Replacing Timing Chain

Posted By: wtucker

Replacing Timing Chain - 01/08/09 12:40 AM

Do you need anything special to replace your timing chain, cam and crank gears? The bolt on the cam gear came loose, and the cam gear broke, so I'm not sure where the timing is. Is it just a matter of lining up the marks on the gears. Or does it need to be at TDC, then the gears put on and marks lined up? Do I need a cam degree wheel to degree the cam?

Posted By: stumpy

Re: Replacing Timing Chain - 01/08/09 12:42 AM

If it is a stock set up just align the marks and you are good to go. Crank dot at 12 o'clock cam dot at 6 o'clock.

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/08/09 12:43 AM

Don't worry about piston location if you are lining up the dots. That will take care of itself. If you degree the cam you need to TDC it and and need a degree wheel, dial indicator, and pointer.

Posted By: wtucker

Re: Replacing Timing Chain - 01/08/09 01:11 AM

So if I line the OEM dots up I don't need to degree the cam, just put the gears on, line the marks up and tighten it down? What's the purpose of degreeing the cam?

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/08/09 01:54 AM

More accuracy. If you are not running for top performance lining up the dots is (IMO) good enough.

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/08/09 03:59 AM

Call Summit and get their degree kit. It isn't much and has all the stuff you need.

If you need help there are plenty of us that can help.

Not degreeing the cam in is asking for trouble. Sure a hundred on here will say it has never bit them. But it is like playing with fire.

Besides it doesn't take long and it does seperate the men from the boys. If you have trouble getting the eninge to run right later, one of the first things you will be asked is what the cam is degreed at. You will lose a bunch of time by not doing now.

Posted By: Anonymous

Re: Replacing Timing Chain - 01/08/09 04:26 AM

Quote:

Call Summit and get their degree kit. It isn't much and has all the stuff you need.

If you need help there are plenty of us that can help.

Not degreeing the cam in is asking for trouble. Sure a hundred on here will say it has never bit them. But it is like playing with fire.

Besides it doesn't take long and it does seperate the men from the boys. If you have trouble getting the eninge to run right later, one of the first things you will be asked is what the cam is degreed at. You will lose a bunch of time by not doing now.

I say horse manure. I'd bet you money you can't find one engine in a thousand on which the factory keys (on the crank and cam) are far enough off to warrant degreeing a cam. When someone DOES degree a cam, it's to try and improve performance from that tiny bit of factory error, and even THEN it won't do you much good unless you "know what you started with." In other words, even if the cam is a little off from perfect (manufacturer's specs), the fact that it's advanced or retarded a degree or two JUST MIGHT make it run "better" for your application.

Also, (generally, don't know specifics) some engines built in the "smog years" had special timing sets OR cams that had retard built in compared to earlier cams for smog control.

Line up the marks on the drive, and make sure the drive isn't a "multi mark" performance drive that IS designed to play with cam timeing. Also know that timing drives for these motors ARE NOT "no1 ready to fire", they are "no6 ready to fire." What this means is, that if you line up the marks, and DO NOT move the engine before you plant the distributor, you need to put the dist in to fire no6

One thing that CAN benefit you (so far as errors) is to use a "positive stop" to check the factory timing marks. This will ensure that if you set the timing to X degrees, it the timing will actually be where you set it. This is easy. Cut the crimp off an old plug, and tack weld a 3/8 nut in the back, and stick a 3/8 bolt through the thing so you can adjust the bolt. Insert the plug in no1 plug hole, and rotate the engine with a wrench, gently, until it stops. Make a temporary mark on the wheel under the TDC tab. Do the same in the opposite (CCW) engine rotation. When you get done, you'll have TWO marks some distance apart. EXACTLY in the middle is the "true" TDC.

Posted By: minivan

Re: Replacing Timing Chain - 01/08/09 04:33 AM

First off may I say I have never degreed a cam, but I have never had a race car engine either.

