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Urgent!! What is the effect if Cam is 2 links out.


wardie

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I've had to replace the head gasket on my L24E R30 Skyline. I set TDC on #1 prior to pulling the head and never moved anything while I had it apart but when I put the Cam Drive Gear back on the #1 mark on the outside of the gear does not align with the light coloured link on the timing chain. The mark is 2-3 teeth back (anti-clockwise) from the light link. I have turned the motor over using the crank damper bolt slowly and nothing seems to touch or bind but I don't want to start it as I know things can hit at engine speeds. I've also checked the lobes on #1 and they are at 2 & 10 which is what I would expect according to what I read.

 

Is this a big issue? Should I just move the Cam around to align the marks? I know that the lower marks are aligned because I have had the timing cover off previously because the water pump corroded thru and I checked.

 

Thanks in advance

 

Wardie

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I've had to replace the head gasket on my L24E R30 Skyline. I set TDC on #1 prior to pulling the head and never moved anything while I had it apart but when I put the Cam Drive Gear back on the #1 mark on the outside of the gear does not align with the light coloured link on the timing chain. The mark is 2-3 teeth back (anti-clockwise) from the light link. I have turned the motor over using the crank damper bolt slowly and nothing seems to touch or bind but I don't want to start it as I know things can hit at engine speeds. I've also checked the lobes on #1 and they are at 2 & 10 which is what I would expect according to what I read.

 

Is this a big issue? Should I just move the Cam around to align the marks? I know that the lower marks are aligned because I have had the timing cover off previously because the water pump corroded thru and I checked.

 

Thanks in advance

 

Wardie

 

First question - did you block the chain when you pulled the head?

 

If so, what did you use to block it?

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TimZ, I used a large square handled screwdriver that was tapped into place prior to unbolting the Cam Drive Gear. The engine was not rotated at all while the head was off.

 

I fell into the chain tensioner trap last time when the piece of wood I used came loose and I had to perform chopstick surgery with two long handled screwdrivers to get it back inplace without taking off the head and timing cover again. Took about 3 hours and a couple of thrown tools.

 

Wardie

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TimZ' date=' I used a large square handled screwdriver that was tapped into place prior to unbolting the Cam Drive Gear. The engine was not rotated at all while the head was off.

 

I fell into the chain tensioner trap last time when the piece of wood I used came loose and I had to perform chopstick surgery with two long handled screwdrivers to get it back inplace without taking off the head and timing cover again. Took about 3 hours and a couple of thrown tools.

 

Wardie[/quote']

 

 

If the chain tensioner came out, then there is a high probablility that the chain came loose and walked on the crank sprocket, so all bets are off with the bright link.

 

Have you checked the alignment of the v-groove and timing mark on the backside of the chain sprocket? If this alignment looks right after rotating the engine once (rotate by the crank pulley in the normal rotation direction of the engine) and returning to #1TDC at the crank, you are probably okay.

 

camalign.jpg

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TimZ, I just checked the alignment of the groove and the mark and they are aligned. The crank timing mark is on 0 and the dizzy is pointing at #1 lead. So things seem OK.

 

Do you know what the effect of being out by 2-3 teeth anti-clockwise would be?

 

Wardie

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Hi Guys

 

I need to have my car running tonight but I am still a bit paranoid as to potential issues if the timing is out. With TimZ's help I believe that things are right enough for it to run but I want to be understanding of the symptoms of if its not right.

 

Will it not rev out or have no grunt in the bottom end, thats the type of thing that I would like to be understanding.

 

Thanks in advance

 

Wardie

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Sorry we couldn't get you running when you wanted. I'm looking over the FSM right now. If the cam sprocket isn't lined up properly you could have several problems, the worst of which is bent valves. I wouldn't risk it.

That said, according to the images provided in the FSM there appears to be 3 alignment wholes in the sprocket. The one that should have the alignment dowel inserted in it is the top hole with the three trailing to the left side. If this is aligned and the chain is properly aligned on the crank sprocket the shiny link should be on the upper right side of the cam sprocket which aligns with the timing mark on the outter ring of the cam. Wish I had a pic of the page in the FSM for you. It's really simple to understand when you can see it.

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Thanks for all the info.

 

Sorry if I seem pushy and demanding but not having a car and having to get to work is getting right up my nose at this time.

