up every bit of loctite on the bolts while the cam is away from the motor so the bits don't fall in. Then put the sprocket back on loosely.

Then insall the cams near to the position they need to be in, notches outward, crankshaft at 1-4 TDC. Don't put the chain on either sprocket while installing the cams. After the cams are fully installed, then put the chain on the exhaust sprocket and make sure it's timed. Then remove the sprocket from the intake cam and put the chain on it. Then slide the sprocket into position while the chain is on it counting the teeth so it is timed. So you are actually timing the sprockets without worrying about the cams yet. Now you rotate the cam to line up the bolts for the sprocket. There should be plenty of slack if the tensioner is out, but you should even bea ble to do it easily with the tensioner installed but with the cross wedge out. I prefer to leave the tensioner installed (cross wedge out) because it reduces the amunt of slop everywhere, then if there is a chain shortage, I know a link has folded etc.

Check you're not 180 degrees out.
If anyone's concerned about stripping cam cap bolts then try the following:
Instead of bolts TEMPORARILY use all thread left in place all the way down using a nut and washer to draw the cam down.When you're happy and would ordinarily button her up,replace each piece of all thread one at a time with the correct bolt.No more stripped bolts/p*ssing about. :kiss:

I don't think this has been mentioned in this thread yet. At least on the 1000 motor, the factory manual gives the wrong cam cap bolt torque. They spec it way too high. I don't know about your engine.

Forget my last post, I re-read your original post and saw you are working on a 550 not a 650. My bad.