My mechanic friend got a timing set for his olds 455 race motor that was so far off ( when lining up the marks) he had to send it back for another timing set.. It does happen...

Posted By: RapidRobert

Re: Replacing Timing Chain - 01/08/09 05:34 AM

I would degree it, it will increase your skill level & you will KNOW its right & you'll know the procedure when you get into wilder cams. As 440sixpack said a positive stop is very important & if your heads are installed Mancini sells the spark plug positive stop for cheap & I would add a 5 cent green or yellow(I forget which) plastic vacuum cap to the stop to keep from possible nicking the aluminum piston top & turn the timing marks to 5BTDC then screw in the stop until it firmly contacts the piston then turn the crank by hand in the other direction & see if the piston stops at 5ATDC. With that being said I've never(yet) encoounterd an error greater than 1 degree but others have found major machining errors & I dont leave ANYTHING to chance.

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/08/09 12:21 PM

Quote:

Call Summit and get their degree kit. It isn't much and has all the stuff you need.

If you need help there are plenty of us that can help.

Not degreeing the cam in is asking for trouble. Sure a hundred on here will say it has never bit them. But it is like playing with fire.

Besides it doesn't take long and it does seperate the men from the boys. If you have trouble getting the eninge to run right later, one of the first things you will be asked is what the cam is degreed at. You will lose a bunch of time by not doing now.

Horse apples. Look at how many cars are on the road. there isn't a one of them that are degreed from the factory. Heck the assemblers probably don't know what it means. About the only engines that have the cam degreed are the all out performance builds where every little thing is tried to be knats a&& perfect. Not even if you buy a reman engine is degreed. For a driver you won't gain enough to tell the difference in performance or mileage to warrant buying a kit or spending the time to get the job done.

Posted By: 4BBodies

Re: Replacing Timing Chain - 01/08/09 07:06 PM

Another option for you would be to buy a timing gear set that has 3 slots on the crank gear.........1 for straight up, 1 for 4 degrees advance, and 1 for 4 degrees retard. This is what I did with my 340, with some advice from guys in here (I would probably have better luck degreeing a toaster) and ended up running it straight up. It runs excellent, but I always have the option of going in later and advancing or retarding the gear.

Posted By: RapidRobert

Re: Replacing Timing Chain - 01/08/09 07:15 PM

Quote:

I always have the option of going in later and advancing or retarding the gear.

& I would suggest checking the V/P clearance at both of those points so no surprises later.

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/08/09 09:53 PM

As I said, the men are seperated from the boys by simply doing this. C'mon boys, man up and degree your cam next time.

BTW, the Summit kit comes with the spark plug stop.

Posted By: stumpy

Re: Replacing Timing Chain - 01/08/09 10:18 PM

I've built over 500 engines and replaced twice that many timing chains and belts and I guess I'm still a boy because the only ones I ever degreed in were race motors. It's not necessary for a daily driver street engine.

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/08/09 10:52 PM

Quote:

I've build over 500 engines and replaced twice that many timing chains and belts and I guess I'm still a boy because the only ones I ever degreed in were race motors. It's not necessary for a daily driver street engine.

A lot of years and motors behind me.

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/08/09 11:16 PM

Attention to detail is important. Don't kid yourself.

Ever wonder why a given car/truck is a dog? Attention to detail.

I bet the nondegree crowd sets timing "by ear".

Posted By: stumpy

Re: Replacing Timing Chain - 01/08/09 11:25 PM

Doing it my way got me an national ss/b record in AHRA in 1966. Have you set a national record yet? Yeah it was tuned by ear.

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/08/09 11:45 PM

This is getting funny. Some of you guys act like degreeing a cam is some sort of high science.

I couldn't care less what you did 40 years ago. Giving a rookie advise like skipping simple check work is crap. It takes a very few minutes to due. Not doing it is just plain LAZY.

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/09/09 12:22 AM

Quote:

This is getting funny. Some of you guys act like degreeing a cam is some sort of high science.

