JD Perf. Double Roller Timing Chain

[JackFish]

"Degreeing the cam" is the way to check and see if the cam you bought actually was ground correctly and matches the advertised specifications.

It is also a means to determine the timing events of an unknown or stock cam.

The keyways allow you to adjust, or compensate the valve timing in relation to the crank as it suits your purposes. Retarding it generally creates more top-end and advancing creates more bottom-end, or torque.

Some manufacturers, like FORD, started to use cams with 4* retard during the emissions era, so advancing that type of stock cam by that amount can perk it up a bit.

 

[Patrick66]

http://www.hotrodder.com/kwkride/degree.html

like jackfish said, degreeing a cam checks for accuracy of the grind. its not the same as setting advance.

What is Meant by Degreeing the Camshaft, and Why is it Necessary?

The term "Degreeing In Your Camshaft" means you are making sure the camshaft's position in the engine coincides with that of the crankshaft, so that their rotation is synchronized. This is the only way you will know if the rise and fall of the pistons properly matches the opening and closing of the valves, so the engine will run properly. A few degrees of misalignment can affect the engine's operation dramatically.

 

[Ecovanner1963]

So If the cam was installed, and it was just Thrown in there. The tab on the end with the gear only allows for the gear to go on ONE WAY. So then you install the CRANK pulley, with the tab on the CRANK, straight in-line with the ZERO mark on the gear itself, THEN, with the trans. in neutral, rotate the crank so the 4 degree advance mark (on the CRANK gear) lines up with the DOT on the CAM gear. THEORETICALLY this would make it @ 108*? and what effect does that actually then put to the performance of the engine itself?? It just won't be to full potential? OR things could break? This is ALL HYPOTHETICAL, and probably good questions for others. So please respond with the preconceived thought that the cam was simply installed and then the above procedure followed, what is the outcome??????

 

[Lazy JW]

.... So then you install the CRANK pulley, with the tab on the CRANK, straight in-line with the ZERO mark on the gear itself, THEN, with the trans. in neutral, rotate the crank so the 4 degree advance mark (on the CRANK gear) lines up with the DOT on the CAM gear. THEORETICALLY this would make it @ 108*?...

Nope.

Please, please forget all about the degree marks on the damper until it is time to set the ignition timing.

You really, really need to follow the link that AzCoupe provided and educate yourself as to just exactly what it means to "degree a cam". Then we can help you with any questions afterward.
Joe

 

[Ecovanner1963]

I am NOT talking about the marks on the Damper, in fact, I DON'T have a Damper. Just a pulley. I am talking about the marks on the JD timing gear that goes on the crank pulley

 

[Lazy JW]

Without a degree wheel you cannot tell if their marks are accurate or not. They may be perfect, and they may not. Do you feel lucky today?
Joe

 

[Patrick66]

google "degreeing a camshaft" and please ignore the marks on your timing gears until you understand the purpose of degreeing the cam.

 

[Ecovanner1963]

Ok, so after the quick education, degreeing the cam is essentially verification that the cam is correct. One COULD put the cam in as I have explained, lint the tooth on the cam up with the gear, install it. Slide the Crank gear on with the tooth of the crank in-line with zero, then turn the CRANK until the 4 degree advance mark on the CRANK pulley lines up with the DOT on the cam. SO, is this correct? It is simply verifiying?

 

[Lazy JW]

.... Slide the Crank gear on with the tooth of the crank in-line with zero, then turn the CRANK until the 4 degree advance mark on the CRANK pulley lines up with the DOT on the cam. SO, is this correct? It is simply verifiying?

In this post you mention both the crank GEAR and the crank PULLEY. Take the crank pulley, put it in the trunk of the car, lock the trunk, and give the key to someone you can trust until you need to re-assemble the engine. YOU DO NOT NEED THE CRANK PULLEY YET!

The crank GEAR should have a mark (or multiple marks) on or near a tooth (teeth) and the CAM gear should have a similar mark (or marks). This gearset should have come with some sort of rudimentary instructions as to which of these marks to line up, then you should be able to slide them on their respective shafts (with the chain on them) and tighten them down. At this time is when you may elect to "degree" the cam to verify if the marks were correct and also if you actually assembled it properly. If you choose to NOT degree the cam you are merely taking the gamble that all is correct, which it may well be.

