cam shaft

Decipha · #1 08-31-2006, 03:30 AM

lets say i removed the timing chain cover on my 4.6 removed the timing chain and spun the cam shaft a full rotation, then lined up the crank shaft and cam shaft and put the timing chain back on... whats the chances of the engine starting up? do you think i bent a valve by turning the cam shaft even though the engine wasn't running?

Towncar · #2 08-31-2006, 10:50 AM

Quote:

Originally Posted by Decipha

lets say i removed the timing chain cover on my 4.6 removed the timing chain and spun the cam shaft a full rotation, then lined up the crank shaft and cam shaft and put the timing chain back on... whats the chances of the engine starting up? do you think i bent a valve by turning the cam shaft even though the engine wasn't running?

Can't be done, not directly the way you put it --

1) There's not one Timing Chain, there's two -- one to each Overhead Cam.
2) There's not one Camshaft, there's two -- you can't spin "the" Camshaft, it's one or the other.

Let's say you removed one Timing Chain, presumably the passenger side since it comes off first, then you tried to "spin" the 1-2-3-4 Camshaft.

There's a hit & miss chance in theory, that the Camshaft 'could' turn 360 degrees back to where it was to begin with however, in actual practice that would proove quite difficult, not impossible but difficult. Remember you'd be fighting the resistance of all the Valve Springs at this point.

I say hit & miss because you also may have some Pistons parked in the operating path of the Valves.. Is a Valve, combined with the strength of your hand tools, strong enough to move a Piston out of it's path, and not bend the Valve stem.. hmmm. In rare cases the Valve hitting a Piston in this scanerio, might cause the Piston to turn the Crankshaft (and all the other pistons) and not bend the Valve stem.... I wouldn't try it though, not on something I intend to use. The slightest bend to a Valve stem isn't detectable by the naked eye and will cause the Valve to not seat properly. Improper seated Valves = Zero compression, or quick leak-down.

What's the chances of the engine starting after that? Well, there's a chance some Valve stems were bent, and maybe not. As for starting up, you would still have at least six unscaved cylinders IF nothing is left out of this post, I thiink the engine would start on six good Cyls.

Here's your engine layout

Decipha · #3 08-31-2006, 06:43 PM

well this is the prob... the engine i have came out of a 94 crown vic and went in to a 92 town car (i don't know if you remember my post about the engine swap) anyway, the crown vic was in a wreck and the timing chain cover was cracked, the cam shaft sproket was also cracked, and the timing chain snaped. The cam shaft is not lined up evenly with the crankshaft, its off by about 35 degrees. Not knowing it, i put the everything back together and tried cranking the engine, for some reason it won't start, no fuel, and no fire. Do you think if i pull the engine back out and realign the cam shaft with the crankshaft it will start? do you think it will run right? Or do you think I just say fuk it and get another engine? if so how hard is it to swap a 5.0 out of a 91 vic into a 92 town car??? I kinda needa finish up on this car by the end of next week.

Decipha · #4 08-31-2006, 06:45 PM

oh just so you know, after i put the engine in the town car we tried cranking it for about 30 min, the car wasn't getting fuel nor fire though.. do you think it bent something? didn't sound like anything unusally while it was trying to start (except for no fire)

Towncar · #5 09-02-2006, 08:47 PM

Quote:

Originally Posted by Decipha

...the car wasn't getting fuel nor fire though.. do you think it bent something? ...

Spark and Fuel delivery can be a number of problems, none include bent valves.

A leak down test in each Cyl will tell more.

The fuel and spark issues are seperate.

rhandwor · #6 09-16-2006, 08:58 PM

Go to an automotive machine shop and ask some engines if you break a chain will bend valves some won't the rebuilder will know this. If it doesn't normally bend valves buy your parts from him cheaper than the dealer.
After it is put together check compression in each cylinder. If it passes this test. Then do a spark test if no spark put an ohm meter on the camshaft position sensor it goes from 0 to 1 check the crankshaft position sensor.
If the valves are bent I would have the machine shop fix the head.
Think and take your time or pay to get it done. Buy a manual for your vehicle and read it before you start.
Junk yards will take you to the cleaners on used engines. All they know is the mileage on the vehicle. They also don't pay for your labor like a good rebuilder.

Decipha · #7 09-19-2006, 06:22 PM

alrite well the computer problem is solved, i jumped off the ground on the ecc relay and voila!

but now the cam shaft issue remains, does anybody have the line up diagram so i can get it back in timing??

Towncar · #8 09-19-2006, 07:17 PM

Quote:

Originally Posted by Decipha

alrite well the computer problem is solved, i jumped off the ground on the ecc relay and voila!

but now the cam shaft issue remains, does anybody have the line up diagram so i can get it back in timing??

THAT's GREAT !!! This is still the 1994 Engine correct? It's going to be a long post for those cam chains ..............

PS --
I've decided it's too much work cutting / pasting / linking all that stuff. I just took the whole section to PDF and set it on my freebie website.
>>> Here ya go <<<

Decipha · #9 09-19-2006, 07:37 PM

your telling me theres no other way to align it back correctly with out those tools??? im hoping to get this done tonight if possible

Towncar · #10 09-19-2006, 07:40 PM

I don't know, I've never had to do the job you're after....

Decipha · #11 09-19-2006, 07:43 PM

yes sir it is still the 94 4.6L engine out the crown vic

Decipha · #12 09-19-2006, 07:46 PM

ohh hmm on the chain itself there are bright links, the haynes manual says align the bright link with the dimple on the cam shaft and align the bright link with the alignment mark on the crankshaft, i don't see any logically way it can be installed wrongly, perhaps i haven't thought of it entirely

btw... should i put on the passenger side camshaft and crankshaft, then turn the crankshaft counterclock-wise until its properly aligned with the driver side cam shaft? it would hurt anything turning it backwards would it?

Towncar · #13 09-19-2006, 07:50 PM

Quote:

Originally Posted by Decipha

btw... should i put on the passenger side camshaft and crankshaft, then turn the crankshaft counterclock-wise until its properly aligned with the driver side cam shaft? it would hurt anything turning it backwards would it?

That PDF says one way only, I can only imagine that there's going to be a valve in the way if you go the wrong way.

rhandwor · #14 09-19-2006, 08:02 PM

The one tool is used to block the cam shaft which could be done with two pair of vise grips if your are careful. The car companies work with the tool companies but if everything lines up it should work double check with the manual. They want you to go to the dealer. Their should aslo be a chain tensioner. Unless it is very tight.

Decipha · #15 09-19-2006, 09:26 PM

i don't see why you need to hold it, its not like it'll move any, its damn near impossible to budge even with an impact it won't move any

im going to try to line it up, im going to put the timing mark at 6 on the crankshaft then throw on the passenger side which i know it already timed correctly, then turn the crankshaft backwards until the camshaft on the driver side lines up with the crankshaft... sounds good? or should i turn the camshaft backwards until it lines up?

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