Timing 180 off despite resetting EVERYTHING

[87ChevyR10]

The truck was set timed prior when the Melling 3-499s timing set was originally put in in November of last year, but its either jumped time again for whatever reason, heck, really i dont know.

What I do know is we've repeated the process, pulled everything off to get to the timing gears. Removed the gears, found compression stroke for cyl 1 with a remote starter hooked up, got both gears on lined up on compression stroke, pulled the distributor and set it in to where it pointed at cylinder 1. Again, had a remote starter set to it, bumped it over, and the distributor and the cam gear keep ending up 180 out.

Couple of interesting things.....

1) Is indeed the wrong timing set as several sites have said(numerous ebay sellers via application guide, northern autoparts and amazon via application guides). Every application I saw was for carbeurated 305s and the 350/5.7 motor, though the 350 wasn't specified as FI/carb. So idk there.  But my R10 definitely wasn't listed. However, the cam sprocket, the only piece i see sold at o'reillys says it does fit. Very very aggravating all the descrepancies. Lending what I believe is supporting evidence in addition to the prior mentioned app guides at several different places saying this set is NOT compatible with the 87 r10 305/5.0 vin H LO3 motor, is this -

A distinct 3-2-3 pattern of scar/abrasion marks on the cam gear, 1 tooth will have 3 scar marks ,the next 2, the next 3, so on and so forth. I dont believe thats right, but im not a mechanic. It just doesnt seem feasible to have a new timing set have those kind of marks on it already. I'll post a picture for visual inspection as soon as I get the gear back. Like the gear has too many or not enough teeth, thus leaving these marks and it being the wrong gears/timing set over all. That CANT be right to have a new timing set marked/scarred up like that.

2) Crank wasn't rolled over completely twice ending up out 180 on the timing gears AND rotor button. I've discovered 2 other instances of this on the internet and both had similar suggestions of turning the crank again after it being 180 off.
https://answers.yahoo.com/question/index?qid=20090911080339AAHcVSE
http://www.thirdgen.org/techboard/tbi/597310-got-timing-out-180-a.html

I can't verify we turned it over twice but we will pull it all off again tomorrow, reset everything including the pain-in-the-#$% distributor,bump the cam gear 2x around and come back with the results. Spent pretty much all weekend screwing with the timing. Took little time to pull everything off, the rest of the time spent fighting with this issue. SMH

A visit to the parts dept at Rick Hendrick Chevrolet was as useful as koolaid with no sugar. A bowl of cereal....with no milk. Very disappointed there.

Video link: http://youtu.be/dS9p3ZFhgCs, my apologies not showing the cam gear off 180, i thought about that after, but, trust me it was. I'll definitely shoot video again tomorrow.

But for now, thoughts? I'm pretty much at a loss here. The old man said he's never seen an engine continuously jump 180 off, be on the compression stroke/cyl #1 being repeatedly verified as well as the dist. pointing to #1.

[87ChevyR10]

Well upon looking at the vid again, i guess i did show the dist pointing out 180 as well as the cam gear out of whack. my apologies. at least you got to see. the start of the video was after everything was set and lined up, then showed it all off 180

[87ChevyR10]

Also seen a post on hotrodders(http://www.hotrodders.com/forum/305ci-timing-gear-marks-do-not-line-up-68832.html) dealing with a 305ci, which, by what the mod said there a good while back, the config where we were getting compression is correct, with the top gear showing 12 o clock, bottom gear at 6. If you look at the settings of the gears on the video, we were getting compression AT that setting. Or nah?

Figure 10.7 pg 75 from Chevy/GMC Pickups 1967-87 Repair manual #24064(420) cites the same.

[bd]

If it makes you feel any better, you've made a common error based on a false assumption.  The common misconception is that 12 & 6 timing mark alignment coincides with TDC compression on cylinder #1.  In fact, when the cam and crank gear timing marks align, the engine is on TDC compression for cylinder #6.  The camshaft timing mark is straight up when on TDC compression for cylinder #1.  So, there's nothing wrong with your gear set & chain installation - you just stabbed the distributor 180° out.  As to the other issue, about how many miles/hours are on that 'new' timing chain?  How deep are the chain marks?

[87ChevyR10]

If it makes you feel any better, you've made a common error based on a false assumption.  The common misconception is that 12 & 6 timing mark alignment coincides with TDC compression on cylinder #1.  In fact, when the cam and crank gear timing marks align, the engine is on TDC compression for cylinder #6.  The camshaft timing mark is straight up when on TDC compression for cylinder #1.  So, there's nothing wrong with your gear set & chain installation - you just stabbed the distributor 180° out.  As to the other issue, about how many miles/hours are on that 'new' timing chain?  How deep are the chain marks?

Less than a 1,000 on the new gears/chain. They're more scuffs than anything, no gouges or gapes, but im not exactly comfortable putting them back in like that. Thats not how they looked when they went in. The truck drove from Savannah to N. GA with it being horribly off time apparently, which explains a plethora of things that have been happening(false codes, low mpg, hesitation under accleration, cutting off at stops while in drive on occasion or when going from park to reverse). Recommended to get a new set? I'm still thrown off on the 50/50 "it fits" "it doesn't fit" thru various online vehicle fitment guides/ebay sellers fit guides, etc of the melling timing set that you see pictured(well, at least the s-390 gear pictured). I'd really prefer a deadset match for this motor as opposed to the it does/it doesn't designation.

Thanks for the response bd.

So pulling the distributor so it points to cyl 1 as close as possible and resetting with the 12/6 TDC setting would be the route to go?

[bd]

Don't over think it.  Leave the cam and crank timing alone - they're fine.  Just restab the distributor 180° away from where it is and set the ignition timing to specs using a light.  With the distributor properly stabbed, as you bar the motor over, when the rotor points to #1 both gear marks will be pointing straight up (12:00).  When the rotor points to #6 the gear marks will be adjacent (12:00 and 6:00).

The timing set you have now should run fine - it's just showing normal surface polish.  But, if it's really bugging you, and it's going to interrupt your sleep, install a Cloyes or similar double roller set.  If you do, however, you will need to pay close attention during installation that you follow the included instructions carefully to install the set @ 0° cam timing.  Stock TBI will not run well with advanced or retarded camshaft timing.

Edit:
Added image showing cam timing marks at cylinder #1 compression and cylinder #6 compression.

[87ChevyR10]

Done deal, reset positioning on distributor and everything lined up. Got everything back together with little issue ASIDE FROM the 2 double-end thread bolts on the oil pan. those were a pain in the ass because of the lines being right next to the pan. i gotta go back in and tighten em one more time tomorrow for good measure. also removed the more than likely stock o2 sensor that had been lodged in the manifold.

Tomorrow new plugs are going in, CR43TS i believe, standard copper delcos. New o2 sensor, change the oil out. Then plan to do the timing set with unplugging the est wire and a timing light. After that, this truck should by all intents and purposes run better than it ever has, since being left to my possession after my grandfather passed. I'm pretty excited. Today was the longest day ever at work, all i could think about was getting home to get her all back together.

Still though, I have begun the hunt for a 350/5.7 tbi motor to begin rebuilding in the background while i enjoy the new life this motor is sure to have after all of this stuff. Its no cam upgrade or performance heads, no, but it should more than suffice to make me happier with it than i have ever been. Goodbye garbage gas mileage? Hmm...

[zieg85]

87ChevyR10---- your mailbox is full so I found this post to respond to the message you sent me.  The Service No. on the ECM box is 1227747 and it is ABHL which was removed from a 1987 C10 Scottsdale with a 5.0L and a 700R4.