OldSch88L Posted June 28, 2021 Share Posted June 28, 2021 I'm in the middle of a timing chain job on my 2.5L. Before tearing if apart, I made sure my crank pulley was at 0 degrees (keyway pointing at 12 o'clock) and took the dstributor cap off to confirm it was pointing at cylinder #1. Didn't move anything during disassembly, and when I went to put my new gears and chain on, I noticed that the dowel pin on the cam was 180 degrees off, like if the dowel (which in my case is a roll pin, is it stock???) was in the wrong hole. If I put the cam gear as is, and properly align the dots on the gears, the distributor points at #4. The new gears are identical to the old ones. I'm confused, so I stopped working and decided to sleep on it. What am I missing here??? Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 28, 2021 Share Posted June 28, 2021 Sounds like your 180* out. There was no need to pull the distributor or look at the crank dampener. Your looking for the marks on the crank and cam sprockets to lineup. That sets your cam timing. Ignition timing can be reset afterwards. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 28, 2021 Share Posted June 28, 2021 Here is what needs to be aligned for cam timing Link to comment Share on other sites More sharing options...
OldSch88L Posted June 28, 2021 Author Share Posted June 28, 2021 2 minutes ago, ghetdjc320 said: Sounds like your 180* out. There was no need to pull the distributor or look at the crank dampener. Your looking for the marks on the crank and cam sprockets to lineup. That sets your cam timing. Ignition timing can be reset afterwards. Ok, but is it normal then that the engine ran fine with the cam 180 off? It idled fine, although a bit lazy on acceleration, but I attributed that to chain slack since the tensionner's plstic block was almost worn through.... Link to comment Share on other sites More sharing options...
OldSch88L Posted June 28, 2021 Author Share Posted June 28, 2021 3 minutes ago, ghetdjc320 said: Here is what needs to be aligned for cam timing Yes, and that's what I did. But, there is two holes on the cam to put the dowel pin in, which dictates the position of the cam gear. I'm wondering if the pin is in the wrong hole, I.E. 180 degrees off. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 28, 2021 Share Posted June 28, 2021 11 minutes ago, OldSch88L said: Yes, and that's what I did. But, there is two holes on the cam to put the dowel pin in, which dictates the position of the cam gear. I'm wondering if the pin is in the wrong hole, I.E. 180 degrees off. Does the sprocket have an advance option, or are the cam sprocket dowel holes 180* out? If that’s the case, it wouldn’t matter since you’ll have to ensure your timing is set again to tdc on the compression stroke. Removing the valve cover is an easy way to verify it. You can watch the rocker arms closing. Just get the two marks aligned on the sprockets for now. Link to comment Share on other sites More sharing options...
OldSch88L Posted June 28, 2021 Author Share Posted June 28, 2021 You can see the two holes in this video from Nickintimefilms at 13:38 Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 28, 2021 Share Posted June 28, 2021 1 hour ago, OldSch88L said: You can see the two holes in this video from Nickintimefilms at 13:38 So they’re 180* out it looks like. In that case it makes no difference. Just get the marks lined up. The crank rotation vs the cam gear is 2:1. You just have to re index your dizzy so it’s not 180 out Link to comment Share on other sites More sharing options...
OldSch88L Posted July 1, 2021 Author Share Posted July 1, 2021 Well, I got it figured out, and the truck runs real nice, but someone, somewhere, made a mistake. The second hole on the camshaft is a smaller and tapered hole, and the dowel doesn't fit, which means it was where it should be. However, when the cam and crank gears line up their respective dots, the #1 piston is at TDC on the exhaust stroke, and not compression like everyone, including the Haynes manual, want you to beleive. The distributor lines up at cyl #4, and the exhaust lobe on #1 points straight up. I tried the distributor pointed a cyl #1 with the dots lined up and it wouldn't start, but pointed at #4 it runs perfect. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted July 2, 2021 Share Posted July 2, 2021 3 hours ago, OldSch88L said: Well, I got it figured out, and the truck runs real nice, but someone, somewhere, made a mistake. The second hole on the camshaft is a smaller and tapered hole, and the dowel doesn't fit, which means it was where it should be. However, when the cam and crank gears line up their respective dots, the #1 piston is at TDC on the exhaust stroke, and not compression like everyone, including the Haynes manual, want you to beleive. The distributor lines up at cyl #4, and the exhaust lobe on #1 points straight up. I tried the distributor pointed a cyl #1 with the dots lined up and it wouldn't start, but pointed at #4 it runs perfect. Yeah, they try to oversimplify the process. Ultimately it doesn’t matter if the cam is 180* off from where it was originally compared to the crank (assuming there are two holes on the sprocket 180 out). The only thing your have to readjust is the dizzy to get it on the comp stroke Link to comment Share on other sites More sharing options...
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