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james lawson
USA
1062 Posts |
 Posted - 07/19/2010 : 15:43:59
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I will spare you the gory details, but could someone tell me how to confirm the camshaft position on the left side? I set it at TDC and confirmed the right side then rotated the crank again to TDC and am not sure about the cam lobe position on cylinder 6.
Thanks
Jim
jim |
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ctmaher
USA
366 Posts |
Posted - 07/19/2010 : 16:08:59
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Are the marks on the cam washers lining up with the marks on the cam stands? I believe one of the cams you can put the washer on two ways...there are two notches where the key fits, 180 degrees apart from each other. The washer needs to go on so that the key is facing up when the marks are lined up. Also, when you rotate the engine and line up the crank at TDC, the left cam should be pretty close to right on the mark, but the right cam may appear a little retarded. This is ok, you could dial it in closer with a degree wheel and an offset key if you were really picky.
Chris |
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Ron B
Australia
7933 Posts |
Posted - 07/19/2010 : 18:55:47
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yes,the cam needs to be lined up at the washer and can stand mark with the damper mark at zero. If in doubt ,take the rockers off then you can rotate the engine without bending valves.
 quote:
12-14-2004, 11:49 PM #8
Tom Hanson
MBCA Member
What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be..
__________________
Tom Hanson
Orange County Section
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james lawson
USA
1062 Posts |
Posted - 07/21/2010 : 00:27:25
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Thanks guys.
It started right up but idles a little unevenly and there is a lot of vibration starting out and seems a little less powerful. Then at higher rpms smooths out.
I rotated the engine by hand multiple times and everything lined up on the marks nicely.
I had to remove the distributor. I aligned the rotor and tdc mark on the housing as best I could but it is a special tool needed to align it?
It needs to cool down before I can check the cams.
Since I never removed the washers from the cams I think as long as everything lines up on the marks I have to be okay.
Do you happen to know the position of the cam lobes at TDC? I ask this because I have to wonder if I could have the distributor out 180*.
jim |
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Gael
539 Posts |
Posted - 07/21/2010 : 00:42:08
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| cam lobes of cyl 1 must face upwards when the rotor in the dizzy faces wire for cyl 1. |
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james lawson
USA
1062 Posts |
Posted - 07/21/2010 : 01:13:06
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Gael thanks,
could you be more specific? Say you are facing the cam with the radiator between you and the lobes were on the face of a clock.
Thanks James
jim |
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cth350
USA
1151 Posts |
Posted - 07/21/2010 : 07:51:20
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"Up" is really "a bit sideways" because it's really when the cam lobes face away from the surface of the rocker, which is tilted because the head's surface is tilted.
There's a spot on the cam where both intake and exhaust lobes are at a minimum (both valves closed). That's the spot that should be over the rocker when the piston is at TDC on a power stroke (when the spark plug fires).
Being a 4-stroke engine, recall that the next time the piston is at TDC, the opposite side of the am will be down (at least one valve open some).
HTH -CTH |
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james lawson
USA
1062 Posts |
Posted - 07/21/2010 : 09:59:00
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Cth, Thank you.
Do you have to have an alignment tool for the distributor? The manual is pretty ambiguous.
jim |
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Ron B
Australia
7933 Posts |
Posted - 07/21/2010 : 18:19:49
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Make sure all of your plugs are good.
do a resistance test on the leads.
Check your spark plug leads to make sure they are in the correct place .
You don't need a special tool for the distributor,just a timing light to make sure your timing is the right place.
quote:
12-14-2004, 11:49 PM #8
Tom Hanson
MBCA Member
What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be..
__________________
Tom Hanson
Orange County Section
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james lawson
USA
1062 Posts |
Posted - 07/21/2010 : 18:37:33
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Ron according to the manual due to the electronic ignition you cannot rotate the dissy to alter the timing and cannot use a light or so it says.
I remember the right hand cam wanted to jump forward past the TDC mark and so had to have Karen hold it while I put the sprocket on. I thought everything was ok because TDC lined up on both cams and the crank when I rotated, but still wanted to spring forward. So I am going to recheck it and see if maybe it is off a tooth.
jim |
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Ron B
Australia
7933 Posts |
Posted - 07/21/2010 : 18:57:10
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In that case I would say it only fits in one place then like a M103 engine and the EZL module does the timing duties .
It does sound like a cam is out though if the plugs are in the right place. A cam will attempt to jump if the bottom side of the chain is not kept tight . i often find cams in engines with marks on them indicating the use of vice grips and pipe wrenchs to hold cams in position. I use a 15/16 wrench on a lobe to move the cams to align them.
quote:
12-14-2004, 11:49 PM #8
Tom Hanson
MBCA Member
What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be..
__________________
Tom Hanson
Orange County Section
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james lawson
USA
1062 Posts |
Posted - 07/22/2010 : 00:15:28
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Ron thanks for the wrench tip.
I will check it all out when I get back. I took the 6.3 instead. Pretty tough
jim |
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Gael
539 Posts |
Posted - 07/23/2010 : 06:38:09
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| Check camshaft timing with chain tensioner in place. As you have noted depending on the position of the lobes on the rockers, the camshafts have sometime a tendency to rotate by themselves. If you aligned everything OK with some slack in the chain in between the two camshafts or between the left camshaft and the crankshaft, then you may be off one tooth when you put the tensioner in place. |
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mpmorris
USA
432 Posts |
Posted - 07/23/2010 : 15:05:41
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Hi James.
To clarify, quantify/qualify all that was before stated:
As for the Dizzy -yes, EZL controls timing but for aesthetic purposes, I set the distributor at center position in the slot at distributor base.
Quick look at cams with crank at TDC #1 cyl: cam lobes #1 intake and exhaust should be pointing equally up while cam lobes # 6 cyl should be pointing equally down((over lap position) intake and exhaust valves are equally closing/opening).
The cam marks should be at or coming up to the corresponding marks on the cam towers -never ever after (they can run late given stretched chain/surfaced heads).
This procedure can only be accurately accomplished as you manually rotate the engine clock wise (as you are facing the engine from front of car). I always take a wrench to the cams, counter clock wise, once I have reached TDC on the crank to be certain there is not any slack in chain (only allowable slack is at tensioner/rail between crank and 1-4 camshaft gear)
If this is all correct with good spark plugs and you have a rough idle and power loss -do a cylinder balance test, leak down test or compression test to ascertain if you've bent a valve.
Michael |
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james lawson
USA
1062 Posts |
Posted - 07/27/2010 : 17:33:19
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I thought some pics of what I have might help. This is TDC from looking about as straight down as possible. If you are angled off to the right a little then it looks like it is past TDC.
next is the right hand cam
and last is the left cam
I rotated the cams counter clockwise to remove any slack.
I put in a new set of plugs. It seems like there is a lot of vibration at idle and at 1500 rpms then everything smooths out at around 2000.
Could the dissy drive be out of sync? The chain slipped out of my hand when my daughter was wrenching the engine forward.
I would think not since the rotor points to one and the crank and cams line up at TDC.
jim |
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Ron B
Australia
7933 Posts |
Posted - 07/27/2010 : 23:22:04
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Are you 100% sure you haven't swapped 5&6 spark plug leads?
Also,try slackening each injector pipe and tightening to find which cylinder isn't firing at idle.
quote:
12-14-2004, 11:49 PM #8
Tom Hanson
MBCA Member
What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be..
__________________
Tom Hanson
Orange County Section
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OT. 560 cam shaft help; '91 560 sec