I couldn't care less what you did 40 years ago. Giving a rookie advise like skipping simple check work is crap. It takes a very few minutes to due. Not doing it is just plain LAZY.

Try for more than 40 years. Experience works. Parts are probably closer to specs now than they were then and it worked then as it does now. You sound like one that thinks that every engine out there off the line has been degreed. Yep I am getting lazier by the year. You will to.

Posted By: HemiStan

Re: Replacing Timing Chain - 01/09/09 12:44 AM

wtucker,
I live up in Newport News. Shoot me a PM with your number and I can talk you through putting that timing chain in.

Stan

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/09/09 01:43 AM

Quote:

Quote:

This is getting funny. Some of you guys act like degreeing a cam is some sort of high science.

I couldn't care less what you did 40 years ago. Giving a rookie advise like skipping simple check work is crap. It takes a very few minutes to due. Not doing it is just plain LAZY.

Try for more than 40 years. Experience works. Parts are probably closer to specs now than they were then and it worked then as it does now. You sound like one that thinks that every engine out there off the line has been degreed. Yep I am getting lazier by the year. You will to.

It is just poor advise to tell a newbie that it isn't needed. What if he gets off a tooth? Not hard to do when you don't have 40 years experience. I just hate to see something so simple get pushed aside. If he has a problem later, guess what, the installed centerline will be asked and he will have to pull it apart again to check. MUCH easier to do now.

Ever have a "factory freak" or a "dog"? Details do matter.

Posted By: dartgame

Re: Replacing Timing Chain - 01/09/09 02:53 AM

If you want to save some money and do not want to check the center line - at least compare your old timing sets gears and marks to the new ones on the replacement set. At least you'll then have some idea if the marks are out of whack.

Once upon at time I had a name brand timing set that was mismarked. I installed it and low and behold the motor ran like crap. I pulled it apart and found one of the marks was a tooth off. Ever since then I check the centerline on every build I do. Better to know, than not know.

Posted By: wings471

Re: Replacing Timing Chain - 01/09/09 03:10 AM

Quote:

wtucker,
I live up in Newport News. Shoot me a PM with your number and I can talk you through putting that timing chain in.

Stan

You can't beat a generous offer like that. The opportunity to learn how to do something like this just makes your mechanical knowledge greater and will aid in understanding other related technical questions/problems

...do it.

Posted By: fastmark

Re: Replacing Timing Chain - 01/09/09 03:14 AM

Quote:

If you want to save some money and do not want to check the center line - at least compare your old timing sets gears and marks to the new ones on the replacement set. At least you'll then have some idea if the marks are out of whack.

Once upon at time I had a name brand timing set that was mismarked. I installed it and low and behold the motor ran like crap. I pulled it apart and found one of the marks was a tooth off. Ever since then I check the centerline on every build I do. Better to know, than not know.

Amen from the cheap seats. You guys can brag all you want to about building a thousand or a million motors. I started about 30 year ago and have built maybe a hundred or so. I have found TWO motors that the timing marks were off from the factory. They were both 340 factory sets or may have been replacement sets. One was off 8 and the other off 16 degrees. The friend with the 16 degree off motor always wondered why it ran like crap. I have found a few aftermarket sets needing as much as 4 degrees to correct.I would say the chances are less than 2-3% it would be off more than a few degrees, but it can happen. Degreeing a cam is not rocket science and is just the first step in learning how to blueprint motors. Buying mics and tools will make it enjoyable to build motors. Get busy and learn.

Posted By: 70dart360

Re: Replacing Timing Chain - 01/09/09 03:31 AM

Quote:

This is getting funny. Some of you guys act like degreeing a cam is some sort of high science.

I couldn't care less what you did 40 years ago. Giving a rookie advise like skipping simple check work is crap. It takes a very few minutes to due. Not doing it is just plain LAZY.