If you DO choose to degree the cam you may need the crank PULLEY to mount the degree wheel on, depending on which type of degree wheel you use so NOW you may go unlock the trunk and retrieve the pulley.
Have fun,
Joe

 

[Anonymous]

the cam was installed straight up, and I don't mean dot to dot. If the cam has a lobe center of 112 degrees, and it was installed with a 112 degree centerline, then that is the correct way of advancing the cam timing. However one normally rotates the cam (and gears), not the crank, until the 4 degree keyway lines up on the crank. This wouldYES. Providing "THEORETICALLY" put the centerline at 108 degrees.


Ok, so after the quick education, degreeing the cam is essentially verification that the cam is correct. One COULD put the cam in as I have explained, lint the tooth on the cam up with the gear, install it. Slide the Crank gear on with the tooth of the crank in-line with zero, then turn the CRANK until the 4 degree advance mark on the CRANK pulley lines up with the DOT on the cam. SO, is this correct? It is simply verifiying[quote][/quote]

it sounds like the confusion is how to set up the crank gear after degreeing the cam. I have the same timing set. There are no instructions in the package or on there web site . This might be a good topic for Mike's tech section .
- Al

 

[Ecovanner1963]

Ok I see the confusion in my typing, but my question was answered. When i say CRANK Gear I am referring to the JD crank gear included in the timing set. The PULLEY is what goes on after its all back together. I DO understand the difference. THANKS for ALL the help. I trust both the man that degreed the cam in, and the marks, as they seem to both provide the same indication. The cam is right on, and the gears indicate such.

 

[Ecovanner1963]

One last time, the dot on the cam gear should line up with the 4 degree advance on the CRANK gear. YES or NO.

 

[addo]

OK, your JP Performance crank gear looks something like this:

First you install it using the keyway labelled "0" - about 11:30 o'clock in the picture. Then you line up (with a straightedge) the dot on your cam gear, with the "0" mark on your crank gear tooth. (Almost 6 o'clock in the picture.) The two dots must be closest to each each other at this time, as as a result the straightedge "line" will also pass through the centre of both the crank and cam.


With this done, you check TDC and examine the cam timing. If you are lucky, it will be perfect as per the grinder's card. If you are unlucky, it will be anything up to eleven degrees wrong on the crank (worst inaccuracy noted on this Forum).

Adjust as required. Do not simply advance or retard the cam because someone suggested it; make sure that there's sound justification for this action.

When this is all done, rotate the motor so it is approaching #1 compression stroke, and set at 10° advanced on your degree wheel. Now install the timing cover and trial fit the balancer. Remember to leave the timing cover bolts hardly finger tight until the balancer is installed; this helps centre the oil seal. Now tighten the cover bolts to spec.

Not at this time, where the timing notch is on your balancer. It should be at ten advanced on the sawtooth timing scale, like when you set the degree wheel. If not, file a new notch clearly and put a spot of white paint in it. There is no need to even turn the motor one degree more before startup.

 

[Lazy JW]

..... I trust both the man that degreed the cam in, and the marks.....

So..... where's the beef?

 

[Ecovanner1963]

Ok is this different if you don't have a balancer, because I know this may be a little strange, but my 63 only has a PULLEY, NO BALANCER/Damper. The crank gear slides on INITALLY so the SINGLE tooth on the crank itself is aligned with the Zero mark on the JD Gear provided in the timing set. THEN align the dot on the CAM gear with the 4 degree advance mark on the CRANK gear. YES or NO???

 

[Ecovanner1963]

So the ONLY mark on the CAM gear is the DOT, and the instructions in the timing set show it as I explained, I will take a pic of the instructions and post it later.

 

[Lazy JW]

Post a picture of the gears as well so we can see what marks you actually have.

 

[Ecovanner1963]

Ok here is the CRANK Gear, with appropriate labels

Here is the CAM Gear, with appropriate Dot

This shows the tab on the Cam (which indicates the DOTS location) pointing to 0 degrees, and at this setting it RUNS GREAT, however it is currently set with the 4 degree advance mark on the Crank Gear, lined up with the DOT on the CAM GEAR, this would be WRONG? And yes I am awair that in the pics the Gears are NOT "Dead ON".

 

[JackFish]

There is nothing "pointing" to 4* advance in that photo that I can see.
It is simply keyed to the 0 line, with no other gear installed for it to have any relationship with.
That gear would have to be installed with the keyway set to something other than 0 for there to be any advance or retard, assuming the cam is ground correctly.
It is set to zero, as far as I can tell.

 

[Ecovanner1963]

his shows the tab on the Cam (which indicates the DOTS location) pointing to 0 degrees, and at this setting it RUNS GREAT, however it is currently set with the 4 degree advance mark on the Crank Gear, lined up with the DOT on the CAM GEAR, this would be WRONG? And yes I am awair that in the pics the Gears are NOT "Dead ON".