Timing questions

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Apr 2, 2011 | 07:09 PM

kevin316

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From: Grande Prairie, Alberta

Timing questions

I had to pull the timing gears off to fix a mistake my son made when rebuilding his 460 in school. When I reinstalled it I made sure #1 was tdc. The mark on the crank gear was at 12 o'clock and I set the mark on the cam gear to 6 o'clock. (I have no information for the cam).

I got everything buttoned up but I can't get it to fire. I checked the timing with a light and it is firing on TDC. I pulled #1 plug and I have spark but, when I put my finger over the plug hole I get spark then my thumb is pushed off by compression.

My question would be, shouldn't I be getting spark just as I am getting compression? Should my timing marks have been at 12 o'clock on both gears?

I would guess yes but it is quite a bit of work to change it so I want to be sure before I go and change it.

Apr 3, 2011 | 04:41 AM

ArdWrknTrk

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From: EXTREME southwest CT

Is the cam timed 180* out? -The crank is at 12 o'clock twice in one cam rotation.
Pull the passenger side valve cover and make sure both valves are closed on #1 when the crankshaft keyway is pointing up.

Welcome to the forum Kevin.

Apr 4, 2011 | 12:39 PM

mcdonaldm

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From: Edmonton, Alberta Canada

actually your cam can't be out if you line up the two marks. the crank does make 2 revs to 1 rev for the cam so they will always line up in the same spot (at 1 complete rev of crank, the cam mark should only go 180deg), but since the piston is at TDC in both spots as long as the marks line up the cam is phased properly. when the engine was rebuilt, you didn't change the balancer and timing marks as there are different blancers and timing mark combos.

that being the case, did you put the gear on the cam in the right position? there is a dowel pin that puts the gear on in the correct spot, did you use the dowel pin.

another thing, do you have the distributor out 180 deg? this is a lot more common then having the cam installed wrong. is it wired correctly? remember a Ford does not use the same cyl numbering as a Chev and the #1 cyl is front passenger side with cyl 2-4 on pass side and 5-8 on drivers side.

sounds more like the dist was not reinsatlled correctly.

rgds
Mike

Apr 4, 2011 | 04:32 PM

kevin316

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From: Grande Prairie, Alberta

Thanks guys. I am going to double check the valves on #1 to make sure I do have the marks lined up but I am 99% sure I do.

I checked the wires and everything checks out. Like I said in my post I have to crank the distributer all the way to the right to get it TDC so I might pull it again just to get it more centered. A couple of times it sounded like it wanted to start but then it would just backfire. I will check everything out again and see what happens.

Just so I'm clear. I want to start at TDC and slowly rotate the distributer to the left (CC) until it fires, correct?

Apr 4, 2011 | 05:15 PM

ArdWrknTrk

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From: EXTREME southwest CT

You want to check that the keyway is at 12 o'clock and the timing pointer shows TDC.
If not, your balancer has slipped and the marks mean nothing.
Drop the distributor in so that after it engages the cam and is fully seated, the rotor points to the #1 terminal on the cap.
I try to start at 10* BTDC, but if you're having a problem backfiring through the carb perhaps it's best to start at 0.
You can shift the timing by 45*if you move all the wires one post over. This might get you to where you have a useable portion of the distributor adjustment.

Apr 10, 2011 | 06:54 PM

kevin316

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From: Grande Prairie, Alberta

I pulled the passenger side valve cover off to check and make sure that the valves on #1 were closed when I was at TDC. They are but I am 180 degrees out on the distributor. I don't think the engine was tuned over after getting the chain installed but unless I screwed up when I lined up the marks it must have been.

My question is, if I was out on the orientation of the marks (both at 12 o'clock or whatever) can I damage something by trying to start it? I would guess no but I hate to guess on something like this.

Should I pull the timing cover to double check the marks? I don't want to if I don't have to.

Apr 10, 2011 | 09:08 PM

kevin316

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From: Grande Prairie, Alberta

I gave it more thought and drew a picture then gave it more thought and it shouldn't make a difference. As long as the crank is TDC and cam is timed to it it shouldn't matter if the marks were at 12 o'clock or 6 o'clock.

I fired it up and it runs!