Finding dead center

jblot

Member
I'm putting a new timing chain on and I know that the cam gear rotated while the bottom gear didn't. So many teeth were broke off the factory cam gear that the chain was really loose. I have everything off the engine up to the block itself, including the oil pan. How can I line up the cam, and set to dead center?
 

bison

Moderator
Staff member
I'm putting a new timing chain on and I know that the cam gear rotated while the bottom gear didn't. So many teeth were broke off the factory cam gear that the chain was really loose. I have everything off the engine up to the block itself, including the oil pan. How can I line up the cam, and set to dead center?

Put the new cam and crank gear on without the chain and line them up. Then pull them off and put the chain on with them.
 

pacecarta

LOGGED OUT
Staff member
Put the new cam and crank gear on without the chain and line them up. Then pull them off and put the chain on with them.



dont turn the cam with the rockers on

align crank keyway so its pointing at the center of the #1 piston , thats TDC
put crank gear on and dot should be pointing straight up at top

with cam gear on cam (will only go on one way) and rockers free , rotate until dot on gear is straight down at bottom

remove gears and install oiled chain making sure to have no slack in chain on driverside of gears and that dots are aligned , if using stock (or stock replacement ) chain set and using tensioner install it and rotate engine (easier with plugs out ) and make sure dots realign after rotation
torque cam bolts to 31ft/lbs with loctite on threads

dont forget the oil slinger disc on crank or the cam button spring (get the newer roller cam button ) in cam shaft end

and after cover is on and crank hub make sure to torque crank bolt to 219 ft/lbs and dont forget to drop the pan and clean the old shredded nylon timing gear off the oil pickup and out of the pan
 

bison

Moderator
Staff member
dont turn the cam with the rockers on

align crank keyway so its pointing at the center of the #1 piston , thats TDC
put crank gear on and dot should be pointing straight up at top

with cam gear on cam (will only go on one way) and rockers free , rotate until dot on gear is straight down at bottom

remove gears and install oiled chain making sure to have no slack in chain on driverside of gears and that dots are aligned , if using stock (or stock replacement ) chain set and using tensioner install it and rotate engine (easier with plugs out ) and make sure dots realign after rotation
torque cam bolts to 31ft/lbs with loctite on threads

dont forget the oil slinger disc on crank or the cam button spring (get the newer roller cam button ) in cam shaft end

and after cover is on and crank hub make sure to torque crank bolt to 219 ft/lbs and dont forget to drop the pan and clean the old shredded nylon timing gear off the oil pickup and out of the pan
good point about the rockers.
 
what will happen if the cam gear is turned w/the rockers on?


Not sure what Paul had in mind, but if the crank and cam are not in sync (i.e. they are not properly connected by the timing chain) and you use enough force to rotate the cam with the valve train intact, you may damage something if a valve comes in contact with a piston.
 

Daniel Jost

Squirtin six
Not sure what Paul had in mind, but if the crank and cam are not in sync (i.e. they are not properly connected by the timing chain) and you use enough force to rotate the cam with the valve train intact, you may damage something if a valve comes in contact with a piston.

I think you both mean the same thing, these are interference engines, so if you force the cam to move with rockers on it will bend valves.. Also its just easier to turn it with no load on it.

Dan
 
Does anybody know how to get the crank gear off? Is there a special tool or something?

It should just slide off. Not sure why yours isn't cooperating?

Does it appear that something is holding it on...like corrosion or the alignment key or physical damage or an obstruction or something else????

Try gently tapping it (striking the gear teeth) with a soft mallet to see if that persuades it to move.

A picture always helps. Maybe someone will see something that could be the problem.
 

jblot

Member
bottom view, top view, front view.
I put some grease around the gear to try and slide it off, it only moves 1/4th of an inch back and forth
 

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DR BOOST

Technical advisor
you can pull the key out of the crank with a pair of pliers or tap the side of it closest to the gear with a hammer.

that should free up the gear.
 

mikestertwo

Well-Known Member
You could put a gear puller on it to pull it off. You might have a worn key or there is a raised spot on the crank snout.
 

jblot

Member
Is there a way to determine tdc while looking at the engine from the bottom up w/the oil pan off?

I just want to make sure everything is right, so I don't tear anything up. I know the cam gear turned while the crank/balancer gear stayed stationary.
 

RmvBfrFlght

Well-Known Member
Is there a way to determine tdc while looking at the engine from the bottom up w/the oil pan off?

I just want to make sure everything is right, so I don't tear anything up. I know the cam gear turned while the crank/balancer gear stayed stationary.

No need to. Turn the crank to put the dot at 12 o'clock. Then turn the cam to put the dot at 6 o'clock. Of course back off the rockers as mentioned before doing this.

Once at 12 & 6 o'clock install the chain. Now one crank revolution will put the cam dot at 12 o'clock. This is TDC # 1.

A second crank revolution will put the cam dot back at 6 o'clock. This is TDC #4.

RemoveBeforeFlight
 

gczarny

fast is cool !
bottom view, top view, front view.
I put some grease around the gear to try and slide it off, it only moves 1/4th of an inch back and forth

I hope your pics here show just greased up crank pulley removal problem and NOT aligment of crank key to cam gear dot that you going to use with the chain later ?:eek:
 
Also from your pictures...

I don't know what timing set you're going with, but your stock style chain tensioner is...uhmm...gone. Where is it?:confused: Chewed up over the years????

Anyway. if you're using a stock style timing set, you might want to to put a new tensioner on there. If you're going with an aftermarket set (like a double roller) that isn't a flat backed chain, then you can leave the tensioner out of the setup.
 

gczarny

fast is cool !
Also from your pictures...

I don't know what timing set you're going with, but your stock style chain tensioner is...uhmm...gone. Where is it?:confused: Chewed up over the years????

Anyway. if you're using a stock style timing set, you might want to to put a new tensioner on there. If you're going with an aftermarket set (like a double roller) that isn't a flat backed chain, then you can leave the tensioner out of the setup.

I plus that.... but also would like to add that with double roller you MUST leave the tensioner out or .......is it why it is gone in the first place ?:confused:
 
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