camshaft alignment, did I do it right

dannyboy · Post by **dannyboy** » 28 Sep 2006, 15:08

OK bobsnow100, now I suppose that when you removed plug wires one after the other engine was running at idle and smooth (if the 5 plugs were connected)
I understood from your previous explanation that it was only during acceleration that the engine was quite rough but when it has reached a certain rev (ie 2000 or 3000 rpm) it was smooth again. Is that correct?
If yes it would probably mean that there could be some misfiring when accelerating only meaning when the sparks really need to be "strong".
I would also check the distributor head inside (humidity, cracks, ...)
If that seems ok you can also check each HV wire with your strobe lamp while somebody else accelerates the engine ie 1000 to 4000 rpm several times and look for "weakness" or misfiring during that.
I do not know why but I am really feeling that this is an ignition problem.
As you have another 850 available why don't you try testing yours with the distributor head and HV wires of that one?
Please keep me posted.
PS : I'll be working on mine tomorrow and away from my PC.

bobsnow100 · Post by **bobsnow100** » 29 Sep 2006, 18:13

I think I got them problem solved. The camshaft have to be 100 % in alignment at TDC,It can't be a hair off, If is is just a hair off ,it makes the engine valve timing open or close at a fraction before it is supposed to and you're not getting a smooth idle, I guess when the engine is being driven at a faster speed the valves are opening and closing so fast that it isn't making it run rough.
Thanks

Post by **Ozark Lee** » 30 Sep 2006, 18:31

Bob,

Just curious, how does it run now?

I changed out the cam in an old 142 (pushrod motor) and the belt on a 740 which was a single overhead cam but the only dual overhead cam motor I've messed with was my wife

bobsnow100 · Post by **bobsnow100** » 01 Oct 2006, 08:01

I am actually going to borrow the volvo tool (cam alignment)from someone I know who works at volvo. I had made a tool which got it close but the engine was a little rough. I could get up to highway speed but it wasn't running as good as it should.I found out it has to be precise,real precise. I tried the straight edge way you want to do it and the engine runs like a vacuum line is off.

sntee · Post by **sntee** » 04 Oct 2006, 15:18

Can you tell me the thickness of the plates on the Cam locking tool? I mean the ones that go into the grooves in the Cams.

My Haynes manual describes how to make the tool but doesn't say how thick the plates need to be and I'm guessing that this is where the precision comes in, cos if the plates are sloppy in the grooves, the cams can rotate slightly.

Also, do you have to remove the pulleys from the Cams?

I'm gonna be replacing my Head Gasket and the only part of the job that really worries me is the re-alignment of the pulleys. When I look at all the pics in the manuals, I can't see any need to remove the pulleys. For that matter, its hard to see why you would even need to seperate the two halves of the head.

Any tips / advice would be appreciated.

bjornfam · Post by **bjornfam** » 04 Oct 2006, 17:51

when i made mine, i used 3/16 flat bar steel. I bolted the flat side squarely to the angle iron and then used a grinder on one side of the steel so that it just squeezed in tightly and was centered by the other side. it worked, car runs gret.

i didn't remove head. think i'd chicken out on that one. no idea how many parts i'd have left over.

bobsnow100 · Post by **bobsnow100** » 04 Oct 2006, 18:37

That's where I got the design ,from the Haynes Book, It is a good idea and only took about a half hour to make. I think that is my problem ,(the two steel pieces that lock the rears of the camshaft), I don't think they are 100% equal or parallel and the cams move the littlest bit and throws it a hair out of sinc. I did make the parts to pull the cam cover down which worked really well. I bought 2 air adaptors from Napa Auto Parts which screws into your spark plug hole, It is an adaptor which usually allows air to be put into your cylinder to do leak down tests or sometime to hold valves up to change valve stem seals on certain engines ,I think it was 14mm for the spark plug hole and had a 1/4" american female thread on the other end. I bought a 1/4" coupling at Home depot and screwed it on the end of the adaptor and welded a 1/4 "threaded rod into it ,and it worked really well on pulling the cam cover down.I used some angle iron about 10" long with a hole in the middle to put under the nut to pull it down

bobsnow100 · Post by **bobsnow100** » 04 Oct 2006, 18:46

Sorry, forgot to tell you about the pulleys, I did take mine off because I put in new cam seals,front and rear, If you do, mark them with some typewriter white out,intake,exhaust, and make sure you know what camshaft is intake and exhaust, and also I marked the top of the camshafts between a couple of the lobes with white out so I knew. If your not taking off the cam seals I suppose you could leave the pulleys on the camshaft and as long as you put the timing belt on the same teeth, I think you would be all set. You would just have to make sure your seals are in correct and square in the cylinder head when you install your cam cover.Make sure you get the right gasket sealer for the cam cover, (there is no gasket)

sntee · Post by **sntee** » 05 Oct 2006, 03:06

Thanks for all the info.

I've bought new Cam oil seals, so I guess fitting them whilst I've got everything apart would be the right thing to.

I'm making the tools for pressing the head back down out of a couple of old spark plugs as recommended by Haynes, but I couldn't "drill out the centres" as suggested. MY GOD that ceramic is tough!!!

I burned out three good drill bits before giving up and just sawing off the threaded section.

I've got some 6mm flat iron bar to make the Cam locking plates and will probably follow bjornfam's advice from earlier in the post and grind away the back face until they fit.

I'll post an update when the job is done to let anyone who's interested know how I got on.... and if I'm successful, I might even sell the tools on ebay

Post by **Ozark Lee** » 05 Oct 2006, 18:34

This thread got very interesting to me today when I went to the Quickbricks site. The other OHC timing belts I have changed in other cars have fixed positions for cam timing (the cam pulleys have no slop), Volvo has +/- 7.5