Engine builders help needed, pics
Hammer, you could have the 1-4 bank and 5-8 bank cams mixed up. The sprocket is offset differently on each bank, if that's the case it would be both cams that are incorrect. BTW, I'm very intimate with cams because I'm making some right now, it's mind boggling to keep up with the details of each but IIRC the sprockets are offset forward on 1-4 and rearward on 5-8.
I will get up to my shop & post my investigative results as soon as I can. I thank everyone for the thought food. With everyone's help I will get to the bottom of it.
One thing, I used someone's illustrated directions on my install. I noticed that in Big Dave's pic the patterns he used & I used were reversed. That may be my problem. I'll check it out.
Thanks again, Hammer
One thing, I used someone's illustrated directions on my install. I noticed that in Big Dave's pic the patterns he used & I used were reversed. That may be my problem. I'll check it out.
Thanks again, Hammer
928 Engine Re-Re-Rebuild Specialist
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Joined: Oct 2001
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From: Brighton, MI
Hammer....I keep staring at your first picture with the chain tensioner. Are you sure it's installed correctly? The oil feed line looks odd, like it's pointing the wrong direction.
Hammer
Does the tool assume that the tensioner is engaged? Your's is totally slack. When I do cam timing, I use Louie's tip of wedging the tensioner open to the same extent it would be if hydraulicly pressurized.
It's not slack. Although I'm sure it would be more extended under oil pressure there is spring pressure as you can see from the bow in the chain.
Hammer
They were plasma welded & reground.
Hammer
Ah, that explains that.
Some random thoughts, if one cam were off a tooth the 113mm would be off by about 4mm at the cast pointers. That doesn't look to be the case.
If the new valve timing was different it could have the tool sitting like that. 10 degrees of valve timing would move the opposite end of the alignment tool 3/8"
Some random thoughts, if one cam were off a tooth the 113mm would be off by about 4mm at the cast pointers. That doesn't look to be the case.
If the new valve timing was different it could have the tool sitting like that. 10 degrees of valve timing would move the opposite end of the alignment tool 3/8"
Ah, that explains that.
Some random thoughts, if one cam were off a tooth the 113mm would be off by about 4mm at the cast pointers. That doesn't look to be the case.
If the new valve timing was different it could have the tool sitting like that. 10 degrees of valve timing would move the opposite end of the alignment tool 3/8"
Some random thoughts, if one cam were off a tooth the 113mm would be off by about 4mm at the cast pointers. That doesn't look to be the case.
If the new valve timing was different it could have the tool sitting like that. 10 degrees of valve timing would move the opposite end of the alignment tool 3/8"

Hammer
how can that be possible???? the exhaust cam for bank 5-8 is totally different . it has the long bearing surface near the pulley.
also, look at the vertical indicators, if the intake cam was change to the 5-8 side, it wouldnt be pointing in the right direction for the tool.
the easy way to check this is just look at the end of the cams for the serial numbers and verify with the manual.
im still thinking its off one tooth, and you can measure the distance to verify that, or he needs to rotate both cams a little until the exhaust side of the alignment tool touches the exhaust cam. notice the tool is on the intake cam lobe but not quite to the exhaust cam lobe? one tooth might be the answer.
This is also why it is important to set the cams in the chains on the ground by using the tool. Then, as long as you dont skip a tooth, you place the cams in the bearings and lock them down. the rest is just double checking, and no surprises.
mk
also, look at the vertical indicators, if the intake cam was change to the 5-8 side, it wouldnt be pointing in the right direction for the tool.
the easy way to check this is just look at the end of the cams for the serial numbers and verify with the manual.
im still thinking its off one tooth, and you can measure the distance to verify that, or he needs to rotate both cams a little until the exhaust side of the alignment tool touches the exhaust cam. notice the tool is on the intake cam lobe but not quite to the exhaust cam lobe? one tooth might be the answer.
This is also why it is important to set the cams in the chains on the ground by using the tool. Then, as long as you dont skip a tooth, you place the cams in the bearings and lock them down. the rest is just double checking, and no surprises.
mk
Hammer, you could have the 1-4 bank and 5-8 bank cams mixed up. The sprocket is offset differently on each bank, if that's the case it would be both cams that are incorrect. BTW, I'm very intimate with cams because I'm making some right now, it's mind boggling to keep up with the details of each but IIRC the sprockets are offset forward on 1-4 and rearward on 5-8.
how can you eyball 5mm. someone needs to confirm the placing. if it is correct, then just rotating the cams will allow the tool to fit. there is no way the cams could be reversed, the bearings on the exhaust cam on the driver side is different.
mk
mk
Ah, that explains that.
Some random thoughts, if one cam were off a tooth the 113mm would be off by about 4mm at the cast pointers. That doesn't look to be the case.
If the new valve timing was different it could have the tool sitting like that. 10 degrees of valve timing would move the opposite end of the alignment tool 3/8"
Some random thoughts, if one cam were off a tooth the 113mm would be off by about 4mm at the cast pointers. That doesn't look to be the case.
If the new valve timing was different it could have the tool sitting like that. 10 degrees of valve timing would move the opposite end of the alignment tool 3/8"