If its stock dude whats the use? Its gonna be a pig anyway ya look at it. And as far as valve to piston clearance in a stocker Mopar? Whatever, the dang piston is 1/4 inch in the hole. Say what ya want, but I been a master mechanic for 25 years and unless its a performance engine why waste the time and try to confuse they guy? Never seen someone degreee a cam in a stock engine doing a basic timing chain job. You must be one of those shop owners that suck every red cent out of their customers for worthless extras!

Line your dots up man and run with it.

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/09/09 04:13 AM

Quote:

Quote:

This is getting funny. Some of you guys act like degreeing a cam is some sort of high science.

I couldn't care less what you did 40 years ago. Giving a rookie advise like skipping simple check work is crap. It takes a very few minutes to due. Not doing it is just plain LAZY.

If its stock dude whats the use? Its gonna be a pig anyway ya look at it. And as far as valve to piston clearance in a stocker Mopar? Whatever, the dang piston is 1/4 inch in the hole. Say what ya want, but I been a master mechanic for 25 years and unless its a performance engine why waste the time and try to confuse they guy? Never seen someone degreee a cam in a stock engine doing a basic timing chain job. You must be one of those shop owners that suck every red cent out of their customers for worthless extras!

Line your dots up man and run with it.

Posted By: mickm

Re: Replacing Timing Chain - 01/09/09 04:42 AM

or how about, if he feels like getting more technical and learning something new, degree it.

if he doesn't, don't.

problem solved.

Posted By: Anonymous

Re: Replacing Timing Chain - 01/09/09 04:47 AM

Quote:

Quote:

Quote:

This is getting funny. Some of you guys act like degreeing a cam is some sort of high science.

I couldn't care less what you did 40 years ago. Giving a rookie advise like skipping simple check work is crap. It takes a very few minutes to due. Not doing it is just plain LAZY.

Try for more than 40 years. Experience works. Parts are probably closer to specs now than they were then and it worked then as it does now. You sound like one that thinks that every engine out there off the line has been degreed. Yep I am getting lazier by the year. You will to.

It is just poor advise to tell a newbie that it isn't needed. What if he gets off a tooth? Not hard to do when you don't have 40 years experience. I just hate to see something so simple get pushed aside. If he has a problem later, guess what, the installed centerline will be asked and he will have to pull it apart again to check. MUCH easier to do now.

Ever have a "factory freak" or a "dog"? Details do matter.

This is absolute nonsense. FIRST degreeing a cam won't do much good if you don't know what you started with. That is, it might run better on the factory marks, anyhow.

SECOND just because you didn't degree the damn thing does not mean you'll "get it off a tooth."

Please don't make fun of 40 years experience. Engines pretty much work the same way now as they did 40 years ago, WAIT!!! WAIT!!! WE ARE talking about a 40 year old engine!!!!

I'll guarantee you that the thousands of 340's 440's 383's and probably street hemi's that went down the production line NEVER SAW A DEGREE WHEEL. The factory assembly line folks slapped the sprocket "on the marks" and down the line it went.

AND ONE LAST TIME. If you get the cam "on the marks" degreeing will NOT do you any good until you have a baseline. Depending on whether this is a "torque monster" street engine or an RPM screamer, you won't know which way to push the wheel until you find the baseline.

From the sounds of the original poster, I doubt that he has access to a chassis dyno, and neither do most of the rest of us.

Posted By: fastmark

Re: Replacing Timing Chain - 01/09/09 05:09 AM

Quote:

I'll guarantee you that the thousands of 340's 440's 383's and probably street hemi's that went down the production line NEVER SAW A DEGREE WHEEL. The factory assembly line folks slapped the sprocket "on the marks" and down the line it went.

AND ONE LAST TIME. If you get the cam "on the marks" degreeing will NOT do you any good until you have a baseline. Depending on whether this is a "torque monster" street engine or an RPM screamer, you won't know which way to push the wheel until you find the baseline.

This is my point exactly.If you lined it up "on the marks" as you call it, the timing marks could be off and you would never know.The only way to check the marks is to degree it. You say that you have done thousands of engines and never degreed a stock motor, then how do you know they were all correct? One of the motors that I found to be off 8 degrees was one that I had built before I started checking the cam degree. I always wondered why is had less low end torque than I expected. I agree that the chances are slim, but I have had two in my "short" 30 years of engine building.

