77 PW 318 timing question

[78Power]

Hi Everyone. Wanted to get some advice from the experts on which way to proceed with a timing chain replacement gone possibly south. I now have another powerwagon 77 and it started with a big time oil leak around the timing chain cover. After removal, looks like the problem could have started with a bad cover (pitted around water channels) and possibly a broken steering pump bracket. Anyway, dad and I decided to replace the chain and gears. The crank was turned by hand to align the timing marks with each other on the old timing gear set. Took the cap off and the rotor is pointing to #5 instead of #1. We then removed the plugs, rotated, and verified TDC on the #1 cylinder. The rotor is still pointing to #5. We were thinking that the dist. could have been installed 180 degrees out in the past. Now for the bad part, the crank was rotated 360 degrees with the chain off. The cam didn’t rotate, so is it as easy as finding TDC #1 again, and re-installing chain? I’ve heard that damage could be done if using starter when the crank and cam are out of sync, but can you do damage just by turning with breaker bar? Thanks Drew

[04 Diesel]

You can replace the chain without putting the motor TDC, just put everything back the way it was. Did the motor run before ? If so, you need to turn the crank backwards to where it was. If you turn it forward your valves will hit the pistons. Someone one correct me if I am wrong. Goodluck

[W_A_Watson_II]

Turning the crank a full 360º while not turning the cam, is a non-issue, as the crank went right back where it was. As you were able to easily do so with out a pistion hitting an open valve, you confirmed you have a non-interference engine.

On the TDC, there are two of them per cycle, so you might be at TDC at combustion, or TDC between exhaust and intake strokes. As long as the marks were aligned at the TDC you confirmed, and you installed the new gears/chain at the same point with out the cam moving, you are good on that part.

The rotor pointing at #5, well the firing order is 1-8-4-3-6-5-7-2.

Did the engine run before? If not, then I'd agree the distributor was installed out of time.

[78Power]

77 PW 318 timing question

Thanks for quick replies. The truck was running good before timing chain removal. When rotating the crank (before chain removal) each time the marks on the gears aligned, the rotor was facing the firewall. We verified the tdc on #1 and rotor was still at firewall. We assumed the distrib. was 180 out. 04' Diesel wrote about moving the crank backwards, but that would be a full rotation? W_A_Watson replied that the crank moving 360 would not be an issue, but I know the cam was also turned 360 with chain off. We still have not turned over with starter, or even put back the timing gearset. I guess the question becomes, whats the best way to verify the cam position and crank position before putting the chain back on. I'm assuming the crank/cam could now be out of sync?

[W_A_Watson_II]

I know the cam was also turned 360 with chain off

Ah, new info. As long as the distributor was not removed during this process, turning both 360º and the marks aligning should be a non-issue. Are you sure you installed the gears correctly?

The best way to properly re-set the timing is to pull the left side valve cover, timing chain cover and rotate the engine to TDC to align the marks and notice as it approaches this point which valve closes, the intake or exhaust. If it's the intake, you are good, if the exhaust you have an issue.

You can also do it with out pulling the valve cover: http://www.wikihow.com/Find-Your-Eng...nter-%28TDC%29

[78Power]

77 PW 318 timing question

Wanted to give an update on the timing question.

I followed W_A_Watson_II's advice and rigged up the oil level trick to be sure about TDC. It looks like the dist. rotor is facing the #1 at TDC. The timing gear set has both the crank and cam timing marks at 12 oclock at TDC. W_A_Watson also wrote:

[QUOTE]
"The best way to properly re-set the timing is to pull the left side valve cover, timing chain cover and rotate the engine to TDC to align the marks and notice as it approaches this point which valve closes, the intake or exhaust. If it's the intake, you are good, if the exhaust you have an issue."

The intake valve is opening and closing before the #1 piston starts to rise on the compression stroke. Both valves are closed during the actual compression stroke.

Sound like I'm good? Here are some photos of the alignment. Also added one of the truck. Thanks

http://i327.photobucket.com/albums/k479/Rinehart_photo1/Valves_4-28-14_zpsa52231df.jpg
http://i327.photobucket.com/albums/k479/Rinehart_photo1/TimingSet_Alignment_TDC_zps363f76ab.jpg
http://i327.photobucket.com/albums/k479/Rinehart_photo1/Rotor-TDC_zps16781062.jpg
http://i327.photobucket.com/albums/k479/Rinehart_photo1/77Powerwagon_zpsdfc2a2fa.jpg

[W_A_Watson_II]

If the above image was taken when you think the engine is at TDC compression on #1, then you DO NOT have it properly timed.

At TDC on #1 compression the timing marks should be pointing at each other. The Cam at 6 o'clock, and the crank at 12 o'clock.

Oh, it's a beautiful truck!

[04 Diesel]

Well? Did you get your truck fixed and back together and yes nice truck.

[78Power]

77 PW 318 timing question

Hey everybody. I finally had time today to look at the timing. Dr. Watson gave me the hint about the intake valve timing on the #1 TDC.
As I think it goes, the #1 and the #6 both reach TDC at the same time during rotation. One overlaps the other with an exhaust stroke.
The way my truck is now, the #6 cylinder's intake is opening right before compression. The #1 cylinder's intake valve closes before it's compression with the crank dot at 12 oclock.
This is with the rotor facing the #6 wire and the timing gear alignment dots facing each other.
So, do I try and change alignment, or re-wire distrib?
http://i327.photobucket.com/albums/k479/Rinehart_photo1/TimingGearSet5-2-14_zps1b210ed3.jpg

[W_A_Watson_II]

With the timing marks correctly aligned as in this last photo, and the #1 intake having closed before getting to this point, I'd pull the distributor and properly re-install it indexing it correctly.

However, before you do that, have you pulled the rotor off and made sure it wasn't installed on the shaft wrong?

Also, did the truck run with everything lined up like this before you did the timing chain change.

[78Power]

77 PW 318 timing question FIXED

Update on the timing problem. I ended up rotating the dist. so rotor is pointing to #1. Put everything back together, and after just a little adjustment, it's running good. The two worst things we did was take the plug wires off and move cam/crank with chain off. Thanks to W_A_Watson_II and 04 Diesel for the help.

[W_A_Watson_II]

Great to hear it's back alive!

[04 Diesel]

Update on the timing problem. I ended up rotating the dist. so rotor is pointing to #1. Put everything back together, and after just a little adjustment, it's running good. The two worst things we did was take the plug wires off and move cam/crank with chain off. Thanks to W_A_Watson_II and 04 Diesel for the help.

Glad you got her going again.