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I installed a timing chain today on my 77 and I couldn't get the marks to line up perfectly. Does this look correct? Instructions said to use inner 0 for SBC.I hope its right as I already installed the cover.
That does not look right to me but it's difficult to see the marks and tell how they are lined up from this angle. Also without seeing the rest of the engine, it's impossible to see where the rest of the assembly is.
I've no direct experience with this timing set, but I'm wondering if you misinterpreted what to align to. I think the crank key way goes to the inner -0- but the cam sprocket is aligned with the outer -0-. From briefly searching, this set only fits the small block, so all marks should apply to that. That may be what's causing the visual misalignment of the cam dot and the crank's inner -0-.
Be aware that if you align the two proper marks (12:00 and 6:00) the pistons and valve train are at TDC #6, not TDC #1
I think your right. Instructions are not the best. Ill have to take it apart tomorrow and call manufacturer to verify. Piston 1 is not quite at TDC in this picture.
Originally Posted by 67:72
I've no direct experience with this timing set, but I'm wondering if you misinterpreted what to align to. I think the crank key way goes to the inner -0- but the cam sprocket is aligned with the outer -0-. From briefly searching, this set only fits the small block, so all marks should apply to that. That may be what's causing the visual misalignment of the cam dot and the crank's inner -0-.
Be aware that if you align the two proper marks (12:00 and 6:00) the pistons and valve train are at TDC #6, not TDC #1
Looking at the sprocket in detail here is what it seems way it should be installed. I'm assuming you are going for a straight up / neutral position. The inner mark is where the keyway should sit for your selection (in your case it appears you selected 0 / straight up). Next. you align the outer marking with on the sprocket with the dot on the cam gear. In your case its currently lined up on the 2R selection but should be aligned with the outer 0 on the sprocket if you want straight up. In the current selection, it won't be 2 degrees retarded as you mixed and matched two different timing selections. If you are installing a single pattern cam straight up and if you put the engine to TDC on the first cylinder, you should see the exhaust and intake valves mirror each other at their level of lift / opening (as a sanity check if you can't take a measurement at the lifters).
I think your right. Instructions are not the best. Ill have to take it apart tomorrow and call manufacturer to verify. Piston 1 is not quite at TDC in this picture.
Calling for clarification is the best plan.
As for piston position, I just want to make sure you understand that both #1 and #6 are at TDC at the same time — my apologies if you already know this, no insult intended. Depending on where the camshaft is in its rotation (opening or closing valves), one of the pistons is at the top of the compression stroke (with both valves closed), the other is at the top of the exhaust stroke (with exhaust valve just closed, intake just opening). When aligning the timing set marks, it's important to know which cylinder is doing what so that you can set the distributor to the proper position to start the engine. When the two marks are at 12:00 and 6:00, you are at the TDC compression stroke on #6 for the spark plug to fire; when the two marks are both at 12:00, you are at the TDC compression stroke on #1 for the spark plug to fire. It's visually easier to align the timing set at #6 firing since the marks are close together, so after assembly, rotate the engine one revolution to get both marks at 12:00 and ready for #1 to fire. Many folks have mistakenly thought they were on #1 firing when really on #6 -- it's a whole mess of back firing and chaos.
Awesome! I fixed it this morning. Ill rotate it to 12/12 be fore putting cover back on.
Originally Posted by 67:72
Calling for clarification is the best plan.
As for piston position, I just want to make sure you understand that both #1 and #6 are at TDC at the same time — my apologies if you already know this, no insult intended. Depending on where the camshaft is in its rotation (opening or closing valves), one of the pistons is at the top of the compression stroke (with both valves closed), the other is at the top of the exhaust stroke (with exhaust valve just closed, intake just opening). When aligning the timing set marks, it's important to know which cylinder is doing what so that you can set the distributor to the proper position to start the engine. When the two marks are at 12:00 and 6:00, you are at the TDC compression stroke on #6 for the spark plug to fire; when the two marks are both at 12:00, you are at the TDC compression stroke on #1 for the spark plug to fire. It's visually easier to align the timing set at #6 firing since the marks are close together, so after assembly, rotate the engine one revolution to get both marks at 12:00 and ready for #1 to fire. Many folks have mistakenly thought they were on #1 firing when really on #6 -- it's a whole mess of back firing and chaos.
Is this timing chain correct?