Posted By: 70dart360

Re: Replacing Timing Chain - 01/09/09 05:14 AM

Quote:

but I have had two in my "short" 30 years of engine building.

Take all the mechanics that dont, and break it down into odds like in Vegas. Bout a million to one that it'll make a drastic difference.

Posted By: Anonymous

Re: Replacing Timing Chain - 01/09/09 05:38 AM

You say that you have done thousands of engines and never degreed a stock motor,

Just for clarity, I never said that.

The point I'm trying to make, though, is that DEGREEING a cam to whatever the grinder specked does not guarantee that is what you are going to want. So without trying it, establishing a baseline, and then deciding to advance/ retard it from there is simply shooting in the dark

Posted By: fastmark

Re: Replacing Timing Chain - 01/09/09 02:49 PM

I agree with that statement. I decided that since I was a decent engine builder, I would build my own Jr Dragster motors a few year back. I did not realize the close tolerances and severe duty that was placed on the parts. I only had one failed motor in all those years so I can safely say I was successful. One of the things I tried was changing the cam timing to kill the low end and give me better finish line power. My engine part provider said not to do it and he had his cams dialed in to the perfect degree as per his R and D. I used his cam timing for awhile and then went to my experiment. Small changes in a 50 hp 3.5 Rhino make a big difference. After that I had less trouble with tire spin and ran max mph. We were usually the fastest kids at the track. Man I miss those days.
Like I said, the marks are probably ok and just lining them up will be fine. It always pays to check.I kind of get like the mad scientist when I get mics in my hand. It's fun!

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/09/09 03:30 PM

So far no one has brought up the fact that the gear broke - where are the pieces? The pan should really really be pulled and cleaned. The threads at least checked for condition to see if they will hold or if a new cam is in order. If this is an old engine it wouldn't hurt to check bearings while the pan is off.
As for degreeing this cam it is an unknown centerline so you need a base line to start with. Put the gears and chain on and run it.

Posted By: Pacnorthcuda

Re: Replacing Timing Chain - 01/09/09 03:33 PM

Quote:

You say that you have done thousands of engines and never degreed a stock motor,

I don't build engines, but I install cams from time to time, and I want to KNOW the installed centerline so I have that baseline info. If I install a cam straight up without degreeing it I don't really know what the ICL is. Then, if some issue comes up, like a soft bottom end, or a top end that lays down early, I am left guessing if its the cam ICL or not. My last install on a Voodoo ended up 106.75 on a recommended 106 install. (yes I installed straight up) If I did not degree it, I would not know.

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/10/09 05:24 AM

Quote:

Quote:

This is getting funny. Some of you guys act like degreeing a cam is some sort of high science.

I couldn't care less what you did 40 years ago. Giving a rookie advise like skipping simple check work is crap. It takes a very few minutes to due. Not doing it is just plain LAZY.

If its stock dude whats the use? Its gonna be a pig anyway ya look at it. And as far as valve to piston clearance in a stocker Mopar? Whatever, the dang piston is 1/4 inch in the hole. Say what ya want, but I been a master mechanic for 25 years and unless its a performance engine why waste the time and try to confuse they guy? Never seen someone degreee a cam in a stock engine doing a basic timing chain job. You must be one of those shop owners that suck every red cent out of their customers for worthless extras!

Line your dots up man and run with it.

This is a performance website so...

A stock engine will need all the help it can get and if it is off it will for sure be a pig.
Why leave it to chance on the sole reason that you feel like being lazy?

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/10/09 05:25 AM

Quote:

Quote:

but I have had two in my "short" 30 years of engine building.

Take all the mechanics that dont, and break it down into odds like in Vegas. Bout a million to one that it'll make a drastic difference.

Why roll the dice?