 

Not being hooked into a knowledge base like this locally plus the time difference between you guys and us can lead to a day+ delay between asking a question and being able to try the solution.

 

I'm really not wanting to pull the timing cover, oil pump, dizzy etc to check the lower mark as I will have to order gaskets and seals, thus incurring another 2-3 days delay as no one holds L series parts in my area.

 

Thanks again

 

Wardie

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How much head and block surface material removed?

 

One tooth is 18 deg ok, but not two.

 

If you have to move the sprocket two teeth to get it on the cam nose while aligned with V notch, then suspect chain slipped. Bring crank to TDC and with the cam dowel pin aligned to the V notch, install cam sprocket on chain so that sprocket can slip onto cam nose. Should be close. may need to rotate cam slightly.

 

Your chain may be too short or to long. Your harmonic balancer ring may have slipped. Check TDC with long screwdriver in plug hole and observe handle while rotating crank.

 

Only way to be sure is to degree cam. See Braap's write up.

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Nobody has mentioned the possibility that the damper ring with the crank timing mark "could" have slipped on the damper.

 

If you know FOR SURE that the crank keyway is strait up, and the cam wheel is lined up at the V notch, it can't be off two teeth.

 

I'd make dam sure the crank keyway is @ the 12:00 position first, then go from there. I don't know how many times I thought my damper marks were right, when they wern't, because of slippage....

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Thanks heaps guys.

 

I took today off sick (Aussies knocked out of W/C last night). Luckily the boss mentioned that I had a bad cold yesterday so won't notice.

 

In day light I noticed that there seems to be a light link and a somewhat light link on my timing chain when I rotated the engine over a few times. When I checked the alignment on the really light link I was only one tooth out anti-clockwise, so I bumped the Cam drive gear around one tooth clockwise.

 

Now when I check everything it all lines up except the "v" and the mark on the Cam tower. The "v" is about 1.5-2 mm past the mark.

 

I hope to have her started before it gets dark (lunch time now).

 

dapiper, I do not know how much material was removed last time the head was off. I was told it was lightly skimmed to remove a scratch that the head shop caused in the face when they picked it up. Could this cause the mis-alignment of the Cam marks that I have now?

 

J. Soileau, I have checked TDC on #1 and the damper timing mark seems to be very close but I am feeling a dead spot where there is not enough movement in the screwdriver to tell so cannot be 100% sure that it is not a couple of degrees off.

 

Once again THANKS!!!

 

Wardie

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spotfitz - It's a bit more than the diagram, maybe another oblong mark to the right.

 

I didn't manage to get it running today, have to get the radiator mount bracket soldered back on. I really think this car does not want to run.

 

Wardie

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spotfitz - It's a bit more than the diagram' date=' maybe another oblong mark to the right.

 

I didn't manage to get it running today, have to get the radiator mount bracket soldered back on. I really think this car does not want to run.

 

Wardie[/quote']

 

Try moving it over one tooth and see what that looks like.

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TimZ - At this time it looks like this - v, when it was 1 tooth anti-clockwise it looked like this -v.

 

I think that it should run as it is now. Most of my concerns where when I was using the wrong light link which gave me Cam timing that was 3 teeth out. This I think would have bent something if I had started it.

 

I have heard that you can change the performance of the engine by using the other marks (2 or 3) but cannot find the source that confirms this. By performance I mean one will give you better mid range but a loss at the top end and the other more top at the expense of mid range. Does anyone know the correct details or the source of this info. It's mainly for my education/understanding that I ask. My car is a daily driver not a Rex killer.

 

Thanks

 

Wardie

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Thanks again for all the input and advice.

 

I finally got her back together and she started 1st go. Took her for a run and she goes well.

 

Now the downer!!!

 

Did a lap of the local block and checked the radiator. EMPTY!!!. Checked the dipstick and it's full of coolant again.

 

If it stops raining I'll have to pull the timing chain cover off tomorrow and check the water pump area for holes as I've had one there before. Did not want to do this, but!!!

 

Has anyone had experience with cracked E88 heads. Are they prone to cracking when hot. I've cleaned and visually inspected mine and can't see any obvious cracking. I've checked it for warpage and it's within specs.

 

Wardie

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