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Discussion Starter #1
Hi Guys,

I am in the middle of doing a head swap on my 95 T-Bird LX 4.6 2V with rebuilt PI heads that I pulled from a Grand Marquis. I realized that I could bend valves..
Here is more information:

1) The heads are torqued down.
2) I tried to make sure the pistons were down in the bore before I placed the heads on, but the crank key way is around 6:00.
3) There are no chains or other timing components installed yet.
4) The Right Cam sprocket looks like its near the correct location around 11:00. However, the Left Cam sprocket is off and looks like it needs to be rotated back a turn.
5) I have not rotated the crank or the cams any since the heads were installed.

Here are my Questions:

1) Do you think I have already bent any valves based on the positions of the cams and crank?
2) What's the best way to rotate the Cams to the correct timing position without bending any valves?
3) Should I remove the cams and followers on both sides in order to time the engine at this point?
4) How do I get the crank back up to TDC once the cams are in the correct position ?

Thanks - I am a little green but any help will be greatly appreciated.


IMG_2206.JPG
 

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Super Moderator
1997 Thunderbird 4.6, 1998 Mark VIII LSC
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If none of the pistons were near the top of the bore when you put the heads on, I wouldn't be concerned about PTV contact. I can't say off the top of my head what the pistons would look like with the crank keyway at 6:00 though.

Assuming condition 1 (pistons not at the top) then you can rotate the cams freely if the heads are torqued. You can just loosen the cam tower bolts to take the pressure off the springs/valves to get the crank to TDC so you can match up the black marks on each chain to the marks on the cam and crank gears. Attached is what this looked like on mine when I put my heads on with TFS adjustable crank gears a number of years back. It looks like I had the crank keyway at about 10:30-11 which is just a bit after TDC in this photo. The crank gear mark would be at about 6:00 in this position.

39716
 

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1991 Mercury Cougar LS 5.0 in restoration
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If the chains are not on the cam sprocket, valves are not opening and closing, so there should be no PTV issues.
 

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1994 Cougar XR7 DOHC/5-Speed
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9 o clock and 3 o clock are the “safe” positions on the keyway where no piston is at TDC IIRC. Personally I absolutely will not install modular heads with the valves open like that, not for PTV reasons(Actually more like “anything to valve“ ATV if anything in the interim) but because the springs will fight you aligning the chains, constantly pushing the cam out of alignment with the markings and it’s very easy for them to jump time when it happens if you didn’t activate the tensioners yet.

So much less hassle in the long run to pop out the followers and pop them back on base circle in the safe positions. All you need to do it is a large flathead screwdriver

If the chains are not on the cam sprocket, valves are not opening and closing, so there should be no PTV issues.
Maybe on that dinosaur 5.0 of yours lol
 

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1991 Mercury Cougar LS 5.0 in restoration
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You can go ahead and delete that comment, now that I feel stupid. Cam in head= valves opened, got it!

So install heads, then cams?
 

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Discussion Starter #6
Thanks that helps a lot! So to clarify:

1) Loosen the cam tower bolts on both sides but don't completely remove them?
2) In the photo you mentioned your crank keyway was set a little past TDC....is it ok to time it like that or did you rotate it back to TDC to time it?

Thanks again, this is very helpful!
 

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Discussion Starter #7
The last post/question was for theTerminator93. Thanks XR7-4.6. for your response also; so you are recommending at this point removing the roller followers? (I've done that on a 4.0 before and believe you have to keep them order) and I have the Ford valve spring compressing tool.

Questions for clarity:
1) leave the cams on but remove roller followers?
2) Would it be best to remove the followers then move the crank to a safe position, then complete timing?
3) Install roller followers back with cam lobes on base circle after chains back on?
4) Move crank back to TDC and torque all timing components?
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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The goal is to keep the valves from being depressed by the cam, and to keep the springs from pushing on the cam lobes as well to ensure it can be spun freely.

Loosening the cam caps OR popping out the followers is sufficient. You need not do both.

The crank doesn't have to be EXACTLY at 10:30 to time it (especially if the valves aren't engaging), just so long as the opposite ends of the timing chain line up to the respective marks on the cam and crank gears.
 

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1994 Cougar XR7 DOHC/5-Speed
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1)You don’t need any special tool like a valve spring compressor to remove the followers, just a large flathead screwdriver to pop them off - you basically insert the tip under the lash adjuster end and twist, and the follower will pop off towards the valve stem where you can easily remove it, alternatively you can simply take the cam out and reinstall the cam after they’re all removed.

2) you want it in the safe position to remove(and install) the followers. When the followers are out then move the crank to #1 TDC to time the chains

3) move the engine back to the safe positions, either 3 o clock or 9 o clock, (you’ll be rotating it a few times to find base circle) and install the followers only in these positions. Here you install them loosely under the cam and using your screwdriver as a lever pivoting on the cam lobe the tip will push against the domed portion of the follower to position it on the lash adjuster (Put duct tape on the screwdriver to not scratch the cam lobe)

4) at this stage it doesn’t matter where the crank is, just slowly rotate it around Clockwise to make sure there isn’t any resistance, after 20 something rotations your timing marks will line back up, which will verify your work.
 
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