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/10/09 05:26 AM

Quote:

You say that you have done thousands of engines and never degreed a stock motor,

Yes, you need a baseline but without doing the job you will be pondering about what to do without a clue.

Posted By: CJK440

Re: Replacing Timing Chain - 01/10/09 12:45 PM

What if the intake lobe for #1 was ground right and all the others ground off???

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/10/09 12:45 PM

Another point being like in this case it is an unknown and unknown spec. No idea what to degree it to. Yep better pull a number out of your A&& and that will be fine, it is degreed now.

Quote:

This is a performance website so..

Whoopie Poopie this is a performance sight, that being the case it is an unwarranted question for it being a stock engine. No more non performance questions asked here. Oh better run right out and degree that driver too because coming from the factory it wasn't. Suprising that they even run not being degreed.

BTW: if it makes you feel better by all means go ahead and degree it. But for a driver you won't gain squat.

Posted By: CJK440

Re: Replacing Timing Chain - 01/10/09 12:48 PM

Quote:

So far no one has brought up the fact that the gear broke - where are the pieces? The pan should really really be pulled and cleaned. The threads at least checked for condition to see if they will hold or if a new cam is in order. If this is an old engine it wouldn't hurt to check bearings while the pan is off.
As for degreeing this cam it is an unknown centerline so you need a base line to start with. Put the gears and chain on and run it.

And what about the valves??? If it broke while running I'm sure some met the pistons in a bad way.

Posted By: BSB67

Re: Replacing Timing Chain - 01/10/09 03:08 PM

"Do you need anything special to replace your timing chain, cam and crank gears?"

No

"The bolt on the cam gear came loose, and the cam gear broke, so I'm not sure where the timing is. Is it just a matter of lining up the marks on the gears."

Yes.

"Or does it need to be at TDC, then the gears put on and marks lined up?"

No.

"Do I need a cam degree wheel to degree the cam?"

Yes. You will need a degree wheel if you decide to degree your cam.

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/10/09 03:51 PM

Quote:

Yes. You will need a degree wheel if you decide to degree your cam.

And a dial indicator, a piston stop to locate true TDC, and preferably a solid lifter to measure off of.

Posted By: SomeCarGuy

Re: Replacing Timing Chain - 01/12/09 01:51 AM

Quote:

Another point being like in this case it is an unknown and unknown spec. No idea what to degree it to. Yep better pull a number out of your A&& and that will be fine, it is degreed now.
Quote:

This is a performance website so..

Whoopie Poopie this is a performance sight, that being the case it is an unwarranted question for it being a stock engine. No more non performance questions asked here. Oh better run right out and degree that driver too because coming from the factory it wasn't. Suprising that they even run not being degreed. BTW: if it makes you feel better by all means go ahead and degree it. But for a driver you won't gain squat.

Keep reaching for straws there.

Knowing the installed CL is important.
A stock engine will have a published number, but hey, don't let that spoil your "fun" in being contrary.

Posted By: MoparforLife

Re: Replacing Timing Chain - 01/12/09 02:02 AM

Quote:

Quote:

Another point being like in this case it is an unknown and unknown spec. No idea what to degree it to. Yep better pull a number out of your A&& and that will be fine, it is degreed now.
Quote:

This is a performance website so..

Whoopie Poopie this is a performance sight, that being the case it is an unwarranted question for it being a stock engine. No more non performance questions asked here. Oh better run right out and degree that driver too because coming from the factory it wasn't. Suprising that they even run not being degreed. BTW: if it makes you feel better by all means go ahead and degree it. But for a driver you won't gain squat.

Keep reaching for straws there.

Knowing the installed CL is important.
A stock engine will have a published number, but hey, don't let that spoil your "fun" in being contrary.

Do what ever turns you little fingers on your crank. But don't go telling some one that in order to replace a timing chain that htye have to go out and buy a bunch of equipment that they will only very likely only use once. PS: I am not groping at straws here but it sure seems like you are. I actually wonder if you have ever done or if you are a text book mechanic.