This is for that 2.8 swap... now turning into a 2.8 top-end rebuild...

The cam and the crank were turned (not by me!) when the timing chain was removed. When I did my chain on my 2.8, I didn't move either, and I still had the heads on. This 2.8 has no heads & no intake manifold.

I know the camshaft sprocket is keyed for the cam, and the crank's got the woodruff keys. (86 2.8's had two.) Here's what I'm guessing at:

1. Spin the crank so #1's at TDC. This should put the timing mark on the crank gear pointing upward.

2. Put the cam sprocket on. Put some downward pressure on the lifters for the #1 cylinder. Spin the cam. When both lifters drop all the way down, that's when the crank & cam sprockets should line up, and when we should slap the chain on.

Good?


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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basically yes you got it.

 

Sweet! Thanks, ODB.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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i like to put it together dot to dot like you said because it's easier to see and line up then spin it 1 turn to where both dots are straight up. on a SBC this is #1 firing, not sure about your v6 but i'd guess it's the same.

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ICON Motorsports

1st & 3rd

 

There should be a mark on the cam sprocket, a dot near the teeth or something, that you would line up with the dot on the crank sprocket. The method you described is nowhere near precise enough, you easily could end up several teeth off. If the cam sprocket has no dot, turn the cam and watch the #4 lifters (I think it's #4 - the one 3 cylinders behind #1 in the firing order, in any case) and line it up so that as you turn it CW, the exhaust is just closing, and the intake is just opening. But there should be some kind of a mark.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Yeah, Ed, it's the same deal. RB, I know about the dots, but I seem to recall two dots being on the cam sprocket- I just wanted to get the right one, and not the one for #4 firing. (grins) Unless I'm thinking of ignition timing, that is. I've just never seen an engine this naked in person before, and it's throwing me off!

He bought a new chain, and wants to run the new chain on the old sprockets. (There's that damn budget again.) I'd rather run the old chain with the old sprockets if the budget's that tight, but, oh well. I forsee some extra metal filings running thru this engine soon...

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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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Old chain w/ old sprockets... maybe ok.
New chain w/ new sprockets... good!
Old chain, new sprockets = bad.
New chain, old sprockets = bad.

I agree with your prediction about the metal shavings. The old sprockets have already established a wear pattern that matches the old chain, and as soon as you install the new chain they will begin to fight each other. Since the links won't fit perfectly into the patterns worn into the old sprockets, the two will begin to wear away at each other rapidly until enough metal has been removed that the new chain now looks just like the old chain. Plus you have all the shavings in the pan now.

Budgets are important, but I think that this is a case of doing it right or not doing it at all.

 

So every time a motorcycle or piece of equipment that is chain driven should have the sprokets replaced when the chain is stretched ? I dont think so. If timing gears still look good then they are. You only need to put on a chain. But you are right on one account. You are already torn apart so why not spend a few extra dollars and put a new setup.

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87z 383,afr 190's, comp hyd roller(242/248-.540/.562,114 sep),Ported and polished mini ram, 30lb inj, 3.42 gears, tremec 5spd, , 1,3/4" slp headers, speed pro bank to bank-wb02.
"Just remember children, no man can beat you once youv'e found the cliterous." 'chef'

 

These timing gears don't look that hot. Granted, they're not crap, but they have ridges worn into them from the chains. Maybe I can convince him to replace it all tomorrow... thanks again guys! (I wish we knew the mileage of the motor...)


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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